Mentor: Bill Keesom, Jacobs Engineering
Improved Nitric Acid Production via
Cobalt Oxide Catalysis for use in
Ammonia-based Fertilizers
Team Foxtrot
Thomas Calabrese
Cory Listner
Hakan Somuncu
David Sonna
Kelly Zenger
4/24/2012
University of Illinois at Chicago – Department of Chemical Engineering
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
TABLE OF CONTENTS
I.
Executive Summary
3
II.
III.
Introduction
Description of Process
4
6
IV.
V.
Process Control
Environmental Concerns
12
13
VI.
Economics
17
VII. Competing Processes
VIII. Recommendations
19
22
IX.
23
24
25
Appendices
Design Basis
Block Flow Diagram
Process Flow Diagram
Material Balance
27
28
Energy Balance
35
Physical Properties of Process Components
47
Annotated Equipment List
Economic Evaluation
Utilities
51
58
66
Conceptual Control Scheme
General Arrangement – Major Equipment Layout
68
71
Distribution and End-Use Issues Review
Constraints Review
Applicable Standards and Safety Review
73
74
79
Project Communications
Special Thanks
86
86
Information Sources and References
87
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
EXECUTIVE SUMMARY
In order to produce the ammonia-based fertilizer, several intermediate processes are
required; nitric acid formation is one such process. The raw materials used to produce nitric acid
include 572 TPD of ammonia, provided to the plant from the upstream ammonia team, and air
that will be taken from the atmosphere. The plant will produce 3,289 TPD of a 63% weight nitric
acid solution. 2,571.2 TPD will be provided to the downstream ammonium nitrate team while the
rest is sold to the open market. 1,843 TPD of high quality steam (1,250 psi and 970°F) is
generated in the process and will be provided to the combined heat and power team in exchange
for electricity.
Ammonia is converted in a catalytic reactor to nitrogen monoxide and is further oxidized
to nitrogen dioxide as the hot gases cool before being absorbed to produce the nitric acid
product. With the continuing rise in precious metal costs, platinum-rhodium catalysts are
becoming less economically viable as a catalyst for ammonia oxidation. The platinum-rhodium
catalyst requires frequent replacement and loss is prevalent at the high reaction temperature. A
relatively new catalyst that has been developed, making use of cobalt oxide, provides the same
conversion benefits of platinum-rhodium, while being vastly cheaper and inhibits the formation
of nitrous oxide, an environmental concern. The energy provided by the highly exothermic
reactions will be recovered through an efficient heat exchanger network which will allow steam
generation and preheating of tail gas for expansion to drive the plant compressors. Through
economic analysis the net-present-value was determined to be $984 million over the 20 year
plant life, with a rate of return of 12 years. Based on the plant economics, and the overall success
of the fertilizer plant, it is recommended to move into stage-gate 2.
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Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
INTRODUCTION
In order to make ammonium nitrate from natural gas several steps must be taken. Our
process is going to concentrate on the production of 3,829 tons per day of nitric acid from
ammonia which will be the feedstock for the ammonium nitrate process. The production of nitric
acid from ammonia undergoes the following process: Nitric oxide is produced by the reaction of
ammonia with oxygen over cobalt oxide catalyst, which is then oxidized to NO2. The NO2 is then
reacted with water in an absorption column to produce a nitric acid solution. Of the 3,289 tons
per day produced, 2571.2 tons will be supplied to the Ammonium Nitrate process while the rest
is sold on the open market. Ammonia is supplied by the ammonia plant at 571.5 tons per day.
Demand for nitric acid increased by 6.5% a year from 2002 to 2007. More recently the
demand increase has fallen to 3% per year and is expected to do so through 2018, however
because of federal rulings for ethanol components in gasoline the demand is not expected to drop
significantly. Prices between 2002 and 2007 went from a low of $145/short ton to a high of
$290/short ton; 42° Baume (67%), bulk, free on board (FOB). The majority (76%) of nitric acid
is used in the production of ammonium nitrate and the majority of the remaining 24% is used in
explosives manufacture. The strong growth for the mature product has been due to the increased
corn prices from ethanol production and also an increase in wheat prices. In addition, natural gas
prices have dropped significantly and look to stay at a low price for the foreseeable future.
The location of the plant will be in the Northwest corner of North Dakota in the Bakken
Formation of the Williston Basin. The Bakken Formation has an estimated undiscovered volume
of 1.85 trillion cubic feet of natural gas. The benefits of this site include a feed source of natural
gas and located in the agriculturally predominant Midwest. The location will have access to rail,
road, with Interstate 94 within three hours for truck transportation, and via pipeline to the little
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
used upper Missouri River or the Great Lakes for transportation. Since this is part of an
integrated process for the production of ammonium nitrate fertilizers and the only one of its kind
in the upper Midwest, the plant will have an ideal location to end users.
Currently, the majority of nitric acid production in the United States is produced by using
the Ostwald Process, which uses a platinum-rhodium catalyst under a single high-pressure. The
process employed will be based on a new cobalt oxide catalyst that has shown to increase yields.
Older plants were built to use a single pressure process to produce nitric acid, however because
the absorption processes favor a higher pressure, new plants use a combination of low and higher
pressure processes to increase yield. By manufacturing nitric acid using newer technologies; this
plant can increase production efficiency and therefore higher overall yield of nitric acid at a
lower cost while decreasing emissions.
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
DESCRIPTION OF PROCESS
General Process:
Among the different processes for nitric acid (HNO3) production the Ostwald Process in
addition to a dual-pressured system were selected for the design of the plant. The Ostwald
Process employs three major process steps for the production of nitric acid. Ammonia (NH3)
must be first oxidized to form nitrogen monoxide (NO). After ammonia oxidation, nitrogen
monoxide must be oxidized to nitrogen dioxide (NO2). The final step is absorption of nitrogen
dioxide with water (H2O) to form nitric acid. The following three chemical reactions are the
major reactions that occur in the process; oxidation of ammonia, oxidation of nitrogen monoxide,
and absorption with water (Ullman’s).
4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O (l)
2 NO (g) + O2 (g) → 2 NO2 (g)
4 NO2 (g) + O2 (g) + 2 H2O (l) → 4 HNO3 (aq)
The first reaction, oxidation of ammonia, has two undesired side reactions that take place.
The first is conversion of ammonia to nitrogen gas (N2). This particular product is of no real
concern as nitrogen is inert and a harmless gas. The second, however, leads to the formation of
nitrous oxide (N2O), more commonly known as laughing gas. As stated previously, the cobalt
oxide catalyst helps inhibit the conversion to these unwanted products. After ammonia oxidation
occurs, the temperature of the process gas exceeds 1600°F and must be cooled to form nitrogen
dioxide. A heat exchanger network allows concurrent cooling of process gases, steam generation,
and tail gas preheating. The network employs the use of a waste heat boiler, steam superheater,
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Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
shell-and-tube heat exchangers, and condensers to achieve this goal. As the process gas cools
nitrogen dioxide will readily dimerize to unwanted nitrogen tetroxide (N2O4).
After cooling, the process gas is sent to an absorption column to allow nitrogen dioxide to
be absorbed with water to produce nitric acid. An adequate amount of make-up water is used to
ensure that the product requirements of 63% acid by weight are met.
Detailed Process:
The following detailed process overview will reference the process flow diagram that can
be found in the appropriate appendix section. The process begins by taking vaporous ammonia
from the back-end ammonia team at 250°F and filtering it to rid it of any particulate that may
have accumulated during transportation to the plant. Air taken from the outside at approximately
60°F is pressurized to 72.5 psia, the desired pressure for ammonia oxidation. The compressor
used is two-stage in order to reduce the chances of equipment failure due to a hot exit gas
temperature. Due to compression the air is preheated to 480°F. The air stream is split into a
primary reactant stream that will be mixed with ammonia and a secondary air stream that will be
sent to the bleacher column to strip nitrogen tetroxide out of the nitric acid formed at the
absorption stage. The primary air stream contacts the ammonia vapor reducing the overall
temperature to 420°F. An adequate amount of air contacts the ammonia to maintain a 9:1 ratio of
air to ammonia. This ratio must be met in order to prevent the ammonia from igniting.
The air-ammonia mixture is sent to the catalytic reactor to pass over the cobalt oxide bed.
The conversion of ammonia to nitrogen monoxide is highly exothermic and increases the
temperature of the gas to 1634°F. An attached waste heat boiler and steam superheater system
allow pressurized water at the saturation point to be preheated to 970°F. The generated steam is
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
sold to the combined heat and power design team in return for electricity. After the steam
generation phase the product gases are cooled to 824°F. No nitrogen dioxide has been formed at
this point.
Following steam generation, the process gas passes over a series of five heat exchangers.
The first heat exchanger reduces the process gas from 824°F to 748°F in addition to preheating
the tail gas of the absorption column from 125°F to 312°F. The second heat exchanger cools the
process gas to 536°F while preheating boiler feed water from 250°F to just below its saturation
point. The third heat exchanger further cools the process gas to 428°F and nitrogen monoxide
begins to convert to nitrogen dioxide and nitrogen tetroxide. The tail gas is further preheated to
478°F at this point. The fourth and fifth heat exchangers cool the process gas 356°F and 230°F
respectively against water.
After the series of heat exchangers the first condenser is met. Further conversion of
nitrogen monoxide to nitrogen dioxide and nitrogen tetroxide occurs. The condenser allows the
formation of a very weak nitric acid solution that is pumped to the appropriate tray of the
absorption column. At this point the process gas is compressed a second time to 145 psia with
the NOx laden gases of the bleacher column. As a result of compression, the process gas is
heated to 508°F. Another heat exchanger and condenser are employed to cool the process gas to
257°F and 197°F respectively while further converting nitrogen monoxide to nitrogen dioxide. A
second weak acid stream is formed as is sent to an acid mixer to be mixed with acid formed at
the absorption column.
At the absorption column nitrogen dioxide is combined with water to form nitric acid.
The acid leaves the column at 198°F and is then combined with the acid stream from the second
condenser raising the overall temperature to 222°F. The acid stream is sent to a bleacher column
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
to strip out dissolved nitrogen tetroxide enabling the 63% by weight acid solution to be achieved.
Before being sent to the bleacher the stream is cooled to 127°F. The final product is sent to the
ammonium nitrate team at 123°F and 144 psia.
The tail gas of the column primarily consists of nitrogen and oxygen with trace amounts
of nitrogen monoxide, nitrogen dioxide, nitrogen tetroxide, and nitrous oxide. These NOx gases
are environmental concerns and their contents are checked against the Environmental Protection
Agency’s (EPA) parts per million (ppm) regulations in order to ensure that they do not surpass
the limit. The tail gas is first preheated against the secondary air stream from the air compressor
and as a result is heated to 125°F. It is further preheated against the process gas leaving the
ammonia burner as described above. The hot tail gas is expanded from 145 psia to atmospheric
pressure which results in the gas being cooled to 60°F and enough power generation to power the
second compressor entirely.
Catalyst:
In the Ostwald process, ammonia oxidation occurs over a catalyst. Traditionally, a 90%
platinum and 10% rhodium based gauze is placed inside the bed and ammonia and air are reacted
over the gauze.
4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O
Low pressures cause low NO yields, while high space velocities and high temperatures
give way to large catalyst losses. At $3-4 per short ton of nitric acid produced platinum losses
accrue for a large amount of the operating cost in the oxidation reactor (Joy Industries). Catalyst
entrapments are used downstream from the reactor to recollect the platinum that is washed out of
the bed.
Platinum based reactors are operated from 1490-1724˚F and achieve a 93-96%
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
conversion to NO. Offsite storage is required for extra platinum gauzes, which must be changed
out every 3-4 months.
Changing the catalyst charges requires a full plant shutdown.
Additionally, every 3-4 weeks the plant must also be shut down in order to remove rhodium
oxide deposits.
Alternatively, a cobalt oxide based catalyst may be used for the ammonia oxidation. Ali
Nadir Caglayan has developed a cobalt oxide based catalyst for use in ammonia oxidation in
nitric acid plants. This catalyst is available through the Catalyst Development Corporation and
Joy Indsturies. Currently a cobalt oxide catalyst is being used in several plants, including Incitec
Pivot’s girdler plant on Kooragang Island, Australia and Simplot Canada’s nitric acid plant in
Brandon, Manatoba.
The operating cost for the catalyst is $0.50-0.75 per short ton of nitric acid produced.
Cobalt oxide is stronger and more durable, keeping it from degrading at high temperatures and
washing away at high space velocities. A 95-98% NO conversion rate can be achieved while
operating at approximately 1550˚F. This lower operating temperature equates to less stress on
the heat exchangers. The higher conversion rate of NO means there is less N2O produced,
resulting in lower green house gas emissions for the plant. The plant may also be operated at a
lower pressure without compromising NO yield, meaning a lower pressure drop and, therefore, a
higher lifespan of the plant.
The cobalt catalyst has a lifespan of approximately a year, in which a smaller volume of
catalyst must be added to the bed. The plant does not need to be shutdown during this process,
and after approximately 6-9 years, the entire catalyst must be changed out. Because the plant
doesn’t need to be shutdown and cooled off repeatedly, there won’t be equipment failure due to
thermal cycling. There is also no rhodium oxide buildup or need for a catalyst entrapment or
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
offsite storage for extra catalyst. Table 3 summarizes the comparison between the two catalyst
options.
Table 3: Catalyst Comparison
Platinum-Rhodium
Cobalt Oxide (Co3O4)
Cost ($/short ton of HNO3
produced)
$3 - $4
$0.50 - $0.75
Lifespan
3-4 months
12 months
Downtime

4 hours to replace gauze at
end of lifespan
None

Remove Rhodium Oxide
buildup (every 3-4 weeks)
Conversion Efficiency
93% - 96%
95% - 98%
Operating Parameters
24-95 psi, 1490-1724 °F
0-95 psi, 1549
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
PROCESS CONTROL
In order to operate the plant safely and maintain specific conditions such as temperature
and pressure, the plant must be properly controlled. The control of the process was broken down
into three stages; ammonia oxidation, nitrogen monoxide oxidation, and absorption. The
diagrams for these three control schemes can be found in the appendix. The primary concern of
the ammonia oxidation portion of the plant is maintaining a 9:1 ratio of air to ammonia in the
gaseous mixture. This ratio provides a mixture of 11% by volume of ammonia in air. It is
important to maintain this ratio because air and ammonia mixtures become explosive beyond a
certain threshold, roughly 15-28% (FAO). The flow rates are controlled by a three-way valve and
flow-indicator-controllers. The other important area of control in the ammonia oxidation stage is
maintaining an outlet temperature of 970°F for the generated steam as the combined heat and
power group needs to have the steam at this specified temperature for their steam turbine.
During the nitrogen monoxide stage the temperature of the process gas must be
maintained. Nitrogen monoxide conversion to nitrogen dioxide and nitrogen tetroxide is
controlled by the temperature of the process gas. By maintaining the flow of cooling water
through the numerous heat exchangers and condensers, the temperature of the process gas can be
controlled. The temperature of the process gas is compared against its requirement and the flow
rate of the cooling water is adjusted accordingly through a temperature-indicator-controller.
During the absorption stage the temperature and pressure of the column must be
controlled. As nitric acid is formed the exothermic reaction releases heat which heats the column.
Heat must be removed from the column through the use of a pump-around. Make-up water to the
column is controlled with a flow-indicator-controller as well as a feed transmitter. The liquid
levels of both the absorption and bleacher columns are controlled in order to ensure that the
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
process gas makes contact with the first stage in both columns. Finally, a density controller is
used after the bleacher column outlet to ensure that the product is at the required specification of
63% nitric acid by weight.
ENVIRONMENTAL CONCERNS
This serves to give a short background on the environmental concerns involved with the
production of nitric acid. Some methods available to mitigate the solid and liquid wastes and the
green house gases (GHG) produced during the process are considered for practical use in plant
operation.
Solid waste can be formed during the ammonia oxidation or any catalytic or filtration
steps employed. Catalysts must be replaced periodically due to poisoning or losses over time.
Solids can be deposited on various parts of a nitric acid plant that uses a platinum based catalyst.
The platinum recovery catchment also degrades over time, and eventually will need replacement.
Cobalt oxide is more durable, and therefore does not leave solid deposits or require a catchment
to recover catalyst loss (Joy Industries). Cobalt oxide can contaminate waterways and therefore
must be disposed of via a licensed waste management contractor when the catalyst needs
replacement (MSDS). The cartridges used for ammonia, air, and the ammonia and air mixture
filtration must be periodically replaced. Over time, the filters will collect debris and develop an
increasing pressure drop. This pressure drop will reduce the space velocity of the streams and
lowered efficiency. To avoid flow imbalances or degraded efficiencies, the filters must be
replaced and the old filters disposed of via a waste management contractor.
Following absorption, the tail gas stream is passed to a flash separator. Here, nitric acid
mist is collected to avoid corrosion of the pipelines and prevent emitting the nitric acid gas into
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
the atmosphere. Periodically the acid mist cups need to be emptied and disposed of via a waste
management contractor.
The Environmental Protection Agency (EPA) has strict regulations on the GHGs that
may be emitted from a nitric acid plant. These regulations are outlined in Table 1. Of main
concern is nitrous oxide (N2O) and nitrogen oxide (NOx) gases, specifically NO and NO2.
Table 1: Tail Gas Specifications:
Species
NOx
N2O
O2
H2O
N2
Limit
100-3,500 ppmv
300-3,500 ppmv
1-4% by volume
0.3-2% by volume
Balance
Start-up and shut-down periods will normally increase the NOx content of the tail gas at
the stack. This lasts for a few hours as is required for the process to reach a steady-state, or for
the NOx to be cleared from the plant. During ammonia oxidation some nitrous oxide (N2O) is
formed. Nitrous oxide formation is favored at temperatures below 932˚F. By keeping the
reactor at 1634°F, the nitrous oxide formation can be kept to a minimum.
NOx gases are formed during the condensation and cooling steps of the process. The
amount formed is dependent upon conditions (temperature and pressure) inside the ammonia
oxidation reactor and the absorber, the catalyst used, and the heat exchanger design. Increasing
the absorber pressure will yield better NOx absorption and lower emissions of NOx into
atmosphere (EPA). Several methods are employed to achieve better absorption of the NOx
gases, which will give a better efficiency and remove the need for added tail gas treatments.
After condensing and cooling the process gas, the weak nitric acid formed is removed and sent to
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
the top of the absorption tower, giving a higher NOx absorption. The NOx gases that were
separated are then compressed and cooled to push the equilibrium towards acid formation
(EFMA). After absorption, a bleaching column is used to purify the product. NO2 in the process
stream causes an undesired yellow or brown color. By heating and adding air, the unreacted
NOx gases can be removed and further reacted. These gases are recycled from the bleacher and
mixed with the NOx gases entering the column prior to compression.
This removes the
pollutants in the product stream. The tail gas that leaves the absorber is separated to remove any
acid mist formed. This avoids corrosion of the tail gas equipment and keeps any gaseous acid
from being emitted into the atmosphere. The tail gas is then heated through the second and first
heat exchanger networks, promoting the decomposition of nitrous gases into nitrogen and
oxygen. The tail gas is then passed through an expander and emitted to the atmosphere.
Nitrous oxide (N2O) is a known GHG. At this time, it is not regulated by the EPA, but it
is recognized as a major pollutant. There are three methods for controlling the N2O emissions
from a nitric acid plant.
Primary methods reduce the N2O formed during the ammonia oxidation step.
For
example, an “empty” reaction chamber may be placed between the catalyst bed and the first heat
exchanger to increase the residence time. Or, an alternative catalyst (e.g. Cobalt Oxide) can be
used in the reaction chamber. When employed, these methods have been shown to an efficiency
of 70-85%.
Secondary methods reduce the N2O formed immediately after the ammonia oxidation
step. This is done through selective catalytic reduction (SCR). SCR has been shown to have up
to a 90% efficiency for reducing N2O.
The second catalyst is used to promote N2O
decomposition via reaction [1] by increasing the residence time in the reactor.
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Reaction 1:
2N2O(g)  2N2(g) + O2(g)
Tertiary methods reduce the N2O either upstream or downstream of the tail gas. This is
referred to as non-selective catalytic reduction (NSCR). NSCR has an efficiency of 80-98+%.
NSCR involves a reagent fuel (e.g. H2 from an ammonia plant purge) being used over a catalyst
via reaction [1]. An alternative method has SCR employed, and the tail gas in then mixed with
ammonia and reacted over a second catalyst bed via reaction [2].
Reaction 2:
3N2O(g) + 2NH3(g)  4N2(g) + 3H2O(g)
Table 2: Methods Used for GHG Control
Method
Primary
Secondary (SCR)
Tertiary (NSCR)
Description
Efficiency
The amount of N2O formed 70-85%
during the ammonia oxidation
is reduced.
N2O is reduced immediately up to 90%
after the ammonia oxidation.
N2O is reduced either up or 80-98+%
downstream of the tail gas.
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
ECONOMICS
Equipment, installation, and operating costs were obtained using Aspen Icarus Simulator.
The direct equipment purchasing and installation for the Nitric Acid Plant will be approximately
$348,000,000. Total equipment cost is approximately $66,000,000. Of this the largest cost comes
from the compressors at a cost of just under $25,000,000. Purchase of used equipment was
looked into, but since this nitric acid plant is one of the largest in the world, using a different
type of catalyst, and must be corrosion resistant, equipment of the proper size is not available.
The rest of the installation costs come from piping, engineering, instrumentation and electrical,
insulation, paint, and safety. Another main cost factor in Nitric Acid plant is material of
construction. The Nitric Acid is very corrosive material and it requires special type of material.
In order to prevent corrosion, SS304L (Aluminum mixed steel) should be used wherever nitric
acid contacts with.
The cost for the cobalt oxide catalyst is $476,000 compared to platinum catalyst that can
run as much as $3,000,000 for the reactor. One of the bonuses of using cobalt oxide over
platinum is the higher conversion rate of 98% with the additional benefit of being able to run for
years versus months without having to change out the catalyst. The catalyst operating costs are
reduced from $3-$4 per ton to $0.50-$0.75 per ton. This can produce a net savings of $453,530 $705,491 per year. The cost savings in using the cobalt oxide catalyst over platinum could pay
for itself.
Catalyst lifespan is at least twelve months and the shutdown time for catalyst
replacement measured in hours instead of days.
Since the turnaround time for catalyst
replacement is quick, the catalyst can be replaced during the normal plant shutdown period. This
will increase overall plant efficiency just by the nitric acid plant running continuously.
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
The plant will have a payback in twelve years from the expected plant life of twenty
years. If this were a stand-alone plant this would be too long of a payback period, however since
this is part of a larger ammonium nitrate plant, the payback period for the overall plant is much
shorter. The economics are assuming an interest rate of 8% and annual inflation rate of 3%.
Because the first three years of the project will be spent on plant installation, production not
being slated to begin until year three, and with interest rates at historic lows, the plant installation
costs will be much lower if the project is started within the year. An internal rate of return of
23.98% will be added to the overall rate of return for the total fertilizer plant. The net present
value after the twenty year life span of the plant works out to be $984 million. Please see details
of the economics below.
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
COMPETING PROCESSES
Organic Fertilizers
Organic fertilizers are made from ingredients ranging from compost to manure. The
bonus of organic fertilizer is that it will not “burn” the plants they are added to. They do not
contaminate groundwater. They are also able to get rid of agricultural waste as well. Many of
the common household organic fertilizers are made from chicken manure. However, organic
fertilizers tend to have a lower nutrient ratio than inorganic fertilizers and the quality can vary
from batch to batch depending on the ingredients. Organic fertilizers have become known more
as soil amendments and do show signs of long term positive effects on the soil.
Inorganic Fertilizers
Inorganic fertilizers are more widely used in the world today. The primary reason for
their use is that they are able to provide the primary compounds plants need as nutrients. The
major bonus of them is that the nutrient levels are consistent batch to batch. This is primarily
because the feedstock is consistent. One of the downsides of inorganic fertilizer is the “burning”
of plant materials. This is caused by a buildup of salts which are what inorganic fertilizers a
made of. This is not an issue if the proper amount of fertilizer is used per square foot of soil.
The other problems that can occur are groundwater contamination and the increase of heavy
metals (EPA http://www.epa.gov/oppt/pubs/fertilizer.pdf) from the mining of phosphate ores.
Many areas of Illinois frequently have problems with nitrates and phosphorus levels in drinking
water. (Illinois State Water Survey)
The major inorganic fertilizers are nitrogen based, potassium based, and phosphorus
based. There are many variations on these fertilizers combining secondary nutrients such as
Senior Design II – CHE 397 Team Foxtrot
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
sulfur, calcium and sodium and micronutrients such as boron and metals such as iron. In
addition, there are many different combinations of the three main types and subtypes of
fertilizers.
NPK fertilizers contain all three main types and can contain secondary and
micronutrients for enhanced plant growth. Through careful research, it has been shown that
nitrogen is the most important ingredient in most fertilizers because it has the quickest and most
pronounced effect. Phosphorus based fertilizers are the second most applied straight fertilizer.
Because it is used by all of the cells in a plant it is a necessary ingredient for plant life. Although
potassium is used as a straight fertilizer in many cases, it is not effective without the addition of
some nitrogen or phosphorus containing compounds. Most fertilizers are some type of NPK
fertilizer and have the percentage of nutrient by weight information in order to help with
application.
Nitric Acid
At present, although there are alternative procedures for making nitric acid, the only way
that is currently practiced industrially is by the Ostwald process. The Ostwald process involves
three primary reactions for the formation of nitric acid; oxidation of ammonia, oxidation of
nitrogen monoxide, and absorption by water.
4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O
2 NO (g) + O2 (g) → 2 NO2 (g)
4 NO2 (g) + O2 (g) + 2 H2O (l) → 4 HNO3 (aq)
Originally nitric acid was produced by the reaction of sulfuric acid and saltpeter primarily
from Chile. There was a fear though, that the rise of the world’s population and knowing the role
of nitrogen in plants that the saltpeter would soon be exhausted. This started the development of
a new way to make nitric acid commercially. For a while, an electric arc was used to remove
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
oxygen and nitrogen from air. This process, developed by Lord Rayleigh (John William Strutt),
was used commercially to some extent, but was only feasible where electricity was cheap. The
Wisconsin process has shown to make very low concentrations of nitric acid under high heat, and
nuclear nitrogen fixation can produce up to 15% nitric acid, but neither can compete with
ammonia oxidation economically.
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
RECOMMENDATIONS
The proposed nitric acid plant that would be part of a fertilizer producing complex
located at the Williston Basin in North Dakota. The plant is capable of producing 3,289 TPD of a
solution of 63% weight nitric acid and water. 2,571 TPD are provided to the downstream
ammonium nitrate team while the rest is sold to the open market. The upstream ammonia team
provides the plant with 672 TPD of ammonia which is converted to nitric acid. 1,843 TPD of
high quality steam (1250 psi and 970°F) is generated and sold to the combined heat and power
team in exchange for electricity. A cobalt oxide catalyst was chosen over platinum for its
economic and environmental benefits. Costing roughly a quarter of that of platinum per ton of
nitric acid produced and its long lifespan provide huge savings. The added benefit of inhibiting
the conversion of ammonia to nitrous oxide saves money in purchasing equipment for tail gas
treatment.
The proposed nitric acid plant has an expected lifespan of 20 years and would result in a
profit of roughly $984 million. The payback period of 7 years is fantastic and the plant would be
worth building even as a standalone unit. The nitric acid plant is a small portion of the overall
fertilizer complex and is worth the initial investment of roughly $348 million. The fertilizer
complex as a whole is estimated to make roughly $7 billion after its full lifespan. As a result,
continuing further investigation into the nitric acid plant and moving to stage-gate 2 is the
recommended course of action. Stage-gate 2 would cut down the estimation of the plant
economics from +/- 50% to a much closer approximation.
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
APPENDICES
DESIGN BASIS
The proposed nitric acid plant must be able to output 3,289 TPD of 63% weight solution
to meet the requirements of the entire fertilizer plant. The nitric acid solution at the end of the
process contains 2,072 short tons of nitric acid and the rest water. 2,571 TPD are provided to the
downstream ammonium nitrate team while the rest is sold to the open market. The upstream
ammonia team provides the plant with 572 TPD of ammonia at 250°F and 72.5 psi which will
inevitably be converted to nitric acid. 1,843 TPD of high quality steam (1250 psi and 970°F)
generated in the process will be provided to the combined heat and power team in exchange for
electricity.
The plant will follow the Ostwald process, a well-known process that is currently the
industry standard for nitric acid production. The Ostwald process involves three basis steps;
ammonia oxidation to nitrogen monoxide, nitrogen monoxide oxidation to nitrogen dioxide, and
absorption of nitrogen dioxide with water to produce nitric acid. The only difference between the
proposed nitric acid plant and the industry standard is the choice of catalyst.
Currently, the most common method of ammonia oxidation is through the use of
platinum-rhodium gauze, containing 90% platinum and 10% rhodium. An ammonia and air
mixture is passed over the platinum-rhodium gauze and converts to nitrogen monoxide. The
proposed plant nitric plant, however, makes use of a recently developed cobalt oxide based
catalyst by Ali Nadir Caglayan of Tulsa, Oklahoma that is both significantly cheaper and more
environmentally friendly than platinum based catalysts. The cobalt oxide catalyst has widespread
advantages over the current platinum based catalyst. Platinum currently costs roughly $4 per
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
short ton of nitric acid produced while cobalt oxide is a mere $0.50 per short ton of acid (CDC).
Additionally, cobalt oxide catalysts result in a 95-98% conversion rate of ammonia to nitrogen
monoxide compared to platinum’s 93-96% (CDC). With a larger conversion to ammonia there
will be less undesired side reactions such as the formation of nitrous oxide, a greenhouse gas.
With significantly less nitrous oxide being formed at the ammonia oxidation stage,
environmental release is far lower than most nitric acid plants. The only other components of
concern for release are nitrogen monoxide, nitrogen dioxide, and nitrogen tetroxide. The plant
sufficiently treats the tail gas to ensure these emissions meet government standards. Finally, the
cobalt oxide catalyst has a much longer lifespan than that of platinum based catalysts. The
catalyst itself lasts for one year after which a volume of catalyst should be dumped into the
reactor bed for further use. The bed will need to be fully replaced after six years. Platinum
catalysts have a much shorter lifespan of 3-4 months and require storage for extra gauzes. With
platinum catalysts the plant must be shutdown periodically for catalyst replacement and removal
of rhodium oxide deposits.
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
BLOCK FLOW DIAGRAM
The overall ammonia-based fertilizer complex can be seen below. The nitric acid plant
that the group is responsible is highlighted in pink. It can be seen that our feedstock is received
from the bank end ammonia team while our products are sold to the ammonium nitrate team as
well as the open market.
Figure 1: Fertilizer Complex Block Flow Diagram
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 25
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Figure 2: Nitric Acid Plant Block Flow Diagram
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
PROCESS FLOW DIAGRAM
Figure 3: Nitric Acid Plant Process Flow Diagram
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
MATERIAL BALANCE
Stream numbres correspond to those indicated on process flow diagram.
Table 3: Ammonia Oxidation: Streams (1) through (6)
Component Mass Flow
H2O
HNO3
NO2
NO
N2O4
O2
N2
H3N
N2O
Mass Flow
Volume Flow
Temperature
Pressure
STREAM
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
CUFT/HR
F
PSIA
1
2
3
4
0
0
0
0
0
0
0
47625
0
47625
8225.483
250
72.876
0
0
0
0.00E+00
0.00E+00
2.01E+05
6.61E+05
0
0.00E+00
8.62E+05
1.13E+07
60
14.69595
0
0
0
0.00E+00
0.00E+00
2.01E+05
6.61E+05
0
0.00E+00
8.62E+05
4.16E+06
480.1289
72.51887
0
0
0
0
0
1.77E+05
5.84E+05
0
0.00E+00
7.62E+05
3.68E+06
480.1289
72.51887
5
0.00E+00
0
0
0
0
23331.3
76835.37
0
0.00E+00
1.00E+05
4.84E+05
480.1289
72.51887
6
0
0
0
0.00E+00
0.00E+00
1.77E+05
5.84E+05
47625
0.00E+00
8.10E+05
3.81E+06
419.9874
72.51887
Tables 4 and 5: Nitrogen Monoxide Oxidation: Streams (7) through (18)
Component Mass Flow
H2O
HNO3
NO2
NO
N2O4
O2
N2
H3N
N2O
Mass Flow
Volume Flow
Temperature
Pressure
STREAM
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
CUFT/HR
F
PSIA
7
75568.07
0
0
82232.27
0.00E+00
66406.46
5.85E+05
0
3.08E+02
8.10E+05
6.32E+06
824
65.26698
8
75568.07
0
0
82232.27
0.00E+00
66406.46
5.85E+05
0
3.08E+02
8.10E+05
4.96E+06
747.58
64.83165
9
75568.07
0
0
82232.27
0.00E+00
66406.46
5.85E+05
0
3.08E+02
8.10E+05
4.96E+06
536
64.54179
10
75568.07
0
27736.82
64141.17
5.33E-01
56760.21
5.85E+05
0
3.08E+02
8.10E+05
4.43E+06
428
63.67157
11
75568.07
0
53292.28
47464.46
1.39E+01
47868.12
5.85E+05
0
3.08E+02
8.10E+05
4.09E+06
356
62.72882
12
75568.07
0
67496.5
38202.91
9.49E+00
42929.82
5.85E+05
0
3.08E+02
8.10E+05
3.49E+06
230
61.78608
Component Mass Flow
H2O
HNO3
NO2
NO
N2O4
O2
N2
H3N
STREAM
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
13
42179.24
0
72961.4
23671.75
8.81E+03
33787.96
5.85E+05
0
14
31819.43
10978.75
0
0
0
0
0
0
15
1.44E+05
519.6035
73158.98
23671.75
1.40E+04
57119.26
6.62E+05
0
16
1.44E+05
583.2365
86085.13
23686.75
1.05E+03
57119.17
6.62E+05
0
17
55401.07
1.55E+05
169.6764
38024.33
2.61E+03
23967.95
6.62E+05
0
18
1.16E+05
7425.028
29.61298
0
2630.171
0
0
0
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
N2O
Mass Flow
Volume Flow
Temperature
Pressure
LB/HR
LB/HR
CUFT/HR
F
PSIA
3.08E+02
7.67E+05
3.33E+06
246.2
60.91585
University of Illinois at Chicago
0.00E+00
42798.17
655.4346
179.3414
145.0377
3.08E+02
9.74E+05
2.58E+06
508.4646
145.0377
3.08E+02
9.74E+05
1.90E+06
257
144.3125
20
2.03E+05
1.73E+05
197.5826
0
5241.625
0
0
0
0
3.81E+05
5.65E+03
221.5714
143.5874
21
2.03E+05
1.73E+05
197.5826
0
5241.625
0
0
0
0
3.81E+05
5322.578
126.68
143.5874
22
1.01E+05
1.73E+05
1.98E-04
0
0
0
19.9772
0
0
2.74E+05
3585.532
122.7036
143.5874
25
87.2205
1.66E+00
3.52E+00
3.80E-04
2.72E-01
23967.95
6.62E+05
0
3.08E+02
6.86E+05
1.55E+06
312.314
130.534
26
87.2205
1.66E+00
3.79E+00
3.80E-04
1.63E-03
23967.95
6.62E+05
0
3.08E+02
6.86E+05
1.90E+06
478.148
129.8088
3.08E+02
9.37E+05
1.36E+06
197.492
143.5874
Table 6: Acid Formation: Streams (19) through (22)
Component Mass Flow
H2O
HNO3
NO2
NO
N2O4
O2
N2
H3N
N2O
Mass Flow
Volume Flow
Temperature
Pressure
STREAM
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
CUFT/HR
F
PSIA
19
87133.28
1.66E+05
167.9797
0
2611.173
0
0
0
0.00E+00
2.56E+05
3500.429
198.1885
143.5874
Table 7: Tail Gas Treatment: Streams (23) through (27)
Component Mass Flow
H2O
HNO3
NO2
NO
N2O4
O2
N2
H3N
N2O
Mass Flow
Volume Flow
Temperature
Pressure
STREAM
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
LB/HR
CUFT/HR
F
PSIA
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
23
87.2205
1.66E+00
1.696764
3.80E-04
2.09E+00
23967.95
6.62E+05
0
3.08E+02
6.86E+05
1.05E+06
71.6
131.9843
24
87.2205
1.66E+00
1.696764
3.80E-04
2.09E+00
23967.95
6.62E+05
0
3.08E+02
6.86E+05
1.17E+06
125.312
131.2592
27
87.2205
1.657789
3.787372
3.80E-04
2.65E-06
23967.95
6.62E+05
0
3.08E+02
6.86E+05
1.44E+07
340.3235
14.50377
Spring 2012
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0.00E+00
1.26E+05
2.10E+03
249.512
143.5874
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Sample Calculations:
Material Balance
Basis: 100 lbmol NH3
*NOTE: Each value will be scaled up to illustrate actual flow rates and will be indicated with
green
*NOTE: Values differ from figures generated in Aspen as some side reactions were ignored for
hand calculations and aspects of the process were changed as the semester progressed.
Actual NH3 Supplied to Plant: 581 TPD (68,920 lbmol), Aspen: 571.5 TPD
Air Supplied to Reactor
Assume 11% v/v mixture of ammonia and air to be below lower explosive limit
𝐴𝑖𝑟 𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑 =
100 𝑙𝑏𝑚𝑜𝑙 𝑁𝐻3
0.11
= 909.09 𝑙𝑏𝑚𝑜𝑙 𝐴𝑖𝑟 = 8,955 𝑇𝑃𝐷
𝑂2 𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑 = (909.09 𝑙𝑏𝑚𝑜𝑙 𝐴𝑖𝑟) × 0.21 = 190.91 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 2,086 𝑇𝑃𝐷
𝑁2 𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑 = (909.09 𝑙𝑏𝑚𝑜𝑙 𝐴𝑖𝑟) × 0.79 = 718.18 𝑙𝑏𝑚𝑜𝑙 𝑁2 = 6,879 𝑇𝑃𝐷
Senior Design II – CHE 397 Team Foxtrot
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Reactor Balance
𝑁𝑂 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 [1] = 100 𝑙𝑏𝑚𝑜𝑙 𝑁𝐻3 × (
4 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂
) × 0.980 = 98.00 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 = 1,004 𝑇𝑃𝐷
4 𝑙𝑏𝑚𝑜𝑙 𝑁𝐻3
2 𝑙𝑏𝑚𝑜𝑙 𝑁2
𝑁2 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 [2] = 100 𝑙𝑏𝑚𝑜𝑙 𝑁𝐻3 × (
) × 0.019 = 0.95 𝑙𝑏𝑚𝑜𝑙 𝑁2 = 9 𝑇𝑃𝐷
4 𝑙𝑏𝑚𝑜𝑙 𝑁𝐻3
2 𝑙𝑏𝑚𝑜𝑙 𝑁2 𝑂
𝑁2 𝑂 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 [1] = 100 𝑙𝑏𝑚𝑜𝑙 𝑁𝐻3 × (
) × 0.001 = 0.05 𝑙𝑏𝑚𝑜𝑙 𝑁2 𝑂 = 0.8 𝑇𝑃𝐷
4 𝑙𝑏𝑚𝑜𝑙 𝑁𝐻3
𝑂2 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑓𝑟𝑜𝑚 [1] = 98.00 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 × (
5 𝑙𝑏𝑚𝑜𝑙 𝑂2
) = 122.50 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 1,338 𝑇𝑃𝐷
4 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂
3 𝑙𝑏𝑚𝑜𝑙 𝑂2
𝑂2 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑓𝑟𝑜𝑚 [2] = 0.95 𝑙𝑏𝑚𝑜𝑙 𝑁2 × (
) = 1.43 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 16 𝑇𝑃𝐷
2 𝑙𝑏𝑚𝑜𝑙 𝑁2
𝑂2 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑓𝑟𝑜𝑚 [3] = 0.05 𝑙𝑏𝑚𝑜𝑙 𝑁2 𝑂 × (
4 𝑙𝑏𝑚𝑜𝑙 𝑂2
) = 0.10 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 1 𝑇𝑃𝐷
2 𝑙𝑏𝑚𝑜𝑙 𝑁2 𝑂
𝑇𝑜𝑡𝑎𝑙 𝑂2 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = (120.25 + 1.43 + 0.10) = 124.03 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 1,355 𝑇𝑃𝐷
𝐻2 𝑂 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 [1] = 122.50 𝑙𝑏𝑚𝑜𝑙 𝑂2 × (
6 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
) = 147.00 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 904 𝑇𝑃𝐷
5 𝑙𝑏𝑚𝑜𝑙 𝑂2
6 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
𝐻2 𝑂 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 [2] = 1.43 𝑙𝑏𝑚𝑜𝑙 𝑂2 × (
) = 2.85 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 18 𝑇𝑃𝐷
3 𝑙𝑏𝑚𝑜𝑙 𝑂2
6 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
𝐻2 𝑂 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 [13] = 0.10 𝑙𝑏𝑚𝑜𝑙 𝑂2 × (
) = 0.15 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 1 𝑇𝑃𝐷
4 𝑙𝑏𝑚𝑜𝑙 𝑂2
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 31
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
𝑇𝑜𝑡𝑎𝑙 𝐻2 𝑂 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 = (147.00 + 2.85 + 0.15) = 150.00 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 923 𝑇𝑃𝐷
𝑈𝑛𝑟𝑒𝑎𝑐𝑡𝑒𝑑 𝑂2 = (190.91 − 122.50 𝑙𝑏𝑚𝑜𝑙 𝑂2 ) = 66.88 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 731 𝑇𝑃𝐷
𝑈𝑛𝑟𝑒𝑎𝑐𝑡𝑒𝑑 𝑁2 = (718.18 + 0.95 𝑙𝑏𝑚𝑜𝑙 𝑁2 ) = 719.13 𝑙𝑏𝑚𝑜𝑙 𝑁2 = 6,879 𝑇𝑃𝐷
Heat Recovery: Steam Superheater, Waste-heat Boiler, Heat Exchangers, Condenser
Assumption: 100% of NO converted to NO2 before condenser inlet, ignore dimerization
Assumption: 100% of water vapor condenses at condenser
Assumption: 45% w/w solution of nitric acid and water is formed at condenser
2 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2
𝑁𝑂2 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 = 98.00 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 × (
) = 98.00 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2 = 1,539 𝑇𝑃𝐷
2 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂
𝑇𝑜𝑡𝑎𝑙 𝐻2 𝑂 𝐶𝑜𝑛𝑑𝑒𝑛𝑠𝑒𝑑 = 150.00 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 923 𝑇𝑃𝐷
1 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
𝐻2 𝑂 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜 𝑃𝑟𝑜𝑑𝑢𝑐𝑒 100 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 = 100 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 × (
) = 50 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
2 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3
63.01 𝑙𝑏 𝐻𝑁𝑂3
𝑀𝑎𝑠𝑠 𝑜𝑓 100 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 = 100 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 × (
) = 6, 301 𝑙𝑏 𝐻𝑁𝑂3
1 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3
𝑊𝑎𝑡𝑒𝑟 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜 𝐷𝑖𝑙𝑢𝑡𝑒 𝑡𝑜 45%
𝑤
6, 301 𝑙𝑏 𝐻𝑁𝑂3
= (
) − 6, 301 𝑙𝑏 𝐻𝑁𝑂3 = 7,701 𝑙𝑏 𝐻2 𝑂
𝑤
0.45
𝑇𝑜𝑡𝑎𝑙 𝑊𝑎𝑡𝑒𝑟 𝑓𝑜𝑟 𝐷𝑖𝑙𝑢𝑡𝑖𝑜𝑛 = 7,701 + (50 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 ×
𝐻𝑁𝑂3 𝐹𝑜𝑟𝑚𝑒𝑑 = 100 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 × (
18.02 𝑙𝑏 𝐻2 𝑂
) = 8,602 𝑙𝑏 𝐻2 𝑂
1 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
150 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
) = 31.41 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 = 675 𝑇𝑃𝐷
477.48 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 32
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
1 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂
𝑁𝑂 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑 = 31.41 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 × (
) = 15.71 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 = 161 𝑇𝑃𝐷
2 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3
3 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2
𝑁𝑂2 𝐶𝑜𝑛𝑠𝑢𝑚𝑒𝑑 = 31.41 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 × (
) = 47.12 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2 = 740 𝑇𝑃𝐷
2 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3
1 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
𝐻2 𝑂 𝐶𝑜𝑛𝑠𝑢𝑚𝑒𝑑 = 31.41 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 × (
) = 15.71 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 97 𝑇𝑃𝐷
2 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3
𝐻2 𝑂 𝑈𝑛𝑟𝑒𝑎𝑐𝑡𝑒𝑑 = (150 − 15.71 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂) = 134.29 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 826 𝑇𝑃𝐷
𝑂𝑥𝑖𝑑𝑒𝑠 𝐸𝑛𝑡𝑒𝑟𝑖𝑛𝑔 𝐶𝑜𝑛𝑑𝑒𝑛𝑠𝑒𝑟 = 98.00 𝑙𝑏𝑚𝑜𝑙
𝑂𝑥𝑖𝑑𝑒𝑠 𝑈𝑛𝑟𝑒𝑎𝑐𝑡𝑒𝑑 𝑡𝑜 𝐹𝑜𝑟𝑚 𝐻𝑁𝑂3 = 98.00 − 31.41 𝑙𝑏𝑚𝑜𝑙 = 66.59 𝑙𝑏𝑚𝑜𝑙
𝑁𝑂2 𝑖𝑛 𝑂𝑢𝑡𝑙𝑒𝑡 𝐺𝑎𝑠 = 98.00 − 47.12 𝑙𝑏𝑚𝑜𝑙 = 50.88 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2 = 799 𝑇𝑃𝐷
𝑂2 𝐸𝑛𝑡𝑒𝑟𝑖𝑛𝑔 𝐶𝑜𝑛𝑑𝑒𝑛𝑠𝑒𝑟 =
98.00 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 0.05 𝑙𝑏𝑚𝑜𝑙 𝑁2 𝑂 150 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
+
+
+ 66.88 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 190.91 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 2,086 𝑇𝑃𝐷
2
2
2
𝑂2 𝐸𝑥𝑖𝑡𝑖𝑛𝑔 𝐶𝑜𝑛𝑑𝑒𝑛𝑠𝑒𝑟
= 190.91 𝑙𝑏𝑚𝑜𝑙 𝑂2 − [
15.71 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 0.05 𝑙𝑏𝑚𝑜𝑙 𝑁2 𝑂 134.29 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
+
+
+ 50.88 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2
2
2
2
3
+ 31.41 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 = 17.88 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 195 𝑇𝑃𝐷
2
𝑇𝑜𝑡𝑎𝑙 𝑂𝑢𝑡𝑙𝑒𝑡 𝐺𝑎𝑠 𝑁𝑒𝑔𝑙𝑒𝑐𝑡𝑖𝑛𝑔 𝐻2 𝑂 = 803.65 𝑙𝑏𝑚𝑜𝑙
𝐻2 𝑂 𝑖𝑛 𝐺𝑎𝑠 𝑆𝑡𝑟𝑒𝑎𝑚 = 803.65 𝑙𝑏𝑚𝑜𝑙 ×
0.56 𝑝𝑠𝑖
= 6.21 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 38 𝑇𝑃𝐷
87.22 𝑝𝑠𝑖
𝐻2 𝑂 𝑖𝑛 𝐿𝑖𝑞𝑢𝑖𝑑 𝑆𝑡𝑟𝑒𝑎𝑚 = 134.29 − 6.21 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 128.09 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 788 𝑇𝑃𝐷
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 33
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Absorber
Assumption: Concentration of O2 in outlet gas is 2.5%
Assumption: Concentration of NO in outlet gas is 0.2%
1 𝑙𝑏𝑚𝑜𝑙 𝑂2
𝑂2 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜 𝑂𝑥𝑖𝑑𝑖𝑧𝑒 𝑁𝑂 𝑡𝑜 𝑁𝑂2 = 15.71 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 × (
) = 7.85 𝑙𝑏𝑚𝑜𝑙 𝑂2
2 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂
= 86 𝑇𝑃𝐷
𝑂2 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜 𝑂𝑥𝑖𝑑𝑖𝑧𝑒 𝑁𝑂 𝐹𝑜𝑟𝑚𝑒𝑑 = (15.71 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 + 50.88 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2 ) ×
1
= 16.65 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 182 𝑇𝑃𝐷
4
𝑂2 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑓𝑜𝑟 𝐶𝑜𝑚𝑝𝑙𝑒𝑡𝑒 𝑂𝑥𝑖𝑑𝑎𝑡𝑖𝑜𝑛 = 16.65 – (17.88 − 7.85) = 6.62 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 72 𝑇𝑃𝐷
𝐴𝑖𝑟 𝑖𝑛 𝑇𝑎𝑖𝑙 𝐺𝑎𝑠 =
[(2.5 × 6.62 𝑙𝑏𝑚𝑜𝑙 𝑂2 ) − (2.5 × 719.13 𝑙𝑏𝑚𝑜𝑙 𝑁2 ) − (100 × 6.62 𝑙𝑏𝑚𝑜𝑙 𝑂2 )]
= 132.05 𝑙𝑏𝑚𝑜𝑙
[(2.5 × 0.79) + (2.5 × 0.21) − (100 × 0.21)]
𝑂2 𝑖𝑛 𝑇𝑎𝑖𝑙 𝐺𝑎𝑠 = (132.05 × 0.21) − 6.62 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 21.11 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 231 𝑇𝑃𝐷
𝑁2 𝑖𝑛 𝑇𝑎𝑖𝑙 𝐺𝑎𝑠 = (132.05 × 0.79) + 719.13 𝑙𝑏𝑚𝑜𝑙 𝑁2 = 823.45 𝑙𝑏𝑚𝑜𝑙 𝑁2 = 7,876 𝑇𝑃𝐷
𝑁𝑂 𝑖𝑛 𝑇𝑎𝑖𝑙 𝐺𝑎𝑠 = (21.11 𝑙𝑏𝑚𝑜𝑙 𝑂2 + 823.45 𝑙𝑏𝑚𝑜𝑙 𝑁2 ) × 0.002 = 1.69 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 = 17 𝑇𝑃𝐷
𝑁2 𝑂 𝑖𝑛 𝑇𝑎𝑖𝑙 𝐺𝑎𝑠 = 0.05 𝑙𝑏𝑚𝑜𝑙 𝑁2 𝑂 = 0.8 𝑇𝑃𝐷
1 1
𝐴𝑑𝑗𝑢𝑠𝑡𝑒𝑑 𝑂2 𝑖𝑛 𝑇𝑎𝑖𝑙 𝐺𝑎𝑠 = 21.11 𝑙𝑏𝑚𝑜𝑙 𝑂2 + 1.69 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 × ( + ) = 22.38 𝑙𝑏𝑚𝑜𝑙 𝑂2 = 245 𝑇𝑃𝐷
4 2
𝐻2 𝑂 𝑖𝑛 𝑇𝑎𝑖𝑙 𝐺𝑎𝑠 = 847.57 𝑙𝑏𝑚𝑜𝑙 𝑔𝑎𝑠 ×
0.248 𝑝𝑠𝑖
= 1.45 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 9 𝑇𝑃𝐷
159.70 𝑝𝑠𝑖
𝑁𝑂𝑥 𝐴𝑏𝑠𝑜𝑟𝑏𝑒𝑑 = (15.71 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 + 50.88 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2 ) − 1.69 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂 = 64.90 𝑙𝑏𝑚𝑜𝑙
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 34
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
2 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂
𝐻2 𝑂 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜 𝑓𝑜𝑟𝑚 𝐻𝑁𝑂3 = 64.90 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2 (
) = 32.45 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 788 𝑇𝑃𝐷
4 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2
4 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3
𝐻𝑁𝑂3 𝐹𝑜𝑟𝑚𝑒𝑑 = 64.90 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2 × (
) + 31.41 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 = 96.31 𝑙𝑏𝑚𝑜𝑙 𝐻𝑁𝑂3 = 2,072 𝑇𝑃𝐷
4 𝑙𝑏𝑚𝑜𝑙 𝑁𝑂2
𝐻2 𝑂 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜 𝐷𝑖𝑙𝑢𝑡𝑒 𝑡𝑜 63%
𝑤 6,068 𝑙𝑏 𝐻𝑁𝑂3 − (6,068 𝑙𝑏 𝐻𝑁𝑂3 × 0.63)
=
= 3,565𝑙𝑏 𝐻2 𝑂 = 1,217 𝑇𝑃𝐷
𝑤
0.63
𝑃𝑟𝑜𝑐𝑒𝑠𝑠 𝐻2 𝑂 𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = (32.45 + 197.84 + 1.45 − 128.09 − 6.21 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂) = 97.44 𝑙𝑏𝑚𝑜𝑙 𝐻2 𝑂 = 599 𝑇𝑃𝐷
ENERGY BALANCE
Sample Calculations:
*NOTE: Hand calculated energy values different slightly from ASPEN values which are given in
green. ASPEN values are used for sizing specifications.
Enthalpy of Reaction
∆𝐻 = ∑ 𝑛𝐻𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠 − ∑ 𝑚𝐻𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠
Ammonia Oxidation
4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O (g)
∆𝐻 = [4 (90.29
𝑘𝐽
𝑘𝐽
𝑘𝐽
𝑘𝐽
) + 6 (−241.82
)] − [4 (−45.90
) + 5(0)] = −906.16
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
4 NH3 (g) + 3 O2 (g) → 2 N2 (g) + 6 H2O (g)
∆𝐻 = [2(0) + 6 (−241.82
𝑘𝐽
𝑘𝐽
𝑘𝐽
)] − [4 (−45.90
) + 3(0)] = −1,267.32
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
4 NH3 (g) + 4 O2 (g) → 2 N2O (g) + 6 H2O (g)
∆𝐻 = [2 (82.05
𝑘𝐽
𝑘𝐽
𝑘𝐽
𝑘𝐽
) + 6 (−241.82
)] − [4 (−45.90
) + 5(0)] = −1,103.22
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
Senior Design II – CHE 397 Team Foxtrot
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Nitrogen Monoxide Oxidation
2 NO (g) + O2 (g) → 2 NO2 (g)
∆𝐻 = [2 (33.2
𝑘𝐽
𝑘𝐽
𝑘𝐽
)] − [2 (90.29
) + (0)] = −114.18
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
Dimerization of Nitrogen Dioxide
2 NO2 (g) ←→ N2O4 (g)
∆𝐻 = [9.16
𝑘𝐽
𝑘𝐽
𝑘𝐽
] − [2 (33.2
)] = −57.24
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
Formation of Nitric Acid
4 NO2 (g) + O2 (g) + 2 H2O (l) → 4 HNO3 (aq)
∆𝐻 = [4 (−207
𝑘𝐽
𝑘𝐽
𝑘𝐽
𝑘𝐽
)] − [4 (33.2
) + (0) + 2(−285.83
)] = −389.14
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
3 NO2 (g) + H2O (l) → 2 HNO3 (aq) + NO (g)
∆𝐻 = [2 (−207
𝑘𝐽
𝑘𝐽
𝑘𝐽
𝑘𝐽
𝑘𝐽
) + (90.29
)] − [3 (33.2
) + (−285.83
)] = −137.46
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
𝑚𝑜𝑙
Senior Design II – CHE 397 Team Foxtrot
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Air Compressor
𝑍𝑅𝑇
𝑛
𝑃2
𝑊=(
)
[( )
𝑀𝑊 𝑛 − 1 𝑃1
𝑛−1
𝑛
− 1]
Stage 1
𝑛=
𝐶𝑝
1
𝛾−1
,𝑚 =
,𝛾 =
1−𝑚
𝛾𝐸𝑝
𝐶𝑣
𝛾 = 1.4, 𝐸𝑝 = 0.76, 𝑚 = 0.376, 𝑛 = 1.602
𝐼𝑛𝑡𝑒𝑟𝑠𝑡𝑎𝑔𝑒 𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑃𝑖 = √𝑃1 𝑃2 = √14.7 ∗ 72.5 = 32.65 𝑝𝑠𝑖𝑎
𝑊1 =
(1)(519.67 𝑅)(1.986
29
𝑙𝑏
𝑙𝑏𝑚𝑜𝑙
𝐵𝑡𝑢
)
𝑙𝑏𝑚𝑜𝑙 ∙ 𝑅 ×
1.602
32.65 𝑝𝑠𝑖𝑎
×[
1.602 − 1
14.70 𝑝𝑠𝑖𝑎
1.602−1
1.602
− 1] = 33.13
𝐵𝑡𝑢
𝑙𝑏
𝑃𝑖 𝑚
32.65 𝑝𝑠𝑖𝑎0.376
𝐼𝑛𝑡𝑒𝑟𝑠𝑡𝑎𝑔𝑒 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑇𝑖 = 𝑇1
= (519.67 𝑅) ×
= 701.51 𝑅
𝑃1
14.70 𝑝𝑠𝑖𝑎
Intercooler: Cool air from 242°F to 120°F
𝑞 = 𝑚𝐶𝑝 ∆𝑇 = 854,624
𝑙𝑏
𝐵𝑡𝑢
𝐵𝑡𝑢
× 0.24
× (242 − 120 𝐹) = 2.502 ∙ 107
ℎ𝑟
𝑙𝑏 ∙ 𝐹
ℎ𝑟
𝐵𝑡𝑢
2.502 ∙ 107
𝑞
𝑙𝑏
ℎ𝑟
𝐶𝑜𝑜𝑙𝑖𝑛𝑔 𝑊𝑎𝑡𝑒𝑟 𝑅𝑒𝑞 𝑑, 𝑚 =
=
= 1.25 ∙ 106
= 15,014 𝑇𝑃𝐷
𝐶𝑝 ∆𝑇 1 𝐵𝑡𝑢 × (100 − 80 𝐹)
ℎ𝑟
𝑙𝑏 ∙ 𝐹
′
Stage 2
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
𝑊2 =
(1)(579.67 𝑅)(1.986
29
𝑙𝑏
𝑙𝑏𝑚𝑜𝑙
𝐵𝑡𝑢
)
𝑙𝑏𝑚𝑜𝑙 ∙ 𝑅 ×
University of Illinois at Chicago
1.602
72.50 𝑝𝑠𝑖𝑎
×[
1.602 − 1
32.65 𝑝𝑠𝑖𝑎
1.602−1
1.602
− 1] = 36.93
𝐵𝑡𝑢
𝑙𝑏
𝑃2 𝑚
72.50 𝑝𝑠𝑖𝑎0.376
(579.67
𝑂𝑢𝑡𝑙𝑒𝑡 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑇2 = 𝑇𝑖
=
𝑅) ×
= 782.43 𝑅
𝑃𝑖
32.65 𝑝𝑠𝑖𝑎
Overall
𝑊 = 𝑊1 + 𝑊2 = 70.06
𝐵𝑡𝑢
𝑙𝑏
𝐵𝑡𝑢
𝑙𝑏
𝑊𝑚 70.06 𝑙𝑏 × 854,624 ℎ𝑟
𝐵𝑡𝑢
𝑃=
=
= 7.87 ∙ 107
𝐸𝑝
0.76
ℎ𝑟
NOx Compressor
𝑍𝑅𝑇
𝑛
𝑃2
𝑊=(
)
[( )
𝑀𝑊 𝑛 − 1 𝑃1
𝑛−1
𝑛
− 1]
Stage 1
𝑛=
𝐶𝑝
1
𝛾−1
,𝑚 =
,𝛾 =
1−𝑚
𝛾𝐸𝑝
𝐶𝑣
𝛾 = 1.4, 𝐸𝑝 = 0.78, 𝑚 = 0.376, 𝑛 = 1.602
𝐼𝑛𝑡𝑒𝑟𝑠𝑡𝑎𝑔𝑒 𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑃𝑖 = √𝑃1 𝑃2 = √72.5 ∗ 145 = 102.5 𝑝𝑠𝑖𝑎
𝑊1 =
(1)(716.67 𝑅)(1.986
𝐵𝑡𝑢
)
𝑙𝑏𝑚𝑜𝑙 ∙ 𝑅 ×
1.602
102.5 𝑝𝑠𝑖𝑎
×[
1.602 − 1
72.5 𝑝𝑠𝑖𝑎
𝑙𝑏
𝑙𝑏𝑚𝑜𝑙
Senior Design II – CHE 397 Team Foxtrot
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29
1.602−1
1.602
− 1] = 18.17
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𝐵𝑡𝑢
𝑙𝑏
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
𝑃𝑖 𝑚
102.5 𝑝𝑠𝑖𝑎0.376
𝐼𝑛𝑡𝑒𝑟𝑠𝑡𝑎𝑔𝑒 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑇𝑖 = 𝑇1
= (716 𝑅) ×
= 817.67 𝑅
𝑃1
72.5 𝑝𝑠𝑖𝑎
Intercooler: Cool gas from 358°F to 332°F
𝑞 = 𝑚𝐶𝑝 ∆𝑇 = 974,249
𝑙𝑏
𝐵𝑡𝑢
𝐵𝑡𝑢
× 0.305
× (358 − 332 𝐹) = 7.72 ∙ 106
ℎ𝑟
𝑙𝑏 ∙ 𝐹
ℎ𝑟
𝐵𝑡𝑢
7.72 ∙ 106
𝑞
𝑙𝑏
ℎ𝑟
𝐶𝑜𝑜𝑙𝑖𝑛𝑔 𝑊𝑎𝑡𝑒𝑟 𝑅𝑒𝑞 𝑑, 𝑚 =
=
= 3.86 ∙ 105
= 4,635 𝑇𝑃𝐷
𝐶𝑝 ∆𝑇 1 𝐵𝑡𝑢 × (100 − 80 𝐹)
ℎ𝑟
𝑙𝑏 ∙ 𝐹
′
Stage 2
𝑊2 =
(1)(791.67 𝑅)(1.986
29
𝑙𝑏
𝑙𝑏𝑚𝑜𝑙
𝐵𝑡𝑢
)
𝑙𝑏𝑚𝑜𝑙 ∙ 𝑅 ×
1.602
145 𝑝𝑠𝑖𝑎
×[
1.602 − 1
102.5 𝑝𝑠𝑖𝑎
1.602−1
1.602
− 1] = 20.04
𝐵𝑡𝑢
𝑙𝑏
𝑃2 𝑚
145 𝑝𝑠𝑖𝑎 0.376
𝑂𝑢𝑡𝑙𝑒𝑡 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑇2 = 𝑇𝑖
= (791.67 𝑅) ×
= 930.67 𝑅
𝑃𝑖
102.5 𝑝𝑠𝑖𝑎
Overall
𝑊 = 𝑊1 + 𝑊2 = 38.21
𝐵𝑡𝑢
𝑙𝑏
𝐵𝑡𝑢
𝑙𝑏
𝑊𝑚 38.21 𝑙𝑏 × 974,249 ℎ𝑟
𝐵𝑡𝑢
𝑃=
=
= 4.77 ∙ 107
𝐸𝑝
0.78
ℎ𝑟
Tail Gas Expander
𝑊 =
(1)(1159.67 𝑅)(1.986
29
𝑙𝑏
𝑙𝑏𝑚𝑜𝑙
𝐵𝑡𝑢
)
𝑙𝑏𝑚𝑜𝑙 ∙ 𝑅 ×
1.602
129.08 𝑝𝑠𝑖𝑎
×[
1.602 − 1
14.7 𝑝𝑠𝑖𝑎
1.602−1
1.602
− 1] = 56.02
14.7 0.376
𝑂𝑢𝑡𝑙𝑒𝑡 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑇2 = (1159.67 𝑅) ×
= 512.67 𝑅
129.08
𝐵𝑡𝑢
𝑙𝑏
𝑊𝑚 56.02 𝑙𝑏 × 686,244 ℎ𝑟
𝑃=
=
= 4.99 ∙ 107
𝐸𝑝
0.77
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𝐵𝑡𝑢
𝑙𝑏
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Pinch Analysis for Heat Exchangers
Figure 4: Pinch Analysis
Heat Exchanger Sample Calculation: Steam Generation
Hot Stream: Process Gas
𝑞 = 𝑚𝐶𝑝 ∆𝑇
𝑞 = (809,575
𝑙𝑏
𝐵𝑡𝑢
𝐵𝑡𝑢
𝐵𝑡𝑢
) (0.268
) (1634 − 824℉) = 1.76 ∙ 108
= 1.96 ∙ 108
ℎ𝑟
𝑙𝑏 ∙ 𝐹
ℎ𝑟
ℎ𝑟
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Cold Stream: Vaporize boiler feedwater and superheat to 970°F
𝑚=
𝑞
𝐶𝑝 ∆𝑇 + ∆𝐻𝑣𝑎𝑝 + ∆𝐻𝑠𝑢𝑝𝑒𝑟ℎ𝑒𝑎𝑡
ℎ𝑟
𝐵𝑡𝑢
24
𝑑𝑎𝑦
ℎ𝑟
𝑚=[
]×
= 1,681 𝑇𝑃𝐷 = 1,843 𝑇𝑃𝐷
𝐵𝑡𝑢
𝐵𝑡𝑢
𝐵𝑡𝑢
𝑙𝑏
(0.58
) (567.4 − 550𝐹) + 970
+ (1481 − 1184
)
2000
𝑙𝑏 ∙ 𝐹
𝑙𝑏
𝑙𝑏
𝑡𝑜𝑛
1.76 ∙ 108
Sizing:
𝑞 = 𝑈𝐴∆𝑇𝐿𝑀
∆𝑇𝐿𝑀 =
∆𝑇𝐿𝑀 =
𝐴=
(𝑇ℎ𝑜𝑡.𝑖𝑛 − 𝑇𝑐𝑜𝑙𝑑.𝑜𝑢𝑡 ) − (𝑇ℎ𝑜𝑡.𝑜𝑢𝑡 − 𝑇𝑐𝑜𝑙𝑑.𝑖𝑛 )
(𝑇
− 𝑇𝑐𝑜𝑙𝑑.𝑜𝑢𝑡 )
𝑙𝑛 ℎ𝑜𝑡.𝑖𝑛
(𝑇ℎ𝑜𝑡.𝑜𝑢𝑡 − 𝑇𝑐𝑜𝑙𝑑.𝑖𝑛 )
(1634 − 970℉) − (824 − 550℉)
= 440.60
(1634 − 970℉)
𝑙𝑛
(824 − 550℉)
1.96 ∙ 108
𝐵𝑡𝑢
ℎ𝑟
𝐵𝑡𝑢
(203 2
) (440.60)
𝑓𝑡 ∙ ℎ𝑟 ∙ ℉
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
= 2,194 𝑓𝑡 2
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Sample Pump Calculation:
𝐻𝑃 =
𝑄∆𝑃
1714𝜖
𝑙𝑏
) (15 𝑝𝑠𝑖)
ℎ𝑟
𝐻𝑃 =
= 3.87 𝐻𝑃
𝑓𝑡 3
𝑙𝑏
𝑚𝑖𝑛
(1714)(0.75)
(58.62 3 ) (0.1337
) (60
)
𝑔𝑎𝑙
ℎ𝑟
𝑓𝑡
(156,083
Storage Tank Sizing
Specifications:
 Product at 120°F and density of 1.3398 kg/L (Handymath).
 3 days worth of storage with a tank capacity of 70% (tank is 70% full)
 4 tanks each with a diameter of 55 ft.
𝜌 = (1.3398
𝑘𝑔
𝑙𝑏
1𝐿
𝑙𝑏
) (2.204 ) (
) = 83.64 3
3
𝐿
𝑘𝑔 0.304 𝑓𝑡
𝑓𝑡
3,289 𝑡𝑜𝑛𝑠
2,000 𝑙𝑏𝑠
𝑚 𝑇𝑂𝑇 = (3 𝑑𝑎𝑦𝑠) (
) = (9,867 𝑡𝑜𝑛𝑠) (
) = 19,734,000 𝑙𝑏𝑠
𝑑𝑎𝑦
1 𝑡𝑜𝑛
𝑉𝑃𝑅𝑂𝐷 = (19,734,000 𝑙𝑏𝑠) (
𝑉𝑇𝑂𝑇 =
𝑉𝑇𝐴𝑁𝐾
1
𝑙𝑏
83.64 3
𝑓𝑡
) = 235,939 𝑓𝑡 3 𝑝𝑟𝑜𝑑𝑢𝑐𝑡
235,939 𝑓𝑡 3
= 337,057 𝑓𝑡 3 𝑡𝑜𝑡𝑎𝑙
0.70
337,057 𝑓𝑡 3
=
= 84,264 𝑓𝑡 3 𝑝𝑒𝑟 𝑡𝑎𝑛𝑘
4
𝐴 = 𝜋(
55 𝑓𝑡 2
) = 2,376 𝑓𝑡 2
2
84,264 𝑓𝑡 3
𝐻=
= 35.5 𝑓𝑡
2,376 𝑓𝑡 2
Senior Design II – CHE 397 Team Foxtrot
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
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Reactor Sizing
Specifications:
 Reference reactor flow = 890,826 ft3/hr, space velocity = 11,000 hr-1
 Reference reactor volume = (890,826 ft3/hr)/(11,000 hr-1) = 81 ft3
 Catalyst depth must be 5-6’ in length
 Disperse flow over three beds
𝑉𝑅𝐸𝑄′𝐷 =
3,808,640
𝑉𝑅𝐸𝐴𝐶𝑇𝑂𝑅
𝐴=
11,000 ℎ𝑟
𝑓𝑡 3
ℎ𝑟 = 346 𝑓𝑡 3
−1
346 𝑓𝑡 3
=
= 115.4 𝑓𝑡 3
3
115.4 𝑓𝑡 3
= 21 𝑓𝑡 2
5.5 𝑓𝑡
4(21 𝑓𝑡 2 )
√
𝐷=
= 5.17 𝑓𝑡
𝜋
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
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Figure 5: Vapor-Liquid Equilibrium Data
Figure 6: Additional Vapor-Liquid Equilibrium Data
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Figure 7: Absorption Column Design
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
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Figure 8: Absorption Column Design Continued
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
PHYSICAL PROPERTIES OF PROCESS COMPONENTS
Air

Appearance: Colorless gas

Formula: N/A

Molar Mass: 29 lb/lbmol

Density (STP): 0.0806 lb/ft^3

Standard Enthalpy of Formation: N/A

Heat Capacity (NTP): 0.24 Btu/lb-F

Melting Point: N/A

Boiling Point: N/A
Ammonia

Appearance: Colorless gas

Formula: NH3

Molar Mass: 17.031 lb/lbmol

Density (STP): 0.0480 lb/ft^3

Standard Enthalpy of Formation: -46 kJ/mol

Heat Capacity (NTP): 0.52 Btu/lb-F

Melting Point: -108F

Boiling Point: -28F
Nitric Acid

Appearance: Colorless to yellow liquid

Formula: HNO3

Molar Mass: 63.01 lb/lbmol

Density (STP): 94.828 lb/ft^3

Standard Enthalpy of Formation: -207 kJ/mol

Heat Capacity:

Melting Point: -44F

Boiling Point: 181F
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Nitrogen

Appearance: Colorless gas

Formula: N2

Molar Mass: 28.0134 lb/lbmol

Density (STP): 0.09495 lb/ft^3

Standard Enthalpy of Formation: 0 kJ/mol

Heat Capacity: 0.25 Btu/lb-F

Melting Point: -346F

Boiling Point: -320.33F
Nitrogen Dioxide

Appearance: Deep orange gas

Formula: NO2

Molar Mass: 46.006 lb/lbmol

Density (STP): 0.2123 lb/ft^3

Standard Enthalpy of Formation: -33.2 kJ/mol

Heat Capacity (NTP): 0.191 Btu/lb-F

Melting Point: 11.84F

Boiling Point: 70F
Nitrogen Monoxide

Appearance: Colorless gas

Formula: NO

Molar Mass: 30.01 lb/lbmol

Density (STP): 0.0780 lb/ft^3

Standard Enthalpy of Formation: 90.29 kJ/mol

Heat Capacity (NTP): 0.23 Btu/lb-F

Melting Point: -263F

Boiling Point: -242F
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Nitrogen Tetroxide

Appearance: Colorless gas, orange liquid

Formula: N2O4

Molar Mass: 92.011 lb/lbmol

Density (STP): 89.896 lb/ft^3 (liquid)

Standard Enthalpy of Formation: -19.5 kJ/mol

Heat Capacity (NTP): 1.12 Btu/lb-F

Melting Point: 11.75F

Boiling Point: 70.07F
Nitrous Oxide

Appearance: Colorless gas

Formula: N2O

Molar Mass: 44.013 lb/lbmol

Density (STP): 0.1234 lb/ft^3

Standard Enthalpy of Formation: 82.05 kJ/mol

Heat Capacity (NTP): 0.21 Btu/lb-F

Melting Point: -131.55F

Boiling Point: -127.26F
Oxygen

Appearance: Colorless gas

Formula: O2

Molar Mass: 32 lb/lbmol

Density (STP): 0.08921 lb/ft^3

Standard Enthalpy of Formation: 0 kJ/mol

Heat Capacity (NTP): 0.22 Btu/lb-F

Melting Point: -361.82F

Boiling Point: -297.31F
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Water

Appearance: Colorless liquid

Formula: H2O

Molar Mass: 18.01528 lb/lbmol

Density (STP): 62.4 lb/ft^3

Standard Enthalpy of Formation (l): -285.83 kJ/mol

Standard Enthalpy of Formation (v): -241.818 kJ/mol

Heat Capacity (NTP): 1 Btu/lb-F

Melting Point: 32F

Boiling Point: 212F
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
ANNOTATED EQUIPMENT LIST
Table 8: Air Compressor Specifications
Air Compressor
Purpose: Compress air stream
Stage 1
Stage 2
28,313,693
Work [Btu/hr]
Work [Btu/hr]
60
Inlet Temp [°F]
Inlet Temp [°F]
242
Outlet Temp [°F]
Outlet Temp [°F]
14.7
Inlet Pressure [psi]
Inlet Pressure [psi]
32.7
Outlet Pressure [psi]
Outlet Pressure [psi]
31,561,264
120
323
32.7
72.5
Table 9: NOx Compressor Specifications
NOx Compressor
Purpose: Further compress process gas stream
Stage 1
Stage 2
17,702,104
Work [Btu/hr]
Work [Btu/hr]
257
Inlet Temp [°F]
Inlet Temp [°F]
358
Outlet Temp [°F]
Outlet Temp [°F]
72.5
Inlet Pressure [psi]
Inlet Pressure [psi]
102.5
Outlet Pressure [psi]
Outlet Pressure [psi]
19,523,949
332
471
102.5
145
Work [Btu/hr]
49,934,298
Table 10: Tail Gas Expander Specifications
Tail Gas Expander
Purpose: Provide boiler feedwater to process
Tin [°F]
Tout [°F]
Pin [psi]
700
58
129
Pout [psi]
14.7
NH3 Vapor Filter
Purpose: Remove particulate, such as rust, from ammonia feed
Air Filter
Purpose: Remove particulate, such as rust, from air feed
Air-Ammonia Mixer
Purpose: Combine air and ammonia feed maintaining a 9:1 ratio
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 11: Steam Superheater Specifications
Heat Exchanger 1 (Steam Superheater)
Purpose: Cool process gas and generate steam from boiler feed water
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
196,259,489
440.60
203
2,194
Cold Side
Hot Side
Steam
Process Gas
Stream
Stream
550
1634
Inlet Temp [°F]
Inlet Temp [°F]
970
824
Outlet Temp [°F]
Outlet Temp [°F]
Table 12: Heat Exchanger 2 Specifications
Heat Exchanger 2
Purpose: Cool process gas and oxidize nitrogen monoxide
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
17,300,854
609.6
5
5,676
Cold Side
Hot Side
Tail Gas
Process Gas
Stream
Stream
125.3
824
Inlet Temp [°F]
Inlet Temp [°F]
226.8
747.6
Outlet Temp [°F]
Outlet Temp [°F]
Table 13: Heat Exchanger 3 Specifications
Heat Exchanger 3
Purpose: Cool process gas and oxidize nitrogen monoxide
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
47,902,178
239.07
28
7,156
Cold Side
Hot Side
Boiler Feedwater
Process Gas
Stream
Stream
250
747.6
Inlet Temp [°F]
Inlet Temp [°F]
550
536
Outlet Temp [°F]
Outlet Temp [°F]
Table 14: Heat Exchanger 4 Specifications
Heat Exchanger 4
Purpose: Cool process gas and oxidize nitrogen monoxide
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
41,937,218
168.18
5
49,871
Cold Side
Hot Side
Tail Gas
Process Gas
Stream
Stream
226.8
617
Inlet Temp [°F]
Inlet Temp [°F]
478
428
Outlet Temp [°F]
Outlet Temp [°F]
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 15: Heat Exchanger 5 Specifications
Heat Exchanger 5
Purpose: Cool process gas and oxidize nitrogen monoxide
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
28,416,546
327.81
28
3,096
Cold Side
Hot Side
Cooling Water
Process Gas
Stream
Stream
80
485.73
Inlet Temp [°F]
Inlet Temp [°F]
100
356
Outlet Temp [°F]
Outlet Temp [°F]
Table 16: Heat Exchanger 6 Specifications
Heat Exchanger 6
Purpose: Cool process gas and oxidize nitrogen monoxide
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
34,598,953
212.24
28
5,822
Cold Side
Hot Side
Cooling Water
Process Gas
Stream
Stream
80
389.7
Inlet Temp [°F]
Inlet Temp [°F]
100
230
Outlet Temp [°F]
Outlet Temp [°F]
Table 17: Heat Exchanger 7 Specifications
Heat Exchanger 7
Purpose: Cool process gas and oxidize nitrogen monoxide
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
34,333,547
223.8
28
5,479
Cold Side
Hot Side
Cooling Water
Process Gas
Stream
Stream
80
378.8
Inlet Temp [°F]
Inlet Temp [°F]
100
257
Outlet Temp [°F]
Outlet Temp [°F]
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 18: Heat Exchanger 8 Specifications
Heat Exchanger 8
Purpose: Cool weak nitric acid stream
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
138,531,238
69.1
62
32,340
Cold Side
Hot Side
Cooling Water
Weak HNO3
Stream
Stream
80
197.7
Inlet Temp [°F]
Inlet Temp [°F]
100
126.7
Outlet Temp [°F]
Outlet Temp [°F]
Table 19: Heat Exchanger 9 Specifications
Heat Exchanger 9
Purpose: Cool secondary air stream
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
9,015,530
146.2
5
12,335
Cold Side
Hot Side
Tail Gas
Secondary Air
Stream
Stream
71.6
480
Inlet Temp [°F]
Inlet Temp [°F]
124
113
Outlet Temp [°F]
Outlet Temp [°F]
Table 20: Cooler-Condenser 1 Specifications
Cooler-Condenser 1
Purpose: Cool process gas and oxidize nitrogen monoxide, form weak acid
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
36,808,340
114.1
220
1,466
Cold Side
Hot Side
Cooling Water
Process Gas
Stream
Stream
80
230
Inlet Temp [°F]
Inlet Temp [°F]
100
179.6
Outlet Temp [°F]
Outlet Temp [°F]
Table 21: Cooler-Condenser 2 Specifications
Cooler-Condenser 2
Purpose: Cool process gas from NOx compressor
Heat Duty [Btu/hr]
ΔTLM
U [Btu/ft2-hr-°F]
Size [ft2]
16,128,848
136
220
539
Cold Side
Hot Side
Cooling Water
Process Gas
Stream
Stream
80
257
Inlet Temp [°F]
Inlet Temp [°F]
100
197
Outlet Temp [°F]
Outlet Temp [°F]
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 22: Reactor Specifications
Catalytic Reactor
Purpose: Convert ammonia to nitrogen monoxide (3 reactors used for flow dispersion)
Flow per
Tot. Vol.
Reactor
Length
Diameter
Tot. Flow [ft3/hr]
3
3
3
Reactor [ft /hr]
[ft ]
Vol. [ft ]
[ft]
[ft]
3,808,640
1,269,547
346
115
5.5
5.2
Waste Heat Boiler
Purpose: Capture heat from reactor, used in steam generation
Steam Drum
Purpose: Capture steam, used in steam generation
Table 23: Absorption Column Specifications
Absorption Column
Purpose: Absorb nitrogen dioxide with water to produce nitric acid
Lower Diameter [ft] Upper Diameter [ft]
Height [ft] Stages
Material
16.4
9
70
30
SS304L
NOx Stage
Weak Acid Stage
Water Stage Tray
1
25
30
Sieve
Table 24: Bleacher Column Specifications
Bleacher Column
Purpose: Strip dissolved NOx in nitric acid against secondary air stream
Diameter [ft]
Height [ft]
Stages
Material
7
35
12
SS304L
Flow [lb/hr]
156,083
Table 25: Pump 1 Specifications
Pump 1
Purpose: Provide boiler feedwater to process
Flow [GPM]
Density [lb/ft3] ΔP [psi]
Eff.
332
58.62
15
0.75
HP
3.87
Flow [lb/hr]
156,083
Table 26: Pump 2 Specifications
Pump 2
Purpose: Recycle boiler feedwater to steam drum
Flow [GPM]
Density [lb/ft3] ΔP [psi]
Eff.
412
47.19
10
0.75
HP
3.21
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 27: Pump 3 Specifications
Pump 3 (SS304L)
Purpose: Transfer weak nitric acid from first condenser to absorption column
Flow [lb/hr]
Flow [GPM]
Density [lb/ft3] ΔP [psi]
Eff.
HP
42,798
82
65.30
40
0.75
2.54
Table 28: Pump 4 Specifications
Pump 4 (SS304L)
Purpose: Transfer weak nitric acid from second condenser to mixer
Flow [lb/hr]
Flow [GPM]
Density [lb/ft3] ΔP [psi]
Eff.
HP
125,758
262
59.76
10
0.75
2.04
Table 29: Pump 5 Specifications
Pump 5 (SS304L)
Purpose: Transfer nitric acid from absorption column to mixer
Flow [lb/hr]
Flow [GPM]
Density [lb/ft3] ΔP [psi]
Eff.
255,690
390
73.04
10
0.75
HP
3.39
Table 30: Pump 6 Specifications
Pump 6 (SS304L)
Purpose: Transfer nitric acid solution to bleacher column
Flow [lb/hr]
Flow [GPM]
Density [lb/ft3] ΔP [psi]
Eff.
381,448
699
68.05
25
0.75
HP
13.59
Table 31: Pump 7 Specifications
Pump 7 (SS304L)
Purpose: Transfer nitric acid product to storage tank
Flow [lb/hr]
Flow [GPM]
Density [lb/ft3] ΔP [psi]
Eff.
274,120
447
76.45
20
0.75
HP
6.95
Table 32: Storage Tank 1 Specifications
Storage Tank 1
Purpose: Store nitric acid product (tank farm can hold 3 days worth of product)
Volume [ft3] Diameter [ft] Height [ft] Capacity [%] Density [lb/ft3] Material
84,264
55
35.5
70
83.64
SS304L
Senior Design II – CHE 397 Team Foxtrot
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Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 33: Storage Tank 2 Specifications
Storage Tank 2
Purpose: Store nitric acid product (tank farm can hold 3 days worth of product)
Volume [ft3] Diameter [ft] Height [ft] Capacity [%] Density [lb/ft3] Material
84,264
55
35.5
70
83.64
SS304L
Table 34: Storage Tank 3 Specifications
Storage Tank 3
Purpose: Store nitric acid product (tank farm can hold 3 days worth of product)
Volume [ft3] Diameter [ft] Height [ft] Capacity [%] Density [lb/ft3] Material
84,264
55
35.5
70
83.64
SS304L
Table 35: Storage Tank 4 Specifications
Storage Tank 4
Purpose: Store nitric acid product (tank farm can hold 3 days worth of product)
Volume [ft3] Diameter [ft] Height [ft] Capacity [%] Density [lb/ft3] Material
84,264
55
35.5
70
83.64
SS304L
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
ECONOMIC EVALUATION
Material
Table 36: Materials Costs
Materials
Requirement
Base Cost
10,344 TPD
$0.00/ton
571.5 TPD
$350/ton
2,571.2 TPD
$220/ton
717.8 TPD
$300/ton
1,843 TPD
$20/ton
$0.50/ton acid
Air
Ammonia Vapor
Nitric Acid* (SOLD)
Nitric Acid** (SOLD)
Steam (SOLD)
Cobalt Oxide Catalyst
TOTAL
*Sold to Ammonium Nitrate, **Sold to Open Market
Total Cost [per year]
$0.00
$73,009,125
$206,467,360
$78,599,100
$13,451,491
$476,454
+ $225,032,372/year
Table 37: Equipment Costs
Equipment Installed Costs
Equipment
Absorption Column
Bleacher Column
Weak Acid Pump 1
Weak Acid Pump 2
Weak Acid Pump 3
Strong Acid Pump
Product Pump
Boiler Feed Pump
Steam Drum Pump
Air Compressor
NO Compressor
Tail Gas Expander
Heat Exchangers (x8)
Condenser 1
Condenser 2
Ammonia Burner
Steam Drum
Waste-Heat Boiler
Storage Tanks (x4)
TOTAL
TOTAL INSTALLED COST (x5)
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Cost
$1,000,000
$200,000
$20,000
$20,000
$20,000
$55,000
$45,000
$15,000
$15,000
$22,000,000
$6,700,000
$9,000,000
$20,000,000
$140,000
$144,000
$2,500,000
$150,000
$850,000
$3,000,000
$65,874,000
$329,370,000
Spring 2012
Page: 58
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 38: ICARUS Installed Costs
ICARUS Installed Costs
Item
Equipment (taken from above)
Piping
Civil
Steel
Instrumentation
Electrical
Paint
Other
G&A Overheads
Contingencies
TOTAL
Cost
$329,370,000
$1,900,000
$530,000
$100,000
$1,000,000
$2,500,000
$100,000
$4,500,000
$1,000,000
$7,000,000
$348,000,000
Table 39: ICARUS Yearly Operating Costs
ICARUS Yearly Operating Costs
Item
Cost
Operating Labor
Maintenance
Supervision
Operating Charges
Plant Overhead
TOTAL
Utility
Cooling Water
Boiler Feed Water
Process Water
Electricity
Sewage
Steam
Natural Gas
TOTAL
$640,000
$905,000
$200,000
$230,000
$912,000
-$2,900,000/year
Table 40: Utility Costs
Utilities
Requirement
Base Cost
169,739 TPD
$0.05/kgal
1842.67 TPD
$3.50/kgal
607.1 TPD
$0.75/kgal
30,000 kWh
$0.025/kWh
Start-up/Misc. Use
Heating
-
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Total Cost
$745,185/year
$161,793/year
$53,305/year
$6,570,000/year
Installed Cost
Est. $2,000,000/year
Est. $5,000/year
-$9,535,283/year
Spring 2012
Page: 59
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 41: Yearly Profit
Yearly Profit
Item
Cost
Raw Materials
Operating Costs
Utilities
TOTAL
+$225,032,372
-$2,900,000
-$9,535,283
Est. Profit: $213,000,000/year
Table 42: Overall Plant Economics
NPV
IRR
Interest Rate
Inflation Rate
Payback Period for Plant
$983,871,359
23.98%
8.00%
3.00%
7 years
Table 43: Net-Present Value / Internal Rate of Return Calculation (Years 0-4)
Income Statement for Team Foxtrot
Year
3
4
Revenues/Annual
201,590,799.11
335,984,665.18
938,488 tons Nitric Acid
Solution at $220/ton
139,427,408.21
232,379,013.68
261,997 tons Nitric Acid
Solution at $300/ton
53,077,972.23
88,463,287.05
672,695 tons Steam at
$20/ton
9,085,418.67
15,142,364.45
44,510,818.57
44,510,818.57
Capital Cost
Expenses
Loan Expense
Start-Up
Engineering
Equip Purchase
Plant Construction
Utilities
Process Water
Cooling water
Process Steam
Electrical
Sum of Years Depreciation
Salaries and Fringes
Maintenance 3% of cap cost
Raw Materials
0
1
2
348,000,000.00
77,448,824.31
34,800,000.00
29,000,000.00
5,800,000.00
17,400,000.00
145,000,000.00
17,400,000.00
34,800,000.00
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
44,510,818.57
17,400,000.00
87,000,000.00
34,800,000.00
32,968,421.05
17,400,000.00
29,000,000.00
14,052,735.00
79,957.50
1,117,777.50
3,000,000.00
9,855,000.00
31,136,842.11
900,000.00
100,000.00
49,303,062.11
9,368,490.00
53,305.00
745,185.00
2,000,000.00
6,570,000.00
29,305,263.16
927,000.00
103,000.00
82,171,770.19
Spring 2012
Page: 60
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Catalysts
1,000,000.00
536,248.98
Total Expenses
292,048,824.31
216,679,239.62
187,403,457.79
166,922,590.89
Income before Taxes
Taxes, 40%
Income After Taxes
Add Back Depreciation
-292,048,824.31
0.00
-292,048,824.31
10,000,000.00
-216,679,239.62
0.00
-216,679,239.62
32,968,421.05
14,187,341.32
74,961,383.12
-60,774,041.79
31,136,842.11
169,062,074.29
66,769,036.36
102,293,037.93
29,305,263.16
Cash Flow From Operations
-282,048,824.31
-183,710,818.57
-29,637,199.69
131,598,301.09
-351,648,824.31
-535,359,642.88
-564,996,842.57
-433,398,541.48
Cumulative Cash Flow
-69,600,000.00
Table 44: Net-Present Value / Internal Rate of Return Calculation (Years 5-8)
Income Statement for Team Foxtrot
Year
5
6
7
8
Revenues/Annual
346,064,205.14
356,446,131.29
367,139,515.23
378,153,700.68
938,488 tons Nitric Acid Solution at
$220/ton
239,350,384.09
246,530,895.61
253,926,822.48
261,544,627.16
261,997 tons Nitric Acid Solution at
$300/ton
91,117,185.66
93,850,701.23
96,666,222.27
99,566,208.94
672,695 tons Steam at $20/ton
15,596,635.38
16,064,534.45
16,546,470.48
17,042,864.59
44,510,818.57
44,510,818.57
44,510,818.57
44,510,818.57
9,649,544.70
54,904.15
767,540.55
2,060,000.00
6,767,100.00
27,473,684.21
954,810.00
106,090.00
84,636,923.29
552,336.45
9,939,031.04
56,551.27
790,566.77
2,121,800.00
6,970,113.00
25,642,105.26
983,454.30
109,272.70
87,176,030.99
568,906.54
10,237,201.97
58,247.81
814,283.77
2,185,454.00
7,179,216.39
23,810,526.32
1,012,957.93
112,550.88
89,791,311.92
585,973.74
10,544,318.03
59,995.25
838,712.28
2,251,017.62
7,394,592.88
21,978,947.37
1,043,346.67
115,927.41
92,485,051.28
603,552.95
167,884,207.22
168,929,619.41
170,061,341.33
171,281,962.27
Expenses
Loan Expense
Start-Up
Engineering
Equip Purchase
Plant Construction
Utilities
Process Water
Cooling water
Process Steam
Electrical
Sum of Years Depreciation
Salaries and Fringes
Maintenance 3% of cap cost
Raw Materials
Catalysts
Total Expenses
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 61
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Income before Taxes
Taxes, 40%
Income After Taxes
Add Back Depreciation
178,179,997.92
67,153,682.89
111,026,315.03
27,473,684.21
187,516,511.88
67,571,847.76
119,944,664.12
25,642,105.26
197,078,173.90
68,024,536.53
129,053,637.37
23,810,526.32
206,871,738.41
68,512,784.91
138,358,953.51
21,978,947.37
Cash Flow From Operations
138,499,999.24
145,586,769.38
152,864,163.69
160,337,900.87
Cumulative Cash Flow
-294,898,542.24
-149,311,772.86
3,552,390.83
163,890,291.70
Table 45: Net-Present Value / Internal Rate of Return Calculation (Years 9-12)
Income Statement for Team Foxtrot
Year
9
10
11
12
Revenues/Annual
389,498,311.71
401,183,261.06
413,218,758.89
425,615,321.66
938,488 tons Nitric Acid Solution at
$220/ton
269,390,965.97
277,472,694.95
285,796,875.80
294,370,782.07
261,997 tons Nitric Acid Solution at
$300/ton
102,553,195.20
105,629,791.06
108,798,684.79
112,062,645.34
17,554,150.53
18,080,775.05
18,623,198.30
19,181,894.25
44,510,818.57
44,510,818.57
0.00
0.00
10,860,647.57
61,795.10
863,873.65
2,318,548.15
7,616,430.67
20,147,368.42
1,074,647.07
119,405.23
95,259,602.82
621,659.54
11,186,467.00
63,648.96
889,789.86
2,388,104.59
7,844,923.59
18,315,789.47
1,106,886.48
122,987.39
98,117,390.90
640,309.32
11,522,061.01
65,558.43
916,483.56
2,459,747.73
8,080,271.30
16,484,210.53
1,140,093.07
126,677.01
101,060,912.63
659,518.60
11,867,722.84
67,525.18
943,978.06
2,533,540.16
8,322,679.43
14,652,631.58
1,174,295.87
130,477.32
104,092,740.01
679,304.16
Total Expenses
172,594,149.21
174,000,649.13
130,993,472.85
132,597,171.77
Income before Taxes
Taxes, 40%
Income After Taxes
Add Back Depreciation
216,904,162.49
69,037,659.69
147,866,502.81
20,147,368.42
227,182,611.92
69,600,259.65
157,582,352.27
18,315,789.47
282,225,286.04
52,397,389.14
229,827,896.90
16,484,210.53
293,018,149.88
53,038,868.71
239,979,281.18
14,652,631.58
672,695 tons Steam at $20/ton
Expenses
Loan Expense
Start-Up
Engineering
Equip Purchase
Plant Construction
Utilities
Process Water
Cooling water
Process Steam
Electrical
Sum of Years Depreciation
Salaries and Fringes
Maintenance 3% of cap cost
Raw Materials
Catalysts
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 62
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Cash Flow From Operations
168,013,871.23
175,898,141.74
246,312,107.43
254,631,912.75
Cumulative Cash Flow
331,904,162.93
507,802,304.67
754,114,412.10
1,008,746,324.86
Table 46: Net-Present Value / Internal Rate of Return Calculation (Years 13-16)
Income Statement for Team Foxtrot
Year
13
14
15
16
Revenues/Annual
438,383,781.30
451,535,294.74
465,081,353.59
479,033,794.19
938,488 tons Nitric Acid Solution at
$220/ton
303,201,905.53
312,297,962.70
321,666,901.58
331,316,908.63
261,997 tons Nitric Acid Solution at
$300/ton
115,424,524.70
118,887,260.44
122,453,878.25
126,127,494.60
19,757,351.07
20,350,071.61
20,960,573.75
21,589,390.97
672,695 tons Steam at $20/ton
Expenses
Loan Expense
Start-Up
Engineering
Equip Purchase
Plant Construction
Utilities
Process Water
Cooling water
Process Steam
Electrical
Sum of Years Depreciation
Salaries and Fringes
Maintenance 3% of cap cost
Raw Materials
Catalysts
0.00
0.00
0.00
0.00
12,223,754.52
69,550.93
972,297.40
2,609,546.37
8,572,359.82
12,821,052.63
1,209,524.74
134,391.64
107,215,522.21
699,683.29
12,590,467.16
71,637.46
1,001,466.33
2,687,832.76
8,829,530.61
10,989,473.68
1,245,810.48
138,423.39
110,431,987.87
720,673.78
12,968,181.18
73,786.59
1,031,510.32
2,768,467.74
9,094,416.53
9,157,894.74
1,283,184.80
142,576.09
113,744,947.51
742,294.00
13,357,226.61
76,000.18
1,062,455.63
2,851,521.77
9,367,249.03
7,326,315.79
1,321,680.34
146,853.37
117,157,295.94
764,562.82
Total Expenses
134,303,929.03
136,116,836.37
138,039,078.31
140,073,934.87
Income before Taxes
Taxes, 40%
Income After Taxes
Add Back Depreciation
304,079,852.28
53,721,571.61
250,358,280.66
12,821,052.63
315,418,458.37
54,446,734.55
260,971,723.82
10,989,473.68
327,042,275.28
55,215,631.32
271,826,643.96
9,157,894.74
338,959,859.33
56,029,573.95
282,930,285.38
7,326,315.79
Cash Flow From Operations
263,179,333.30
271,961,197.50
280,984,538.69
290,256,601.17
1,271,925,658.15
1,543,886,855.65
1,824,871,394.35
2,115,127,995.52
Cumulative Cash Flow
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 63
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Table 47: Net-Present Value / Internal Rate of Return Calculation (Years 17-19)
Income Statement for Team Foxtrot
Year
17
18
19
Revenues/Annual
493,404,808.02
508,206,952.26
523,453,160.83
938,488 tons Nitric Acid Solution at
$220/ton
341,256,415.89
351,494,108.36
362,038,931.62
261,997 tons Nitric Acid Solution at
$300/ton
129,911,319.44
133,808,659.02
137,822,918.79
22,237,072.70
22,904,184.88
23,591,310.42
672,695 tons Steam at $20/ton
Expenses
Loan Expense
Start-Up
Engineering
Equip Purchase
Plant Construction
Utilities
Process Water
Cooling water
Process Steam
Electrical
Sum of Years Depreciation
Salaries and Fringes
Maintenance 3% of cap cost
Raw Materials
Catalysts
0.00
0.00
0.00
13,757,943.41
78,280.19
1,094,329.30
2,937,067.43
9,648,266.50
5,494,736.84
1,361,330.75
151,258.97
120,672,014.81
787,499.70
14,170,681.71
80,628.60
1,127,159.17
3,025,179.45
9,937,714.49
3,663,157.89
1,402,170.67
155,796.74
124,292,175.26
811,124.69
14,595,802.16
83,047.45
1,160,973.95
3,115,934.83
10,235,845.93
1,831,578.95
1,444,235.80
160,470.64
128,020,940.52
835,458.43
Total Expenses
142,224,784.49
144,495,106.97
146,888,486.50
Income before Taxes
Taxes, 40%
Income After Taxes
Add Back Depreciation
351,180,023.53
56,889,913.80
294,290,109.73
5,494,736.84
363,711,845.29
57,798,042.79
305,913,802.50
3,663,157.89
376,564,674.33
58,755,394.60
317,809,279.73
1,831,578.95
Cash Flow From Operations
299,784,846.57
309,576,960.39
319,640,858.68
2,414,912,842.09
2,724,489,802.48
3,044,130,661.16
Cumulative Cash Flow
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 64
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Sensitivity Analysis for Nitric Acid Plant
500,000,000
475,000,000
450,000,000
425,000,000
400,000,000
375,000,000
350,000,000
325,000,000
300,000,000
275,000,000
250,000,000
225,000,000
200,000,000
175,000,000
150,000,000
125,000,000
100,000,000
75,000,000
50,000,000
25,000,000
0
USD ($)
Produ
cts
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19
Years
Figure 9: Sensitivity Analysis
Total Revenues vs. Total Expenses
Tota…
Tota…
USD ($)
500,000,000
475,000,000
450,000,000
425,000,000
400,000,000
375,000,000
350,000,000
325,000,000
300,000,000
275,000,000
250,000,000
225,000,000
200,000,000
175,000,000
150,000,000
125,000,000
100,000,000
75,000,000
50,000,000
25,000,000
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Years
Figure 10: Total Revenues vs. Expenses
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 65
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
UTILITIES
A summarized table with all utility cost and requirement information can be found in the
economic evaluation section of the report.
Cooling Water
Cooling water is received from the combined heat and power group at 80 psia and 80°F.
The nitric acid plant requires 169,739 TPD of cooling water used in the heat exchanger network
and condensers for process gas cooling. All of the cooling water used is returned to CHP at
100°F.
Boiler Feed Water
Boiler feed water is received from the combined heat and power group at 1,350 psia and
250°F. 1,843 TPD of boiler feed water are required. The boiler feed water is used in the process
to both cool down the process gas and eventually be converted to 1,250 psia steam at 970°F to be
sold back to the combined heat and power team. They will then use this steam to power a steam
turbine to generate electricity for the fertilizer complex.
Process Water
Process water is received from the combined heat and power group at 114 psia and 80°F.
607 TPD of process water are required. The process water is used as make-up water in the
absorption column. The absorption column is responsible for converting nitrogen dioxide into
the nitric acid product.
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Electricity
Electricity is received from the combined heat and power group. The major use of
electricity comes from the air compressor at a whopping 17 MW. The remainder of the
electricity is used for pumps, lighting, controllers, and other general areas. For estimation
purposes the plant assumes a usage of 30 MW per day with the majority used by the air
compressor.
Steam
Steam is not used in the plant, but rather generated and sold to the combined heat and
power team. The 1,843 TPD of boiler feed water is turned into 1,250 psia and 970°F steam.
Upon plant startup steam will most likely need to be used to bring the ammonia burner up to
temperature. A second option is burning hydrogen or some other gas.
Sewage
Sewage systems will need to be installed within the plant.
Natural Gas
Natural gas is received by the gas purification team. Natural gas is not used in the
process, but it would be required for heating offices and other buildings for the staff.
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
CONCEPTUAL CONTROL SCHEME
Figure 11: Control Scheme for Ammonia Oxidation
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Figure 12: Control Scheme for Nitrogen Monoxide Oxidation
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 69
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Figure 13: Control Scheme for Absorption
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 70
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
GENERAL PLANT LAYOUT
Figure 14: General Plant Layout
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 71
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
The plant was laid out with the idea of safety and ease of access in mind. The plant
offices and parking lot are located away from the process block with a road as a barrier. The
prevailing wind in the figure above blows towards the south. Within the process block,
equipment was laid out based on the location of the pipe rack in order to minimize piping costs
while remaining safe. The compressor shack is located in the southwest corner of the process
block and is accessible by two roads for ease of maintenance. Within the compressor shack are
the two process compressors as well as the tail gas expander. The three pieces of equipment are
placed in a sheltered environment in order to minimize sound and protect them from the
elements. Along the northeastern edge of the pipe rack the ammonia oxidizer reactor with
attached waste heat boiler, steam drum, and steam superheater can be found. The pieces of
equipment are located near each other to maximize heat recovery for steam generation and
minimize piping costs as the boiler feed water and steam are at 1250 psi.
The northwestern edge of the pipe rack contains the air and ammonia filters as well as the
static mixer. The southern edge of the pipe rack houses many of the process heat exchangers that
are used for boiler feed water and tail gas preheating. Each of the heat exchangers has a tubepulling area in order to pull bundles should maintenance on the unit be required. The condensers
and their respective pumps are located near each other to minimize piping costs as a very weak
acid is produced at this point. The brown line that surrounds the acid mixer, absorption column,
and bleacher column represents a dike. The dike is used in case of catastrophic failure of the
absorption column. The dike will ensure that the acid does not spill into the rest of the process
block. The pumps within column area are near the columns in order to minimize costs. The
material for this stronger acid is much more expensive than other parts of the plant. The
southeast corner of the process block contains the nitric acid storage area which contains surge
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 72
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
tanks and product holding tanks. Should the plant need to be shutdown, additional nitric acid will
be ready. The loading zone allows for products to be shipped to the market or the ammonium
nitrate plant by tanker, rail, or pipeline.
DISTRIBUTION AND END-USE ISSUES REVIEW
The hot steam output from the nitric acid production process will be sent to the combined
heat and power plant, and the bulk of the 63 weight % nitric acid solution produced will be sent
to the urea plant. Both will delivered using simple piping.
The nitric acid not required by the urea plant will be sold at market value outside of the
plant. Contacts should be made with companies that will have a use for the product now or in the
future, when the plant is operational. Nitric acid has a relatively low price per weight, which will
probably make long-distance transport and handling economically infeasible. Due to this, most
sales are expected to be to nearby firms.
The nitric acid for sale will be stored upon production in a vertical cylindrical tank with a
fixed roof. It will be transported by truck, so the tank will be located near the periphery of the
overall plant near road access. The storage tank will be fitted with proper couplings and hoses.
To prevent damage from a truck leaving the loading area with the hose attached, a breakaway
hose coupling should be used. The loading area will be the area of the plant with the highest risk
of dangerous leakage due to the potential for operator error. Operators of the loading area must
be thoroughly trained and follow strict protocols and checklists. There should also be careful
maintenance of the hoses to anticipate and prevent corrosive failure.
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
Page: 73
Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
CONSTRAINTS REVIEW
Feedstock Definition
This process will utilize natural gas from hydraulic fracturing of shale in the Bakken
Formation of the Williston Basin in North Dakota. This natural gas will be sweetened in the gas
purification unit and sent to the Ammonia Plant where the natural gas will be converted to
99.98% pure ammonia vapor. The ammonia plant will deliver 571.5 tons of ammonia vapor per
day to the nitric acid plant. The ammonia vapor will be filtered and mixed with 9100 tons per
day of filtered air and sent to the ammonia burner.
Conversion Technology
The ammonia-air mixture is sent to the ammonia burner where by utilizing a cobalt-oxide
catalyst will be converted to nitric oxide (NO). Because this is an exothermic process, there is a
tremendous amount of heat produced. The heat that is generated will produce high pressure
steam which will be sent to the Combined Heat and Power Group for electricity generation.
Nitric oxide will then be converted primarily to nitrogen dioxide as it cools down through a
series of heat exchangers and condensers. However, there is a small amount of weak nitric acid
produced. The weak nitric acid is removed from the system and introduced to the absorption
column higher up than the nitrogen dioxide. The nitrogen dioxide is then compressed and sent to
the absorption column where it runs through a series of sieve trays counter currently to water.
During the absorption process, nitrogen dioxide and water undergo a chemical reaction that
again, generates heat. The acid is drawn out at different stages, cooled, and sent back to the
column to continue the process. The acid that eventually leaves the column is approximately
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
63% by weight nitric acid. At this point the nitric acid is known as “red acid” and must be
purified by the bleacher column.
Separation Technology
As stated above, during the conversion of nitric oxide to nitrogen dioxide, a small amount
of weak nitric acid is produced. Before introduction to the absorption column, the weak acid and
nitrogen dioxide must be separated. This is accomplished with the condensers. As the vapor
stream passes through the first condenser, weak nitric acid separates from the vapor stream and is
pumped to the absorption column at a higher stage. In addition, as the vapor cools even further it
is sent to a compressor and second condenser. The very weak (2-3% by weight) nitric acid
separated by the second condenser is used as make-up in nitric acid purification in the bleacher
column. The acid mixture stream is sent to the bleacher column to remove impurities. The
bleacher column consists of a stripping section and a reboiler. The acid stream is run counter
current to an air stream.
The air stream absorbs impurities such as nitrogen dioxide and
dinitrogen tetraoxide from the acid mixture and is sent to the compressor.
Product Description
2289 tons per day of 63% by weight purified nitric acid leaves the bleacher column. From
here the nitric acid either enters storage or is sent directly to the ammonium nitrate group. It
should be noted that any nitric acid sent to storage should be used as quickly as possible if color
is important because as the acid sits, the acid can “yellow due to the separation of NOX. The
ammonium nitrate group will convert nitric acid, ammonia, and urea into either ammonium
nitrate or urea ammonium nitrate to be used as fertilizer for crop production.
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Location Sensitivity Analysis
The nitric acid plant will be located in the Bakken Shale Deposit of the Williston Basin in
Northwestern North Dakota. The Bakken Shale Deposit lies in a relatively non-geologically
active zone, and therefore earthquakes are rare. The largest earthquake on record occurred on
July 8, 1968 and was magnitude 4.4. Should accidental release of nitric acid or vapors from the
process occur, the damage should be insignificant. The only concern would be nitric acid leakage
to the Missouri river. The effect of an accidental spill will be minimized by proper containment
and neutralization, training, and communication with the local officials. This plant has been
designed to keep emissions from the tail gas low by use of an economizer. The area of
Northwestern North Dakota is sparsely populated with the largest community being Williston
with a population of just over 13,000 residents. Any accidental spill should not adversely affect
the community there, but safety protocols have been put into practice to avoid such releases.
ESH Law Compliance
This plant’s emissions are under the USEPA regulations for air contaminants. The state
of North Dakota does not have its own EPA regulations and as such only the USEPA standards
apply. The only major pollutant is NO2, the EPA maximum allowable emissions is 53 parts per
billion. The nitric acid plant produces over 5000 parts per billion, however because the plant
utilizes tail gas treatment to power a turbine at the end of the process, the emissions fall below
EPA standards. The EPA does not currently regulate NO2 emissions, however, design has been
that there may be regulations of NO2 in the future and when regulations are implemented this
plant will be well below the limit.
Senior Design II – CHE 397 Team Foxtrot
Calabrese, Listner, Somuncu, Sonna, Zenger
Spring 2012
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Improved Nitric Acid Production via Cobalt Oxide
Catalysis for use in Ammonia-Based Fertilizers
University of Illinois at Chicago
Employee safety is of the utmost importance in this plant. Plant process controls are
installed in order to prevent any catastrophic accidents from occurring. The largest source of
danger is in the ammonia oxidation process. The ammonia to air ratio has to be held at under
14% in order to prevent an explosion hazard. The nitric acid plant will run at a ratio of under
11% as well as having controls to prevent higher concentrations from occurring. The plant is
designed to alarm workers to a dangerous condition first and if it is not alleviated the process
will in effect shut itself down. Workers are to be trained in all aspects of safety in regards to
nitric acid production with repeat training occurring at least annually. Should an emergency
arise, teams of first responders trained in that situation will respond immediately, while clear
communication to local emergency officials ensures the situation will be contained quickly. In
addition, weekly safety meetings with the supervisors are to be performed. Each department is to
conduct its own safety review on a monthly or sooner basis. Safety teams and the safety
committee headed by the EHS director will conduct routine safety audits to ensure the plant is in
compliance with any and all regulations.
Laws of Physics Compliance
None of the laws of thermodynamics are shown to be broken. There is no decrease in
entropy at any point. Oxidation of ammonia produces nitric oxide and heat employs the first and
second laws of thermodynamics. The heat generates steam which powers a turbine for electricity
employs the first law. Nitric oxide is oxidized in a series of heat exchangers that lowers the
temperature of the system proving the zeroth, first and second laws. Condensers separate the
streams proving the second law. Compressors add work to the system once again proving the
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first and second laws to be in effect. Turbines utilize gas expansion to provide work proving the
first and second laws.
Turndown Ratio
If for some reason, the production of nitric acid needs to be slowed down the plant has
the ability to achieve a turndown ratio of 2-3:1. The main reasoning for this is the minimum
vapor velocity on the trays in the absorption column. However, if there is a complete stoppage of
production in one of the downstream processes, surge tanks will be utilized. For emergency
purposes of the downstream processes being down for a week, four 250,000 gallon storage tanks
made from 304L stainless steel will be utilized. Each tank will have a dike that will contain the
one and one half times the contents of the tank in case of a leak. In addition, there will be four
more storage tanks storage for transportation. These tanks can also be used for emergency
storage if needed.
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APPLICABLE STANDARDS / SAFETY REVIEW
The safety of employees and the public are of utmost concern for a chemical production
plant. Economic and logistical concerns as detailed in this report drive the design and
construction of the plant, but safe use is the number one goal of such an operation. There are
numerous important safety precautions to be taken. Some are to be considered during equipment
design and plant layout, some will be regular actions to take during operation, and some others
are to be performed during an emergency. The following is an outline of safety matters that are
relevant to the production of nitric acid.
Environmental
A great concern for the process at hand is a catastrophic equipment failure (Perry). A
likely cause for this is a situation of thermal runaway. The two highly exothermic reactions in the
Ostwald process make unchecked heating a serious problem with severe consequences. Process
controls have been prepared to carefully monitor and regulate these reactions, and cease them
immediately if need be. They also keep the ratio of ammonia to air below a safe level. The
catalytic reactor, absorption column, bleacher, heat exchangers, and various pipes and fittings
have been designed to withstand fluctuations in operation conditions within a reasonable margin.
They will be fitted with relief valves to prevent dangerous over-pressurization. With or without
thermal runaway, equipment will fail if it is sufficiently degraded (European Fertilizer
Manufacturers' Association). It will be important to ensure that the equipment is of quality
construction, and proper materials have already been selected for each of the components to
prevent corrosion. Corrosion is important to consider because of the chemicals used in the plant.
Equipment must be tested regularly for corrosion and replaced if need be.
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The total failure of a key piece of equipment will result in the release of some or all of its
contents. The plant designer must take the small chance of this occurrence seriously and
adequately prepare for the plant and employees to withstand such an event. For the components
handling gases, failure will lead to the release of dangerously hot gases. It will be important for
plant personnel to be immediately made aware of the failure and evacuate the area downwind
from the failed equipment (Towler). The absorption column and adjacent piping will contain a
liquid solution of highly reactive nitric acid, and the release of a large amount of heated nitric
acid from this section is the greatest safety concern in the entire plant. Once again, plant
personnel should be alerted, and the layout of the area should allow for immediate evacuation to
avoid contact with liquid and vapor release. A large amount of liquid, when spilled, has the
potential to travel far along the ground. Bunding should be used in this area to contain a spill
within this section of the plant, which will defend personnel as well as other equipment from
damage and harm. A thick foundation of concrete may be necessary as well to prevent
contamination of groundwater. Nitric acid itself has low flammability, but it it is still a fire
hazard. Its reactions involve exothermic oxidation, which can produce flammable vapors and
enough heat to ignite them. Equipment and support structures within reach of the ground in the
area of the absorption column should be coated with a material that can withstand fire and
insulate from high heat.
In the case of any large failure, it is vital for the public and plant employees to be
prepared. Evacuations and other emergency procedures should be planned and reviewed with
employees before the possibility of a spill. Contacts should be previously established with nearby
chemical cleanup specialists. Proper Personal Protective Equipment (PPE) should be acquired
and kept on-hand for work that must be performed immediately in the area of a spill. The PPE
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required to handle a dangerous spill would be a hazardous materials suit, including protective
clothing and a breathing apparatus.
The Environmental Protection Agency details the work that must be done by a Local
Emergency Planning Committee (LEPC) (EPA). These committees are established to protect the
safety of the public near the plant, and it is especially relevant in emergency preparations. Its
tenets, as detailed by the EPA, are as follows:
 “Write emergency plans to protect the public from chemical accidents;
 Establish procedures to warn and, if necessary, evacuate the public in case of an
emergency;
 Provide citizens and local governments with information about hazardous chemicals and
accidental releases of chemicals in their communities; and
 Assist in the preparation of public reports on annual release of toxic chemicals into the
air, water, and soil.”
The light release of chemicals is a hazard for employees as well. It can be caused by an error
by a plant operator, such as leaving a sample point open, or spilling material while loading or
unloading. It can also be caused by leaks from degraded or improperly fitted equipment. Liquidhandling areas of the plant should have ground formations to contain and direct the flow of
hazardous liquids to storage containers. Neutralization of small quantities of the nitric acid
solution can be done by slowly adding a weak base or a third-party product to the spill. Some
neutralization materials, equipment, and training for doing so should be prepared in the plant
beforehand.
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Indeed, a more in-depth study of plant risks is necessary. The Occupational Safety and
Health Administration (OSHA) requires a formal process hazard assessment for the plant. A
failure-mode effect analysis, which is a discussion panel with experts in aspects of the plant, is
also recommended to ensure that all potential hazards are fully considered.
Occupational Health & Safety
The long-term well-being of plant personnel is vital to consider. OSHA in the United States
regulates this facet of plant operation, and the following are many of the things that must be
minded while constructing and operating the plant.
The dilute presence of airborne chemicals is a hazard requiring constant management
(Wells). This presence must be kept within acceptable levels by containing leaks, using proper
ventilation around work areas, and by engineering controls. OSHA allows for certain levels of
airborne chemicals, and the permitted concentrations are as follows. The terms used are defined,
followed by the concentration limits accepted by OSHA for key chemicals in the process.

PEL: Permissible Exposure Limit.

TWA: Time-Weighted Average. Defined by OSHA as "… the employee's average
airborne exposure in any 8-hour work shift of a 40-hour work week which shall not be
exceeded."

STEL: Short Term Exposure Limit.

IDLH: Immediately Dangerous to Life or Health.
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Table 48: OSHA Chemical Exposure Limits (from OSHA online)
Material
NH3
HNO3
NO
NO2
PEL, TWA [ppm]
25
2
25
5
STEL [ppm]
35
4
-
IDLH [ppm]
300
25
-
Another risk to be managed is that of noise. OSHA allows for a 90 decibel PEL, and it
will be imperative to maintain that for the sake of employees' ear health. There are several ways
for one to keep noise exposure within acceptable levels. They include using machinery which is
inherently low-noise, keeping bearings lubricated, erecting sound barriers, and limiting time
which personnel spend near sources of noise. If the plant exceeds a level of 85 decibels, it will be
required that an employee Hearing Conservation Program be enacted. OSHA also regulates noise
pollution of the area surrounding the plant, but that is a lesser concern due to its remote location.
There are numerous OSHA regulations regarding working spaces. There will be
numerous heated vessels and pipes throughout the plant which are burn risks. There is a zone
defined as seven feet from the ground or floor and within 15 inches of stairs and ladders which
much be protected from contact with employees. Hot components within this area must be
sufficiently insulated or guarded. Moving parts should also have guards around them. Platforms
should have guard rails, be wide enough, and have non-slip surfaces. The work area should also
be well-lit and have plenty of emergency exits.
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The following is a list of components used in the process and their associated risks.
HNO3

MSDS: http://www.inchem.org/documents/icsc/icsc/eics0183.htm

Nitric acid is a strong acid and its vapors can cause severe burns to eyes, skin, respiratory
tract, and gastrointestinal tract on contact.

Strong oxidizing agent

Adequate ventilation and engineering controls to maintain airborne levels below
workplace exposure limits.

Small spills should be neutralized with soda ash or other neutralizing materials. Reaction
will release heat and CO2 gas. Flush contaminated area with water.

Industrial spills: Evacuate personnel upwind and ventilate area
NH3

MSDS: www.airgas.com/documents/pdf/001003.pdf

Corrosive to the skin, eyes, respiratory tract, and mucous membranes.

Contact with liquid ammonia may cause chemical burns and frostbite.

Explosively mixes with air should concentration climb above 15%

MSDS: www.airgas.com/documents/pdf/001039.pdf

Nitrogen monoxide in air can convert to nitric acid producing acid rain

Can be fatal if inhaled

Causes skin irritation and severe eye irritation

Oxidizer
NO
NO2

MSDS: www.airgas.com/documents/pdf/001041.pdf

Strong nitrating or oxidizing agent in organic synthesis

Can be fatal if inhaled

Causes severe respiratory tract, eye, and skin burns
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University of Illinois at Chicago
N2O4

MSDS: http://www.orcbs.msu.edu/msds/linde_msds/pdf/050.pdf

Strong nitrating or oxidizing agent in organic synthesis

Can be fatal if inhaled

Causes severe respiratory tract, eye, and skin burns
Cobalt Oxide Catalyst

MSDS: http://msds.orica.com/pdf/shess-en-cds-010-000034612601.pdf

May cause slight skin and eye irritation
Major Process Hazards

Equipment/Piping Failure
o Corrosion protection through use of proper nitric acid grade stainless steel.

Explosion of Air Ammonia Mixture
o Control air/ammonia mixture to ensure it is below the explosive threshold.
o Automatic closure of ammonia control valve and separate shutdown trip valve a
large ratio is measured.

Explosion of Nitrite/Nitrate Salts
o Should ammonia remain in nitrous gas steam deposits can occur. Local washing
and common operating practices easily prevent this hazard.
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PROJECT COMMUNICATIONS
The project website can be reached at:
http://www.che397-nitric-acid.wikispaces.com
The previous link contains all project related files and information sources used in a few zip
files. These zipped files include project presentations, expo information, research articles,
catalyst information, as well as all other working files for the project. This report itself is also
uploaded as a separate file.
SPECIAL THANKS
CHE 397 Project Supervisor:
 Jeffery P. Perl: UIC Department of Chemical Engineering
Project Mentor:
 Bill Keesom: Jacobs Engineering
Project Aid:
 Dennis O’Brien: Jacobs Engineering
Cobalt Oxide Catalyst Inventor:
 Ali Nadir Caglayan: Catalyst Development Corporation
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Senior Design II – CHE 397 Team Foxtrot
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Keesom, Bill. Personal Interview. 27 Mar. 2012
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