Methanol Production from Synthesis Gas
derived from Municipal Solid Waste
Department of Chemical Engineering
University of Illinois at Chicago
ChE. 397
Group Charlie: Priya Chetty, Scott Morgan, Brian Mottel, Daniyal Qamar, Sukhjinder Singh
Mentor: Dennis O’Brien
Instructor: Dr. Jeffery Perl
3/3/11
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Table of Contents
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
Abstract
Executive Summary
Introduction
Process Description
Process Control
Environmental Concerns and their mitigation
Economics
Recommendations
Appendices
1. Design Basis
2. Block Flow Diagram
3. Process Flow Diagram
4. Material and Energy balances
5. Calculations
6. Process Simulation in ASPEN
7. Annotated Equipment List
8. Economic Evaluation
9. Utilities
10. Conceptual Control Scheme
11. General Arrangement
12. Distribution and End-use Issues review
13. Constraints Review
1. Feedstock definition
2. Conversion technology description
3. Separation technology description
4. Product description
5. Location sensitivity Analysis
6. ESH law compliance
7. Laws of physics compliance
8. Turndown ratio
14. Applicable Standards
15. Project Communications File
16. Information Sources and References
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I. Abstract
Methanol is a chemical which is used in many diverse applications. Methanol is
commonly used as a fuel, as antifreeze, and as a solvent, but can also be utilized to produce
plastics, adhesives, and dyes. The most common method for producing methanol involves
combining methane (natural gas) and water to produce synthesis gas, which is carbon monoxide
and diatomic hydrogen.
This synthesis gas is then used to produce methanol. The issue with this process is that
methane is very useful as a heating fuel which is why it is used to fulfill residential heating
needs. This method of methanol production is essentially using a fuel to produce another fuel as
the product. Our goal is to make Methanol by using a sustainable source of fuel. The source of
our synthesis gas is Chicago Land Municipal Solid Waste. We are utilizing a waste stream rather
than a fossil sourced feed stock. This will be the source of our synthesis gas. We will then
compress the synthesis gas, and feed it into a multiple feed reactor which contains
Cu/ZnO/Al2O3 catalysts to produce methanol.
Unused synthesis gas will be separated from the initial product stream and recycled back
into the reactor. The initial product stream will contain methanol, along with water, as well as
other alcohols such as ethanol, and propanol. To ensure that the methanol produced will meet
the grade AA industry standard, which states that it must be 99.85% pure, the initial product will
go through a flash separator followed by two distillation columns.
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II. Executive Summary
By utilizing the process outlined in this report, 99.85% pure methanol can be produced at
a rate of 1060 tons per day from a feed stock of 1700 tons per day of synthesis gas which will be
produced by gasification of 5,000 tons per day of municipal solid waste. Conversion of
synthesis gas to methanol is conducted in a Lurgi reactor which will utilize a Cu/ZnO/Al2O3
catalyst, and a recycle stream. The desired product will then be separated from byproducts via
flash separation, and purified using two distillation columns.
The capital cost needed to build a plant of this magnitude is $116.8 million. The internal
rate of return for this plant would be 25.60%, and the payback period would be 5 years.
III. Introduction
The objective of the syngas to methanol process is to produce 1060 tons/day of grade AA
methanol for use in the chemical, automotive, and plastics industries. The syngas that is
procured for this process will have been produced by gasification of municipal sold waste.
There are many advantages to utilizing syngas produced via this method, such as; it eliminates
the need for methane, it is less expensive due to the solid waste tipping fee, and it is a much more
green technology which is important to consumers.
Currently there are 90 methanol plants worldwide with an annual production of 11 billion
gallons, generating $12 billion per year in revenue. The market outlook for the future of the
methanol industry is good, with global demand expected to rise in the years to come.
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The gasification plant will be located in the Chicagoland area because ample municipal
solid waste is produced there; in fact the average production is 25,000 tons per day. The
methanol plant will be located near the gasification plant, because geographic proximity will
reduce transportation costs, which also reduces the consumer price of the product.
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IV. Process Description
The overall process starts as syngas from group Delta enters the very first heat exchanger. The syngas,
now cool enough to enter a compressor, goes through a two stage compressor with cooling between
stages. The syngas at a high enough pressure to react under catalytic conditions now enters a reactor. A
catalyst based on Cu/Zn/Al oxides is used and it gives a conversion of Carbon Monoxide to methanol of
0.5 per pass (based on reaction 1 below). As reactions 1 through 4 (listed below) take place in the
reactor all the products are discharged towards a heat exchanger. Methanol synthesis involves highly
exothermic reactions and the heat accumulates in the product stream. This heat must be taken out so it
can be utilized in reboilers for distillation columns. The product stream is also highly pressurized thus it
goes through a turbo expander so we can run it through a turbine and make power to use in air coolers
and put into the grid. After the turbo expander the products go through heat exchangers and finally into
a flash drum. The flash drum operates at conditions where the non condensables are separated easily
and sent back to the compressor in the beginning of the process as a recycle stream. This recycle stream
contains a high concentration of CO2 that accumulates as the process goes on. A purge from this recycle
stream works to minimize the accumulation of this CO2. The condensables, ethanol, butanol, methanol,
and water proceed to the separations train where they go through a couple distillation columns. The
first column gets rid of any left over non condensables, CO, CO2, H2 and the second one gives AA grade
methanol separated from ethanol, butanol, and water.
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Detailed descriptions of units are given below:
Compressor
The syngas from the gasifier will reach the methanol synthesis plant at 300 psi. But this
pressure is too low for the reactor and needs to be raised. There will be a multistage compressor
to raise the pressure to the needed value of 1200 psi. Since it is a multistage compressor there is
some pressure drop between each of the stages, due to the fact that when the gas is heated in the
compressor it will need to be cooled, and this cooling will decrease the pressure. So instead of
having an overall compression ratio of 2:1, the total compression will need to be around 2.5:1 to
overcome the pressure drop from the inter-stage coolers. The cooling water in this part of the
process will be at 90 °C, because this will eliminate the need for a cooling tower which is fairly
expensive to install.
Reactor
Methanol synthesis is a very complex process since it is very equilibrium limited, and
quite exothermic; therefore it is imperative that the correct type of reactor is chosen to obtain the
desired results. There are many diverse types of reactors which may be used in the synthesis of
methanol, which utilize various methods of catalysis, and removal of heat from the reaction. A
significant amount of time was spent evaluating the different types of reactors to ensure that the
correct one was chosen. Below is an example of some of the reactors that were considered
along with information about each:
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ICI Multiple Feed Quench Reactor
The ICI reactor uses multiple feeds to bring the reaction temperature down to the desired
value. This however requires a very high flow of air into the reactor which reduces the
effectiveness of the compressor. The reactor utilizes multiple catalyst beds to reach a conversion
of 35-40%. The maximum production rate of the ICI multiple feed quench reactor is 5000 tons
per day. The amount of syngas required to remove the heat of the reaction is in excess of that
which is able to be procured, therefore this reactor did not meet the necessary requirements for
this process.
Lurgi Combination Converter Reactor
The Lurgi reactor works as an ICI reactor but it also combines water cooling to control
the reaction temperature. The reactor works as a heat exchanger with tube and shell sides. The
reactions take place in the shell side while coolants go through the tube side. There are
essentially two reactor vessels the first one has two feeds to it. The first feed (cooling stream) is
the cold fresh syngas; the second feed (reactant stream) is the hotter product gas from the second
reactor vessel. This hot product stream has leftover CO and H2 that can react again and it does so
in the first vessel. This essentially gives two reactors in series and therefore a higher conversion.
The cold fresh syngas is used to control the temperature of the first reactor and this colder gas
proceeds to the second reactor as the reactant stream. To control the temperature of the second
reactor, steam is used. Water at its saturation point (428 F and 420.61 psi) is kept in a steam
drum and as this water goes through the reactor it removes energy from the product stream in
the reactor and evaporates, the steam is sent back to the drum where new cooling water
controls the saturation point. This loop continues until the process reaches steady state, and
before that a light up heater is used to bring the reactant temperature up to the desired value.
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Example of Lurgi Methanol Reactor courtesy of http://www.lurgi.com/
In the production of methanol from syngas, which will have a H2 to CO ratio of 2:1, there
are several reactions that will have to be considered:
CO + 2H2 ↔ CH3OH
(1)
CO2 + H2 ↔ CO + H2O
(2)
CO2 + 3H2 ↔ CH3OH + H2O
(3)
2CO + 4H2 ↔ C2H5OH + H2O
(4)
These reactions occur simultaneously inside of the reactor, during the methanol synthesis step.
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The kinetics of the above reactions can be found in literature. From all of the reaction kinetics, it
is possible to find the production yield of each of the components in the syngas. The following
reactions are for the kinetics of methanol synthesis:
 3OH , A3 
rCH
rH 2O , B 2 
k ps , A3 K CO [ f CO f 3/ 2 H 2  fCH 3OH /( f 1/ 2 H 2 K o p1 )]
(1  K CO f CO  K CO2 f CO2 )[ f 1/ 2 H 2  ( K H 2O / K 1/ 2 H 2 ) f H 2O ]
k ps , B 2 K CO2 ( fCO2 f H 2  f H 2O f CO / K o p 2 )
(1  K CO fCO  K CO2 fCO2 )[ f 1/ 2 H 2  ( K H 2O / K 1/ 2 H 2 ) f H 2O ]
 3OH ,C 3 
rCH
k ps ,C 3 K CO2 [ fCO2 f 3/ 2 H 2  fCH3OH f H 2O /( f 3/ 2 H 2 K o p 3 )]
(1  K CO fCO  K CO2 f CO2 )[ f 1/ 2 H 2  ( K H 2O / K 1/ 2 H 2 ) f H 2O ]
Catalyst
In the reactor there will be a Cu/Zn/Al catalyst to drive the overall reaction towards methanol.
This catalyst is used in many other reactors. The poisons of this specific catalyst are sulfur,
chlorine, CO2, and high temperatures. The amount of CO2 activates the catalyst and it also
deactivates it, so an adequate amount of CO2 must be allowed into the reactor. So in order to
ensure that the catalyst life can stay at a reasonable time, the syngas that is fed into the reactor
must have none of the above chemicals, and the temperature of the reactor will need to stay at
518 F. The conversions are 50% for reaction 1, 13% for reaction 2, 2 % for reaction 3, and 2%
for reaction 4.
After the syngas has been reacted it will be at 1185 psi and 518 F. The reacted gas will
then go through several pieces of equipment until it reaches the distillation columns for
purification of the product. The gas will need to be split for a recycle feed and remaining gas.
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The remaining gas will have a high amount of crude methanol and fewer impurities than before.
After this the stream will be put through a condenser and heat exchanger in order to have the
methanol in the liquid phase and to be at a much lower temperature. Then the crude methanol is
put through a flash tank and finally to the distillation unit.
Heat Exchangers
Since many of the different pieces of equipment throughout the process need the syngas
or methanol at different temperatures, there will be three heat exchangers throughout the entire
process. These particular heat exchangers will be a shell and tube heat exchangers, which
consists of a series of tubes. One set of these tubes contains the fluid that must be either heated
or cooled. The second fluid runs over the tubes that are being heated or cooled so that it can
either provide the heat or absorb the heat required. The fluid used in this case will be water. A
heat exchanger will be present before and after the multi-stage compressor in order to utilize the
energy from a high compression process. The third heat exchanger will be present after the
reactor. The reactor will be producing heat at an amount of -12,891,1520 Btu/hr, which can be
utilized with this heat exchanger. The first heat exchanger will have an area of 64.18 ft2, with 6
inner tubes having an inner and outer diameter of 0.33ft and 0.34ft respectively. The second
heat exchanger will have an area of 1200 ft2, with 105 inner tubes having an inner and outer
diameter of 0.11ft and .12ft respectively. The third heat exchanger will have an area of 425 ft2,
with 15 inner tubes having an inner and outer diameter of 0.33ft and .34ft respectively. The
energy balances around the heat exchangers can be found in the appendix, and they show how
much energy is needed to run each of them.
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There will be several non condensables in the product stream coming from the reactor. Since
these gasses do not dissolve very readily in the crude product they are very easy to separate. A
flash drum is used to do so.
Flash Drum
A flash drum with a diameter of 4.63 ft and a height of 7.79 ft is being used for a simple
separation of CO, H2, and CO2 from methanol, water, n-butane, and ethanol. The drum operates
at a temperature of 118 °F and a pressure of 638 psi (Grue et. al.). The energy lost in the flash
drum is minimized by using a heat exchanger before and lowering the product temperature to
118 °F, this heat is then used in the distillation columns. High separation percentages of non
condensables were achieved using this flash drum. 97.5% of CO, 76.44% of CO2, 3.9%
methanol, 99.99% of H2, and 2.3% of Ethanol are the percentages of feed components to the
flash drum that are sent to the vapor stream, the rest was sent into the liquid stream which is
distilled twice to obtain grade AA methanol. It can be noted that the lesser CO2 than CO goes
into the vapor stream and this can be attributed to the fact that CO2 readily dissolves in the H20
and methanol rich stream that goes off as liquid to the distillation column.
Distillation Columns
In order to obtain the grade AA methanol at the end of the process, there will need to be
two distillation columns installed. Both of the columns will need both condensers and reboilers
on them. After the second distillation column the methanol will be pure enough to sell as Grade
AA Methanol. The first distillation column will need to be at 31psi, 118°F, have 15 trays, and
the feed will be located above the 5th tray. The second distillation column will need to be at
31psi, 120°F, have 33 trays, and the feed will need to be at the 13th tray to obtain to correct
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purity of methanol. After the first distillation process there will be water, ethanol, and other
higher hydrocarbons, along with the methanol. Majority of the methanol will be in the bottom
stream, including water and ethanol, which will then be fed to the second distillation column.
After the second distillation column, methanol will be present the distillate stream and the water
along with methanol and ethanol will be in the bottom stream. The water will be used for either
cooling another part of the process, or it could be heated to produce steam to be used in a heat
exchanger or to power some of the necessary equipment. The ethanol and higher hydrocarbons
will need to be separated from methanol and then they can be sold to a different company to be
used for a different process. Using ASPEN it is possible to find the dew and bubble points of the
streams exiting the columns. From all of the information, the height of the columns can be found
and from that the sizing.
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V. Process Control
A control process is very important in the aspect of manufacturing a quality product.
This can be assured by having the quality designed into the product and also into the
manufacturing process. Achieving this will allow the use of the process control to ensure that
the methanol produced meets the standards of grade AA methanol. At this point, the design
basis is not set to ensure a complete process control. However, there are a few vendors that
provide process control solutions.
Methanol@Max provided process controls specifically for methanol production plants.
They use particular software, which connects to the DCS and controls. This helps to optimize
the plant minute by minute, every hour of the day, every day of the year. The software does use
the PLC method. The program will reduce the variance in the parameters and reduce the need
for operator intervention. This will also help in improved separation, reduce energy
consumption, and improve the overall plant stability. Maximizing conversion and increasing
methanol production will be the key components of this software. Also, maintaining the
reactor’s parameters and adjusting them accordingly to the software will help ensure
productivity.
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VI. Environmental Concerns and their mitigation
Methanol is highly flammable and may result in fire and explosive hazards, therefore
fireproof walls must be incorporated in the plant design to ensure personnel safety. Furthermore,
respirators and gloves must be utilized while working in areas of high vapor methanol
concentrations since prolonged human exposure to methanol has resulted in headaches,
dizziness, nausea, gastric upsets, blurred vision, and blindness. Humans should not be exposed
to methanol concentrations greater than 198ppm based on OSHA regulations. Overall, methanol
does not pose a high hazard to health; however, effective procedures must be implemented to
ensure the health and safety of the personnel.
Methanol synthesis generates CO2 resulting in greenhouse gases emissions into the
atmosphere and over long term global warming. In addition, CO2 is heavier than air, therefore,
increasing its tendency to leak through open valves; therefore, stringent guideless must be
executed while operating valves. To ensure environmental concerns, the plant will abide to EPA
and all other environmental regulation agencies and never discharge material that is detrimental
to the environment without utilizing proper guidelines.
The plant will abide by the waste water stream regulation proposed by the municipal
waste water treatment agency. Most heavy metals in the slag or fly ash flue can be either used in
asphalt construction or converted to fine, gritty material similar to sand respectively. Remaining
heavy metals which may have run into the waste water can be removed through flocculation and
precipitation and discarded as chemical waste. Further research will be conducted to ensure the
processes discussed have competing edge, and all technological advances to impede harmful
environmental impact will be embedded in the plant design.
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VII. Economics
VIII. Recommendations
With all industrial processes there will be many recommendations to ensure that the process
would work both efficiently and economically. Some things that could change throughout our process
would be reactor conditions, catalyst for the reactor and CO2 removal, and conditions for any other
piece of equipment. Changing conditions for any piece of equipment would help to decrease the price
of the process, but on the other hand it could cause inefficiency in the system. A cost evaluation would
have to be preformed not only on the entire system but each piece of equipment to ensure that the
process can make the most profit. Any piece of equipment that needs high pressure or temperature will
increase the cost of that equipment. If the process was able to make the same amount of final product
with lower pressure or temperature, this would decrease the price of installment and increase the final
profit.
Catalysts are used in almost all chemical productions nowadays and choosing the best catalyst
for the process is extremely important. We are using a Cu/Zn/Al catalyst for the methanol synthesis
from syngas, and it seems to be the same one that is used in industrial processes for methanol synthesis.
Since catalysts are extremely expensive the choice of the correct one is vital. If there were to be a
cheaper or one that produced higher yields, they would need to be considered in our process. There is a
lot of research in the field of catalysis, and ones of the future seem that they will be able to make
processes run at lower conditions, which will in turn create lower prices on equipment.
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The most expensive part of our process, along with industrial processes, is the reactor to
produce crude methanol. This is due to the fact that very high pressure is needed to ensure the crude
methanol is produced with the fewest impurities. Our reactor is running at 420 psi and 491°F. If it were
possible to lower both pressure and temperature in the reactor, this would decrease the overall price of
the process. The Lurgi reactor seems to be the best reactor for the methanol synthesis reaction,
because it does not require an excess amount of syngas to cool it like the ICI Synetix reactor. There
could be other reactors better suited for the process, but it seems that the Lurgi will be the most cost
effective and efficient.
IX Appendices
1. Design Basis
By utilizing the process outlined in this report, 99.85% pure methanol can be produced at
a rate of 1059 tons per day from a feed stock of 1700 tons per day synthesis gas which will be
produced by gasifying 25,000 tons per day of municipal solid waste. Conversion of synthesis
gas to methanol is conducted in a LURGI quench reactor which will utilize a Cu/ZnO/Al2O3
catalyst, and a recycle stream. The desired product is then separated from byproducts via flash
separation followed by two distillation columns. Ideally the plant would be located in the
Chicagoland area, because this is where the synthesis gas feedstock will be produced, and
geographic proximity will reduce transportation costs. The capital cost needed to build a plant
of this magnitude is $116.8 million. The internal rate of return for this plant would be 25.60%,
and the payback period would be 5 years.
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. A thermal oxidizer will be used to destroy hazardous air pollutants and volatile organic
compounds. They will be destroyed via thermal combustion and eventually changed to form
CO2 and water. CO2 will also be released from distillation column 1 in the distillate stream at an
amount of 23,180.57 lb/hr. This CO2 will be released into the atmosphere.
The methanol produced at this particular power plant will have a purity of 99.85%, which will qualify it
to be sold as grade AA methanol. There are several requirements that need to be met in order for it to be called
grade AA methanol. The amounts of acetone and aldehyde can only be at max 30 wt-ppm. Acetone and ethanol can
only be present at a max limit of of 10 wt-ppm and there also cannot be any higher alcohols present. Finally, water
must be only present at maximum limit of 1,000 wt.-ppm.
2. Block Flow Diagram
3. Process Flow Diagram
The following figure shows the overall process flow diagram. Smaller pieces of the picture are
shown below for more detail
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This figure shows the first heat exchanger, compressor, and the second heat exchanger.
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This figure shows the stream coming into the reactor, the steam drum for the reactor, the turbo
expander, and finally a heat exchanger that cools the product down.
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This figure shows an air cooler, a heat exchanger, and then the flash drum. The stream leaving
the flash drum on the top is the recycle stream that loops back to join fresh syngas into the
compressor.
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This shows the final step of the process where crude methanol is put through distillation columns
and grade AA methanol is produced(P-64)
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4. Material and Energy balances:
5. Calculations:
Flash Drum:
Calculations were made to determine the amount of vapor going into the vapor stream of the flash
drum:
Component n
CO
CO2
METHA-01
N-BUT-01
ACETO-01
H2O
HYDRO-01
DIMET-01
ETHANOL
Total Flow in
(lbmol/hr)
Flash Drum Concentrations
In
Vapor
Liquid
(lbmol/hr) (lbmol/hr) (lbmol/hr)
3223.377 3141.149 82.22929
2235.352 1708.629 526.7114
3184.629 125.1214 3059.511
7.702618
0.03732
7.6653
0
0
0
305.458 3.630568 301.8272
5746.344 5746.338 0.000514
0
0
0
31.36592 0.740183 30.62576
% in vapor
97.449
76.43666
3.928915
0.484515
1.188566
99.99991
2.359832
14734.23
To calculate percentage the following formula was used:
%n 
Vaporn
Feed n
Where:
%n is the percentage of component n
Vaporn is the lbmol/hr of component n in the vapor stream
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Feedn is the lbmol/hr of component n in the feed stream
The flash drum was also sized:
Vapor In
Liquid In
Vapor Out
Liquid In
Max Vapor ft3/s (outlet)
Density of vapor lb/ft3
Density of Liquid lb/ft3
k value @ 300 psi
max velocity ft/s
area of drum ft3
Radius of drum ft
Diamter ft
Length
Total Volume
Flash Drum Sizing
Fractions
Total flows ft3/hr
0.781183
190665.198
0.218817
190665.198
1
187124.047
1
3540.05861
51.9789
1.734489
49.19985
0.33
1.726301
30.10998
3.095853
6.191706
3.84889
115.89
radius good ft
Area good
Length good
Flows ft3/hr
148944.455
11.589
187124.047
3540.05861
20
1256.637
0.092222
To get the max vapor velocity the Sauders Brown equation was used:
Vmax
l  v
K
v
Where:
Vmax is the maximum vapor velocity allowed in ft/s
K is a constant known for Flash drums at several different pressures
ρl is the liquid density lb/ft3
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ρv is the vapor densiy lb/ft3
Once the vapor velocity was found, it was used to find the total area of the flash drum
required:
A
V
Vmax
Where:
A is the area of the flash drum in ft2
V is the highest vapor velocity the flash drum needs to handle according to the design in ft3/s
V is the max vapor velocity as calculated above
The diameter of the drum can be found very easily using the simple area of a circle formula
A=ΠR2
The height of the drum depends on the amount of liquid that is present in the flash drum for a
given amount of time. The following formula was used to determine the height of the drum:
2  T W
H
A
Where:
A factor of two is used because it is assumed the tank is halfway full of liquid
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H is the height of the drum
T is the time in s that the liquid stays in the drum (5 minutes was used for liquid inventory)
W is the liquid flow rate in ft3/min that flows out
Heat Exchangers:
Calculations were made to find heat exchanger sizes:
HX 1 sizing
90/10 CU/NI .049 400 psig 600°F
Area of heat exchanger ft2
Heat exchanged Btu/hr
OD ft
ID ft
wall thickness
Length ft
Area of single tube ft2
Overall Heat Transfer Coefficient Btu/F ft2 hr
LMTD F
Area requirement calculation
Number of Tubes
64.175
3396590
0.3415
0.333333
0.004083
10
10.72854
149.6937
353.5688
64.175
5.981709
HX 2 Sizing
Area of heat exchanger ft2
Heat exchanged Btu/hr
OD ft
ID ft
wall thickness
Length ft
Area of single tube ft2
Overall Heat Transfer Coefficient Btu/F ft2 hr
LMTD F
Area requirement calculation
Number of Tubes
1200
43795974
0.124672
0.111549
0.006562
20
7.833368
149.6937
356.5221
820.6243
104.7601
HX 3 Sizing
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Max Pressure psi
Area of heat exchanger ft2
Heat exchanged Btu/hr
OD ft
ID ft
wall thickness
Length ft
Area of single tube ft2
Overall Heat Transfer Coefficient Btu/F ft2 hr
LMTD F
Area requirement calculation
Number of Tubes
1200
425.3894
10752639
0.3415
0.333333
0.004083
15
16.09281
149.6937
303.4667
236.7013
14.70852
The amount of heat exchanged was calculated using ASPEN and the heat exchange area was
based on the equations below:
Calculate Q (this gives the same results as ASPEN does):
Q  m  C  T
Calculate Area of heat exchanger:
Q  U  A  Tlm
Where:
Q is the heat exchanged in Btu/hr
U is the overall heat transfer coefficient, assume: U = 100 (BTU/F*ft^2*h)
Delta Tlm is the log mean temperature difference in F
To Calculate log mean temp (countercurrent flow):
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Where:
T1 inlet shell fluid temp
T 2 outlet shell fluid temp
t 1 inlet tube side temp
t 2 outlet tube-side temp
Calculate tubes required using pipe parameters from Towler.
Based on the number of tubes, utilize Seider Table and obtain the closest number of tubes with
corresponding shell diameter
Equipment Cost procedure:

Cost of Pumps
Cost of centrifugal pump is based on volumetric flowrate and head required
1.) Utilize cost equation
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Pc is the power consumption
S is the sizing factor for the pump
2.) Utilize sizing and power consumption equation respectively to plug into cost equation
Pc (power consumption) in HP
Q (flowrate) in Gal/min
H (pump head) in Ft
(density) in lbs/gal
np = -0.316 + 0.24051* (lnQ)-0.01199*(lnQ)^2 (fractional efficiency of the pump) in
dimensionless units
nm = 0.80 + 0.0319 * (lnPc)-0.00182 * (lnPc)^2 (fractional efficiency of the motor) in
dimensionless units
3.) Applying Seider’s value, calculate purchasing cost utilizing the equations
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Pump: Cp = Ft * Fm * Cb
Motor: Cp = Ft * Cb
Ft (type factor) 2.7
Fm (material factor) 1.0

Cost of Compressors
I.) Purchase cost values obtained from Garrett and Walas (1988) for electric motor drive, cast
iron or carbon-steel construction since Cp= Cb
II.) For other drives and materials of construction
Cp = Fd * Fm * Cb
Drive
Steam turbine
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Fd
Material
Fm
1.15
Stainless steel
2.5
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Gas turbine

1.25
Nickel Alloy
5
Cost of Methanol Synthesis Reactor
Utilize shell and tube exchanger approach
Fixed head
A is area for heat exchanger in square ft.
Cb = exp (11.0515-0.9228(ln(A))+0.09861(ln(A))^2)
Fm = a+((A/100)^b)
Fp = 0.9803 + 0.018*(P/100)+0.0017*(P/100)^2
FI values can be obtained in Seider and Seader
Cp= Fp*Fm*FI*Cb
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Base and Purchasing cost of the MSR
Type
Fixed
P
a
b
A
Psig
sqft
1000?
418,879?
Fm
1
FI
1
Fp
1.33
Cb
Cp
$
$
5,302,257? 7,053,593?
* data need to be verified through aspen simulation and operating parameters keep
changing.

Cost of Distillation Columns
*need operating conditions and dimensions
Towers for 9,000 < W < 2,500,000 lb (?)
Cv = exp (7.0374+0.18255(ln(W))+0.02297(ln(W))^2
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Towers for 3 < Di < 24ft and 27< L<170 ft
Cpl = 237.1 * (Di)0.63316*(L)^0.80161
Weight calculation: W = pi()*(Di+ts)*(L+0.8Di)*ts*rho
For Po min = 10 psig
Po > 1000psig use Po= 1.1* Po and neglect equation below
Pd = exp (6.60608+0.91615(ln(Po))+0.0015655(ln(Po))^2)
tp= (Pd*Di)/(2S*E-1.2*Pd)
tp must be greater than a minimum value for rigidity based on the diameter
S is the maximum allowable stress of the shell material, at the designed temp in lbs per
square inch
E is the fractional weld efficiency
6. Process Simulation in ASPEN:
An Overall process in ASPEN is shown below; each section is then broken down for simplicity
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Compression:
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Reactor:
Separations Train:
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Simulation Detail:
The process was simulated in ASPEN and the results were used for sizing calculations and reactor details.
The mapping of the following units is discussed below:
1) Reactor
2) Compressor
3) Heat exchangers
4) Turbo expander
5) Flash drum
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6) Distillation columns
1. REACTOR:
The process was started with a simple RSTOIC reactor:
The inlet flow was defined to be 1700 tpd, temperature of 518 F and a pressure of 1190 psi. A pressure
drop of 10 psi was taken through the reactor.
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The temperature and pressure were defined as in the screen above. These values were obtained from
literature. Furthermore four reactions were defined as below, with conversions taken from literature:
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The new button is hit to add new reactions and this is where the reactants, products, and the
conversions are defined:
2. Compressor:
After adding the reactor, a compressor was added but since the feed syngas was too hot to be fed to a
compressor it was cooled using a heat exchanger. To map the compressor in ASPEN the following
window was used:
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Only vapor phase (selected in the convergence tab) was used through this condenser since only syngas
and some recycled components well above their boiling points will be going through the compressor.
The discharge pressure was the only number required for this unit and it was set at 1200 psi.
3. Heat Exchangers:
Several heat exchangers were used through the whole simulation. There was one before the
compression train, another one cooling down the compressed syngas. Two more heat exchangers were
used to cool down the products from the reactor, and finally another one was used to simulate air
coolers. The hot stream outlet temperature and the pressure drop through the tubes were the only
specifications made for the heat exchanger block. The pressure drop was defined as 5 psi for all the heat
exchangers (Gulley). Cooling water stream temperature and flow rates going into heat exchangers were
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also defined. The amount of heat exchangers and cooling water used were determined by the
optimization of heat exchanger size. For example using a single heat exchanger with very small
temperature approaches resulted in immense heat exchange areas .The following pictures show how
they were modeled:
Temperature exchange:
Pressure drop:
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All the heat exchangers were designed in a similar manner. After the reactor the product stream goes
through a turbo expander.
4. Turbo Expander:
In the pressure changers tab in ASPEN the compressor can be selected to act as a turbine as well. The
following screen shot describes that procedure:
The stream coming from the reactor is fed into the turbo expander and the discharge pressure is
defined. This discharge pressure is the same as the pressure required for the flash drum plus the
pressure drop for the two heat exchangers. A technicality that arises in the turbo expander design
is the fact the turbines can only be fed gases. So any liquid would cause a problem and ASPEN
will show errors. So it was made sure that there were no heat exchangers installed before the
expander and all the product was in gas phase.
After the turbo expander the product stream goes into a flash drum.
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5. Flash Drum:
Literature values were obtained to get the pressure and temperature needed for an appropriate
separation of the non condensables from the liquid streams. The gases obtained from the flash
drum are sent as a recycle stream back to the compressor and the liquid stream are sent to
distillation columns via a valve to lower the pressure to the distillation tower pressure.
The temperature and pressure of the flash drum are defined in the specifications section of the
flash drum as shown above.
6. Distillation Columns
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7. Annotated Equipment List:
Refer to the PFD for the equipment naming
E-12 Air Cooler
The air cooler is used between the third and fourth heat exchangers. It will cool the stream
between these two pieces of equipment so that the fourth heat exchanger can use the crude methanol
stream.
E-4 Steam Drum
This piece of equipment is the steam drum that is used for the reactor. The reactor uses
saturated water to cool it and produces steam from the heat created from the reactions that occur. The
steam drum sends water to a pump and receives steam from the reactor that will be condensed so it can
be used again to cool the reactor.
E-35 Condenser
This condenser is used to turn the final grade AA methanol produced from the second
distillation column into a liquid. After the methanol is in liquid form it will be sent to several storage
tanks.
E-32, 33, and 34
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These three tanks are shown in the PFD to show where the final product will be collected. Three
tanks are shown, but in reality there will be a total of 11 tanks that will be able to hold the methanol
product. The methanol will be at 99.85% purity, which is defined to be sold at grade AA.
Heat Exchanger 1
The first exchanger is used to cool the synthesis gas from 500°F to 458°F to be used in the
compressor unit. Cooling water is used on the tube side of the exchanger in order to cool the syngas.
The water enters at 80°F and 20 psi, and then leaves the exchanger at 169.79°F and 20psi. This
exchanger will be run at 218°psi. The heat transfer area of this heat exchanger 87.72 ft2.
Heat Exchanger 2
The second heat exchanger is another shell and tube heat exchanger. It will receive the
compressed syngas from the condenser and will send the gas to the reactor at a much lower
temperature. The syngas will enter at 1200 psi and 716.63°F and then leave at 1190 psi and 482°F.
Cooling water will be used on the tube side of the exchanger in order to cool the syngas. The heat
transfer area of this exchanger is 1,119.8 ft2.
Heat Exchanger 3
The third heat exchanger in the process will be a shell and tube heat exchanger. It will receive
the stream from the turbo expander and sent it to another heat exchanger. The stream will consist of
CO, H2, CO2, Methanol, N-Butanol, and Ethanol. The stream will enter at 648.3 psi and 424.1°F and then
will be sent to the fourth heat exchanger at 638 psi and 350°F. Cooling water will be used in order to
cool the stream inside of the exchanger. The hot water that is taken out of the heat exchanger will be
sent into the fourth heat exchanger to be used as the cold stream. The heat transfer area of the third
heat exchanger is 366.1 ft2.
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Heat Exchanger 4
The fourth heat exchanger will take the stream from the third heat exchanger and send it to the
flash column. The stream will enter at 638 psi and 350°F, and then be leaving at 638 psi and 118.13°F.
The heat transfer area of this heat exchanger is 61,006 ft2. Cooling water will once again be used in
order to cool the stream inside of the heat exchanger except the colder stream will be from the third
heat exchanger.
Pump E-36
This pump is used in order to pump the syngas received from group Delta into the first heat
exchanger. Due to pressure drop in pipes, this pump is used to ensure that the first heat exchanger
receives then clean syngas at the pressure specified in the heat exchanger.
Pump E-5
This pump is used to pump the cooling water into the first heat exchanger. Since there is a
pressure drop in piping a pump is used in order to ensure that the cooling water will enter the heat
exchanger at the correct pressure.
Pump E-38
This pump is used between the steam drum and the reactor. Since water is needed to cool the
reactor, this pump is used to pump the water from the steam drum to the reactor.
Pump E-9
This pump is used to pump cooling water into the steam drum. This is used to cool the steam
that is produced from the reactor so that it condenses the steam back into water.
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Pump E-37
This pump is used on the purge stream. It will pump the purge stream from the recycle stream
to a combustion unit because there will be a large amount of CO2 in the stream and that cannot be put
into the atmosphere.
Pump E-10
This pump is used to pump cooling water into the third heat exchanger. After the pump the
water will be at 70°F and 20 psi.
Reactor
The reactor is a Lurgi reactor that takes in syngas at 1190 psi and 482°F to produce crude
methanol and other products. After the main reaction occurs, along with other side reactions, the
product stream leaves the reactor at 1200 psi and 518°F. Since the reaction creates a lot of heat, water
will be fed into the reactor to produce steam. This steam will be condensed in order to keep cooling the
reactor. Inside of the reactor there will be the Cu/Zn/Al catalyst. This catalyst is used in order to keep
the pressure needed to run the reaction lower than without a catalyst.
Compressor block
In ASPEN this is shown as one compressor, but in reality it is a multistage compressor. The
compressor unit takes the syngas from the first heat exchanger at 300 psi and 458°F, and then increases
the pressure to 1200 psi which is needed to run the reactor. When pressure increases so does the
temperature which will leave the compressor unit at 716.63°F. In order to obtain the high pressure the
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compressor will need to have 44,391 HP. The exiting stream from this unit will be sent to a second heat
exchanger before entering the reactor.
Turbo Expander
Since the reactor is at such high pressure, a turbo expander is needed downstream in order to
decrease the pressure quickly. The crude methanol stream from the reactor, which enters the turbo
expander, will enter at 1200 psi and 518°F. After going through the expander the stream will be at 648
psi and 424°F. This exiting stream will be sent to the third heat exchanger to cool it before the stream
heads to the flash column. The turbo expander will be able to drive a turbine to produce 7,726 HP, and
has an isentropic efficiency of 0.72 or 72%.
Flash column
This piece of equipment is used to take the crude methanol stream and separate it into two
streams. The stream enters the flash column at 638 psi and 118°F. After going through the column the
vapor is sent back to the compressor as a recycle stream at the same temperature and pressure. The
liquid stream from the flash column is sent to an expansion valve to decrease the pressure before
distillation. The liquid stream is still at the same temperature and pressure but the composition of the
stream is different than the vapor stream.
Expansion Valve
The expansion valve is used to decrease the pressure of the liquid crude methanol stream
before it reaches the distillation columns. The stream enters the valve at 638 psi and 118F, and then
leaves at 31.5 psi and 87.8°F. This temperature and pressure is needed for the distillation column to run
effectively.
E-20 and E-29
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These two drums are used to hold the distillate that is formed from the two distillation columns.
They will hold the distillate so it can condense and then be pumped back into their respective distillation
column.
E-18 and 30 are reboilers
E-19 and 31 are condensers
Distillation Column 1
Distillation Column 2
8. Economic Evaluation
Economics
Windy City Methanol has faith that the project under-hand will be financeable if various contractual
arrangements being negotiated with group Delta are satisfactorily executed. The complexity of the
project makes it essential for credible parties, viable technology, profitable economic basis, and
adequate incentives to be implemented for the project to be successful. Windy City Methanol believes it
has identified all major risk areas affiliated with the project, and will provide the types of risk protection
required by investors and interest parties to attain project financing. The following sections provide
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detail on the economic sector of the project, contractual arrangements established, and type of risk
Windy City Methanol anticipates.
Capital Cost:
The project’s earlier estimates were re-evaluated and modified to reflect more accurate figures. The
largest modification to the project was utilizing a Lurgi methanol reactor as opposed to the traditional
ICI quench reactor. The total equipment cost for the project is estimated to be slightly over $43 million.
The following table shows a breakdown of the capital costs including a contingency reserve allocated for
any fiscal disparities during the construction of the Windy City Methanol plant.
The funds required to complete the Project are estimated below (in US dollars).
The installation factor figures were obtained from the “Plant Design and Economics for Chemical
Engineers” by Peters & Timmerhaus.
Total Installed Costs
Equipment sub-total
$ 43,969,504
Direct Costs
Factor
Cost
Piping
0.68
29,899,262
Instillation
0.47
20,665,667
Buildings
0.18
7,914,511
Electrical installation
0.11
4,836,645
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Service facilities
0.70
30,778,652
Controls and valves
0.36
15,829,021
Subtotal
109,923,760
Indirect Costs
Factor
Cost
Construction Expenses
0.41
18,027,496
Supervision and Engineering
0.33
14,509,936
Legal Expenses
0.04
1,758,780
Contingency
0.44
19,346,581
Subtotal
53,642,794
Total Capital Investment
207,536,058
Please see “economic tables” for a detail breakdown of all the capital costs and descriptive equipment
list.
The following table shows the low and high ranges of capital costs based on cost estimation (in millions
of US dollars).
Low
Likely
High
Plant Cost
207
209
300
Vessel Cost
22
32
35
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Land Cost (75 acre)
28
37
75
Total
257
278
410
Windy City Methanol estimates the total cost of the Project will be approximately $245 million and the
loan attained by a reputable bank will be used to finance 100% of the cost during the construction
period. Upon completion of the plant, approximately $61 million of the equity from the owners will be
used to reduce the outstanding bank debt. The remaining $184 million debt will be repaid over the next
19 years of the plant life. The sole purpose of financing the cost of designing, building and equipping the
Windy City Methanol plant is to construct a facility capable of producing 3,200 TPD of grade AA
methanol. The plant will be build over a 75 acre field located in Gary Avenue Indiana near Delta’s
gasification plant thus eliminating the transportation cost of the feedstock. Syngas will be supplied
under a long term contract and the methanol will be sold under a long term agreement with a
reputable, major US company. All necessary authorizations and design specifications, including all
relevant infrastructure development essential for normal operations for the project will be attained by
the end of the test period. Windy City Methanol believes that equity investors will be seeking a
minimum internal rate of return in the range of 16%-18% per annum. This minimum return is obtained
at a methanol price of $ 1.35 per gallon, and $ 200 per ton of feedstock.
Sensitivities and Assumptions:
The financial model is structured to reflect a realistic and feasible undertaking. The project model is
developed within the following parameters.
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 Selling price of methanol is $1.35 per gallon
 Feedstock price of syn-gas is $ 200 per ton
 Tax rate is 40%
 Inflation rate is 0%
 Contingency is $ 19 million
 Total costs are $ 245 million
The internal rate of return (IRR) has be computed for three methanol prices; the results are shown
below:
Price of Methanol
Cost of Syn-gas Feedstock (dollars/ton)
dollars/gal
$200
$250
1.35 (base price)
16.00%
6.73%
1.50
41.68%
34.90%
1.75
96.30%
69.62%
Windy City Methanol believes a 16-18% IRR is highly attractive return for equity investors. The table
shows that this is easily attainable for all cases except for the scenario where the syngas feedstock costs
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$250/ton and the methanol price is $1.35 per gallon. Based on historic methanol market prices patterns,
Windy City Methanol believes that a market price of $ 1.35 per gallon is realistic since there is increased
demand with limited world supply. A futuristic increase in methanol market prices is highly promising
since crude oil price is highly susceptible to political turmoil and is a limited resource.
Risk Profile
Market Risk:
Inaccurate demand estimates. The selling price of methanol is not economically
feasible for the project.
Protection:
Attain a long term methanol purchase contract with a large, creditworthy US
Corporation.
Syngas Supply Risk:
Inaccurate supply estimates. The price at which syngas is bought is not
economical for the project.
Protection:
A long term syngas supply contract with a fixed price and a pledge of adequate
MSW reserve to meet contractual agreement between Windy City Methanol
and Group Delta.
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Construction Risk:
Construction overruns due to factors such as poor cost estimates, inflation, and
construction delays caused by environmental or regulation mishaps. Overruns
can cause funding problems and make the project uneconomical.
Protection:
Fixed price contract agreements. Orchestrate several feasibility studies on cost
estimates and implement stringent construction deadlines.
Operational Risk:
Operation interruption caused by various situations such as plant failure,
malfunctions, prolonged maintenance and repair, and natural disasters.
Protection:
Have business interruption insurance to pay debt caused by plant failure or
natural disaster.
Legal Risk:
Long-term contracts among twp parties can result in legal disputes.
Protection:
Attain high-quality legal advice. Have a devisable dispute settlement
mechanism.
Labor-related Resources and Technical Feasibility:
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Special skills are essential for a planned project; therefore, specific skill required for the Windy City
Methanol plant are listed below.
Personnel
Description
Number
Annual Salary
Subtotal
Plant Operating Crew:
Operator
6
$40,000
$240,000
Lab Tech.
2
$30,000
$60,000
Mechanical Tech.
2
$35,000
$70,000
Process Engineer
4
$60,000
$240,000
Electrical Tech
1
$35,000
$35,000
Shift Supervisor
2
$45,000
$90,000
Maintenance
2
$40,000
$80,000
Superintendent
1
$100,000
$100,000
Plant Manager
1
$80,000
$80,000
Total:
21
Administration:
$995,000
*plant operating crew will have two 12-hour shifts to provide 24-hour coverage
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Each personnel salary is based on accurate, current, and reputable pay-scales salary calculator websites
in the Indiana state area and was validated by comparing other similar salary calculator sites. The
salary figure median was taken into account and implemented in the cost estimation section of this
report.
9. Utilities
Throughout the process there is a lot of cooling water needed along with electricity. Each
piece will need electricity to run, and power is also needed to run all of the temperature and
pressure controls. There will also need to be a facility to treat the cooling water needed in the
heat exchangers. The overall process will need 13,349.36 gallons/hr of cooling water, along with
_____ MW/day of electricity.
The process will also require 132898.47 pounds of steam/hour. Steam is needed for the
reactor.
10. Conceptual Control Scheme
The following figure shows the overall control scheme for the process.
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11. General Arrangement
Process equipment arrangement and plant layout must be carefully analyzed before construction of a
new facility can begin, because these factors affect nearly every aspect of plant design and operation,
including: land requirements, permits, safety systems, construction, piping arrangements and costs,
operating costs, and future expansion. The location of the plant must be chosen prior to plant layout
because specifics such as average wind direction, and access to roads cannot be determined without a
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plant location. The area chosen for the methanol plant is in Gary Indiana, just north of Gary Ave, which
can be seen in the image below. This location provides several advantages because it allows access to
nearby Hwy 90 for ease of transportation via freight, and is situated across the street from Group Delta’s
syngas plant. The proximity to the syngas plant is important because the syngas could be piped
underground directly into the methanol plant, significantly reducing transportation costs.
It was discovered that at this geographic location, the most common wind direction is the southwest to
the northeast. It is important because anywhere that there is an open flame must be upwind of any
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flammable materials. This was used in the placement of the ground flare at the methanol plant which is
used to burn off unusable flammable materials. The location chosen for the ground flare was at the
southeast corner of the facility, so that the most common wind direction does not have the possibility of
blowing the flames of the ground flare towards the syngas and methanol storage tanks.
The plant layout itself was derived from the process flow diagram, and implemented into the chosen
location of the facility. The dimensions of the facility are 156ft by 775ft. Access will be provided
through an entrance at Cline Ave, which will lead to the west side of the facility. Visitors and employees
will be greeted by security officials at the gatehouse, and those granted access will be able to park in
one of the two available parking lots. The main offices are located in the northwest corner of the main
production building, and control rooms are located just south of the offices. The main production
building also houses the methanol synthesis components including: heat exchangers, flash drums,
compressors, turbo expanders, and the reactor. The main pipe rack is easily accessible to every piece of
equipment because it runs directly down the center of the building. The two distillation columns are
located outside the building on the east side. Storage tanks line the northern edge of the facility, with
plenty of area between the building and the tanks for easy access for tractor trailers. The specifics of
the plant layout can be seen in the image below.
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Wind Direction
12. Distribution and End-use Issues review
The global market for methanol is forecasted to reach nearly 55.3 million metric tons by
the year 2015. This is mainly due to the growing consumption of methanol in Asia-Pacific,
specifically in China. A key factor that leads to the growing consumption of methanol is its use
in alternative fuels and the production of acetic acid. The three largest derivatives of methanol
are formaldehyde, methyl tertiary butyl ether (MTBE) and acetic acid. Methanol consumption
in gasoline blending, especially in China, has grown significantly over the last few years, with
this use accounting for approximately 7% of world methanol consumption. This is mainly due
to Beijing settling on a national standard for methanol as an automotive fuel. China uses nearly
3 million tons of methanol, which gets blended yearly into the gasoline market. Just as the
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United State uses E85 for cars that use ethanol blended with gasoline, the Chinese will be using
M85, to represent the use of methanol and gasoline. The numbers in these labels represent
the use of 85% methanol or ethanol and 15% gasoline.
Methanol can be used in a variety of industrial applications. Its largest use is as a raw
material for the production of methyl t-butyl ether (MTBE), a gasoline additive. MTBE is
manufactured via the chemical reaction of methanol and isobutylene. MTBE is used as an
oxygenate to raise the octane number in gasoline. MTBE is favored over ethanol because of its
superior performance in reducing benzene and formaldehyde in gasoline, and its lower volatile
organic compound content. It is also used in organic chemistry as a relatively
inexpensive solvent with properties comparable to diethyl ether but with a higher boiling point
and lower solubility in water. We will be specifically targeting companies that require
methanol as a use to produce MTBE. Some of these companies include Amoco and Citgo.
There are 27 companies producing methyl-tert-butyl ether at 32 facilities in the United States,
with these two companies included.
Methanol is also used in the production of formaldehyde, chloromethanes, methyl
methacrylate, methylamines, dimethyl terephthalate, and as a solvent or antifreeze in paint
strippers, aerosol spray paints, wall paints, carburetor cleaners, and car windshield washer
compounds. Formaldehyde accounts for about 36% of the estimated methanol demand; it is
used in resins for buildings materials and the wood products and in the construction of housing,
commercial and industrial structures, laminates in the furniture industry and engineering
plastics in the automotive industry. Acetic acid represents 11% of total demand. Vinyl acetate
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(VAM), a derivative of acetic acid, is used in the manufacture of paints, adhesives, film, paper
and textiles and is the largest and fastest growing consumer of acetic acid.
The methanol produced at this particular power plant will have a purity of 99.85%,
which will qualify it to be sold as grade AA methanol. There are several requirements that need
to be met in order for it to be called grade AA methanol. The amounts of acetone and aldehyde
can only be at max 30 wt-ppm. Acetone and ethanol can only be present at a max limit of of 10
wt-ppm and there also cannot be any higher alcohols present. Finally, water must be only
present at maximum limit of 1,000 wt.-ppm.
In the long run methanol is being researched as a source of hydrogen for fuel cells
used in transportation, stationary power generation, and portable power applications. Many
recent U.S. patents and patent applications involve methanol fuels cells. Some of the
technologies patented for methanol cells include: anode structures, catalysts, membrane
assemblies for direct cells, and sensor-less optimization of methanol concentration in a cell.
13. Constraints Review
1. Feedstock definition:
Feedstock will be taken from group Delta that produces syngas from municipal solid
waste. 5000 tons per day of municipal solid waste will be gasified using a plasma gasifier
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to produce syngas. The final product, feedstock to this process, will be syngas with a 2:1
ratio of H2 to CO at 1700 tons per day (141666.662 lb/hr) at 500 psi and 700 ºF.
2. Conversion technology description:
The conversion technology used in this process is in the face of a chemical reactor. A
Lurgi reactor is used to synthesize methanol from synthesis gas. A Lurgi reactor works as
a shell and tube heat exchanger. The reaction takes place in the shell side while cooling
water (that evaporates into steam) runs tube side. The catalyst covers the outside of these
tubes and since this is the hottest part of the reactor heat is efficiently extracted from the
reactor in the form of high pressure steam. In the 1900s catalysts were not perfected to
methanol synthesis and this resulted in very high reaction temperatures and pressures.
Pressures as high as 2000 psi were not uncommon and temperatures exceeding 800 F
were required, the introduction of the Cu/Zn/Al catalyst for methanol synthesis has rid us
the need to compress the reactants at such high pressures. Today these catalysts have
allowed saving a lot of money on the compression and temperature costs. Pressures as
low as 700 psi have been employed for methanol synthesis but increasing pressures result
in a better conversion of CO to methanol.
3. Separation technology description:
The separations train includes the flash drum and two distillation columns. The flash
drum operates at 638 psi and 118.13 F. It is basic flash technology where the lower pressure lets
the vapor evaporate and go off in a vapor stream. The liquid is let out in the bottom. The
distillation columns also do not employ any special technology. There are basic stages and
separations takes place based on the efficiencies of the trays. Energy produced in the reactor is
recycle in the distillation columns, the re boiler employs this energy.
4. Product Description:
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Grade AA methanol is being produced in this process, this is methanol with a purity of
99.85 wt%.
5. Location Sensitivity Analysis:
6. ESH law compliance:
Methanol Storage and Handling
The most common ways of transporting methanol is through bulk transportation, which includes
rail, truck, and pipelines. During transferring or storage, the systems should be cleaned, flushed, and
sampled in order to ensure integrity of the product. Materials and methods of construction must be
compatible with methanol service. Methanol is non-corrosive to most metals at ambient temperatures,
except to lead, magnesium, and platinum. Mild steel is usually selected as the construction material.
Also, coatings of copper, zinc, or aluminum are attacked slowly by methanol. Preferred methods of
methanol service include, nylons, rubber, particularly nitrile and ethylene propylene rubber. Teflon and
neoprene are also preferred components of equipment in methanol service.
Storage tanks of welded construction are considered satisfactory for methanol. They should
have secondary containment such as dikes to reduce fire or prevent large spills. Large tanks should have
control devices such as level gauges, conservation vents, and pressure vacuum relief valves.
Sources of Exposure to Methanol
Inhalation of methanol vapors is the most frequent exposure. The methanol threshold limit
value is 200 ppm. This is the maximum average concentration a worker should be exposed to over a
eight hour period. The short term exposure limit is 250 ppm. This is the maximum average
concentration a worker should be exposed to over 15 minute periods, four times per day with at least 60
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minutes between exposure periods. Methanol can also be ingested orally. One to four ounces of
methanol have been known to cause fatalities. There are no serious effects from skin contact to
methanol as long repeated and excessive exposures are avoided. Personal protective equipment should
be used in the presence of exposure to methanol. This can include appropriate footwear, face shields,
respiratory protection, or chemical suits.
Methanol is labeled as a Class 1B flammable liquid by the Occupation Safety and Health
Administration (OSHA). Pure methanol has a flash point of 12°C. Flash point is defined as the minimum
temperature at which the vapour pressure of a liquid is sufficient to form an ignitable mixture with air
near the surface of the liquid. The lower explosive limit (LEL) of methanol is 6% by volume and the
upper explosive limit (UEL) of methanol is 36% by volume. The UEL corresponds to a methanol
temperature of 41°C. In order to deal with the flammability of methanol, many precautions have to be
considered. Smoking must be prohibited, grounding is required for all equipment, including tanks, pipe
racks, pumps, vessels, and filters. Ventilations must be sufficient to cope with the maximum expected
vapor levels in the buildings. There will be relief valves in place on distillation columns, flash drum, and
reactor. All controls can be viewed under the control scheme section of this report.
Another safety hazard in this plant is the amount of CO that will be released. A thermal oxidizer
will be used to destroy hazardous air pollutants and volatile organic compounds. They will be destroyed
via thermal combustion and eventually changed to form CO2 and water. CO2 will also be released from
distillation column 1 in the distillate stream at an amount of 23,180.57 lb/hr. Precautions muse be
taken to ensure there no leaks and that the CO2 is successfully released into the atmosphere and not
built up inside the buildings.
7. Law of physics Compliance
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8. Turn Down ration
A turn down ratio of 50% was used to prevent clogging of pipes and equipment. This
number is very common in the methanol industry and is often seen in literature
14. Applicable Standards
Talk about Grade AA Methanol. Can discuss EPA standards for the whole process and
that no waste is being produced and everything is being oxidized in a thermal oxidizer.
15. Project Communications File
To view any more information about the process and the components, visit
http://charlie497.wikispaces.com. This site can be used to view all files and references used in
the research of our process. Any questions that arise about the process can be answered within
the wiki site.
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16. Information Sources and References
"Gulley News Page 2002." Homepage.jpg. 2011. Web. 23 Apr. 2011.
<http://www.gulleyassociates.com/news2002.htm>.
Law , Nicole, Caitlin Nichols, and David Tamayo. "Final Report: Methanol Synthesis." Chemical
Engineering Program (2008): 11-14. Web. 2 Mar 2011.
Amirkhas, Elton, Raj Bedi, Steve Harley, and Trevor Lango. "Methanol Production in Trinidad and
Tobago." Final Report (2006): 7-8. Web. 2 Mar 2011.
Grue, J; Bendtsen, J.D. Synthesis and Optimisation of a Methanol Process. Paper presented at 44th Scandinavian
Conference on Simulation and Modelling, 2003.
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