Chemical Process Industry,
Chemical Engineering,
Chemical Engineer
Anand V. Patwardhan, IIT Kharagpur
1
A presentation for the 1st year Chemical Engineering UG students
by
Anand Vinayak Patwardhan
Associate Professor
Faculty Advisor (2006−entrants UG)
Chemical Engineering Department
Indian Institute of Technology Kharagpur
Kharagpur−721302
India
Email: avp@che.iitkgp.ernet.in
Anand V. Patwardhan, IIT Kharagpur
2
Abbreviations used in this Presentation
A.I.Ch.E.
ChE
ChEngineer
I.I.Ch.E.
MOC
Q and Q
QA
American Institute of Chemical Engineers
Chemical Engineering
Chemical Engineer
Indian Institute of Chemical Engineers
Material of Construction
Quality and Quantity (in the context of a Product)
Quality Assurance
Anand V. Patwardhan, IIT Kharagpur
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CHEMICAL PROCESS INDUSTRY
INTRODUCTION
WHAT IS CHEMICAL PROCESS INDUSTRY ?
ORIGINS AND DEVELOPMENT OF CHEMICAL PROCESS
INDUSTRY
Pre−scientific Chemical Industry
Scientific Chemical Industry
INDIAN CHEMICAL INDUSTRY TODAY
Growth with Restraints
Green Challenges to Chemical Industry
SYSTEMATIC ANALYSIS OF CHEMICAL PROCESSES
Mass and Energy Balances
Conservation of Mass
Conservation of Energy
Anand V. Patwardhan, IIT Kharagpur
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Thermochemistry
Chemical Reaction Equilibrium
Chemical Kinetics
Ideal Gas Laws
Phase Equilibrium
Unit Operations
Classification of Unit Operations
Plant Equipment
Chemical Reactors
Heat Exchangers
Mass Transfer Equipment
Ancillary Equipment
Transportation Equipment
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Process Flow Diagrams
Flow Sheets
Instrumentation and Control
Economics
WHAT IS ChE ?
WHAT DOES A ChEngineer DO ?
Research
Fundamental Research
Exploratory Research
Process Research
Process Development
Process Design and Evaluation
Plant Design
Production and Supervision
Plant Technical Service
Anand V. Patwardhan, IIT Kharagpur
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Product Sales
Market Research
Product Development
Technical Sales and Customers Service
ChEngineers IN THE COMING YEARS
GENERAL ASPECTS OF ChE
Communication
Human Relations
Professional Activities
Technical Reading
Anand V. Patwardhan, IIT Kharagpur
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INTRODUCTION
Products – all areas of everyday life
Chemical fertilisers
Food supplements
Building materials (metals, concrete, roofing materials, paints,
plastics)
Clothing (synthetic fibres, dyes)
Transportation (gasoline and other fuels)
Written communication (paper, ink)
Electronic communication (insulators, conductors)
Health (drugs, pharmaceuticals, soaps, detergents, insecticides,
disinfectants)
Intermediates (consumed within the Industry)
CHEMICAL INDUSTRY is a sprawling complex of raw material
sources, manufacturing plants, and distribution facilities
Anand V. Patwardhan, IIT Kharagpur
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WHAT IS CHEMICAL PROCESS INDUSTRY ?
Most processes involve a “Chemical Change”,
chemical reactions
physico−chemical change
related mechanical changes
Definition (just satisfactory !): An industry whose
principal products are manufactured by processes based
upon the chemical, physical, mathematical, and
biological principles, which are included in the field of
ChE discipline.
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Industry: Inorganic Chemicals
Typical Products
End Uses
Sulphuric acid
Fertilisers, chemicals
Petroleum refining
Paints
Pigments
Metal processing
Explosives
Nitric acid
Explosives
Fertilisers
Sodium hydroxide
Chemicals
Rayon and film processing
Petroleum refining
Pulp and paper processing
Lye
Cleansers
Soap
Metal processing
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Industry: Organic Chemicals
Typical Products
Acetic
anhydride
Ethylene
glycol
End Uses
Rayon
Resins
Plastics
Antifreeze
Cellophane
Dynamite
Synthetic fibres
Formaldehyde
Plastics
Ethanol
Formaldehyde
Antifreeze
Solvent
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Industry: Petroleum and Petrochemical
Typical Products
End Uses
Gasoline
Kerosene
Oils
Ammonia
Ethanol
Fuel
Fuel
Lubricating
Heating
Fertilisers
Chemicals
Acetaldehyde
Solvent
Other chemicals
Alkyl aryl sulphonate
Detergents
Styrene
Synthetic rubber
Plastics
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Industry: Pulp and Paper
Typical Products
Paper
Cardboard
Fibreboard, etc.
End Uses
Books
Records
Newspapers, etc.
Boxes
Building materials
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Industry: Pigment and Paint
Typical Products
Zinc oxide (ZnO),
Titanium dioxide (TiO2),
Carbon black (C),
Lead chromate,
Iron oxides (FeO, Fe2O3,
Fe3O4)
Linseed oil
Phenolic resins
Alkyd resins, etc.
End Uses
Pigments for paints, inks
Plastics
Rubbers
Ceramics
Linoleum
Drying oil
Basic lacquer
Varnishes
Enamel constituents
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Industry: Rubber
Typical Products
Natural rubber
(Isoprene),
Synthetic rubbers
(GR−S, neoprene,
butyl)
End Uses
Automobile tyres
Mouldings and
sheetings
Footwear
Insulation
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Industry: Plastic
Typical Products
Phenol−formaldehyde,
Polystyrene,
Polymethylmethacrylate,
Polyvinyl chloride,
Polyethylene,
Polyesters
End Uses
Various uses in
all areas of
everyday life
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Industry: Synthetic Fibre
Typical Products
Rayon,
Nylon,
Polyesters,
Acrylics
End Uses
Cloth and clothing
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Industry: Mineral
Typical Products
Glass,
Ceramics
End Uses
Windows
Containers
Bricks
Pipe
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Industry: Cleansing Agent
Typical Products
Synthetic detergents
(sodium alkyl aryl sulphonates),
Wetting agents
End Uses
Household cleaning
Industrial cleaning
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Industry: Biochemical
Typical Products
Pharmaceuticals,
Drugs
End Uses
Health applications
Medicinal applications
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Industry: Metal
Typical Products
Steel,
Copper,
Aluminium,
Zirconium
Uranium
End Uses
Building materials
Machinery, etc.
Nuclear fuel
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ORIGIN AND DEVELOPMENT OF
CHEMICAL PROCESS INDUSTRY
Pre−Scientific Chemical Industry
Fermentation – oldest Chemical Industry ! (folk craft)
Ethanol and Vinegar (dilute CH3COOH)
HNO3 from Salt Petre (KNO3) and FeSO4 (heating the
mixture and condensing the distilled HNO3)
HNO3 – used in separation of Au from Ag
H2SO4 – later – generate Cl2 for bleaching bath
HCl – cheapest and most widely used mineral acid
Alkali found in wood−ashes – early cleansing agents
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Scientific Chemical Industry
Progress and growth slow
little understanding of
the scientific principles underlying processes during
the initial periods
Increased understanding of chemical sciences
new developments in chemical processing
Principal chemical industries in the early−19th
century: alkalis, acids, metals manufacture
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INDIAN CHEMICAL INDUSTRY TODAY
Phases of trials and turbulence
Mid−30’s: batch processes for indigenous production of
Inorganic Chemicals
Then, Petroleum Refining, Organic Chemicals, Fertilisers,
Agro−chemicals, Drugs and Pharmaceuticals, Paints and
Varnishes, Toiletries and Cosmetics, Coal Chemicals, Rubber
Chemicals, Fine and Specialty Chemicals, Plastics, Synthetic
Fibres, Petrochemicals
Well−planned network of specialised Institutions of Learning
and Research
need for Technological Transformation of
Industry
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Growth with Restraints
Major restraints:
Matching with the international standards, rapidly changing demand
pattern and customer preferences
Continuous upgradation of process technology
investments
additional
High cost of BORROWING of Capital
Inadequate, inefficient, and yet highly expensive infrastructure and
utilities like power, water, transport, etc.
erosion of Indian
industry’s competitiveness vis-à-vis imported goods.
Make things worse
high levels of Excise duties, local levies
(consumers’ wallet !) + frequent removal / reduction of Customs tariff
(manufacturers’ nightmare !)
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Safety, Health, and Environment within the plant and the
surroundings: Central and State Governments’ Laws
NGOs often oppose and resist the setting up of new projects which
have certain locational advantages (alternative location
extra
capital + extra operating cost)
Low manufacturing capacities
Several Treaties: Chemicals Weapons Convention, Basel Convention,
Montreal Protocol (O3−depleting substances), etc.
Several Conventions: Prior Informed Consents (Dual Purpose
Chemicals), Persistent Organic Pollutants, etc.
Provisions of WTO, IPR, and other non−tariff barriers
Dumping of goods from other countries !
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“Responsible Care” and “ISO” certifications are becoming
preconditions for International markets !
IT (E−commerce)
bids struck instantly
Customers and consumers becoming ever more demanding
discriminating
safer
products,
cleaner
and
environmentally benign processes
erstwhile QC has
become QA and Total Quality Management
training cost
for the manufacturer
Technologies becoming more complex, equipment more
sophisticated
laxity and lapses at “operational” level are
ill−afforded (1984 BHOPAL DISASTER of Union
Carbide, remember ?)
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Green Challenges to Chemical Industry
Threat
Challenge
Opportunity
Two facets:
From the developed world through several International conventions
(existing and proposed)
The way Indian Chemical Process Industry is structured
very large
number of small and medium scale manufacturers, not yet geared to
meet “minimum safety standards” of environment and health
protection laid down in Indian (Central and State) Laws.
Demand for pollution−free processes: an overriding factor
Research and Development on “Totally Clean Technologies”, and
“Pollution−Free Alternatives” WILL HAVE TO BE an integral part of
Industry’s business
Opportunity in terms of more profit, in
the long run
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SYSTEMATIC ANALYSIS OF CHEMICAL
PROCESSES
Production of large quantities at lowest possible cost, for many NEW
molecules as well
Experience−based improvements no longer
sufficient
Systematic analysis of chemical processes elucidated many underlying
principles
synthesis of new processes
Mass and energy balances
Thermochemistry
Unit operations
Plant equipment
Ancillary equipment
Process flow diagrams
Instrumentation and control
Vitamin−M: balances, operations, flow & control (Economics !)
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Mass and Energy Balances
Fundamental principles that Engineers and Scientists employ in
performing design calculations and predicting performance of equipment
Conservation of mass
Mass in − out + generated = accumulated
Total mass involved, individual species, individual “atoms”
Steady state processes, unsteady state processes
Batch processes, continuous processes
One equipment, several equipment, complete process
Calculation of unknown quantity directly
Check the validity of experimental data
Express one or more of the independent relationships among the unknown
quantities in a particular problem (mathematical modeling)
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Conservation of energy
Energy in − out + generated = accumulated
First law of thermodynamics
∆E = Q − W … for batch processes
Q
∆H = Q − WS … for continuous processes
= heat energy transferred across the system boundary
W
= work energy transferred across the system boundary
WS
= mechanical work energy transferred across the system boundary
E
= internal energy of the system
H
= enthalpy of the system
∆E, ∆H = changes in internal energy and enthalpy during the process
Engineers are concerned with CHANGES in energy,
rather than with ABSOLUTE energy
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Thermochemistry
Concerned with the energy effects associated with chemical reactions
Enthalpy is the most convenient term to work with
Different types of enthalpy effects:
Sensible heat (CP)
Latent heat (λ)
Heat of reaction (∆HR): enthalpy change of a system undergoing
chemical reaction. If the reactants and products are at the same
temperature and in their standard states (pure chemical, 1 atm), the
heat of reaction is termed the standard heat of reaction.
Chemical reaction equilibrium
Chemical kinetics
Ideal gas law
Phase equilibrium
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Chemical reaction equilibrium
1. How far the reaction will go ?
2. How fast the reaction will go ?
Chemical Thermodynamics provides the answer to the 1st question
Chemical Kinetics provides the answer to the 2nd question
Both Chemical Thermodynamics and Chemical Kinetics must be
considered in an overall analysis of a chemical reaction
Chemical reaction equilibrium calculations are structured around “free
energy CHANGE” in a reacting system:
∆GR = R T ln (KR)
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Chemical kinetics
2. How fast the reaction will go ? (Question 2 of the previous slide)
Study of reaction RATES and variables that affect these rates
RATE: time rate of change in the amount of any of the components
participating in the reaction
Based on arbitrary factor related to the reacting system size, geometry
(volume, interfacial area), mass, etc.
dn
1
A
R =
A V dt
dc
= A ... in case V = constant
dt
R
A
=R
⎛
⎜
⎜
⎝
c , P, T, catalyst variables
A i
R
A
= ±k
⎛
⎜
⎝
⎞
⎟
⎠
⎛
⎜
⎜
⎝
c
A i
⎞
⎟
⎟
⎠
⎞
⎟
⎟
⎠
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Ideal gas law
P V = constant = n R
T
Works best at higher temperatures and lower pressures, that is, when
R T ≥ 22.4 m3/kmol ⎛⎜ or L/mol⎞⎟, the ideal molar volume
⎜
⎟
⎜
⎟
P
⎝
⎠
At lower temperatures, and higher pressures, for REAL gases
R T < 22.4 m3/kmol ⎛⎜ or L/mol⎞⎟
⎜
⎟
⎜
⎟
P
⎝
⎠
For engineering calculations, the IDEAL GAS LAW is almost always
valid
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Phase equilibrium
PURE substances: Phase = state of matter − solid, liquid, gas
(vapour)
MIXTURES: a phase is characterised by uniformity or homogeneity
of properties
Most important equilibrium phase relationship: liquid and gas
(vapour)
Roult’s law:
“partial pressure of any component in the vapour = vapour
pressure of the pure component × mole fraction of the component
in liquid”
Henry’s law:
“partial pressure of any component in the vapour = Henry’s
constant for the given system × mole fraction of the component in
liquid”
Alternately, phase equilibrium calculations:
Ki = yi/xi
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Unit Operations
The seemingly different chemical, physical, or biological processes can
be broken down into a series of separate and distinct steps called unit
operations
Distillation: purification of ethanol; separation of hydrocarbons
(petroleum industry)
Drying of grain; other foods (food industry); drying of lumber;
filtered precipitates; rayon yarn
Reactive absorption of O2 from air in a fermenter; reactive absorption
of H2 in vegetable oil
Evaporation of salt solutions; evaporation of sugar solutions
Flow of liquid hydrocarbon; flow of milk
Although the number of individual processes is great, each one can be
separated into a series of steps or operations
The individual operations have common techniques and are based on the
same scientific principles
The treatment of all processes is unified and simplified
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Some of the Important Unit Operations
Fluid flow
Heat transfer
Evaporation
Drying
Distillation
Absorption
Adsorption
Liquid−liquid extraction
Liquid−solid leaching
Crystallisation
Membrane separation
Mechanical−physical separations
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Fluid flow
Concerns the principles that determine the flow of transportation of any
fluid one point to another
Heat transfer
A unit operation that deals with the principles that govern accumulation
and transfer of heat and energy from one place to another
Evaporation
A special case of heat transfer, which deals with the evaporation of the
volatile solvent, such as water, from a non−volatile solute, such as salt or
any other material in solution
Drying
An operation in which volatile liquids (usually water) are removed from
solid materials
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Distillation
An operation whereby components of a liquid mixture are separated by
boiling because of the differences in their vapour pressures
Absorption
A process whereby a component is removed from a gas stream by
treatment with a liquid
Adsorption
A process whereby a component is removed from a gas or a liquid stream
by treatment with a solid (adsorbent) whereby the component is adsorbed
either physically or chemisorbed on the solid’s surface
Liquid−liquid extraction
A process in which a solute in a liquid solution is removed by contact
with another liquid (solvent) that is relatively immiscible with the solution
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Liquid−solid leaching
It involves treating a finely divided solid with a liquid that dissolves out
and removes a solute contained in the solid
Crystallisation
The removal of a solute such as a salt from a solution by precipitating the
solute from the solution
Membrane separation
The removal of a component from a liquid mixture or a gas mixture by
virtue of its molecular size and/or (±)affinity with the separating
membrane and/or difference in the osmotic pressure
Mechanical−Physical Separations
Involves separation of solids, liquids, or gases by mechanical means, such
as filtration, settling, and size reduction, which are classified as separate
unit operations
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Unit operations are applicable to processes that are physical and chemical
Most frequently, it is desirable to separate the original substance into its
component parts
Entirely mechanical: separation of solid from liquid during filtration;
classification of granular solid into fractions of different particle size by
screening; etc.
Diffusional or mass transfer operations: involve changes in composition
of solutions. This involves TRANSFER of one substance through
another, on a molecular scale
For example: water evaporation from a pool into an air stream
flowing over the water surface. Water molecules diffuse through
those of gas at the surface into the main portion of the air stream,
from where they are carried away
Sometimes, one molecular species may diffuse through another which
is itself diffusing in the opposite direction
Mass transfer is a result of concentration difference (driving force)
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Classification of DIFFUSIONAL unit operations
1. Contact of two immiscible phases, with mass transfer (or
diffusion) through the surface (interface) between the
phases
2. Contact of two miscible phases separated by a permeable
or semi−permeable membrane, with diffusion through
the membrane
3. Direct contact of miscible phases
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CONTACT OF TWO IMMISCIBLE PHASES
The 3 states (S, L, G) permit 6 possibilities:
1) GAS−GAS: completely soluble in each other, hence infeasible category
2) GAS−LIQUID:
If all components are present in appreciable amount in both GAS and
LIQUID phases
fractional distillation
All the components of the solutions involved may not be present in
appreciable amounts in both GAS and LIQUID phases. If the LIQUID
phase is a pure liquid containing one component whereas the GAS phase
contains 2 or more
humidification / humidification
Both phases may be solutions, each containing only one common
component that distributes between phases
gas absorption/desorption
(stripping)
Gas phase contains only one component and liquid several
evaporation (but this is NOT a diffusional operation because the rate does
NOT depend on concentration gradient, but on rate of heat transfer
(temperature difference). However, if evaporation is only by diffusion of
solvent
diffusional operation
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CONTACT OF TWO IMMISCIBLE PHASES …
3) GAS−SOLID:
If a solid solution is partially evaporated without the appearance of a
LIQUID phase
fractional sublimation (practically inconvenient)
All components may NOT be present in both the phases
desorption / adsorption
drying /
In case the GAS phase is a pure vapour
sublimation of a pure solid
/ desublimation of a pure vapour
non−diffusional, depends only
the heat transfer rates
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CONTACT OF TWO IMMISCIBLE PHASES
4) LIQUID−LIQUID:
Liquid−liquid extraction OR liquid extraction OR solvent extraction
operations
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CONTACT OF TWO IMMISCIBLE PHASES
5) LIQUID−SOLID:
Fractional solidification of a liquid / fractional melting of a solid
Liquid−solid extraction OR leaching
Crystallisation (heat transfer dependent rather than diffusional)
Dissolution
6) SOLID−SOLID:
Because of extraordinary slow rates of diffusion within solid
phases, there is no industrial separation operation in this category
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CONTACT OF
MEMBRANE
MISCIBLE
PHASES
SEPARATED
BY
A
1) GAS−GAS:
Gaseous diffusion OR effusion: if a gas mixture whose components
are of different molecular weight is brought into contact with a
porous diaphragm, the various components of the gas mixture will
diffuse through the pores at different rates. This leads to different
compositions on the opposite sides of the diaphragm and,
consequently, to separation of the gas mixture
2) LIQUID−LIQUID:
Separation of a crystalline substance from a colloid with a membrane
permeable only to the crystalline substance
dialysis
3) SOLID−SOLID:
The operation in the solid−solid category has found little, if any,
practical application in the chemical process industry
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DIRECT CONTACT MISCIBLE PHASES
Very impractical because of the difficulty involved in maintaining Δc
Formation of a Δc within a single LIQUID or GAS phase by imposition
of a temperature gradient upon the fluid, thus making possible the
separation of the components of the solution. For example, the separation
Thermal diffusion
of Uranium isotopes in the form of UF6
If a condensable vapour such as steam, is allowed to diffuse through a gas
mixture, it will preferentially carry one of the components along with it,
thus making a separation by an operation called sweep diffusion. If the
two zones within the gas phase where the concentrations are different are
separated by a screen containing large size openings, the operation is
called atmolysis.
If a gas mixture is subjected to a very rapid centrifugation, the compounds
will be separated because of the slightly different forces acting on
different components (ΔMW). The heavier molecules thus tend to
accumulate at the periphery of the centrifuge.
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Plant Equipment
Chemical reactors
Heat exchangers
Mass transfer equipment
Distillation
Absorption
Adsorption
Evaporation
Extraction
Drying
Ancillary equipment
Transportation equipmentc
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Distillation (Laboratory)
1.
2.
3.
4.
Heat source
Still pot
Still head
Thermometer/Boiling point temperature
5.
6.
7.
8.
Condenser
Cooling water in
Cooling water out
Distillate/receiving flask
9. Vacuum/gas inlet
10. Still receiver
11. Heat control
12. Stirrer speed control
13. Stirrer/heat plate
14. Heating (Oil/sand) bath
15. Stirrer bar/anti-bumping granules
16. Cooling bath
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Distillation (Industrial)
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CHEMICAL REACTORS
Often the heart of a chemical process
Where the raw materials are usually converted into products
Reactor design is the vital step in the overall design of the process
Chemical factors: mainly the kinetics. Sufficient residence time for
the desired reaction to get the desired conversion
Mass transfer factors: The rates of heterogeneous reactions may be
controlled by the rates of diffusion of the reacting species, rather than
chemical kinetics
Heat transfer factors: These involve the removal, or addition, of the
heat of reaction
Safety factors: These involve the confinement of any hazardous
reactants and products, as well as the control of the reaction and the
process conditions
The above factors are interrelated, and often contradictory
design is a complex and difficult task
Anand V. Patwardhan, IIT Kharagpur
reactor
53
Reactors types
The characteristics normally used to classify reactor design are:
1) Mode of operation: batch; continuous
2) Phases present: homogeneous; continuous
3) Reactor geometry: flow pattern and manner of contacting the
phases
5 major classes of reactors are:
1) Batch
2) Stirred Tank
3) Tubular
4) Packed (Fixed) Bed
5) Fluidised Bed
Anand V. Patwardhan, IIT Kharagpur
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Batch processes
All the reagents are added at the beginning
Reaction proceeds
Composition changes with time
Reaction is stopped after the desired conversion is reached
Product(s) is(are) withdrawn
Suitable for small scale production, and for processes that
use the same equipment to make a range of different
products or grades
Examples: pigments, dyestuffs, pharmaceuticals, some
polymers
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Continuous processes
Reactants fed continuously and products withdrawn
continuously
Almost always operates under steady state
Usually lower production costs than batch processes
Lacks flexibility of operation
Usually suitable for large scale production
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Semi−batch processes
Some of the reactants may be added to the batch as
the reaction proceeds
Some of the products may be withdrawn from the
batch as the reaction proceeds
Semi−continuous processes
Basically a continuous process that is interrupted
periodically, for example, for the regeneration of the
catalyst
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Homogeneous processes
Reactants, products, catalysts (if any) form one
continuous phase, either gaseous or liquid
Homogeneous gas phase reactions are almost always
operated continuously, whereas homogeneous liquid
phase reactions may be batch or continuous
Tubular (pipeline) reactors are normally used for
homogeneous gas phase reactions
Both tubular and stirred tank reactors are used for
homogeneous liquid phase reactions
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Heterogeneous processes
Two or more phases exist
The overriding problem is promotion of mass transfer rate
between different phases
Possible combination of phases are:
Liquid−liquid: with immiscible phases
Liquid−solid: with one or more liquid phases in contact
with a solid; the solid may be a reactant or a catalyst
Liquid−solid−gas: where the solid is normally a catalyst
Gas−solid: where the solid may take part in the reaction
or act as a catalyst
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Heterogeneous processes …
Stirred tank reactor:
Basic chemical reactor, modeling on a large scale the conventional
laboratory reaction flask !
A tank fitted with a mechanical agitator and usually a cooling
(heating) jacket or coil. Operated batch or continuous mode
Several tanks in series is a possibility
Tank size: a few litres to several thousand litres
Homogeneous reactions
Heterogeneous L−L, G−L, G−L−S reactions
Degree of agitation is under designer’s control
suitable for
reactions that require good mass transfer and/or heat transfer rates
When operated in a continuous manner, the composition in the
reactor is constant, and is the same as that of the product (except for
very rapid reactions)
limits the conversion that can be obtained in
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one stage
Heterogeneous processes …
Tubular reactor:
Generally used for gaseous reactions, but also suitable for
liquid phase reactions
If high heat transfer is required
smaller diameter tubes to
increase the surface−to−volume ratio
Several tubes may be arranged in parallel
For very high temperature reactions, tubes are arranged in
furnace
Two basic types of tubular reactors:
1) Solid as reactant(s)
2) Solid as catalyst(s)
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Heterogeneous processes …
Tubular reactor … :
1) Solid as reactant(s): in extractive metallurgical industries
2) Solid as catalyst(s): catalytic reactors. Industrial packed bed
catalytic reactors are used for gas and gas−liquid reactions.
If high heat transfer rates are required, fluidised bed reactors
are considered
Fluidised bed reactors: the solids are suspended by the
upward flow of the reacting fluids high heat and mass
transfer rates. The solid may be a catalyst, a reactant, or
an inert powder to promote heat transfer
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Operational factors that contribute to WASTE and
EMMISSIONS in chemical reactors are:
Incomplete conversion resulting from inadequate
temperature control
By−product formation resulting from inadequate
mixing
Catalyst deactivation resulting from poor feed control
or purity control
Improper design of the reactor itself
Improper catalyst selection
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HEAT EXCHANGERS
Transfer of heat to and from process fluids
The chemical process industry uses 4 principal types of heat exchangers:
1) Double−pipe heat exchanger: concentric pipe arrangement. Made from
standard fittings. Useful only for a small heat transfer area is required
2) Shell and tube heat exchanger: bundle of tubes enclosed in a cylindrical
shell. The tube ends are fitted into tube−sheets, which separate the
shell−side and tube−side. Baffles are provided to direct the fluid flow
and to increase heat transfer. most commonly used, because of the
following advantages:
Large surface−to−volume ratio (compact)
Good mechanical layout (good shape for pressure operations)
Reliance on well established fabrication techniques
Wide range of construction materials available
Easily cleaned equipment
Well established design procedures
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HEAT EXCHANGERS …
3) Plate and frame heat exchangers: very compact, high heat transfer
rates
4) Direct contact heat exchanger: no wall to separate hot and cold
streams, ∴ very high heat transfer rates are achieved. For example,
reactor off−gas quenching, vacuum condensers, desuperheating, and
humidification. Water cooling tower is an example of direct contact
cooling. Considered whenever the process stream and coolant are
compatible. The equipment is simple, for example, spray chamber,
spray column, plate column, packed column
Heat exchangers contribute to WASTE generation by the
presence of CLING formation (process side), and SCALE
formation (service side). This can be corrected by designing for
lower film temperature and high turbulence.
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MASS TRANSFER EQUIPMENT
1) DISTILLATION
Most widely used separation process
Rectification of alcohol (practised since antiquity)
crude oil
fractionation of
Based on differences in volatility between the mixture components
The greater the relative volatility, the easier the separation
Vapour flows up the column, liquid flows down the column
Vapour and liquid are brought into contact on plates, or packings
Part of the condensate (reflux) from the condenser is returned to the
top of the column to provide the liquid flow above the feed point
Part of the liquid from the base of the column is vaporised in the
reboiler and returned to the column to provide the vapour flow
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1) DISTILLATION …
In stripping section (below the feed), the more volatile components
are stripped from the liquid.
In enrichment (rectification) section (above the feed), the
concentration of more volatile components increases
In the case of multiple feed and/or multiple products, the basic
operation remains the same; complicates the analysis
Rectification section may be omitted, if the requirement is to strip the
MVC from a relatively non−volatile solvent stripping column
If the top product is required a vapour, the liquid condensed is
sufficient only to provide the reflux to the column
partial
condenser
In a partial condenser, the vapour leaving is in equilibrium with the
reflux
When the vapour is totally condensed, the reflux will have the same
composition as the top product
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2) ADSORPTION
Operation can be applied to either gas or liquid mixtures
One or more components from a mixture are preferentially removed
by a solid (called adsorbent)
Influenced by the surface area of the adsorbent, nature of the
substance to be adsorbed (adsorbate), pH of system (in case of
liquids), and temperature of operation
Normally performed in a column
Either a packed bed or a fluidised bed
The adsorbent, after its useful life, can either be discarded or
regenerated
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3) ABSORPTION
Intimate contacting of a mixture of gases with a liquid so that part of
one or more constituents of the gas dissolves in the liquid.
Usually packed column
Also, plate column, bubble column, venturi scrubbers, mechanically
agitated contactors, etc.
Countercurrent packed column is the most common equipment:
The gas stream moves upward through the packed bed against a
physically absorbing and reacting liquid that is injected at the
top of the column
This results in the highest possible contacting efficiency
Since the concentration of the gas stream decreases as it rises, it
comes into contact with fresher liquid coming from the top
This provides the maximum average driving force for the
diffusion process
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4) EVAPORATION
Operation involves heat transfer to a boiling liquid
Results in an increase in the concentration of certain species in the
feed stream
Most common application: removal of water from a process stream
Food, chemical, petrochemical industries
Factors affecting: concentration of the liquid, solubility, pressure,
temperature, scaling, materials of construction
Major types of evaporators:
Open kettle or pan evaporator
Horizontal tube natural convection evaporator
Vertical tube natural convection evaporator
Forced convection evaporator
Efficiency can be increased by operating the equipment in multiple
effect mode
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4) EXTRACTION (L−L and S−L)
Liquid−liquid extraction involves transfer of solutes from
one liquid phase into another solvent
Conducted in a mixer−settler, plate column, agitated
column, packed column, etc.
S−L extraction (Leaching) involves passing of a solvent over
a solid phase to remove solute
Conducted in a fixed−bed, moving bed, or agitated
columns
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5) DRYING
Involves removal of small amounts of water or other volatile liquids
Drying removes the liquid as a vapour by warm gas (usually air)
currents
Batch or continuous processes
4 basic dryer types:
Continuous tunnel dryer: warm air is blown over the trays
Rotary dryer: inclined hollow cylinder that rotates. The wet
solids are fed from one side, hot air is passed counter−currently
over the wet solids
Drum dryer: a heat cylinder in which the wet solids spread
across the outside of the hot, rotating drum, are dried on this
surface, and are then scraped off
Spray dryer: a liquid or slurry is sprayed through a nozzle, and
the fine droplets are dried by a hot gas. This may be operated
co−currently, counter−currently, or in some combination of the
two modes
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ANCILLARY EQUIPMENT
These are devices for transporting gases and liquid to, from, or
between various units of process equipment
Some are simply conduits (pipes, ducts, fittings, stacks)
Some control the flow of material (valves)
Some provide mechanical driving force for the flow (fans,
pumps, compressors)
Storage facilities
Holding tanks
Materials−handling devices and techniques
Utilities (gas, steam, water)
Air, water, and solid waste control equipment
Pollution prevention and loss prevention can be implemented by the use
of seal−less pumps, bellow−sealed valves, and other specified equipment.
Selection of proper equipment in the Design and Construction phase of
a transport system is very important
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ANCILLARY EQUIPMENT …
PIPES
Pipes and tubings
Pipes: larger diameter, thicker walls, hence can be threaded
Tubings: smaller diameter, thinner walls, hence can NOT be threaded
Many materials of construction = f (corrosivity of fluids, system pressure)
Steel pipes can be LINED with Sn, plastic, rubber, lead, or other
corrosion−resistant coating
Special MOCs such as glass, porcelain, thermosetting plastic, or hard
rubber are available
Several techniques to join pipe sections
For small pipes, threaded connections are most common
For larger pipes, FLANGED fittings, WELDED connections
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ANCILLARY EQUIPMENT …
DUCTS
Only for gases
Always thin−walled, generally used for flows at ambient pressure
0, ○, □, etc. shapes are available
Larger cross sections à gases are often transported with low density and
high flow rates
Field−fabricated galvanised sheet steel, fibrous glass board,
factory−fabricated round fibrous glass, spiral sheet metal, flexible duct
materials, black steel, plastic and plastic−coated steel, cement, asbestos,
copper
For maximum resistance to corrosion, stainless steel and copper are used
where their cost can be justified
Aluminum sheet is used where lighter weight and superior resistance to
moisture are needed
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FITTINGS
A piece of equipment that has one or more of the following functions:
1. Joining of 2 pieces of straight pipes (coupling, union, etc.)
2. Changing the direction of pipeline (elbow, T, etc.)
3. Changing of pipeline diameter (reducer, bushing, etc.)
4. Joining of 2 streams (T , Y)
Coupling: short piece of pipe threaded on the inside (some plastics are not
threaded). Used to connect straight sections of pipe
Union: Used to connect straight sections of pipe, but differs from the coupling
in that it can be opened conveniently without disturbing the rest of the
pipeline
Elbow ╔═: an angle fitting for changing flow direction usually by 900
T joint ═╦═: change of direction or mixing of 2 streams
Y joint Υ: similar to T joint
Reducer: a coupling for 2 pipe sections of different diameter
Bushing: a connector for 2 pipe sections of different diameter, but is threaded
from both inside and outside
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VALVES
Control the amount of flow, redirect the flow
GATE valve and GLOBE valve are most commonly used
GATE valve
Contains a disk that slides perpendicular to the flow direction
Primarily used for on−off control of a liquid flow
Not suitable for adjusting the flow rates because small lateral
adjustments of the disk cause extreme changes in the flow
cross−sectional area.
GLOBE valve
Designed for flow control
Liquid route is circuitous
The seal is a horizontal ring in which a plug with a slightly beveled
edge is inserted when the stem is closed
Good flow control, but pressure losses are more than those in gate
valve
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VALVES …
Some other types of valves are:
Check valve: permits the flow in one direction only
Butterfly valve: operates in a damper−like fashion by rotating a flat
plate to either || or ⊥ position relative to the flow
Plug valve: a rotating tapered plug provides on−off service
Needle valve: a variation of the globe valve, which gives improved
flow control
Diaphragm valve: specially designed to handle fluids such as very
viscous liquids, slurries, or corrosive liquids that might clog the
moving parts of the other valves
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FANS / BLOWERS
For low pressure drop operation, generally < 2 lbf/in2
For generating pressure heads in the range of 2 – 14.7 lbf/in2
Operations at higher pressures require COMPERSSORS
Centrifugal and axial flow type
Centrifugal fans: the gas is introduced at the centre of the revolving wheel
(eye), and is discharged at angles to the rotating blades
Axial flow fans: the gas moves directly (forward) through the axis of
rotation of the fan blades.
Both types are used in industry
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PUMPS
1) RECIPROCATING PUMP (positive displacement type)
Direct action of piston on the liquid in the cylinder
During the piston compression, higher pressure forces the liquid
through the discharge valve of the pump outlet
During the piston retraction, the next batch of low−pressure
liquid is drawn into the cylinder
This cycle is repeated
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PUMPS …
ROTARY PUMP (positive displacement type)
Combination of liquid rotation and positive displacement
the rotating elements MESH with the elements of stationary
casing
As the rotating elements come together, a pocket is created that
first enlarges, drawing in liquid from the suction line
As the rotation continues, the pocket of liquid is trapped, reduced
in volume, and then forced into the discharge line at a higher
pressure
Flow rate = f (size and speed of rotation)
Liquid of any viscosity without abrasive solids, can be handled
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PUMPS …
CENTRIFUGAL PUMPS:
Consists of an impeller rotating within a casing
Fluid enters near the centre of the impeller, and thrown
outward by the centrifugal force
The kinetic energy of fluid increases from the centre to the
tip of the impeller
The kinetic energy is converted to higher pressure in the
discharge line
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COMPRESSORS
Same working principles
Same classification as that of pumps
Obvious difference: large decrease in GAS volume, but negligible change
in LIQUID volume
CENRIFUGAL: large volumes of GASES, at low−to−moderate pressure
enhancements (ΔP = 0.5−50 lbf/in2)
ROTARY: small capacities, at discharge pressures up to 100 lbf/in2
RECIPROCATING: most common type. Capable of compressing small
gas flows to as much as 3,500 lbf/in2.
With specially designed compressors, discharge pressures as high as
25,000 lbf/in2 can be reached, but these devices are capable of handling
very small capacities, and do not work well for all gases
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STACKS (chimneys)
Discharge of flue gases into atmosphere
STUB (short stacks)
fabricated of steel (unlined or refractory−lined) or refractory brick
Extend a minimum distance up from the discharge of an induced
draft fan
Tall stacks
Constructed of the same material as short stacks
Provide a greater driving force (draft)
Ensure more effective dispersion of flue gases into atmosphere
Some chemical and utility applications use metal stacks made of
double−wall with an air space
The insulating air packet prevents condensation on the inside of the
stack, thus avoiding corrosion of the metal sheets.
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Process Diagrams
Key in defining, refining, and documenting a chemical
process
Authorised process blueprint
Framework for SPECIFICATIONS used in equipment
designation and design
Single, authoritative document to define, construct, and
operate the chemical process
Also used in other processes and Industries
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Flow sheets
Equipment symbols, process stream flow lines, equipment
identification numbers and names, temperature and pressure
designations, utility designations, mass / volumetric / molar flow rates
of each process stream, material and energy balance tables pertaining
to all process flow lines, physical properties of process streams
Instrumentation
Provides coherent picture of the overall process, point up some
deficiencies in the process that may have been overlooked, for
example, by−products and recycle requirements
Basically, FLOW SHEET symbolically and pictorially represents the
interrelations among the various flow streams and equipment, and
permits easy calculations of M & E B.
Universal symbols to represent equipment, equipment parts, valves,
piping, etc.
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Flow sheets … (stages in its development) …
Crude flow sheet: simple, free−hand block diagram (equipment only)
Line drawing with process data (overall and component flow rates,
utility and energy requirements, instrumentation)
Highly detailed piping and instrumentation diagram (P & I D)
OR
1. Block diagram
2. Graphic flow diagram
3. Process flow diagram
4. Process piping and instrumentation flow diagram
5. Utility piping and instrumentation flow diagram
6. The combination of (4) and (5) above
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Instrumentation and Process Control
Measurement, Indication, Recording of necessary process data
Necessity for knowing process data: so that the Operator and Production
Engineer can know that the process is functioning properly or not.
Automatic control: often desirable, because it reduces human
intervention and human errors, and also gives faster and more accurate
control
Coupling of automatic controllers to electronic computers
Necessary to have highly skilled and trained maintenance staff
The more complex the system, the greater the chance for breakdown
For designing an automatic process control system, it is absolutely
essential to consider the INTERACTION of all components of a process
to determine the overall behaviour (dynamics) of the process
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Economics
The process is a failure if the product can not be sold at a profit
Thorough market analysis (how much, what price) before the
construction of a chemical process plant
Often MORE SALE with LOWER PRICE !
PRESENT AND FUTURE COMPETITION
During plant design: determine the least expensive (least fixed capital
investment) design, with least expensive PRODUCT COST
If the product is successful and profitable, a competitor may find the
market attractive and enter it with (definitely) a somewhat better product
produced at a lower price, and moreover, sold at a lower price, by an
improved or the same process !
It is necessary for the older producer to improve her/his PROCESS and
PRODUCT, or she/he will be FORCED OUT of the market.
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WHAT IS ChE ?
Synthesis of Chemistry and Engineering
Grew out of Industrial Chemistry
fundamentals
physical principles + chemistry
“A ChEngineer carries out reactions on a large scale, developed by the
chemist in the laboratory” – narrow, UNIT OPERATIONS are NOT
included in this definition
Unique characteristic of a ChEngineer: can talk to, and understands,
both chemists and engineers
A.I.Ch.E’s definition: “the application of principles of the chemical and
physical sciences, together with the principles of economics and human
relations, to fields that pertain directly to processes and process
equipment, in which matter is treated to effect a change in state, energy
content, or composition”
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WHAT DOES A ChEngineer DO ?
Some major areas of work within “ChE”
Research
Process development
Process design and evaluation
Plant design
Construction
Production supervision
Plant technical service
Product sales
o
Market research
o
Product development
o
Technical sales and customer technical service
The ChEngineer works closely with specialists in chemistry and other
fields of engineering and pure science.
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RESEARCH
Fundamental research
Exploratory research
Process research
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Fundamental research
New knowledge of the principles of unit operations, industrial
reaction kinetics, chemical process control, etc.
Development of new theories, and their experimental testing.
For example, turbulent fluid flow
To increase the general knowledge rather than for specific
application
Requires excellent background in
mathematics AND principles of ChE
physics,
chemistry,
Specialises and becomes expert in one area, for example, mass
transfer
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Exploratory research
To find a particular reaction with commercial possibilities
Less frequently the responsibility of a ChEngineer. Typically, it is the
task of a Chemist
To find a particular catalyst, reaction temperature, pressure → product
having higher Octane Number
A Chemist investigates several PURE compounds for the reaction in
question. For example, CYCLOHEXANE is a common constituent of
NAPHTHA (octane number = 78.6, too low for modern petrol)
H2
C
0
H2C
CH2
catalyst, 500 F
H2C
CH2
500 lb/in
C
H2
2
H
C
HC
CH
HC
CH
octane number = 113.6
C
H
+ 3H2 ; conversion = 90%
Other catalysts and conditions give different conversions
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Another reforming reaction is isomerisation
For example, n−heptane may be converted to an isomeric heptane with a
higher octane number
0
catalyst, 900 F
CH3CH2CH2CH2CH2CH2CH3
octane number = 0
500 lb/in2
CH3
CH3CCH2CH2CH2CH2CH3
CH3 octane number = 93
The exploratory research group would try many catalysts and various
operating conditions on a small laboratory scale to explore a wide range
of possibilities.
The research programme would extend over several months or even years
Many attempts would prove infeasible
A few results may be commercially promising, and will be passed on to
the process research group
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Process research
Takes promising results from exploratory research, and intensively
studies them on a bench scale to determine their commercial feasibility
Determines operating conditions for a commercial process
Yields data for a preliminary economic evaluation
Provides information for the design of a pilot plant
Studies not only pure starting materials, but also the real feed
Relatively more expensive because of more complex equipment
requirement and greater operating costs.
Demonstrates chemical feasibility of the new process, preliminary
economic feasibility, market evaluation (satisfactory profit level)
PROCESS DEVELOPMENT
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PROCESS DEVELOPMENT
Admission of ignorance !
If all the fundamentals of ChE were well understood, it would be possible
to build a full size plant based on the results of the extensive process
research !!
Large uncertainties regarding process operating conditions and product
yield semi−works or pilot plant
Expensive to build and operate, but saves much more money by
eliminating uncertainties in the construction, start−up, and operation of
the commercial plant
Also required to produce new product for market research
Pilot plant must duplicate the proposed plant the proposed full−size plant
Planning the development programme
Designing and building the pilot plant
Operation of the pilot plant
Correlation, presentation and evaluation of the data obtained
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PROCESS DESIGN AND EVALUATION
Process Design Engineer is responsible for design of
overall process
Project Engineer is responsible for detailed design of
equipment
Process Design Engineer must look at many alternative
process steps to determine an economic optimum
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Process Design includes the following major items:
Process flow sheet showing all pieces of equipment, instrumentation
and control, operating pressures, temperatures, flow rates
Overall mass balances, equipment−wise mass balances, yields of
products, composition of all streams
Energy balances for all units, including heat exchangers requirements
Specification of pump capacities, flow, and pressure requirements
Specification of size and configuration of chemical reactors and
storage tanks
Determination of optimum operating conditions for the mass transfer
operations required for the separation and purification of raw
materials and products
Estimation of utility requirements, such as steam, water, electricity
and fuel
Economic evaluation with an estimate of capital investment and
operating cost
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The Process Design Engineer:
Utilises all the data of process research and development
Works closely with development engineer to determine most economical
processing units and optimum operating conditions
Must use her/his judgement in filling the gaps in the data
Must estimate many quantities, using previous experience as well
Must be well−grounded in the fundamentals of chemical kinetics and unit
operations
Must exercise her/his imagination and judgement to design a process
with often incomplete data
Must be to able use analytical as well as numerical methods of
calculations, AND computers for the routine long calculations
Must be fully familiar with the latest process design and simulation
software
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PLANT DESIGN
Translation of results of Process Design Engineer
specifications construction of the plant
complete plans and
Complete plant design
firm estimate of plant cost AND basis for
contract between chemical company and construction firm
Plant Design group: chemical, mechanical, electrical, civil engineers,
supervised by Project Engineer who is frequently a ChEngineer having
overall process knowledge
Project Engineer: co−ordination of various specialists’ activities; analysis
of data supplied by process design engineer; makes suggestions for
modifying the fundamental process which result in substantial savings.
MUST CONCERN with peripheral problems (water supply, other
utilities, waste disposal, safety)
Process Design Engineer and Project Engineer work closely in analysing
the suggestions of Project Engineer
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Designer and Draftsman: work closely with Project Engineer
Designer: a specialist of a particular phase of the plant. For example:
after a ChEngineer has determined the number, size, and spacing of
plates in a distillation column, a Mechanical Designer may specify the
physical details of the column, Electrical Designer may specify the
location and type of instrumentation and control, Structural Designer
considers the support framework and foundations for the column and
auxiliary equipment
The Designers make suggestions to the project Engineer on specific points
where money might be saved
Designer: supervises the Draftsman who make the detailed drawings of
each unit of the process
Project Engineer: works closely with contractor; materials unavailability,
change in a unit (based on further pilot plant data), changes in foundation
(unexpected soil change)
Project Engineer: present during start−up
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The Young Engineer:
May start as an Assistant in Plant Design Group
Becomes a Designer
Project Engineer
Many equipment (pump, heat exchanger, instrumentation, etc.): supplied
by vendors.
Vendor: a company specialising in the design and construction of a
particular type of equipment
Vendor may build a unit to the Plant Design group’s specifications (tailormade) OR may suggest a standard unit
Vendor employs many engineers in the development, design, and sale of
her/his equipment
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CONSTRUCTION
Role of ChE is limited
Construction Supervisor:
Responsible for completing the plant in shortest time within the allotted
budget
Must establish a construction schedule, and must expedite it
Must set up equipment delivery schedules
Must carefully schedule manpower requirements, keeping in mind the
craft union regulations
Must maintain good labour relations to avoid poor workmanship,
slowdowns, or complete work stoppages
Must test the equipment after construction
Must be available for start−up of the plant
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PRODUCTION SUPERVISION
Production Supervisor:
Gets the new plant running to give Q and Q of the product
Checks the daily record
Improves the plant operation (element of unknown in Design)
Improves product Quality by removing contamination and reducing
deterioration
Reduces steam, water, power, materials requirement
Reduces labour costs by maintaining good labour relations, efficient
methods, and workable safety practices
Develops efficient maintenance procedures to ensure minimum shutdown
for routine repairs
Sets up a procurement schedule to maintain adequate inventories of raw
materials
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Production Supervisor (continued…):
Finds and eliminates bottlenecks when an attempt is made to increase
production (exploiting the overdesign)
Sees her/his profits directly in terms of more efficient operation and
additional production
Works closely with Process Development and Design Group in modifying
the plant
Should be ready to abandon the old plant and move on to a new one
Need a broad background in Engineering
The Graduating ChEngineer:
May start as Assistant Production Engineer in a small area of process
With experience she/he becomes Production Engineer, Assistant
Supervisor, Supervisor Plant Manager
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PLANT TECHNICAL SERVICE
Assists the Operating Engineer in start−up and operation problems
More technical and less routine duties
Some companies consider Technical Services as a part of Production
Department
Extremely important in the start−up of the new process: Technical
Service Engineer works closely with Process Development and Process
Design groups during start−up, where minor design and construction
errors are corrected
The Engineers involved in start−up need a wealth of theoretical and
practical knowledge to overcome the difficulties involved during the
start−up and during operation
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PRODUCT SALES
The ultimate economic justification of a chemical process
4 closely related areas of interest to ChEngineers:
1. Market research
2. Product development
3. Technical sales
4. Customer technical service
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MARKET RESEARCH
Begins long before the new process is launched
Fundamental question: “Will It Sell ?”
Starts as soon as promising results are reported by the
Exploratory Research Group
For new product: contact potential users to determine their
needs and establish whether a market exists. Pilot Plant
produces sufficient samples for potential users
For existing product: how much more could be sold ?; New uses
Continual surveys of the chemical market to find out facts on
general trends in New Products
May suggest areas of possible economic return to the
Exploratory Research Group
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PRODUCT DEVELOPMENT
Uses of new products and new uses of existing product
Applied research:
problems
solution of complex chemical and engineering
Assists Market Research by suggesting and developing new uses
Assists Technical Salesperson by developing a modified product for the
use of a particular customer
Assists Customer Service Group by suggesting processing methods which
the customer might use with the product
Some long term and exploratory; some immediate answers
For example: Customer requires very high purity product. Usual product
may not be sufficiently pure. The Product Development Engineer will
work out means of purifying it (either before or after Sales) OR she/he
might suggest a change in the customers’ process to eliminate the need
for high purity saving customers’ money and selling less pure product
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TECHNICAL SALES & CUSTOMER TECHNICAL SERVICE
These two are closely related
Same Engineer may act in both capacities
Customer satisfaction should be demonstrated
Solution of customers’ problems during the use of product
Some companies may have special groups; others expect their
salespersons to handle the customers’ technical problems; Some
companies assign this responsibility to their QA Departments
Technical Salesperson may call the Product Development Group to
answer customers’ questions
Often this service is the key factor for Sales
Contact with customers
personality and interest need to be developed.
Pleasant personality helps to get the customer, and core theoretical and
practical knowledge helps retain the same
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ChEngineers IN THE COMING YEARS
ChE improves lifeline, safety, health, energy, environment
ChE faces serious macroeconomic problems, such as:
☺ Energy and feedstock for fertiliser and heavy chemical industry
☺ Infrastructure for transportation, energy, telecommunication
☺ Environment protection
☺ Development of agriculture and agro−industries
☺ Transformation of rural economy, industrialisation, privatisation
Centre versus State
Command Economy versus Liberalisation & Privatisation (the often
misunderstood market economy)
Internal (budget) and external balances
World Trade Organisation and India
Overriding problem of Indian competitiveness (rather, the lack of it)
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Identification of future scenarios and selection of appropriate ones:
Collaboration of Professional Bodies (I.I.Ch.E, and others) will help
Lack of transport infrastructure and transport fuel: blocks interaction with the
World Trade Community
Lack of electric power: puts the nation in uproar
Role of renewable energy to be determined (hydro−power, wind−power, solar
cells, biomass, etc.) vis-à-vis Coal, Natural Gas, Oil, Nuclear Power
Modest quantity of proven Hydrocarbon reserves (≈ 30 × 109 ft3) may exhaust
shortly
Enhancement of energy utilisation efficiency ?
Today, the feedstock for fertilisers (Natural Gas) competes with that of Power
Industry. For long term benefits, Power Industry should not use Natural Gas
Transport fuel: efforts are needed to use Hydrogen in fuel cells
Nuclear energy: ecologically attractive, but useless today because of public
opposition and high investments required
Updated ENERGY POLICY is required URGENTLY
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Updated energy policy should be supplemented by all necessary
programmes: possibly only by collaboration of Economists and
Engineers on one hand, and benign and strong political will on the other
hand: here, the ChEngineers are well placed to make a major
contribution:
The role of ChEngineers is evident but the problem of developing
laws, standards, and trade−offs between the perceived Air Purity and
investments is a problem for Governments and private institutes, etc.,
and health hazards pose a major challenge to the Medical profession
Dealing with “trade−offs” between health risks and the cost of air
cleaning is indeed a difficult task for politicians
Serious environmental problems: CO2
warming
greenhouse effect
global
If the oceans are heated up, they will loose part of their absorbed CO2
further global warming (self−accelerating or autocatalytic effect)
We can not stop the rate of increase in energy usage to reduce CO2 !
ChEngineers can help solve these problems
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Certainly, the ChEngineers and the other technological professionals
can do a lot to draw attention to the facts discussed here before
An understanding between Economists and Engineers to develop joint
advise to political problems and introduction of innovative technologies
have to be worked out by ChEngineers. For example:
Co−production of electric power, chemicals, and hydrocarbons
Use of Dimethyl Ether (DME), as a carrier of energy from, say, the
Middle east to India
Use of DME in India for generation of electricity, and as fuel in diesel
engines
Use of DME as chemical feedstock
Development of long range, high capacity, high voltage DC
transmission
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GENERAL ASPECTS OF ChE
COMMUNICATIONS
Clear expression of technical ideas in oral and written
communication
Often the major contact is with the Administrative Manager
OR Human Resources (HR) Manager (mostly neither an
engineer nor a technologist), who decides on an Engineer’s
promotion based on written reports
All the reports should be written clearly and concisely with
the reader (audience) in mind
Writing and speaking are important in all fields of ChE from
RESEARCH to SALES
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GENERAL ASPECTS OF ChE …
HUMAN RELATIONS
Many failures are NOT due to technical weakness, but can be attributed
to failure of Engineer to work effectively in group/team: Must work
effectively in group/team
Must sell ideas effectively and tactfully
Any effective group/team activity = f (sensitivity to and respect for
rights and needs of others)
Must realise that no matter how lucid her/his idea is to her/him, it may
not be clear to others, and the idea may NOT be right !
Development and Design Engineers must work closely together and with
their respective groups
Production Engineer must work closely with other Engineers and with the
Unionised Labour Force
Technical Services Engineer must work closely with the operators of the
Process, carefully explaining the suggested process changes
Sales Engineer must be particularly sensitive to her/his customers’ needs
(the customer is not always right, but it will do no good to tell point
blank so !)
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GENERAL ASPECTS OF ChE
PROFESSIONAL ACTIVITIES
All Engineers should be active in their respective
Professional Societies. For example, I.I.Ch.E.
TECHNICAL READING
The ChEngineer should keep up−to−date in her/his field,
not only by attending professional meetings, but also by
reading technical journals (periodicals).
There are a number of general publications and many
specialised publications in ChE
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If you wish to find out MORE about the Chemical
Process Industry, read on the following lines:
1)
Basic laws and processes of chemical technology
2)
Raw materials, fuel, and power for Chemical Process
Industry
3)
Water conditioning in Chemical Process Industry
4)
Catalysts and catalysis
5)
Explosives and propellants
6)
Industrial gases
7)
Industrial carbon
8)
Sulphur and sulphuric acid
9)
Hydrochloric acid and miscellaneous inorganic chemicals
10)
Nitrogen industries
11)
Phosphorous industries
12)
Salt and miscellaneous sodium compounds
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13)
Alkali and chlorine products
14)
Potassium industries
15)
Barium and its compounds
16)
Fertiliser industries
17)
Portland cement, calcium, and magnesium compounds
18)
Ceramic and refractories
19)
Glass industries
20)
Nuclear industries
21)
Iron and steel
22)
Energy conservation in Chemical Process Industries
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23)
Petroleum refinery and petrochemicals
24)
Synthetic fibres and film industries
25)
Rubber industries
26)
Plastic industries
27)
Oils, fats, and waxes
28)
Soaps and detergents
29)
Essential oils
30)
Surface coating industries
31)
Pulp and paper industries
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32)
Sugar and starch industries
33)
Fermentation and distillery
34)
Food processing industries
35)
Leather and tannery
36)
Dyes and dyes intermediates
37)
Agrochemical industries
38)
Coal and coal chemicals
39)
Pollution control
40) Green technologies through ChE
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Acknowledgements
1st year B.Tech. (2006 entrants − ChE) students: suggested an
INTRODUCTORY lecture on this topic
Professor Dibyendu Mukherjee (Head, Chemical Engineering
Department, IIT Kharagpur): instantly supported the idea
My present and past students: shared their valuable experiences. I learn
from them more than I can teach them
All my teachers from UICT (Mumbai): introduced to me, not only the
wonderful words and world of ChE, but also the tricks of the trade !
Some of my bosses, colleagues, and peers from M/s. Indian Organic
Chemicals Limited (Khopoli, Raigad, Maharashtra) and M/s. Asian
Paints Limited: mentored me in knowledge−based problem−solving
All the Plant Operators in the above−mentioned organisations: imparted
those lessons, which are not available in any text−book !
My esteemed colleagues in Chemical Engineering Department, IIT
Kharagpur: for their latent contribution and support
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