Chemical Process Industry_ Chemical Engineering_ and Chemical Engineer

Anand V. Patwardhan, IIT Kharagpur 1

Chemical Process Industry,Chemical Engineering,Chemical Engineer


A presentation for the 1st year Chemical Engineering UG studentsby

Anand Vinayak PatwardhanAssociate Professor

Faculty Advisor (2006−entrants UG)Chemical Engineering Department

Indian Institute of Technology KharagpurKharagpur−721302

IndiaEmail: [email protected]


Abbreviations used in this Presentation

A.I.Ch.E. American Institute of Chemical EngineersChE Chemical EngineeringChEngineer Chemical EngineerI.I.Ch.E. Indian Institute of Chemical EngineersMOC Material of ConstructionQ and Q Quality and Quantity (in the context of a Product)QA Quality Assurance


CHEMICAL PROCESS INDUSTRYINTRODUCTIONWHAT IS CHEMICAL PROCESS INDUSTRY ?ORIGINS AND DEVELOPMENT OF CHEMICAL PROCESS INDUSTRY

Pre−scientific Chemical IndustryScientific Chemical Industry

INDIAN CHEMICAL INDUSTRY TODAYGrowth with RestraintsGreen Challenges to Chemical Industry

SYSTEMATIC ANALYSIS OF CHEMICAL PROCESSESMass and Energy Balances

Conservation of MassConservation of Energy


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


Process Flow DiagramsFlow Sheets

Instrumentation and ControlEconomics

WHAT IS ChE ?WHAT DOES A ChEngineer DO ?

ResearchFundamental ResearchExploratory ResearchProcess Research

Process DevelopmentProcess Design and EvaluationPlant DesignProduction and SupervisionPlant Technical Service


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


INTRODUCTIONProducts – all areas of everyday life

Chemical fertilisersFood supplementsBuilding 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


WHAT IS CHEMICAL PROCESS INDUSTRY ?

Most processes involve a “Chemical Change”,chemical reactionsphysico−chemical changerelated 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.


ChemicalsRayon and film processingPetroleum refiningPulp and paper processingLyeCleansersSoapMetal processing

Sodium hydroxide

ExplosivesFertilisersNitric acid

Fertilisers, chemicalsPetroleum refiningPaintsPigmentsMetal processingExplosives

Sulphuric acid

End UsesTypical ProductsIndustry: Inorganic Chemicals


Industry: Organic ChemicalsEnd UsesTypical Products

FormaldehydeAntifreezeSolvent

Ethanol

PlasticsFormaldehyde

AntifreezeCellophaneDynamiteSynthetic fibres

Ethylene glycol

RayonResinsPlastics

Acetic anhydride


Industry: Petroleum and PetrochemicalEnd UsesTypical Products

Synthetic rubberPlasticsStyrene

DetergentsAlkyl aryl sulphonate

AcetaldehydeSolventOther chemicals

Ethanol

FertilisersChemicalsAmmonia

LubricatingHeatingOils

FuelKeroseneFuelGasoline


Industry: Pulp and Paper

End UsesTypical Products

Building materialsFibreboard, etc.BoxesCardboard

BooksRecordsNewspapers, etc.

Paper


Industry: Pigment and PaintEnd UsesTypical Products

Basic lacquerVarnishesEnamel constituents

Phenolic resinsAlkyd resins, etc.

Drying oilLinseed oil

Pigments for paints, inksPlasticsRubbersCeramicsLinoleum

Zinc oxide (ZnO),Titanium dioxide (TiO2),Carbon black (C),Lead chromate,Iron oxides (FeO, Fe2O3, Fe3O4)


Industry: Rubber

End UsesTypical ProductsAutomobile tyresMouldings and sheetingsFootwearInsulation

Natural rubber (Isoprene),Synthetic rubbers (GR−S, neoprene, butyl)


Industry: Plastic


Various uses in all areas of everyday life

Phenol−formaldehyde,Polystyrene,Polymethylmethacrylate,Polyvinyl chloride,Polyethylene,Polyesters


Industry: Synthetic Fibre


Cloth and clothing

Rayon,Nylon,Polyesters,Acrylics


Industry: Mineral


WindowsContainersBricksPipe

Glass,Ceramics


Industry: Cleansing Agent


Household cleaningIndustrial cleaning

Synthetic detergents(sodium alkyl aryl sulphonates),Wetting agents


Industry: Biochemical

End UsesTypical ProductsHealth applicationsMedicinal applications

Pharmaceuticals,Drugs


Industry: Metal

Nuclear fuelUranium


Building materialsMachinery, etc.

Steel,Copper,Aluminium,Zirconium


ORIGIN AND DEVELOPMENT OFCHEMICAL 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


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


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


Growth with Restraints

Major restraints:

Matching with the international standards, rapidly changing demand pattern and customer preferences

Continuous upgradation of process technology additional investments

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 !)


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 !


“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 ?)


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


SYSTEMATIC ANALYSIS OF CHEMICAL PROCESSES

Production of large quantities at lowest possible cost, for many NEW molecules as well Experience−based improvements no longer sufficientSystematic analysis of chemical processes elucidated many underlying principles synthesis of new processes

Mass and energy balancesThermochemistryUnit operationsPlant equipmentAncillary equipmentProcess flow diagramsInstrumentation and controlVitamin−M: balances, operations, flow & control (Economics !)


Mass and Energy BalancesFundamental 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)


Conservation of energyEnergy in − out + generated = accumulated

First law of thermodynamics∆E = Q − W … for batch processes∆H = Q − WS … for continuous processes

Q = heat energy transferred across the system boundaryW = work energy transferred across the system boundaryWS = mechanical work energy transferred across the system boundaryE = internal energy of the systemH = 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


Thermochemistry

Concerned with the energy effects associated with chemical reactionsEnthalpy is the most convenient term to work withDifferent 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 equilibriumChemical kineticsIdeal gas lawPhase equilibrium


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)


Chemical kinetics

2. How fast the reaction will go ? (Question 2 of the previous slide)Study of reaction RATES and variables that affect these ratesRATE: time rate of change in the amount of any of the components participating in the reactionBased on arbitrary factor related to the reacting system size, geometry (volume, interfacial area), mass, etc.

dn1 AR = A V dtdcA= ... in case V = constantdt

R = R c , P, T, catalyst variablesA A i

R = k cA A i

⎛ ⎞⎜ ⎟⎜ ⎟⎝ ⎠

⎛ ⎞⎛ ⎞ ⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠±


Ideal gas law

Works best at higher temperatures and lower pressures, that is, when

At lower temperatures, and higher pressures, for REAL gases

For engineering calculations, the IDEAL GAS LAW is almost always valid

3 m /kmol or L/mol , the ideal molar voR T l 22.4P ume⎛ ⎞⎜ ⎟⎜ ⎟⎜ ⎟⎝ ⎠

≥

3m /kmol or L/molR T 22.4P⎛ ⎞⎜ ⎟⎜ ⎟⎜ ⎟⎝ ⎠

<

P V = constant = n RT


Phase equilibriumPURE substances: Phase = state of matter − solid, liquid, gas (vapour)MIXTURES: a phase is characterised by uniformity or homogeneity of propertiesMost 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


Unit OperationsThe 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 yarnReactive absorption of O2 from air in a fermenter; reactive absorption of H2 in vegetable oilEvaporation of salt solutions; evaporation of sugar solutionsFlow 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 operationsThe individual operations have common techniques and are based on the same scientific principlesThe treatment of all processes is unified and simplified


Some of the Important Unit OperationsFluid flowHeat transferEvaporationDryingDistillationAbsorptionAdsorptionLiquid−liquid extractionLiquid−solid leachingCrystallisationMembrane separationMechanical−physical separations


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


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


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


Unit operations are applicable to processes that are physical and chemicalMost frequently, it is desirable to separate the original substance into its component partsEntirely 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 awaySometimes, 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)


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


CONTACT OF TWO IMMISCIBLE PHASESThe 3 states (S, L, G) permit 6 possibilities:1) GAS−GAS: completely soluble in each other, hence infeasible category2) GAS−LIQUID:

If all components are present in appreciable amount in both GAS and LIQUID phases fractional distillationAll 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 / humidificationBoth 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


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 drying / desorption / adsorption

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


CONTACT OF TWO IMMISCIBLE PHASES

4) LIQUID−LIQUID:

Liquid−liquid extraction OR liquid extraction OR solvent extraction operations


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


CONTACT OF MISCIBLE PHASES SEPARATED BY A MEMBRANE

1) GAS−GAS:

Gaseous diffusion OR effusion: if a gas mixture whose componentsare of different molecular weight is brought into contact with a porous diaphragm, the various components of the gas mixture willdiffuse 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


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 of Uranium isotopes in the form of UF6 Thermal diffusion

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.


Plant EquipmentChemical reactorsHeat exchangersMass transfer equipment

DistillationAbsorptionAdsorptionEvaporationExtractionDrying

Ancillary equipmentTransportation equipmentc


Distillation (Laboratory)1. Heat source2. Still pot3. Still head4. Thermometer/Boiling point temperature5. Condenser6. Cooling water in7. Cooling water out8. Distillate/receiving flask9. Vacuum/gas inlet10. Still receiver11. Heat control12. Stirrer speed control13. Stirrer/heat plate14. Heating (Oil/sand) bath15. Stirrer bar/anti-bumping granules16. Cooling bath


Distillation (Industrial)


CHEMICAL REACTORSOften the heart of a chemical processWhere the raw materials are usually converted into productsReactor 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 conversionMass transfer factors: The rates of heterogeneous reactions may be controlled by the rates of diffusion of the reacting species, rather than chemical kineticsHeat transfer factors: These involve the removal, or addition, of the heat of reactionSafety 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 reactor design is a complex and difficult task


Reactors types

The characteristics normally used to classify reactor design are:1) Mode of operation: batch; continuous2) Phases present: homogeneous; continuous3) Reactor geometry: flow pattern and manner of contacting the

phases5 major classes of reactors are:

1) Batch2) Stirred Tank3) Tubular4) Packed (Fixed) Bed5) Fluidised Bed


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


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


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


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


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


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 one stage



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)



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 reactorsare 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


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


HEAT EXCHANGERSTransfer of heat to and from process fluidsThe 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 required2) 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 techniquesWide range of construction materials availableEasily cleaned equipmentWell established design procedures


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 arecompatible. 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 SCALEformation (service side). This can be corrected by designing for lower film temperature and high turbulence.


MASS TRANSFER EQUIPMENT

1) DISTILLATION

Most widely used separation process

Rectification of alcohol (practised since antiquity) fractionation of crude oil

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


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 increasesIn the case of multiple feed and/or multiple products, the basicoperation remains the same; complicates the analysisRectification section may be omitted, if the requirement is to strip the MVC from a relatively non−volatile solvent stripping columnIf the top product is required a vapour, the liquid condensed issufficient only to provide the reflux to the column partial condenserIn a partial condenser, the vapour leaving is in equilibrium with the refluxWhen the vapour is totally condensed, the reflux will have the same composition as the top product


2) ADSORPTION

Operation can be applied to either gas or liquid mixtures

One or more components from a mixture are preferentially removedby 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


3) ABSORPTIONIntimate 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 columnAlso, 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 thetop of the columnThis results in the highest possible contacting efficiencySince the concentration of the gas stream decreases as it rises, it comes into contact with fresher liquid coming from the topThis provides the maximum average driving force for the diffusion process


4) EVAPORATIONOperation involves heat transfer to a boiling liquidResults in an increase in the concentration of certain species in the feed streamMost common application: removal of water from a process streamFood, chemical, petrochemical industriesFactors affecting: concentration of the liquid, solubility, pressure, temperature, scaling, materials of constructionMajor types of evaporators:

Open kettle or pan evaporatorHorizontal tube natural convection evaporatorVertical tube natural convection evaporatorForced convection evaporator

Efficiency can be increased by operating the equipment in multiple effect mode


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


5) DRYINGInvolves removal of small amounts of water or other volatile liquidsDrying removes the liquid as a vapour by warm gas (usually air) currentsBatch or continuous processes4 basic dryer types:

Continuous tunnel dryer: warm air is blown over the traysRotary dryer: inclined hollow cylinder that rotates. The wet solids are fed from one side, hot air is passed counter−currentlyover the wet solidsDrum 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 offSpray 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


ANCILLARY EQUIPMENTThese 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 facilitiesHolding tanksMaterials−handling devices and techniquesUtilities (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


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


ANCILLARY EQUIPMENT …

DUCTS

Only for gases

Always thin−walled, generally used for flows at ambient pressure

0, ○, □, etc. shapes are available

Larger cross sections 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


FITTINGSA 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 pipeUnion: 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 pipelineElbow ╔═: an angle fitting for changing flow direction usually by 900

T joint ═╦═: change of direction or mixing of 2 streamsY joint Υ: similar to T jointReducer: a coupling for 2 pipe sections of different diameterBushing: a connector for 2 pipe sections of different diameter, but is threaded from both inside and outside


VALVESControl the amount of flow, redirect the flowGATE valve and GLOBE valve are most commonly usedGATE valve

Contains a disk that slides perpendicular to the flow directionPrimarily used for on−off control of a liquid flowNot suitable for adjusting the flow rates because small lateral adjustments of the disk cause extreme changes in the flow cross−sectional area.

GLOBE valveDesigned for flow controlLiquid route is circuitousThe seal is a horizontal ring in which a plug with a slightly beveled edge is inserted when the stem is closedGood flow control, but pressure losses are more than those in gate valve


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


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


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 liquidthrough the discharge valve of the pump outlet

During the piston retraction, the next batch of low−pressureliquid is drawn into the cylinder

This cycle is repeated


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 thatfirst 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


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


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


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.


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


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, andpermits easy calculations of M & E B.

Universal symbols to represent equipment, equipment parts, valves, piping, etc.


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)

OR1. 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


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


EconomicsThe 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.


WHAT IS ChE ?

Synthesis of Chemistry and Engineering

Grew out of Industrial Chemistry physical principles + chemistryfundamentals

“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”


WHAT DOES A ChEngineer DO ?Some major areas of work within “ChE”

ResearchProcess developmentProcess design and evaluationPlant designConstructionProduction supervisionPlant technical serviceProduct sales

o Market researcho Product developmento Technical sales and customer technical service

The ChEngineer works closely with specialists in chemistry and other fields of engineering and pure science.


RESEARCH

Fundamental research

Exploratory research

Process research


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 physics, chemistry, mathematics AND principles of ChE

Specialises and becomes expert in one area, for example, mass transfer


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)

Other catalysts and conditions give different conversions

H2C

H2CCH2

CH2

CH2

H2C

HC

HCCH

CH

CH

HC

catalyst, 500 0F

500 lb/in2+ 3H2 ; conversion = 90%

octane number = 113.6


Another reforming reaction is isomerisation

For example, n−heptane may be converted to an isomeric heptane with a higher octane number

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

CH3CH2CH2CH2CH2CH2CH3 CH3CCH2CH2CH2CH2CH3

CH3

CH3

catalyst, 900 0F

500 lb/in2octane number = 93octane number = 0


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


PROCESS DEVELOPMENTAdmission 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 plantExpensive to build and operate, but saves much more money by eliminating uncertainties in the construction, start−up, and operation of the commercial plantAlso required to produce new product for market researchPilot plant must duplicate the proposed plant the proposed full−size plant

Planning the development programmeDesigning and building the pilot plantOperation of the pilot plantCorrelation, presentation and evaluation of the data obtained


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


Process Design includes the following major items:Process flow sheet showing all pieces of equipment, instrumentation and control, operating pressures, temperatures, flow ratesOverall mass balances, equipment−wise mass balances, yields of products, composition of all streamsEnergy balances for all units, including heat exchangers requirementsSpecification of pump capacities, flow, and pressure requirementsSpecification of size and configuration of chemical reactors andstorage tanksDetermination of optimum operating conditions for the mass transfer operations required for the separation and purification of raw materials and productsEstimation of utility requirements, such as steam, water, electricity and fuelEconomic evaluation with an estimate of capital investment and operating cost


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


PLANT DESIGN

Translation of results of Process Design Engineer complete plans and specifications construction of the plant

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


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


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 (tailor-made) OR may suggest a standard unit

Vendor employs many engineers in the development, design, and sale of her/his equipment


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


PRODUCTION SUPERVISION

Production Supervisor:Gets the new plant running to give Q and Q of the productChecks the daily recordImproves the plant operation (element of unknown in Design)Improves product Quality by removing contamination and reducing deteriorationReduces steam, water, power, materials requirementReduces labour costs by maintaining good labour relations, efficient methods, and workable safety practicesDevelops efficient maintenance procedures to ensure minimum shutdown for routine repairsSets up a procurement schedule to maintain adequate inventories of raw materials


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


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


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


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


PRODUCT DEVELOPMENT

Uses of new products and new uses of existing product

Applied research: solution of complex chemical and engineering problems

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


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


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)


Identification of future scenarios and selection of appropriate ones: Collaboration of Professional Bodies (I.I.Ch.E, and others) will helpLack of transport infrastructure and transport fuel: blocks interaction with the World Trade CommunityLack of electric power: puts the nation in uproarRole of renewable energy to be determined (hydro−power, wind−power, solarcells, biomass, etc.) vis-à-vis Coal, Natural Gas, Oil, Nuclear PowerModest quantity of proven Hydrocarbon reserves (≈ 30 × 109 ft3) may exhaust shortlyEnhancement 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 GasTransport fuel: efforts are needed to use Hydrogen in fuel cellsNuclear energy: ecologically attractive, but useless today because of public opposition and high investments required

Updated ENERGY POLICY is required URGENTLY


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 professionDealing with “trade−offs” between health risks and the cost of air cleaning is indeed a difficult task for politiciansSerious environmental problems: CO2 greenhouse effect global warmingIf 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


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 jointadvise 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



COMMUNICATIONS

Clear expression of technical ideas in oral and written communication

Often the major contact is with the Administrative ManagerOR 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


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/teamMust sell ideas effectively and tactfullyAny 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 groupsProduction Engineer must work closely with other Engineers and with the Unionised Labour ForceTechnical Services Engineer must work closely with the operators of the Process, carefully explaining the suggested process changesSales 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 !)



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


If you wish to find out MORE about the Chemical Process Industry, read on the following lines:1) Basic laws and processes of chemical technology2) Raw materials, fuel, and power for Chemical Process

Industry3) Water conditioning in Chemical Process Industry4) Catalysts and catalysis5) Explosives and propellants6) Industrial gases7) Industrial carbon8) Sulphur and sulphuric acid9) Hydrochloric acid and miscellaneous inorganic chemicals10) Nitrogen industries11) Phosphorous industries12) Salt and miscellaneous sodium compounds


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


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


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


Acknowledgements1st year B.Tech. (2006 entrants − ChE) students: suggested an INTRODUCTORY lecture on this topicProfessor Dibyendu Mukherjee (Head, Chemical Engineering Department, IIT Kharagpur): instantly supported the ideaMy present and past students: shared their valuable experiences. I learn from them more than I can teach themAll 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−solvingAll 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


Documents

Chemical Process Industry_ Chemical Engineering_ and Chemical Engineer