20 Heat Integration of Reactors

20.1 THE HEAT INTEGRATIONCHARACTERISTICS OF REACTORS

The heat integration characteristics of reactors depend bothon the decisions that have been made for the removal oraddition of heat and the reactor mixing characteristics. Inthe rst instance, adiabatic operation should be consideredsince this gives the simplest design.

1. Adiabatic operation. If adiabatic operation leads to anacceptable temperature rise for exothermic reactors or anacceptable decrease for endothermic reactors, then thisis the option that would normally be chosen. If this isthe case, then the feed stream to the reactor requiresheating and the efuent stream requires cooling. Theheat integration characteristics are thus a cold stream(the reactor feed) if the feed needs to be increasedin temperature or vaporized, and a hot stream (thereactor efuent) if the product needs to be decreased intemperature or condensed. The heat of reaction appears asincreased temperature of the efuent stream in the case ofexothermic reaction or decreased temperature in the case ofendothermic reaction.

2. Heat carriers. If adiabatic operation produces an unac-ceptable rise or fall in temperature, then the option dis-cussed in Chapters 7 and 13 is to introduce a heat carrier.The operation is still adiabatic, but an inert material is intro-duced with the reactor feed as a heat carrier. The heatintegration characteristics are as before. The reactor feedis a cold stream and the reactor efuent a hot stream. Theheat carrier serves to increase the heat capacity owrate ofboth streams.

3. Cold shot. Injection of cold fresh feed for exother-mic reactions or preheated feed for endothermic reac-tions to intermediate points in the reactor can beused to control the temperature in the reactor. Again,the heat integration characteristics are similar to adia-batic operation. The feed is a cold stream if it needsto be increased in temperature or vaporized and theproduct a hot stream if it needs to be decreased intemperature or condensed. If heat is provided to thecold shot or hot shot streams, these are additionalcold streams.

Chemical Process Design and Integration R. Smith 2005 John Wiley & Sons, Ltd ISBNs: 0-471-48680-9 (HB); 0-471-48681-7 (PB)

4. Indirect heat transfer with the reactor. Although indirectheat transfer with the reactor tends to bring about the mostcomplex reactor design options, it is often preferable to theuse of a heat carrier. A heat carrier creates complicationselsewhere in the owsheet. A number of options for indirectheat transfer were discussed earlier in Chapter 7.

The rst distinction to be drawn, as far as heat transferis concerned, is between the plug-ow and mixed-owreactor. In the plug-ow reactor shown in Figure 20.1, theheat transfer can take place over a range of temperatures.The shape of the prole depends on the following.

Inlet feed concentration Inlet temperature Inlet pressure and pressure drop (gas-phase reactions) Conversion Byproduct formation Heat of reaction Rate of cooling/heating Presence of catalyst diluents or changes in catalyst

through the reactor

Figure 20.1a shows two possible thermal proles forexothermic plug-ow reactors. If the rate of heat removal islow and/or the heat of reaction if high, then the temperatureof the reacting stream will increase along the length of thereactor. If the rate of heat removal is high and/or the heat ofreaction is low, then the temperature will decrease. Underconditions between the two proles shown in Figure 20.1a,a maximum can occur in the temperature at an intermediatepoint between the reactor inlet and exit.

Figure 20.1b shows two possible thermal proles forendothermic plug-ow reactors. This time, the temperaturedecreases for low rates of heat addition and/or high heatof reaction. The temperature increases for the reverseconditions. Under conditions between the proles shownin Figure 20.1b, a minimum can occur in the temperatureprole at an intermediate point between the inlet and exit.

The thermal prole through the reactor will, in mostcircumstances, be carefully optimized to maximize selec-tivity, extend catalyst life, and so on. Because of this, directheat integration with other process streams is almost nevercarried out. The heat transfer to or from the reactor isinstead usually carried out by a heat transfer intermediate.For example, in exothermic reactions, cooling might occurby boiling water to generate steam, which, in turn, can beused to heat cold streams elsewhere in the process or acrossthe site.

440 Heat Integration of Reactors

ReactorFeed

ReactorEffluent

Cooling/HeatingMedium

T

Length

(b) Endothermic reaction.(a) Exothermic reaction.Length

CoolingMedium

CoolingMedium

T

Low rate ofheat transfer

and/orhigh heat

of reaction

Reactor

Reactor

High rate ofheat transfer

and/orlow heat

of reaction

T

Length

HeatingMedium

Reactor

T

Length

Reactor

HeatingMedium

Figure 20.1 The heat transfer characteristics of plug-ow reactors.

By contrast, if the reactor is mixed-ow, then the reactoris isothermal. This behavior is typical of stirred tanks usedfor liquid-phase reactions or uidized-bed reactors used forgas-phase reactions. The mixing causes the temperature inthe reactor to be effectively uniform.

For indirect heat transfer, the heat integration character-istics of the reactor can be broken down into the followingthree cases.

a. If the reactor can be matched directly with otherprocess streams (which is unlikely), then the reactorprole should be included in the heat integrationproblem. This would be a hot stream in the case of anexothermic reaction or a cold stream in the case of anendothermic reaction.

b. If a heat transfer intermediate is to be used and the cool-ing/heating medium is xed, then the cooling/heatingmedium should be included and not the reactor pro-le itself. Once the cooling medium leaves an exother-mic reactor, it is a hot stream requiring cooling beforebeing returned to the reactor. Similarly, once the heatingmedium leaves an endothermic reactor, it is a cold streamrequiring heating before being returned to the reactor.

c. If a heat transfer intermediate is to be used but thetemperature of the cooling/heating medium is not xed,then both the reactor prole and the cooling/heatingmedium should be included. The temperature of theheating/cooling medium can then be varied withinthe content of the overall heat integration problem toimprove the targets, as described in Chapter 19.

In addition to the indirect cooling/heating within the reactor,the reactor feed is an additional cold stream, if it needs tobe increased in temperature or vaporized and the reactorproduct an additional hot stream, if it needs to be decreasedin temperature or condensed.

For the ideal-batch reactor, the temperature can beassumed to be uniform throughout the reactor at any instantin time. Figure 20.2a shows typical variations in tempera-ture with time for an exothermic reaction in a batch reac-tor. A family of curves illustrates the effect of increasingthe rate of heat removal and/or decreasing heat of reac-tion. Each individual curve assumes the rate of heat trans-fer to the cooling medium to be constant for that curvethroughout the batch cycle. Figure 20.2b shows typicalcurves for endothermic reactions. Again, each individualcurve in Figure 20.2b assumes the rate of heat additionfrom the heating medium to be constant throughout thebatch process.

Fixing the rate of heat transfer in a batch reactor is oftennot the best way to control the reaction. The heating orcooling characteristics can be varied with time to suit thecharacteristics of the reaction (see Chapter 14). Because ofthe complexity of batch operation and the fact that operationis usually small scale, it is rare for any attempt to be madeto recover heat from a batch reactor or supply heat byrecovery. Instead, utilities are normally used.

The heat duty on the heating/cooling medium is given by

QREACT = (HSTREAMS + HREACT ) (20.1)

Appropriate Placement of Reactors 441

Time

Increasing Rate of HeatTransfer and/or DecreasingHeat of Reaction

T

Decreasing Rate of HeatTransfer and/or Increasing

Heat of Reaction

Time

T

(a) Exothermic reaction. (b) Endothermic reaction.Figure 20.2 The heat transfer characteristics of batch reactors for a xed rate of heat transfer.

whereQREACT = reactor heating or cooling requiredHSTREAMS = enthalpy change between feed and

product streamsHREACT = reaction enthalpy (negative in the

case of exothermic reactions)

5. Quench. As discussed in Chapter 7, the reactor efuentmay need to be cooled rapidly (quenched). This can beby indirect heat transfer using conventional heat transferequipment or by direct heat transfer by mixing withanother uid.

If indirect heat transfer is used with a large temperaturedifference to promote high rates of cooling, then the coolinguid (e.g. boiling water) is xed by process requirements.In this case, the heat of reaction is not available at thetemperature of the reactor efuent. Rather, the heat ofreaction becomes available at the temperature of the quenchuid. Thus, the feed stream to the reactor is a cold stream,the quench uid is a hot stream, and the reactor efuentafter the quench is also a hot stream. This was discussedunder data extraction in Chapter 19.

The reactor efuent might require cooling by direct heattransfer because the reaction needs to be stopped quickly,or a conventional heat exchanger would foul, or the reactorproducts are too hot or corrosive to pass to a conventionalheat exchanger. The reactor product is mixed with a liquidthat can be recycled, cooled product, or an inert materialsuch as water. The liquid vaporizes partially or totally andcools the reactor efuent. Here, the reactor feed is a coldstream, and the vapor and any liquid from the quench arehot streams.

Now consider the placement of the reactor in terms ofthe overall heat integration problem.

20.2 APPROPRIATE PLACEMENTOF REACTORS

In Chapter 16, it was seen how the pinch takes onfundamental signicance in improving heat integration.Now consider the consequences of placing reactors indifferent locations relative to the pinch.

Figure 20.3 shows the background process representedsimply as a heat sink and heat source divided by the pinch.Figure 20.3a shows the process with an exothermic reactorintegrated above the pinch. The minimum hot utility can bereduced by the heat released by reaction.

By comparison, Figure 20.3b shows an exothermicreactor integrated below the pinch. Although heat is beingrecovered, it is being recovered into part of the process,which is a heat source. The hot utility requirement cannotbe reduced, since the process above the pinch needs at leastQHmin to satisfy its enthalpy imbalance.

There is no benet by integrating an exothermic reactorbelow the pinch. The appropriate placement for exothermicreactors is above the pinch1.

Figure 20.4a shows an endothermic reactor integratedabove the pinch. The endothermic reactor removes QREACTfrom the process above the pinch. The process above thepinch needs at least QHmin to satisfy its enthalpy imbalance.Thus, an extra QREACT must be imported from hot utilityto compensate. There is no benet by integrating anendothermic reactor above the pinch. Locally, it might seemthat a benet is being derived by running the reaction byrecovery. However, additional hot utility must be importedelsewhere to compensate.

By contrast, Figure 20.4b shows an endothermic reactorintegrated below the pinch. The reactor imports QREACTfrom part of the process that needs to reject heat anyway.Thus, integration of the reactor serves to reduce the

442 Heat Integration of Reactors

QCmin + QREACT

QHmin

QREACT

(b) Exothermic reactor integrated below the pinch.

ExothermicReactor

Pinch

T*

QCmin

QHmin - QREACT

QREACT

(a) Exothermic reactor integrated above the pinch.

Pinch

ExothermicReactor

T*

Figure 20.3 Appropriate placement of an exothermic reactor.

QCmin + QREACT

QHmin

QREACT

(b) Endothermic reactor integrated below the pinch.

EndothermicReactor

Pinch

T*

QCmin

QHmin + QREACT

QREACT

(a) Endothermic reactor integrated above the pinch.

Pinch

EndothermicReactor

T*

Figure 20.4 Appropriate placement of an endothermic reactor.

cold utility consumption by QREACT . There is an overallreduction in hot utility because, without integration, theprocess and reactor would require (QHmin + QREACT ) fromthe utility.

There is no benet by integrating an endothermicreactor above the pinch. The appropriate placement forendothermic reactors is below the pinch1.

20.3 USE OF THE GRAND COMPOSITECURVE FOR HEAT INTEGRATIONOF REACTORS

The above appropriate placement arguments assume that theprocess has the capacity to accept or give up the reactor heatduties at the given reactor temperature. A quantitative toolis needed to assess the capacity of the background process.For this purpose, the grand composite curve is used and thereactor prole treated as if it was a utility, as explained inChapter 16.

The problem with representing a reactor prole is that,unlike utility proles, the reactor prole might involveseveral streams. The reactor prole involves not onlystreams such as those for indirect heat transfer shown inFigure 20.1, but also the reactor feed and efuent streamsthat can be an important feature of the reactor heating andcooling characteristics. The various streams associated withthe reactor can be combined to form a grand compositecurve for the reactor. This can then be matched againstthe grand composite curve for the rest of the process. Thefollowing example illustrates the approach.

Example 20.1 Consider again the process for the manufactureof phthalic anhydride discussed in Example 19.1. The datawas extracted from the owsheet in Figure 19.10 and listed inTable 19.1. The composite curves and grand composite curve areshown in Figure 19.11.

a. Examine the placement of the reactor relative to the rest ofthe process.

b. Determine the utility requirements of the process.

Evolving Reactor Design to Improve Heat Integration 443

Solution

a. The stream data used to construct the grand composite curvein Figure 20.5a include those associated with the reactor andthose for the rest of the process. If the placement of the reactorrelative to the rest of the process is to be examined, thosestreams associated with the reactor need to be separated fromthe rest of the process. Figure 20.5b shows the grand compositecurves for the two parts of the process. Figure 20.5b is basedon Streams 1, 2, 6 and 7 from Table 19.1 and Figure 20.5c isbased on Streams 3, 4, 5, 8, 9, 10 and 11.

In Figure 20.5d, the grand composite curves for the reactorand that for the rest of the process are superimposed. Toobtain maximum overlap, one of the curves must be taken asa mirror image. It can be seen in Figure 20.5d that the reactoris appropriately placed relative to the rest of the process. Hadthe reactor not been appropriately placed, it would have beenextremely unlikely that the reactor would have been changedto make it so. Rather, to obtain appropriate placement ofthe reactor, the rest of the process would more likely havebeen changed.

b. Figure 20.6 shows the grand composite curve for all thestreams with a steam generation prole matched against it.The process cooling demand is satised by the generationof high-pressure (41 bar) steam from boiler feedwater, whichis superheated to 270C. High-pressure steam generation is

0 2000 4000 6000 8000 10,000 12,000

400350300250200150100500

0 2000 4000 6000 8000 10,000 12,000Reactor Rest of process

400350300250200150100500

T(C)

H(kW)

0 2000

400350300250200150100500

0 2000 4000 6000 8000 10,000 12,000

400350300250200150100500

T*(C)

Rest of process Reactor

(a)

(d)

(b) T(C) (c) T(C)

H(kW) H(kW)

H(kW)

Figure 20.5 The problem can be divided into two parts, oneassociated with the reactor and the other with the rest of theprocess (Tmin = 10C) and then superimposed.

preferable to low-pressure generation. There is apparently noneed for cooling water.

A greater amount of steam would be generated if the non-condensible vent was treated using catalytic thermal oxidation(see Chapter 25) rather than absorption. The exotherm fromcatalytic thermal oxidation would create an extra hot streamfor steam generation.

20.4 EVOLVING REACTOR DESIGN TOIMPROVE HEAT INTEGRATION

If the reactor proves to be inappropriately placed, then theprocess changes might make it possible to correct this. Oneoption would be to change the reactor conditions to bringthis about. Most often, however, the reactor conditionswill probably have been optimized for selectivity, catalystperformance, and so on, which, taken together with safety,materials-of-construction constraints, control, and so on,makes it unlikely that the reactor conditions would bechanged to improve heat integration. Rather, to obtainappropriate placement of the reactor, the rest of the processwould most likely be changed.

If changes to the reactor design are possible, then thesimple criteria introduced in Chapter 19 can be used todirect those changes. Heat integration will always benetby making hot streams hotter and cold streams colder.This applies whether the heat integration is carried outdirectly between process streams or through an intermediatesuch as steam. For example, consider the exothermicreactions in Figure 20.1a. Allowing the reactor to work athigher temperature improves the heat integration potentialif this does not interfere with selectivity or catalyst life orintroduce safety and control problems, and so on. However,if the reactor must work with a xed intermediate coolinguid, such as steam generation, then the only benet willbe a reduced heat transfer area in the reactor. The steambecomes a hot stream available for heat integration afterleaving the reactor. If the pressure of steam generationcan be increased, then there may be energy or heattransfer area benets when it is integrated with the restof the process.

Care should be taken when preheating reactor feedswithin the reactor using the heat of reaction. This isachieved in practice simply by passing the cold feedsdirectly to the reactor and allowing them to be preheatedby mixing with hot materials within the reactor. However,if the exothermic reactor is appropriately placed abovethe pinch and the feeds start below the pinch, then thepreheating within the reactor is cross-pinch heat transfer.In this case, feeds should be preheated by recoveryusing streams below the pinch before being fed to thereactor. This increases the heat generated within the reactor,and heat integration will benet from the increased heatavailable for recovery from the reactor.

444 Heat Integration of Reactors

0 2000 4000 6000 8000 10,000 12,000

400

350

300

250

200

150

100

50

T (C)

H(kW)

Superheat

BFW Preheat

Steam Generation

Figure 20.6 The grand composite curve for the whole process apparently requires only high-pressure steam generation fromboiler feedwater.

20.5 HEAT INTEGRATION OFREACTORS SUMMARY

The appropriate placement of reactors, as far as heatintegration is concerned, is that exothermic reactors shouldbe integrated above the pinch and endothermic reactorsbelow the pinch. Care should be taken when reactorfeeds are preheated by heat of reaction within thereactor for exothermic reactions. This can constitute cross-pinch heat transfer. The feeds should be preheated topinch temperature by heat recovery before being fed tothe reactor.

Appropriate placement can be assessed quantitativelyusing the grand composite curve. The streams associatedwith the reactor can be represented as a grand composite

curve for the reactor and then matched against the grandcomposite curve for the rest of the process.

If the reactor is not appropriately placed, then it is morelikely that the rest of the process would be changed tobring about appropriate placement rather than changingthe reactor. If changes to the reactor design are possible,then the simple criterion of making hot streams hotterand cold streams colder can be used to bring aboutbenecial changes.

REFERENCE

1. Glavic P, Kravanja Z and Homsak M (1988) Heat Integrationof Reactors: I. Criteria for the Placement of Reactors intoProcess Flowsheet, Chem Eng Sci, 43: 593.

Chemical Process Design and IntegrationContentsPrefaceAcknowledgementsNomenclatureChapter 1 The Nature of Chemical Process Design and Integration1.1 Chemical Products1.2 Formulation of the Design Problem1.3 Chemical Process Design and Integration1.4 The Hierarchy of Chemical Process Design and Integration1.5 Continuous and Batch Processes1.6 New Design and Retrofit1.7 Approaches to Chemical Process Design and Integration1.8 Process Control1.9 The Nature of Chemical Process Design and Integration SummaryReferences

Chapter 2 Process Economics2.1 The Role of Process Economics2.2 Capital Cost for New Design2.3 Capital Cost for Retrofit2.4 Annualized Capital Cost2.5 Operating Cost2.6 Simple Economic Criteria2.7 Project Cash Flow and Economic Evaluation2.8 Investment Criteria2.9 Process Economics Summary2.10 ExercisesReferences

Chapter 3 Optimization3.1 Objective Functions3.2 Single-variable Optimization3.3 Multivariable Optimization3.4 Constrained Optimization3.5 Linear Programming3.6 Nonlinear Programming3.7 Profile Optimization3.8 Structural Optimization3.9 Solution of Equations using Optimization3.10 The Search for Global Optimality3.11 Summary Optimization3.12 ExercisesReferences

Chapter 4 Thermodynamic Properties and Phase Equilibrium4.1 Equations of State4.2 Phase Equilibrium for Single Components4.3 Fugacity and Phase Equilibrium4.4 VaporLiquid Equilibrium4.5 VaporLiquid Equilibrium Based on Activity Coefficient Models4.6 VaporLiquid Equilibrium Based on Equations of State4.7 Calculation of VaporLiquid Equilibrium4.8 LiquidLiquid Equilibrium4.9 LiquidLiquid Equilibrium Activity Coefficient Models4.10 Calculation of LiquidLiquid Equilibrium4.11 Calculation of Enthalpy4.12 Calculation of Entropy4.13 Phase Equilibrium and Thermodynamic Properties Summary4.14 ExercisesReferences

Chapter 5 Choice of Reactor I Reactor Performance5.1 Reaction Path5.2 Types of Reaction Systems5.3 Reactor Performance5.4 Rate of Reaction5.5 Idealized Reactor Models5.6 Choice of Idealized Reactor Model5.7 Choice of Reactor Performance5.8 Choice of Reactor Performance Summary5.9 ExercisesReferences

Chapter 6 Choice of Reactor II - Reactor Conditions6.1 Reaction Equilibrium6.2 Reactor Temperature6.3 Reactor Pressure6.4 Reactor Phase6.5 Reactor Concentration6.6 Biochemical Reactions6.7 Catalysts6.8 Choice of Reactor Conditions Summary6.9 ExercisesReferences

Chapter 7 Choice of Reactor III Reactor Configuration7.1 Temperature Control7.2 Catalyst Degradation7.3 GasLiquid and LiquidLiquid Reactors7.4 Reactor Configuration7.5 Reactor Configuration for Heterogeneous Solid-Catalyzed Reactions7.6 Reactor Configuration from Optimization of a Superstructure7.7 Choice of Reactor Configuration Summary7.8 ExercisesReferences

Chapter 8 Choice of Separator for Heterogeneous Mixtures8.1 Homogeneous and Heterogeneous Separation8.2 Settling and Sedimentation8.3 Inertial and Centrifugal Separation8.4 Electrostatic Precipitation8.5 Filtration8.6 Scrubbing8.7 Flotation8.8 Drying8.9 Separation of Heterogeneous Mixtures Summary8.10 ExercisesReferences

Chapter 9 Choice of Separator for Homogeneous Fluid Mixtures I Distillation9.1 Single-Stage Separation9.2 Distillation9.3 Binary Distillation9.4 Total and Minimum Reflux Conditions for Multicomponent Mixtures9.5 Finite Reflux Conditions for Multicomponent Mixtures9.6 Choice of Operating Conditions9.7 Limitations of Distillation9.8 Separation of Homogeneous Fluid Mixtures by Distillation Summary9.9 ExercisesReferences

Chapter 10 Choice of Separator for Homogeneous Fluid Mixtures II Other Methods10.1 Absorption and Stripping10.2 LiquidLiquid Extraction10.3 Adsorption10.4 Membranes10.5 Crystallization10.6 Evaporation10.7 Separation of Homogeneous Fluid Mixtures by Other Methods Summary10.8 ExercisesReferences

Chapter 11 Distillation Sequencing11.1 Distillation Sequencing Using Simple Columns11.2 Practical Constraints Restricting Options11.3 Choice of Sequence for Simple Nonintegrated Distillation Columns11.4 Distillation Sequencing Using Columns With More Than Two Products11.5 Distillation Sequencing Using Thermal Coupling11.6 Retrofit of Distillation Sequences11.7 Crude Oil Distillation11.8 Distillation Sequencing Using Optimization of a Superstructure11.9 Distillation Sequencing Summary11.10 ExercisesReferences

Chapter 12 Distillation Sequencing for Azeotropic Distillation12.1 Azeotropic Systems12.2 Change in Pressure12.3 Representation of Azeotropic Distillation12.4 Distillation at Total Reflux Conditions12.5 Distillation at Minimum Reflux Conditions12.6 Distillation at Finite Reflux Conditions12.7 Distillation Sequencing Using an Entrainer12.8 Heterogeneous Azeotropic Distillation12.9 Entrainer Selection12.10 Trade-offs in Azeotropic Distillation12.11 Multicomponent Systems12.12 Membrane Separation12.13 Distillation Sequencing for Azeotropic Distillation Summary12.14 ExercisesReferences

Chapter 13 Reaction, Separation and Recycle Systems for Continuous Processes13.1 The Function of Process Recycles13.2 Recycles with Purges13.3 Pumping and Compression13.4 Simulation of Recycles13.5 The Process Yield13.6 Optimization of Reactor Conversion13.7 Optimization of Processes Involving a Purge13.8 Hybrid Reaction and Separation13.9 Feed, Product and Intermediate Storage13.10 Reaction, Separation and Recycle Systems for Continuous Processes Summary13.11 ExercisesReferences

Chapter 14 Reaction, Separation and Recycle Systems for Batch Processes14.1 Batch Processes14.2 Batch Reactors14.3 Batch Separation Processes14.4 Gantt Charts14.5 Production Schedules for Single Products14.6 Production Schedules for Multiple Products14.7 Equipment Cleaning and Material Transfer14.8 Synthesis of Reaction and Separation Systems for Batch Processes14.9 Optimization of Batch Processes14.10 Storage in Batch Processes14.11 Reaction and Separation Systems for Batch Processes Summary14.12 ExercisesReferences

Chapter 15 Heat Exchanger Networks I Heat Transfer Equipment15.1 Overall Heat Transfer Coefficients15.2 Heat Transfer Coefficients and Pressure Drops for Shell-and-Tube Heat Exchangers15.3 Temperature Differences in Shell-and-Tube Heat Exchangers15.4 Allocation of Fluids in Shell-and-Tube Heat Exchangers15.5 Extended Surface Tubes15.6 Retrofit of Heat Exchangers15.7 Condensers15.8 Reboilers and Vaporizers15.9 Other Types of Heat Exchange Equipment15.10 Fired Heaters15.11 Heat Transfer Equipment Summary15.12 ExercisesReferences

Chapter 16 Heat Exchanger Networks II Energy Targets16.1 Composite Curves16.2 The Heat Recovery Pinch16.3 Threshold Problems16.4 The Problem Table Algorithm16.5 Nonglobal Minimum Temperature Differences16.6 Process Constraints16.7 Utility Selection16.8 Furnaces16.9 Cogeneration (Combined Heat and Power Generation)16.10 Integration Of Heat Pumps16.11 Heat Exchanger Network Energy Targets Summary16.12 ExercisesReferences

Chapter 17 Heat Exchanger Networks III Capital and Total Cost Targets17.1 Number of Heat Exchange Units17.2 Heat Exchange Area Targets17.3 Number-of-shells Target17.4 Capital Cost Targets17.5 Total Cost Targets17.6 Heat Exchanger Network and Utilities Capital and Total Costs Summary17.7 ExercisesReferences

Chapter 18 Heat Exchanger Networks IV Network Design18.1 The Pinch Design Method18.2 Design for Threshold Problems18.3 Stream Splitting18.4 Design for Multiple Pinches18.5 Remaining Problem Analysis18.6 Network Optimization18.7 The Superstructure Approach to Heat Exchanger Network Design18.8 Retrofit of Heat Exchanger Networks18.9 Addition of New Heat Transfer Area in Retrofit18.10 Heat Exchanger Network Design Summary18.11 ExercisesReferences

Chapter 19 Heat Exchanger Networks V Stream Data19.1 Process Changes for Heat Integration19.2 The Trade-Offs Between Process Changes, Utility Selection, Energy Cost and Capital Cost19.3 Data Extraction19.4 Heat Exchanger Network Stream Data Summary19.5 ExercisesReferences

Chapter 20 Heat Integration of Reactors20.1 The Heat Integration Characteristics of Reactors20.2 Appropriate Placement of Reactors20.3 Use of the Grand Composite Curve for Heat Integration of Reactors20.4 Evolving Reactor Design to Improve Heat Integration20.5 Heat Integration of Reactors SummaryReference

Chapter 21 Heat Integration of Distillation Columns21.1 The Heat Integration Characteristics of Distillation21.2 The Appropriate Placement of Distillation21.3 Use of the Grand Composite Curve for Heat Integration of Distillation21.4 Evolving the Design of Simple Distillation Columns to Improve Heat Integration21.5 Heat Pumping in Distillation21.6 Capital Cost Considerations21.7 Heat Integration Characteristics of Distillation Sequences21.8 Heat-integrated Distillation Sequences Based on the Optimization of a Superstructure21.9 Heat Integration of Distillation Columns Summary21.10 ExercisesReferences

Chapter 22 Heat Integration of Evaporators and Dryers22.1 The Heat Integration Characteristics of Evaporators22.2 Appropriate Placement of Evaporators22.3 Evolving Evaporator Design to Improve Heat Integration22.4 The Heat Integration Characteristics of Dryers22.5 Evolving Dryer Design to Improve Heat Integration22.6 Heat Integration of Evaporators and Dryers Summary22.7 ExercisesReferences

Chapter 23 Steam Systems and Cogeneration23.1 Boiler Feedwater Treatment23.2 Steam Boilers23.3 Steam Turbines23.4 Gas Turbines23.5 Steam System Configuration23.6 Steam and Power Balances23.7 Site Composite Curves23.8 Cogeneration Targets23.9 Optimization of Steam Levels23.10 Site Power-to-heat Ratio23.11 Optimizing Steam Systems23.12 Steam Costs23.13 Choice of Driver23.14 Steam Systems and Cogeneration Summary23.15 ExercisesReferences

Chapter 24 Cooling and Refrigeration Systems24.1 Cooling Systems24.2 Recirculating Cooling Water Systems24.3 Targeting Minimum Cooling Water Flowrate24.4 Design of Cooling Water Networks24.5 Retrofit of Cooling Water Systems24.6 Refrigeration Cycles24.7 Process Expanders24.8 Choice of Refrigerant for Compression Refrigeration24.9 Targeting Refrigeration Power for Compression Refrigeration24.10 Heat Integration of Compression Refrigeration Processes24.11 Mixed Refrigerants for Compression Refrigeration24.12 Absorption Refrigeration24.13 Indirect Refrigeration24.14 Cooling Water and Refrigeration Systems Summary24.15 ExercisesReferences

Chapter 25 Environmental Design for Atmospheric Emissions25.1 Atmospheric Pollution25.2 Sources of Atmospheric Pollution25.3 Control of Solid Particulate Emissions to Atmosphere25.4 Control of VOC Emissions to Atmosphere25.5 Control of Sulfur Emissions25.6 Control of Oxides of Nitrogen Emissions25.7 Control of Combustion Emissions25.8 Atmospheric Dispersion25.9 Environmental Design for Atmospheric Emissions Summary25.10 ExercisesReferences

Chapter 26 Water System Design26.1 Aqueous Contamination26.2 Primary Treatment Processes26.3 Biological Treatment Processes26.4 Tertiary Treatment Processes26.5 Water Use26.6 Targeting Maximum Water Reuse for Single Contaminants26.7 Design for Maximum Water Reuse for Single Contaminants26.8 Targeting and Design for Maximum Water Reuse Based on Optimization of a Superstructure26.9 Process Changes for Reduced Water Consumption26.10 Targeting Minimum Wastewater Treatment Flowrate for Single Contaminants26.11 Design for Minimum Wastewater Treatment Flowrate for Single Contaminants26.12 Regeneration of Wastewater26.13 Targeting and Design for Effluent Treatment and Regeneration Based on Optimization of a Superstructure26.14 Data Extraction26.15 Water System Design Summary26.16 ExercisesReferences

Chapter 27 Inherent Safety27.1 Fire27.2 Explosion27.3 Toxic Release27.4 Intensification of Hazardous Materials27.5 Attenuation of Hazardous Materials27.6 Quantitative Measures of Inherent Safety27.7 Inherent Safety Summary27.8 ExercisesReferences

Chapter 28 Clean Process Technology28.1 Sources of Waste from Chemical Production28.2 Clean Process Technology for Chemical Reactors28.3 Clean Process Technology for Separation and Recycle Systems28.4 Clean Process Technology for Process Operations28.5 Clean Process Technology for Utility Systems28.6 Trading off Clean Process Technology Options28.7 Life Cycle Analysis28.8 Clean Process Technology Summary28.9 ExercisesReferences

Chapter 29 Overall Strategy for Chemical Process Design and Integration29.1 Objectives29.2 The Hierarchy29.3 The Final Design

Appendix A Annualization of Capital CostAppendix B Gas CompressionB.1 Reciprocating CompressorsB.2 Centrifugal CompressorsB.3 Staged Compression

Appendix C Heat Transfer Coefficients and Pressure Drop in Shell-and-tube Heat ExchangersC.1 Pressure Drop and Heat Transfer Correlations for the Tube-SideC.2 Pressure Drop and Heat Transfer Correlations for the Shell-SideReferences

Appendix D The Maximum Thermal Effectiveness for 12 Shell-and-tube Heat ExchangersAppendix E Expression for the Minimum Number of 12 Shell-and-tube Heat Exchangers for a Given UnitAppendix F Algorithm for the Heat Exchanger Network Area TargetAppendix G Algorithm for the Heat Exchanger Network Number of Shells TargetG.1 Minimum Area Target for Networks of 12 ShellsReferences

Appendix H Algorithm for Heat Exchanger Network Capital Cost TargetsIndex