Chemical Process DevelopmentChemical Process Development((Scale up issue in chemical industry)Scale up issue in chemical industry)

A. HisyamA. HisyamFaculty of Chemical and Natural Resources EngineeringFaculty of Chemical and Natural Resources Engineering

University Malaysia PahangUniversity Malaysia Pahang

ResourcesResources

E. Tirronen and T. Salmi, Chemical E. Tirronen and T. Salmi, Chemical Engineering Journal 91 (2003) 103-114Engineering Journal 91 (2003) 103-114

G. Donati and R. Paludetto, Catalysis Today G. Donati and R. Paludetto, Catalysis Today 34 (1997) 483-53334 (1997) 483-533

Chemical process development may have one of the following objectives

Design and construction of a new plant (grass root designing)

The design and development of a new process for an old process (modernizing an existing plant)

Modifications and additions to existing plant; usually carried out by the plant design group (process modification)

Phases of chemical process developmentPhases of chemical process development

Conceptual chemical phaseConceptual chemical phase Conceptual process development phaseConceptual process development phase Chemical and process development phase and process Chemical and process development phase and process

engineering phaseengineering phase Commissioning and start up phaseCommissioning and start up phase

Conceptual chemical phaseConceptual chemical phase

Identification of different chemical routesIdentification of different chemical routes Do you know how many ways we can produce eugenol Do you know how many ways we can produce eugenol

from clove oil?from clove oil? Generation of alternative chemical synthesis Generation of alternative chemical synthesis

pathways process schemespathways process schemes Find other possible ways to produce ethanol other than Find other possible ways to produce ethanol other than

fermentation from glucosefermentation from glucose Preliminary experimentsPreliminary experiments Preliminary process schemePreliminary process scheme Preliminary cost estimationPreliminary cost estimation

Conceptual process development phaseConceptual process development phase

Mass balanceMass balance Preliminary heat balancePreliminary heat balance Preliminary block diagram and flowsheetPreliminary block diagram and flowsheet Gantt Chart for schedulingGantt Chart for scheduling Production capacityProduction capacity Cost estimationCost estimation Preliminary safety evaluationPreliminary safety evaluation

Gantt chartGantt chart

Chemical and process development Chemical and process development phase and process engineering phasephase and process engineering phase

Dynamic reactor model generation and Dynamic reactor model generation and calculationcalculation

Dynamic separation model generation and Dynamic separation model generation and calculationcalculation

Scale up of process and equipmentScale up of process and equipment Control designControl design Dynamic utility calculationDynamic utility calculation Dynamic waste and emission calculationDynamic waste and emission calculation

Commissioning and start up phaseCommissioning and start up phase

Operator trainingOperator training TroubleshootingTroubleshooting Model validationModel validation OptimizationOptimization Process improvementsProcess improvements

Chemical and process engineeringChemical and process engineering

Process modelsProcess models

Kinetic modelsKinetic models Reactor modelsReactor models

Liquid phaseLiquid phase Gas phaseGas phase Interfacial fluxesInterfacial fluxes Solid-liquid reactionSolid-liquid reaction Catalytic reactionCatalytic reaction

Scale up issueScale up issue

Similarity principle says thatSimilarity principle says that

“For any two dynamically similar systems, all the dimensionless numbers necessary to describe the process have the same numerical value”.

Similarity Similarity

GeometricalGeometrical KinematicKinematic Dynamic Dynamic

Scale up procedureScale up procedure

Describe the process using a complete set of dimensionless numbers

Match these numbers at different scales

Dimensional analysisDimensional analysis

Dimensional analysis is a method for producing dimensionless numbers that completely describe the process. The analysis should be carried out before the measurements have been made, because dimensionless numbers essentially condense the frame in which the measurements are performed and evaluated. It can be applied even when the equations governing the process are not known.

Dimensional analysisDimensional analysis

Newton (Np)Newton (Np) Froude (Fr)Froude (Fr) Reynolds (Re)Reynolds (Re)

P - power consumption [ML2T-5] ρ - specific density of particles [M L-5] n - impeller speed [T-1] d - impeller diameter [L] g - gravitational constant [LT-2] η - dynamic viscosity [M L-1 T-1]

ndR

g

dnF

)dn(

PN

e

r

p

2

2

53

RésuméRésumé

Dimensional Analysis provides a powerful scientific technique for scale up

This technique is proven by a century of engineering applications

Rational scale-up should replace empirical approach

Thank youThank you

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