1/31/99 Choice of Process Type 1
DESIGN METHODOLOGY:
CHOICE OF PROCESS TYPE
GOAL -- Choose the process type appropriate
to the plant to be designed
1/31/99 Choice of Process Type 2
MAJOR PROCESS TYPES
uCONTINUOUS STEADY-STATE
eUsed for world-scale production of commodity chemicals
eLarge,centrally located plants
uBATCH
eUsed for small-scale production of high value-added chemicals
uJIT MINIPLANT
eUsed for on-site production of hazardous or difficult to transport
chemicals
Continuous Steady-State is the dominant process type.
1/31/99 Choice of Process Type 3
CONTINUOUS STEADY-STATE
(Continuous Steady State)
uWHEN USED
eLarge scale production (50 - 1000 MM Kg/yr)
eMostly for vapor/liquid processes
uADVANTAGES
eLow cost of production through economy of scale
eAllows on-site support infrastructure
uDISADVANTAGES
eLarge plant s often located in environmentally sensitive areas
eRequire storage and transportation of hazardous chemicals
eLarge on-site inventories of hazardous materials
eEmissions control a problem
1/31/99 Choice of Process Type 4
BATCH
uWHEN USED
eSmall scale production (1 - 10,000,000 Kg/yr)
eFouling materials
eRecipe driven process technology
uADVANTAGES
eFlexibility of operation
eMultiple product slates
eMaintenance of sterile conditions for bioprocessing
uDISADVANTAGES
eLabor intensive
eHigh cost of production
eComplex operations
eHigh inventories
1/31/99 Choice of Process Type 5
JIT MINIPLANTS
uWHEN USED
eIntermediate scale production (1000 - 1,000,000 Kg/yr)
eOn-site manufacture of hazardous or difficult to transport
materials
eSteady-state continuous operation
uADVANTAGES
eMinimal transportation and storage of hazardous materials
eTight control of emissions
uDISADVANTAGES
eLoss of economy of scale
eDesign methodology new and relatively untested
eOperation by non-expert personnel