FLOWSHEET DESIGN

PROCESS FLOWSHEET

• IS A DELIVERABLE FOR THE PROJECT

• IS A PRIMARY COMMUNICATION COMPONENT

• USED TO CALCULATE CAPITAL & OPERATING COST ESTIMATES

• USED TO DESCRIBE THE PROPOSED PROJECT

FLOWSHEETING

• SKILL IS USED BY ENGINEERING FIRMS TO WORK WITH CLIENTS ON POTENTIAL PROJECTS AND ACTUAL PROJECTS

• THIS METHOD IS GENERALLY APPLIED USING SIMULATORS

• FOR AN EXAMPLE SEE Chemical Engineering Research and Design, Volume 87, Issue 1, January 2009, Pages 36–46

FLOWSHEETING STEPS• A RIGOROUS

FLOW CHART FROM FIGURE 4.1 IN TEXT

• DETAIL DEPENDS UPON HOW MUCH DATA IS ACTUALLY AVAILABLE

SOURCES OF DATA

• PROCESS DATA FROM LIBRARY: Ullmann's Encyclopedia of Industrial Chemistry

• THE SRI PROCESS ECONOMICS PROGRAM (http://www.sriconsulting.com/PEP/home.html) WILL PROVIDE INFORMATION, BUT THIS IS FOR SUBSCRIBERS ONLY

USES OF FLOWSHEETING

• TO LEARN A PROCESS FOR A NEW ASSIGNMENT

• OPERATING PROCESSES HAVE DETAILED DESIGN DRAWINGS, BUT RARELY HAVE THE ORIGINAL PFD’S OR BLOCK FLOW DIAGRAMS

• OPTIMIZATION OF A PROCESS ALSO CAN BE MANAGED USING THE FLOWSHEETING METHODS

PROCESS OPTIMIZATION• EXAMPLE EXAMINES OPTIMUM

PROCESS ARRANGEMENT FOR OBTAINING BUTANOL, ETHANOL, AND ACETONE FROM GRAINS

Liu, J.; Fan, L. T.; Seib, P.; Friedler, F.; Bertok, B., Downstream Process Synthesis for Biochemical Production of Butanol, Ethanol, and Acetone from Grains: Generation of Optimal and Near-Optimal Flowsheets with Conventional Operating Units , Biotechnol. Prog.; (Article); 2004; 20(5); 1518-1527.

OPTIMIZATION RESULTS• RESULTS ARE IN TERMS OF

OPERATING COSTSLiu, J.; Fan, L. T.; Seib, P.; Friedler, F.; Bertok, B., Downstream Process Synthesis for Biochemical Production of Butanol, Ethanol, and Acetone from Grains: Generation of Optimal and Near-Optimal Flowsheets with Conventional Operating Units , Biotechnol. Prog.; (Article); 2004; 20(5); 1518-1527.

EXAMPLES OF OTHER USES OF FLOWSHEETING

• Palaniappan, C.; Srinivasan, R.; Tan, R. B., Expert System for the Design of Inherently Safer Processes. 2. Flowsheet Development Stage, Ind. Eng. Chem. Res.; (Article); 2002; 41(26); 6711-6722.

• Urmila M. Diwekar, H. Christopher Frey, Edward S. Rubin, Synthesizing optimal flowsheets: applications to IGCC system environmental control , Ind. Eng. Chem. Res.; 1992; 31(8); 1927-1936.

DESIGN GUIDELINES

• SIMPLICITY– SIMPLE PROCESSES ARE MORE

RELIABLE THAN COMPLEX PROCESSES– SIMPLE PROCESSES CAN BE MODIFIED

TO ADD COMPLEXITY IF THAT HAS A SIGNIFICANT ECONOMIC ADVANTAGE

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RAW MATERIALS FACTORS• AVAILABILITY IN THE FORM REQUIRED

– IS RAW MATERIAL CURRENTLY PRODUCED IN NECESSARY FORM AND QUANTITIES?

• AMOUNT OF PREPROCESSING AVAILABLE– CAN INITIAL STEPS BE COMPLETED AT

SUPPLIER?– IS IT COST EFFECTIVE TO DO PREPARATION

ON SITE?

• COST– IS THE CURRENT PRICE STABLE?– CAN CURRENT PRICE BE CONTROLLED BY

CAPTIVE PURCHASE?

BY-PRODUCT CONSIDERATIONS

• CAN BY-PRODUCTS BE MARKETED OR WILL ALTERNATE DISPOSAL BE REQUIRED.

• IF POSSIBLE, CHOOSE THE PROCESS CONFIGURATION THAT AVOIDS PRODUCING BY-PRODUCTS

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ENERGY CONSUMPTION

• ENERGY COSTS ARE GENERALLY A MAJOR PORTION OF THE OPERATING COST

• NORMALLY SELECT THE PROCESS CONFIGURATION WITH THE LOWER ENERGY COSTS

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DETAIL OF INFORMATION AVAILABLE

• COMMERCIAL PROCESSES TEND TO HAVE THE MOST COMPLETE INFORMATION BASE

• PROCESSES IN DEVELOPMENT CAN BE USED TO OBTAIN SOME OF THE NECESSARY DESIGN DATA

• CONCEPTUAL PROCESSES HAVE LOWEST LEVELS OF CERTAINTY

OTHER DESIGN FACTORS• PATENTS AND ROYALTIES – CAN ADD

TO THE OPERATING COSTS• ENVIRONMENTAL ASPECTS• SAFETY CONSIDERATIONS

– MSDS DATA FOR ALL PURE STREAMS (http://hazard.com/msds/)

– ESTIMATED RISKS FOR MIXED STREAMS BASED ON MSDS DATA – USE MOST EXTREME PURE COMPONENT DATA UNLESS MIXTURE PROPERTIES ARE AVAILABLE

DEVELOPMENT OF BFD• FIRST LEVEL IS THE BLOCK FLOW

DIAGRAM (BFD)• EACH AREA SHOULD BE DEFINED BY

FUNCTION – EXACT PROCESS IS NOT NECESSARILY

DEFINED– EQUIPMENT TYPES ARE NOT SPECIFIED

• CONNECTING FLOWS SHOULD INCLUDE PRESSURES, TEMPERATURES AND COMPOSITIONS, WHEN AVAILABLE

– UTILITIES ARE NOT TYPICALLY INCLUDED

• ALL FLOWS SHOW FINAL DEPOSITION – TERMINAL DESIGNATIONS

TYPICAL BFD

• http://www.ocrwm.doe.gov/documents/rpa140m3_a/figures/fig4_3.htm

PFD DEVELOPMENT

• PROCESS FLOW DIAGRAM INCLUDES MASS AND ENERGY BALANCE DATA, SPECIFIC PROCESSES AND EQUIPMENT

• SIMSCI®, SUPERPRO®, ASPEN® , AND OTHER PROCESS SIMULATORS PRODUCE FLOWSHEET DIAGRAMS

– NEED CHEMICAL AND THERMOPHYSICAL DATA TO COMPLETE THIS PART OF THE DESIGN

• BASE CASE IS CREATED FOR USE IN SUBSEQUENT OPTIMIZATION

PFD DEVELOPMENT

• FLOWSHEETS MAY HAVE SINGLE OR PARALLEL TRAINS

• BATCH AND SEMI-BATCH STEPS ARE INCLUDED

– FOR BATCH OPERATIONS, AVERAGED FLOWRATES ARE PROVIDED FOR THE OVERALL MASS BALANCES FOR SIMSCI

– FOR BATCH OPERATIONS, MAXIMUM FLOWRATES ARE PROVIDED FOR DESIGN OF THE FACILITIES WITH SIMSCI®

• WITH SUPERPRO®, BATCH IS THE BASE METHOD

PFD EXAMPLE

USES OF PFD RESULTS

• AS THE BASIS FOR CAPITAL COST ESTIMATES

– SPECIFICATIONS FOR PURCHASING EACH EQUIPMENT ITEM ARE DEVELOPED DURING THE EQUIPMENT DESIGN

– SOME PROGRAMS (SUPERPRO®) INCLUDE EQUIPMENT COSTS

– CAPITAL COSTS FOR EQUIPMENT ARE USED AS THE BASE FOR CALCULATION OF ALL OTHER INSTALLED CAPITAL COMPONENTS FOR THE PROJECTS

APPLICATION OF PFD RESULTS• OPERATING COST ESTIMATES.

• RAW MATERIAL YIELDS ARE DETERMINED DURING THE DESIGN PHASE

• UTILITY CONSUMPTION IS DETERMINED DURING THE DESIGN PHASE

• LABOR FUNCTIONS CAN BE ASSIGNED TO PROVIDE A BASIS FOR LABOR CALCULATIONS

OPTIMIZATION ANALYSIS

• EVALUATED USING THE BASE CASE AS A REFERENCE

• CAPITAL COSTS ARE ADJUSTED FOR PARTICULAR EQUIPMENT ITEMS

• OPERATING COST VARIATIONS FOR SPECIFIC PROCESSES CAN BE EVALUATED

http://instruct1.cit.cornell.edu/courses/ipm444/03Economics/Optimization.gif

POSSIBLE FLOWSHEET ERRORS

• TAKEN FROM Project Evaluation in the Chemical Process Industries, J. Frank Valle-Riestra, McGraw-Hill, 1983, p. 169

• MISSING TERMINAL DESIGNATIONS – LINES THAT COME FROM NOWHERE AND GO NOWHERE ARE UNACCEPTABLE

• MISSING STORAGE TANKS FOR RAW MATERIALS AND FINISHED GOODS

• IN-PROCESS STORAGE TANKS FOR SURGES, SAMPLING, OFF-SPECIFICATION, AND OTHER INVENTORY FUNCTIONS

• MISSING REDUNDANT EQUIPMENT – IN-PLACE SPARES

OVERLOOKED ITEMS• AUXILIARY EQUIPMENT

• VACUUM SYSTEMS• INERTING SYSTEMS

• START-UP FACILITIES• RECYCLE LINES• SURGE TANKS

• EMERGENCY AND SAFETY DEVICES• PRESSURE RELIEF SYSTEMS• SCRUBBERS• FIRE SUPPRESSION EQUIPMENT• EMERGENCY GENERATORS

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TYPICAL RELIEF SYSTEM• http://www.plastomatic.com/relief-

diagram.gif

OVERLOOKED ITEMS

• MAINTENANCE FACILITIES• BLOW DOWN LINES• HIGH POINT VENTS• LOW POINT DRAINS• ISOLATION VALVES AND BYPASSES

• GENERAL USE UTILITIES• WASTE DISPOSAL FACILTIES

• DRAINS TO PROCESS SEWERS• DRAINS TO STORM SEWERS

EXAMPLE OF THE FINAL RESULT

Competitive Rankings - 2009 Cost Basis Cl2 Production

Status Plant TypeCapacity (St

Cl)Cash Cost per

Co-Ton

Formosa Plastics Point Comfort, TX Membrane 870 105.2

Bayer Corp Baytown, TX Membrane 550 107.6

Dow Chemical Freeport, TX Membrane 540 108.8

New GGC Proj Plaquemine Membrane 450 109.2

PPG Lake Charles, LA Membrane 275 116.4

New ShinTech Post Expansion Plaquemine, LA Membrane 1000 116.8

PPG Lake Charles, LA Diaphragm 1100 123.7

Current ShinTech Plaquemine, LA Membrane 300 123.7

Dow Chemical Plaquemine Diaphragm 1070 127.8

Westlake CA&O Calvert City, KY Membrane 205 131.7

Olin Corp Niagara Falls, NY Membrane 250 131.9

New GGC Proj L Charles Membrane 450 133.9

Current GGC Current Plaquemine Diaphragm 450 135.2

Sunbelt Corp. (Olin-PolyOne) McIntosh, AL Membrane 290 139.3

New GGC Proj L Charles Membrane 250 140.4

Basic Chemicals Geismar, LA Membrane 215 149.2

Occidental Corpus Christi, TX Diaphragm 650 150.6

Basic Chemicals Wichita, KS Diaphragm 198 156.4

Occidental Convent, LA Diaphragm 389 165.3

Occidental LaPorte, TX Diaphragm 580 168.4

Occidental Niagara Falls, NY Diaphragm 335 168.5

Occidental Taft, LA Diaphragm 540 168.6

Olin Corp McIntosh, AL Diaphragm 402 171.2

Basic Chemicals Geismar, LA Diaphragm 268 179.1

FROM T. PAVONE – DETAILS TO FOLLOW