《化学工程设计技术》课程教学资源（参考资料，英文版）13 Introduction to Process Design Methodology

DESIGN METHODOLOGY GOAL Produce a design for a chemical plant that: 9 Is economically acceptable ◆ Is operable,,ie, Is safe → Is controllable Es reliable, and Els environmentally acceptable 1/31/99 Design Methdology -Intro

1/31/99 Design Methdology - Intro 1 DESIGN METHODOLOGY GOAL -- Produce a design for a chemical plant that: u Is economically acceptable and uIs operable, i.e., ðIs safe ðIs controllable ðIs reliable, and ðIs environmentally acceptable

What are the basic steps in designing a chemical process 1/31/99 Design Methdology -Intro

1/31/99 Design Methdology - Intro 2 What are the basic steps in designing a chemical process?

Determine Specifications Generate Alternate Conceptual Designs Design #1 Design #2: Design #3: 限限重重果聚果美重限 Evaluate Design Criteria 0 Y es Iterate OK? D one 1/31/99 Design Methdology -Intro

1/31/99 Design Methdology - Intro 3 Determine Specifications Generate Alternate Conceptual Designs Design #1 Design #2 Design #3 Evaluate Design Criteria OK? Yes Done No Iterate

DESIGN METHODOLOGY PHASES Q Phase I. Conceptual Design E Generate alternate designs E Select best based on performance indices Phase IL. Detailed design E Rigorous equipment design E Develop command and control strategy E Rigorous reliability and safety analysis Phase ill. Mechanical design 1/31/99 Design Methdology -Intro

1/31/99 Design Methdology - Intro 4 DESIGN METHODOLOGY PHASES u Phase I. Conceptual Design ðGenerate alternate designs ðSelect best based on performance indices uPhase II. Detailed Design ðRigorous equipment design ðDevelop command and control strategy ðRigorous reliability and safety analysis uPhase III. Mechanical Design

GENERATION OF ALTERNATE FLOWSHEETS BY HIERARCHICAL DECOMPOSITION Q Level 1: Choice of process type Q Level 2: Input-Output Structure Level 3: Recycle structure Level 4: Separation System synthesis Q Level 5: Heat and Power Network Synthesis Levels 2 through 5 will depend upon the choice of process type (Based on J.M. Douglas, Conceptual Design of Chemical Processes, McGraw-Hill. 1988 1/31/99 Design Methdology -Intro 5

1/31/99 Design Methdology - Intro 5 GENERATION OF ALTERNATE FLOWSHEETS BY HIERARCHICAL DECOMPOSITION uLevel 1: Choice of process type uLevel 2: Input-Output Structure uLevel 3: Recycle Structure uLevel 4: Separation System Synthesis uLevel 5: Heat and Power Network Synthesis Levels 2 through 5 will depend upon the choice of process type. (Based on J.M. Douglas, Conceptual Design of Chemical Processes, McGraw-Hill, 1988)

DESIGN CRITERIA ◆ Plant Capacity Q Product Purity or Composition Raw Materials or Feedstock availability ◆ Operability E Safety E Controllability AVailability E Environmental acceptability 1/31/99 Design Methdology -Intro

1/31/99 Design Methdology - Intro 6 DESIGN CRITERIA uPlant Capacity uProduct Purity or Composition uRaw Materials or Feedstock Availability uOperability ðSafety ðControllability ðAvailability ðEnvironmental Acceptability

EVAULATION INDICES ◆ Performance E Make capacity MEet product quality specs ◆F Profitability E DCFROR, ROL, Payout Time, etc TRansfer Price ◆ Operability E Minimum holdup of hazardous chemicals E Minimal complexity for safety and control 1/31/99 Design Methdology -Intro

1/31/99 Design Methdology - Intro 7 EVAULATION INDICES uPerformance ðMake capacity ðMeet product quality specs uProfitability ðDCFROR, ROI, Payout Time, etc. ðTransfer Price uOperability ðMinimum holdup of hazardous chemicals ðMinimal complexity for safety and control