1 / 21

Hierarchy of Decisions

Hierarchy of Decisions. LEVEL 3. :. purge. reactor. separator. products. feeds. Liquid ? Liquid / Vapor ? Vapor ?. LEVEL 4. :. 1 ) Liquid. LEVEL 3. reactor. liquid separation system. liquid. products. feeds. Liquid recycle. purge. LEVEL 4. :. 2 ) Liquid / Vapor.

anais
Download Presentation

Hierarchy of Decisions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Hierarchy of Decisions

  2. LEVEL 3 : purge reactor separator products feeds Liquid ? Liquid / Vapor ? Vapor ?

  3. LEVEL 4 : 1 ) Liquid LEVEL 3 reactor liquid separation system liquid products feeds Liquid recycle

  4. purge LEVEL 4 : 2 ) Liquid / Vapor Vapor Recovery system vapor gas recycle vapor 35C Phase Split liq. liq. reactor liquid separation system liquid products feeds Liq. recycle LEVEL 3

  5. purge LEVEL 4 : 3 ) Vapor Vapor Recovery system vapor gas recycle 35C Phase Split liquid liquid vapor reactor liquid separation system products feeds Liquid recycle LEVEL 3

  6. LOCATIONS OF VAPOR RECOVERY SYSTEM Gas Recycle Purge 2 1 3 vapor from phase split 1 ) The purge stream 2 ) The gas-recycle stream 3) The flash vapor stream 4 ) None

  7. RULES FOR PLACING THE VAPOR RECOVERY SYSTEM 1 ) Place the vapor recovery system on the purge stream if significant amounts of valuable materials are being lost in the purge. 2 ) Place the vapor recovery system on the gas-recycle stream if materials that are deleterious to the reactor operation (catalyst poisoning, etc.) are present in this stream or if recycling of some components degrades the product distribution. 3 ) Place the vapor recovery system on the flash vapor stream if both 1 ) and 2 ) are valid. 4 ) Do not use a vapor recovery system if neither 1 ) nor 2 ) are important.

  8. TYPE OF VAPOR RECOVERY SYSTEM 1 ) Condensation - low. T and/or high P 2 ) Absorption 3 ) Adsorption 4 ) Membrane separation 5 ) Reaction ADJUST MATERIAL BALANCE ?

  9. DECISION IN SYNTHESIZING LIQUID SEPARATION SYSTEM 1. How should light ends be removed, if they might contaminate the product ? 2. What should be the destination of light end ? 3. Do we recycle components that from azeotropes with reactants, or do we split the azeotropes ? 4. What separations can be made by distillation ? 5. What sequence of columns do we use ? 6. How should we accomplish separations if distillation is not feasible ?

  10. 1 ) ALTERNATIVES FOR LIGHT-ENDS REMOVAL  Phase Splitter — T and/or P Partial Condenser on Product Column   Pasteurization Section on Product Column   a Stabilizer Column before the Product Column  Lower cost Higher cost lights    lights lights product product product

  11. 2 ) DESTINATION OF LIGHT ENDS a ) vent or flare stacks - if light ends have very little value. b ) fuel - if light ends are flammable. c ) vapor recovery system - if light ends are valuable. 3 ) AZEOTROPES WITH REACTANTS 4 ) APPLICABILITY OF DISTILLATION 5 ) SEQUENCING OF SIMPLE COLUMNS 6 ) COMPLEX COLUMNS

  12. Purge Compressor H2, CH4 Reactor Flash Toluene Benzene H2, CH4 Recycle Product Stablizer Diphenyl

  13. Process Simulation Run ChemCAD to obtain M&E balance data !

  14. ECONOMIC POTENTIAL AT LEVEL 4 EP4 = EP3 - annual purge loss - annualized distillation costs - annualized vapor recovery costs 2106 1106 $/yr 0 -1106 -2106 -3106 0.2 0.4 0.6 0.1 0.3 0.5 0.7

  15. 2 ) DESTINATION OF LIGHT ENDS a ) vent or flare stacks - if light ends have very little value. b ) fuel - if light ends are flammable. c ) vapor recovery system - if light ends are valuable. 3 ) AZEOTROPES WITH REACTANTS 4 ) APPLICABILITY OF DISTILLATION 5 ) SEQUENCING OF SIMPLE COLUMNS 6 ) COMPLEX COLUMNS

  16. A B C Design 1 : Direct Sequence

  17. A C B Design 2 : Indirect Sequence

  18. A B C Design 3 : Side-stream rectifier

  19. A B C Design 4 : Side-stream Stripper

  20. A A , B B B , C C Design 5 Prefractionator arrangement

  21. A A B B C C Design 6Design 7 side stream

More Related