1. LOGO Plantwide Control Structure Design of Tert-Amyl Methyl Ether (TAME) Process Thitima Tapaneeyapong and Montree Wongsri Department of Chemical Engineering Chulalongkorn University

2. Contents 2 Introduction 1 Literature Reviews 2 Objectives 3 Contribution 4 Scopes of research 5 Plantwide control structure design 1 2 3 Results 4 Summary 5 Process description Objective

3. Plantwide control structure design 3

4. tert-Amyl methyl ether Tert-Amyl Methyl Ether (TAME)  To be used as an oxygenate 4

5. tert-Amyl methyl ether process 5

6. tert-Amyl methyl ether reactions Three main reactions.  2M1B + MeOH TAME  2M2B + MeOH TAME  2M1B 2M2B 6

7. Design Objective To design and evaluate plantwide control structures of TAME production process by using new design procedure of Wongsri (2012). 7

8. Plantwide control structure design 8

9. 9

10. Step1 : Gather plant information 10  Operating pressure of reactive distillation 4 bar.  Operating pressure of methanol recovery column 2 bar.  Operating pressure of C5s column 10 bar. Control objectives:  Preserve TAME purity of 99.2 %.  Product capacity more than 217,408 tons/year.

11. Step2 : Plant Analysis 11 2.1 List manipulated variables (control degree of freedom, CDOF). 2.2 Identify material pathways. 2.3 Identify material quantifiers.

12. Number of Control degree of freedom 12 UnitManipulated variableQuantityCDOF Independent streamsFlow rate 33 Reactor Outlet flow Cooling flow 24 Distillation column Distillate flow, Bottom flow, Reflux flow, Reboiler heat removal Condenser heat input 315 Total degrees of freedom22

13. Material pathways 13 Isoamylene pathway

14. Material pathways 14 MeOH pathway

15. Material pathways 15 TAME pathway

16. Material pathways 16 Inert pathway

17. Step3 : Establish fixture plant 17  3.1 Keep the raw materials entered and reentered fixed.  3.2 Adjust the flow of exit material streams according to their accumulation (products, by-products, and inert).  3.3 Control the inventory of the rest of the component at their quantifiers.

18. Keep the raw materials entered and reentered fixed. 18 FC

19. Adjust the flow of exit material streams according to their accumulation 19 LC

20. Control the inventory of the rest of the component at their quantifiers 20 LC FC

21. Step4 : Handing the disturbances 21  4.1 Heat Disturbances. 4.1.1 Direct the thermal disturbances that are not directly related to quality to the environmental via the next and nearest exit points. 4.1.2 Manage the heat disturbance that related to quality in order to maintain the product specification constraints.  4.2 Material disturbances. The configuration of the control loops depend on the desired material pathways.

22. Handling thermal disturbances 22 TC dq1 dq3 dq4 dq5 TC dq2

23. Handling material disturbances 23 Handling Isoamylene FC

24. Handling material disturbances 24 Handling MeOH FC

25. Handling material disturbances 25 Handling TAME TC FC

26. Handling material disturbances 26 Handling Inert CC

27. Step 5 27 Design the control loops for the remaining control variables and/or adding enhanced controls, i.e. cascade, feed forward controls.

28. Adding ratio control loops 28 FC ratio FC ratio

29. Step 6,7 29 Step 6: Energy management via heat exchanger networks. Step 7: Optimize economics and/or improve control performance.

30. Step 8: Validate the designed control structures by rigorous dynamic simulation. 30

31. Performance test : C5s feed flow change 31

32. Performance test: Component changes 32

33. In summary  The new design procedure of Wongsri provides a simple methodology to design plantwide control structure.  The design procedure can be applied to tert-amyl methyl ether (TAME) production process.  This control structure provides effective control of the process; it can handle effectively disturbances, which came across the process and can be used in real plant. 33

34. LOGO