Methanol Converter Types

1. Gerard B. Hawkins Managing Director

2. • Quench Converter • ARC Converter • Tube Cooled • Toyo MRF-Z • Adiabatic Beds

3. Exit Catalyst Discharge Chute Catalyst Discharge Chute Manway Manway Inlet Inert Balls

5. Vessel Wall Shot Pipe Sparge Pipe Sparge Holes Mesh

6. 180 200 220 240 260 280 300 320 0 2 4 6 8 10 Temperature (°C) MethanolConcentration(mol%) Max Rate Curve Methanol Equilibrium

7. MUG Flash Drum Separator

8. • Benefits are ◦ Simple ◦ Reliable ◦ Well proven ◦ Capacity up to 3000 mtpd • Recover heat into saturator circuit • The catalyst doesn’t see all the gas. • Poor catalyst loading can lead to cold core developing

9. • Significant flow mal-distribution • Some zones are cold ◦ Can lose reaction • Some zones are hot ◦ High byproducts levels ◦ High rate of catalyst deactivation

10. Cool NormalNormal Catalyst density Low flow

11. • It is not caused by the quench lozenges being poor distributors of the cool incoming gas. • The reverse is true - the lozenges are very good distributors. • The problem is that voidage variations across the bed can cause varying flows down different parts of the reactor. • ARC retrofit developed to overcome problem.

12. Catalyst Support Plates Individual / Separate Catalyst Beds Gas Mixing System

13. x x xx x x x xx x x xx x x x xx x x x xx x x x xx x x x xx x x x xx x x x xx x x x xx x x xx x x x xx x x x xx x C a t aly s t be d

14. Inlet Temperature Exit Temperature Bed 3 237 °C Bed 1 223 °C Bed 4 230 °C Bed 3 270 °C Bed 1 270 °C Bed 2 223 °C Bed 4 260 °C Bed 2 270 °C Bed 3 261 °C Bed 1 251 °C Bed 4 269 °C Bed 3 289 °C Bed 1 291 °C Bed 2 262 °C Bed 2 301 °C * Figures in red are from current operating records (Sept. '96) * Figures in black are from ARC design case

15. Temperature % Methanol Equilibrium Line Quench Converter ARC Converter Increase in Methanol %

16. 0 10 20 30 40 50 0 50 100 150 200 temperature stand. dev. °C %increaseinby-products

17. QCC + ICI 51-7 ARC + ICI 51-7 Ethanol 200 69 ppm Propanol 71 28 ppm Butanol 71 33 ppm MEK 13 <5 ppm Decane C10 2.6 0.9 ppm Undecane C11 1.8 0.6 ppm Dodecane C12 1.2 0.4 ppm Tridecane C13 0.7 0.3 ppm Comp A Comp A

18. 0 200 400 600 800 1,000 1,200 1,400 1,400 1,450 1,500 1,550 1,600 1,650 Days on line Production(te/day)

19. Key features improved gas mixing no penalty on pressure drop better utilisation of the converter volume minimise the by-product levels

20. Arc Revamp Catalyst Loading Lozenge removal Converter inspection Fit ARC internals Catalyst loading Bed 5 Bed 4 Bed 3 Bed 2 Bed 1 0 7 14 21 activity days

21. • ARC converters have exhibited an instability • This is highlighted by inlet and outlet temperatures varying as per a sine wave • Feedback occurs over warm loop interchanger • Normally stable but can become unstable ◦ Leads to loss of strike in converter • Action is to reduce circulation rate

22. Manway Outlet Manway Inlet Catalyst Discharge Port

23. Heat Recovery Unit Crude Crude Cooler Loop Interchanger Syn Gas Purge

25. • Cheaper loop with heat transfer and reaction • Smooth catalyst temperature profile • Good catalyst utilisation • Mechanically simple • All converter effluent available at high temperature ◦ Can be used to heat saturator water

26. • Mixing shall be effective • Mixer should ◦ either not impede loading ◦ or be easy to install and remove. • Mixer should enhance safe operation and be mechanically robust. • Leakage of gas bypassing mixer should be minimized.

28. Steam Outlet Central Pipe Catalyst Loading Gas Inlet Gas Outlet & Catalyst Unloading BFW Inlet Cooling Tube Catalyst Inert Balls

29. Outlet Collector Scallops Adiabatic Beds Cooled Bed Cooling Tube

30. 180 200 220 240 260 280 300 320 3 4 5 6 7 8 9 10 Temperature (°C) MethanolConcentration(mol%) Max Rate Curve Methanol Equilibrium

31. • 28-32 Bara steam raised • Good approach to equilibrium • Low pressure drop, 0.5 to 0.75 bar • Catalyst discharge complex • Small number of tubes (c.f. Lurgi converter)

33. Crude Crude Cooler Loop Interchanger Syn Gas Purge Steam

35. • Cross flow means high heat transfer coefficient ◦ Smaller surface area • Good utilisation of shell volume • Raised steam at between 30-40 bara • But ◦ Costly (not as expensive as Uhde/Lurgi) ◦ Large interchanger required ◦ Pressure is slightly lower than Uhde/Lurgi

36. Casale Horizontal Adiabatic Converter

38. • All the gas sees all of the catalyst • Cheap vessels - can be spherical • Vessels can be designed the same ◦ Reduces CAPEX • But ◦ Large loop interchanger ◦ Multiple vessels (excluding Casale’s Horizontal Converter) ◦ Beds are shallow and so mal distribution can be a problem

39. Relative Catalyst Volumes Base Case 2800 te/day plant (Chile 3) Fixed circulation rate (recycle ratio = 4.2) Reactor Catalyst Volume (m3) ARC 242 TCC 175 SRC 150

40. • Loop pressurised to 7 bar with nitrogen • Heated to 180°C • Add small amount of H2 for calibration • Heat to give peak temperature of 220°C • Add hydrogen to 2% • Monitor temperatures • When exotherm profile moves through bed start soak • Increase H2 and temperature

41. • Similar to Reduction • Use air instead • Again exothermic • Also requires soak • Can not fully guarantee full oxidation • Procedure is available

42. Process Information Disclaimer Information contained in this publication or as otherwise supplied to Users is believed to be accurate and correct at time of going to press, and is given in good faith, but it is for the User to satisfy itself of the suitability of the Product for its own particular purpose. GBHE gives no warranty as to the fitness of the Product for any particular purpose and any implied warranty or condition (statutory or otherwise) is excluded except to the extent that exclusion is prevented by law. GBHE accepts no liability for loss or damage resulting from reliance on this information. Freedom under Patent, Copyright and Designs cannot be assumed.

Methanol Converter Types

Methanol Converter Types

Recomendados

Más contenido relacionado

Was ist angesagt?

Was ist angesagt?(20)

Similar a Methanol Converter Types

Similar a Methanol Converter Types(20)

Más de Gerard B. Hawkins

Más de Gerard B. Hawkins(20)

Último

Último(20)

Methanol Converter Types