dear all,
firstly, very thanks to Art Montemayor for providing information to me.
but i still got some problems:
since methanator is adiabatic single bed reactor, the temperature rise will be unacceptable high due to high exorthemic reaction.
now my question is:
(i) is it possible for multibed reactor or shell and tubes reactor applied on methanation process to make it become isothermal operation?
(ii) if possible, then is the reactor consists of internal heat exchanger or external heat exchanger?
(iii) also where can i find the kinetic data for methanation process?
i had search through the synetix website, it provide the information about the methanation catalyst only (nickel based catalyst), but without kinetic data, it is hard for me to design.
hope anyone can help me as soon as possible.
thanks
|
Methanator - Help Again
Started by Guest_ahboon_*, Oct 09 2003 01:43 PM
2 replies to this topic
Share this topic:
#1 Guest_ahboon_*
Posted 09 October 2003 - 01:43 PM
#2
Posted 09 October 2003 - 03:52 PM
Ahboon:
This is not a direct answer to your questions, but I think you may find some useful information at this web site:
www.synetix.com/refineries/pdfs/manuals/700W.pdf
This is not a direct answer to your questions, but I think you may find some useful information at this web site:
www.synetix.com/refineries/pdfs/manuals/700W.pdf
#3
Posted 09 October 2003 - 11:14 PM
Ahboon:
Milton Beychok's website recommendation is just the ticket you needed to learn further points about the methanation process.
I suspect that you are having a problem debating about an isothermal reactor for the methanation step because of your misunderstanding of what an adiabatic reactor does and how it works. Your comments seem to indicate that you expect an accumulation of heat in an adiabatic reactor. This is not what happens. The high exothermic heat generated by the reactants is carried out by the products that are exiting under a steady state. This is NOT a batch reactor where the products remain in the vessel. Of course, there is an increase in operating temperature in accordance with the stabilized temperature reached due to the reaction. The higher the amount of reactant CO & CO2, the higher the ultimate stabilized temperature in the reactor. The Nickel catalyst is a rugged catalyst and can take the high temperature operation.
Believe me, you are wasting your time debating about using an isothermal reactor. There is no need to use multiple catalyst beds. This is a once-in-once-out process where the reaction essentially goes to completion with the excess amount of H2 present. The space velocity is used to design the size of the vessel - as you should know from your theory lectures.
Without trying to belittle your effort, I believe you should know that this Methanator design is probably the easiest design in an Ammonia process plant. You don't have to worry about multi-beds, intercoolers, catalyst regeneration, elaborate temperature controls, side streams, etc. The catalyst just sits there and works - period.
Good luck on putting your design together.
Milton Beychok's website recommendation is just the ticket you needed to learn further points about the methanation process.
I suspect that you are having a problem debating about an isothermal reactor for the methanation step because of your misunderstanding of what an adiabatic reactor does and how it works. Your comments seem to indicate that you expect an accumulation of heat in an adiabatic reactor. This is not what happens. The high exothermic heat generated by the reactants is carried out by the products that are exiting under a steady state. This is NOT a batch reactor where the products remain in the vessel. Of course, there is an increase in operating temperature in accordance with the stabilized temperature reached due to the reaction. The higher the amount of reactant CO & CO2, the higher the ultimate stabilized temperature in the reactor. The Nickel catalyst is a rugged catalyst and can take the high temperature operation.
Believe me, you are wasting your time debating about using an isothermal reactor. There is no need to use multiple catalyst beds. This is a once-in-once-out process where the reaction essentially goes to completion with the excess amount of H2 present. The space velocity is used to design the size of the vessel - as you should know from your theory lectures.
Without trying to belittle your effort, I believe you should know that this Methanator design is probably the easiest design in an Ammonia process plant. You don't have to worry about multi-beds, intercoolers, catalyst regeneration, elaborate temperature controls, side streams, etc. The catalyst just sits there and works - period.
Good luck on putting your design together.
Similar Topics
MethanatorStarted by Guest_jigs1403_* , 17 Aug 2010 |
|
|
||
MethanatorStarted by Guest_ELI_* , 06 Feb 2008 |
|
|
||
Methanator - HelpStarted by Guest_ahboon_* , 08 Oct 2003 |
|
|
||
MethanatorStarted by Guest_Alejandro Torres_* , 29 May 2003 |
|
|