3 replies to this topic

[TONYTHEREXOR]

hi,

I would like to have information about the hydrotreating process control (the reactor more specificaly). What's the best way to control this process?

thank you

[USR]

Though your question is not very specific,i would like to give you some points regarding the hydrotreater reactor:
1.The basic thing is that hydrotreating reactions are taking place in the presence of hydrogen,these reactions typically in a refinery are hydrodesulfurisation,hydrodenitrification,dehydrohalogenation etc.The process licensor specifies the reactor pressure and reactor temperature for these favourable reactions to take place.So from control point of view these are your process variables.
2.All these catalyst based reactors are designed for a specific LHSV(Liquid Hourly Space Velocity)
3.As hydrotreating reactions are exothermic you must have a quench control valve to prevent any thermal runaway condition.
For controlling the reactor inlet temperature as per licensor guidelines you may a heater and rector pressure could be controlled by a back pressure controller.
4.You may also want to monitor the pressure drop across your catalyst bed and thus differential pressure transmitters are employed.
Your reactor conditions will very from your Start Of Run(SOR) to End Of Run(EOR) conditions.

Edited by USR, 05 February 2012 - 07:52 PM.

[sulphurwala]

Apart from what has been mentioned already by USR, another important parameter for the reactor is the WABT ie. Weighted Average Bed Temperature which is a calculated value. It gives us a holistic idea of the temperature profile across the reactor. The quenches at the reactor side not only helps you control runaway exo rxns but also helps you control the reactor temperature profile (WABT). So while one needs to reduce sulphur levels in the product, we increase both the inlet temp as well as the WABT.

Hello!
I am student and have to design a 4 catalytic bed reactor with hydrogen quench between each bed. The scope of the project is to produce green diesel by co-processing renewable feedstock with kerosene and now i am having some problems in the reactor mass balance because of the H2 comsuption, make-up and quench.
I would like to have some information about how to establish the necessary quench and some guidelines, or a proper book to follow.
I have already the LHSV, recycle gas/ HC ratio and the reactor operating conditions.
Any information would be very helpful.
Thank you.