Hi everone. I have a question. woul 1

[Jack Nicholson]

Hi everone. I have a question. would you please help me?
We want to <methane run> our demethanizer column. As illustrated in picture, in order to reduce flaring during start up, methane at 30 barg is pressurized at demethanizer and then recycle compressor start, and through jump over line (red line) methane is gonna recycled back to feed line. So methane is recycled through demethanizer and coldbolx and demethanizer cool down before start up. Do you have any recommendation? any similar exprience?
Thanks in advance.

 

[georgeverghese]

Good idea, but check reboiler operation when in this mode, since there is little or no condensate product with large recycle of resid gas to feed gas line - can the reboiler turndown to such low reboil duty in a stable manner? What is the min turndown of the reboiler? No details provided of reboiler.

 

[Jack Nicholson]

ِDear georgeverghese
Thank you.
We can not start the reboiler, till the condensate has been accumulated.

 

[georgeverghese]

So what type of reboiler do you have here? If it is a kettle, then reboiler turndown will only be a function of reboil heat medium control valve turndown.

 

[Jack Nicholson]

No, It's BHU (simple u-type bundle).

 

[georgeverghese]

Presume you mean a stab in U tube bundle in the column bottoms. So similar to external kettle type reboiler.