Quench Oil

[cokingcommitteeteam]

Hello,

Does anybody use Heavy Gas Oil as quench oil for their coke drums? Compared to Light Gas Oil?

For those who use heavy gas oil, do you have coking issues in your overhead vapor lines?

Thanks,
Coking Committee Team

[evan]

Hello Coking Committee

Yes, many cokers use HCGO as drum vapor line quench and it works well. In fact, I believe it works better than LCGO because the higher boiling point keeps the oil in a liquid form and promotes a washing effect of the piping walls. LCGO can quickly cool the drum vapors but solids can still accumulate along the wall. IF your line velocities are very, solids could be washed away by the vapor but less likely.

However, the even better drum vapor quench medium is blowdown tower bottoms, if you ask me. It is a great way to recover slop internal to the unit.

Curious, how many people are in your committee and where are you based?

[cokingcommitteeteam]

Thanks for the response.

We have about 8-10 people in our committee. We are based out of Lake Charles, La.

When using HCGO we tend to choke up the vapor return line fairly quickly; however, when we use LCGO we do not have this issue.

We have discussed using blowdown tower bottoms but we do not have enough at a consistent enough rate.

Thanks Again,
Coking Committee

[evan]

Hello

I’m going to be in the Lake Charles area the first few weeks of April, I would like to meet the committee and hear more about this phenomenon if you have time. My email is “Evan at coking.local”

[wdcollin]

When you use HCGO, how much do you use as a percent of feed? How much does the temperature drop from the coke drum to the column? The latter is the important parameter.

[evan]

Hello

dT from the drum vapor quenching is controlled a number of ways but is typically 20-50F. The dT after quenching to the fractionator inlet is typically quite small. The flow is 5-10% of the drum vapor to achieve that dT. You would need to back calculate that on a unit feed basis.

Some of the 5-10% quench oil is recovered as product and does not end up a recycle but some does. The exact amounts vary but 3-5% TPR can still be achieved with the quench values.

Any chance I can meet the coking committee? The coker road show is in Louisiana right now….http://coking.local/roadshow/

[Author]

Posts