4 replies to this topic

[BJD]

Dear all,

 

In hydrocracker process reactions like hydrogenation & hydrocracking take place and as a result significant amount of hydrogen is consumed in the reaction process.As per licensor design data there is certain wt% of chemical hydrogen consumption In hydrocracker unit as a whole. I would like to know that out of hydrogenation & hydrocracking reaction which one consume more hydrogen chemically in a typical hydrocracker process unit ? In out unit chemical hydrogen consumption is 2.6 wt% of feed. Out of 2.6 wt% how much wt% is consumed by hydrogenation reactions is not specified. Feed to our unit is (VGO + CGO )& IBP is -11 Deg C & EP is 565 Deg C .  

 

Thanks & Regards,

 

[P.K.Rao]

One reason could be the change in the quality and quantity of CGO (Coker Gas OIl, I hope you mean by CGO) for higher consumption of hydrogen. Higher olefins in CGO and higher percentage  consume more hydrogen.  You may monitor both and compare with the hydrogen consumption. (higher olefins is indicated by higher bromine number by test method ASTM D 1159 or 1160 or UOP 304.

[gegio1960]

the hydrogen consumptions can generally classified as follows:

- chemical consumptions

- solution losses, because of the high pressure some H2 is diluted into the oil

- mechanical losses, due to the presence of compressors in the process

moreover, the hydrogen balance should also consider that

- an excess of H2 is needed for the good operation of the catalyst

- part of the inlet H2 (the excess) goes with the outlet gases (at high and low pressure) and then recovered, purified, compressed, recycled or sent to fuel gas network 

[BJD]

I would like to know about the break up of chemical hydrogen consumption in %wt in the entire (85% VGO+ 15 %CGO) hydrocracker unit.

We have three Recators in the Two stage full conversion Hydrocracker unit licensed by Chevron, USA. 1st stage having one hydrogenator reactor followed by one hydrocracker reactor and 2nd stage has only one hydrocracker reactor ( almost 50% - 50 % conversion in the 2 stage). Total chemical hydrogen consumption in the entire unit is 2.6 wt%. Is there any methodology to determine which one reactor consume more hydrogen chemically ? Is it the hydrogenation reactions that take place in the 1st reactor consume more hydrogen or the hydrocracking reactions that take place in the other reactors. May Please specify the approx wt% hydrogen consumption in the case of hydrogenation reactions and hydrocracking reactions.

 

PingPong please give some inputs on the above..

 

Regards,

[gegio1960]

bjd,

you have the plant...

you have the licensor documents, including PFD and H&MB...

you have the chemical process engineering role and knowledge...

you have the contacts and relations with the licensor...

why do you ask outside?