2 replies to this topic

[CHEMSTRONG]

Hi,
I Have side by side Refinery CCR reactors in which case I m getting more than required net Hydrogen gas flow.i m getting almost double the amount of required hydrogen flow.. Also my LHSV is only 0.88.. Hydrogen to HC ratio is only 2.088.. reaxtor inlet temp is 515 for four reactors.. Is it that i m getting only dehydrogenation of naphthenes reactions with hydrogen production in my reactor and no hydrocracking happens.. How to control and reduce net hydrogen ex reactors.. also delta T across my fourth reactor is very less as compared to H & MB.
Can you suggest solution ?

Also tell me how to calculate Hydrogen to Hc ratio mole basis? Is it at reactor inlet or what ?

[Amit J]

Following points may help you to conclude :

1. Dehydrogenation of naphthenes is an endothermic reaction hence dT across reactor will be higher due to this reaction. Typically this is quick reaction and hence primarily will complete in first & second reactor for your desired feedstock.

2. Hydrocracking is an exothermic reaction and hence dT across reactor will be comparatively lesser (contribution of other reactions will also effect dT across reactor, but in totality dT across reactor will be lesser). Typically little slow reaction and requires comparatively higher temperature, hence will happen in 3rd & 4th reactor. (your dT across 4th reactor is less which suggests that hydrocracking is happening)

3. Hydrogen to HC ratio need to be calculated at reactor inlet.

4. Why do you want to control Hydrogen? I think Hydrogen environment is necessary in CCR reactor so that reaction happens effectively.

 

Get samples across inlet and outlet of each reactor to analyse same.

[CHEMSTRONG]

Sir,

I m getting net hydrogen flow of 44000 at the outlet whereas H and MB indicates that it should be around 21000.. My LHSV is 0.87.. whether increasing LHSV and keeping all other parameters constant will change hydrogen at the outlet ?