3 replies to this topic

[Geetanjali]

Hello members,

 

I have a query. I need to size a hydrocracker for economic estimations.

 

The hydrocracker receives melted plastic stream = 10,000 kg/hr

Catalyst = 714 kg/h

Hydrogen = inlet = 1228 kg/h, outlet = 600 kg/hr, actual consumed = 628 kg/hr [ Note, I am giving a stochiometric excess of H2]

 

Other conditions: T = 280 C, P = 30 bar, residence time = 16 hr

 

 

My approach to size the reactor:

 

Vol of reactor = Volumetric flow x residence time

 

Volumetric flow of outlet stream = (mass of plastic/density + mass of catalyst/density + mass of hydrogen/density)   {eq.1}

 

At this pressure, hydrogen density is 1.5 kg/m3

 

Eq. 1 becomes = (10000/925 + 714/873 + 600/1.5184) = 425 m3

 

So, the overall volumetric flow rate = 425 m3

For 16 hr residence time = 402 x 16 = 6445 m3/hr

 

If I select a reactor that has a length = 9.5 m and height = 47.5 m, the volume of such a reactor would be 3365 m3

 

Therefore, the number of reactor I need = 6445/3365 = 2.

 

 

My question is: Is my approach correct? Should I include Hydrogen is eq. 1 or not? or should I only take liquid and solid volumes while calculating size of reactor?

 

I am calculating the cost from Aspen Economic analyzer.

 

 

This will be a huge help for me.

 

Thanks,

Geetanjalli

Edited by Geetanjali, 27 September 2022 - 04:12 PM.

[Bobby Strain]

None of this makes sense.

 

Bobby

[Geetanjali]

To size a reactor that has a flow rate of approximately 11,942 kg/hr (10,000 kg/hr liquid (highly viscous), 714 kg/hr solid, and 1228 kg/hr gas), Is my approach correct to calculate the volume of reactor?

 

Volumetric flow rate = (mass of liquid/density + mass of solid/density + mass of gas/density)   {eq.1}

 

Else, could you please suggest what type of reactor is suitable for such a process and how to size it?

 

Thank you,

Geetanjali

Edited by Geetanjali, 27 September 2022 - 04:10 PM.

[SilverShaded]

You need to know what space velocity you need to maintain conversion and catalyst life.