4 replies to this topic

[abhivmairal]

I was designing pressurized water packed bed column for biogas purification wherein I am having the issue that the loading factor (X) as predicted in simulation is very high and falling outside the range of the generalized pressure-drop correlation (GPDC).

X = L/G sqrt ( Dens G/ Dens L). 

Request you to suggest me a method in calculation of column diameter and also how to determine the height of the packed bed column.

Regards
Abhijeet

[breizh]

hi ,

share with us your calculation and assumptions and probably someone will support .

 

good luck

Breizh

Edited by breizh, 22 April 2019 - 06:43 AM.

[abhivmairal]

Dear Mr. Breizh,

 

We are trying to simulate the pressurized water scrubbing column for biogas purification wherein the biogas flow we have taken is 1Nm3/hr and the water required is coming out to be 200 kg/hr in order to acheive 90% specification of methane (compressed biogas ).

 

We are operating the column at 10 barg pressure in ASPEN HYSYS and using the NRTL thermodynamic model.

 

The  raw biogas composition at the inlet of scrubber is shown below.

 

Component Mol frac Methane 0.56 CO2 0.35 H2O 0.01 H2S 0.02 Ammonia 0.00 Nitrogen 0.03 Oxygen 0.02 Hydrogen 0.01

 

We also tried with WILSON thermodynamic model but getting almost same water requirement. 

Please let us know if selected thermodynamic model is incorrect. The issue that because of high loading factor X, we are not able to determine the flooding velocity using the "Generalized Sherwood flooding and pressure drop correlation."

[breizh]

Hi ,

I've no experience on this process , difficult for me to comment .

 

From the paper I provided You are on the right track in term of process . You may need to perform a bibliography study , references are in the document .

 

Regarding Thermodynamic  models, it sounds correct (refer to the document attached)  NRTL or Wilson

 

Note : Make sure your ratio L/G is consistent ,using the same  set of unit  (mole /h or  kg/h or mole /h/m2 or kg/h/m2   )

 

Don't forget to ask your supervisor.

Good luck

Breizh

[breizh]

Hi ,

To add to my previous emails an extract of: Biogas from Waste and Renewable Resource by Dieter Deblein and Angelika Steinhauser .

 Good luck

Breizh