4 replies to this topic

[Pressure Vessel Design]

Hi everyone, 

 

I am at the beginning stages of doing my individual design project which involves designing a CO2 Absorber to remove ethanol and VOC  from CO2, produced in the fermentation of ethanol.

The first part of the project was group work to design a sugar and ethanol plant so I am working with the material balance conducted by my teammates, which I can not change.

 

The inlet mass fraction of each component at 306K and 1atm is:

 

CO2 at 95%

Ethanol at 4%

VOC at 1%

 

After researching physical and chemical solvents, I decided to go with a physical solvent such as water because as previously mentioned sugar is also being produced and I looked into the potential risk of using a chemical solvent in a food production industry. Also everything I find concerning ethanol-CO2 absorber from the fermentation process used water as the solvent due to the volatile organic components in the feed.

 

However, I am thinking that this system may not work after researching the solubility of ethanol-CO2 (around 55.9 at 1atm and 306K) and comparing it to what I have (which is much smaller). Since ethanol is at 4% I looked into condensing the ethanol instead and then feed the CO2-VOC mix into an activated carbon system.

 

What are your thoughts about this? As am at the beginning unfortunately I have no PFD and detailed mass balances conducted I know it would be better if I did but am still trying to research the potential of the system wohe volatile organic components in the feed. 

 

Your advice is much appreciated 

Edited by Pressure Vessel Design, 17 January 2015 - 04:13 PM.

[breizh]

Pressure vessel design ,

 

To my knowledge , Ethanol plants are using water to remove the VOC prior to discharge the CO2 and it works well.

 

After absorption , the ethanol content is below 10 000 ppm and the CO2 content is about 98.5%

 

http://ethanolproduc.../9001/stop-loss

 

http://www.haffmans....l_Recovery.aspx

 

 

Hope this helps

 

Breizh

Edited by breizh, 18 January 2015 - 06:44 PM.

[Pressure Vessel Design]

Hi Breizh,

Thank you for that, from researching I had found the same information about using ethanol to remove VOC however even though we designed an ethanol and sugar plant it was design for a ratio of 2:1 (sugar:ethanol) so am unable to use the ethanol produced in the plant and would have to buy in ethanol instead. I would then have to feed the then ethanol and co2 mix into another absorber column. What are the usual concentrations for an inlet stream containing ethanol and co2? Are my concentrations too low in your opinion?

Edited by Pressure Vessel Design, 18 January 2015 - 04:56 AM.

[breizh]

Hi ,

Additional resource .

 

http://www.envitechi...thanol scrubber

 

Hope this helps

 

Breizh

[Pressure Vessel Design]

Hi Breizh,

 

Thank you for your help, I had found this information during my research and was planning on doing a similar method. However, the issue is that my inlet concentrations for the impurities are too small so I plan on condensing out the ethanol (which would be a liquid anyway at 306K) and then feed the stream into an activated carbon system to further remove any impurities from the CO2 and purify it.