Removal of CO2 through Lo-Heat Benfield Process

by whatsmind

Natural gases are primary fuels, but they are not available for direct use in their natural state. Hence, they should be pre-treated to get rid of unnecessary substances. There are several options to get rid of these impurities. Here we shall find out about the removal of CO2 using the Benfield process.  

It is also called the hot potassium carbonate and is useful to remove CO2 from gases such as natural form or reformed ones. It is essential to remove the gas as it poisons downstream catalysts causing more operational expenses, poor production, and downtime.

The process is majorly applied in the ammonia industry. The process is efficiently used and is known to be quite reasonable in price and efficiency. The current system lowers energy by 15% or more and enhances 30-40% capacity, lowering operational expense. 

Lo Heat Benfield process 

Removal of CO2 using the Benfield process is done in two stages 

  • Absorption 
  • Stripping 

In the first stage, the gas that needs to be treated is kept in the absorber’s bottom and flows countercurrent to the Benfield solution, added from the top. The CO2 gets absorbed by absorbing liquid flowing downside. The dry gas passes from the absorber’s top with little CO2. The Benfield solution is fully saturated with carbon dioxide leaving the absorber’s bottom preheated and regenerated in the second stage. 

In this stage, the CO2 is removed from the solution by going for a counter-current flow process. It is done with steam on the opposite end as the stripping agent flows up and the Benfield solution flows down.  

Consistent vapors are produced when the solution passes through the internal compartments. This regenerates CO2 from a semi-clean solution because of its absorption ability. The free CO2 and steam are sent to the regenerator chamber. The lean Benfield is cooled and sent to the top of the absorber again to restart the process. 

The reactions are reversible and can be processed from both chambers. The cycle is consistent; the solution gets degraded after some time and should be reactivated. The Benfield solution reaches V+4, which lowers the efficacy of the corrosion inhibitor. To maintain it in its best condition, you should add other chemicals. It can be done by adding Potassium Nitrite to the solution. It will re-set the V5 inactive form.  

Also read: How to make electricity in little alchemy?

Benefits of using Benfield 

  • If the Co2 ingredient of the purification procedure gas goes up, raise the Benfield solution flow rate to enhance the CO2 absorption. 
  • Enhance the solution’s concentration. A concentrated solution will help to absorb CO2 better. 
  • If the CO2 ingredient of the lean Benfield solution stream rises, you can enhance the heat duty of the carbon dioxide stripper to increase the CO2 stripping rate with the help of Benfield solution. Eradicating CO2 from the solution will lower the solution’s corrosiveness. The lower the CO2 is present in the solution, the higher is its ability to absorb CO2. 

Using the benfield process, you can easily remove CO2 from any gas you want. It is a reliable, effective, and affordable solution. 

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