One of the methods used to prevent the damage of hydrogen sulfide gas (Hâ‚‚S) in biogas to the process and process equipment is chemical washing of biogas. In this method, called chemical desulphurization system, biogas is passed through towers filled with special filling material. During the transition, it is contacted with the chemical that will react with hydrogen sulfide. Hydrogen sulfide changes phase during the reaction into water.
For chemical desulphurization system design; Information such as hydrogen sulfide value in biogas, gas flow rate, desired hydrogen sulfide amount after washing is critical. In the chemical desulphurization method, unlike the biological desulphurization system, no oxygen is introduced into the tower. Thus, there is no decrease in the calorific value of the biogas. When operating at variable flow rates, oscillations in hydrogen sulfide values are not allowed. After planned or unplanned shutdowns, the chemical desulphurization system continues to purify hydrogen sulfide from where it left off. The initial investment cost is lower than the biological desulphurization system.
