Dry desulfurization 
* The dry absorption method employs zinc oxide or iron oxide. 
* The dry oxidation method includes Claus process for sulfur recovery. 
* The adsorption method uses activated carbon to adsorb and oxidize H2S.

Wet desulfurization 
* The absorption method primarily uses MDEA to remove both H2S and CO2 simultaneously. 
* The oxidation method, like the LO-CAT process, uses an iron-based solution. It is favored for small-scale recovery due to its flexibility, selectivity, and environmental friendliness.