Activated Carbon to Remove H2S

Activated carbon is mainly used to remove organic sulfur and a small amount of hydrogen sulfide. Due to different reaction mechanisms, it can be divided into three methods: adsorption, oxidation and catalysis.

Adsorption method: Activated carbon has a large specific surface area, strong adsorption capacity, and strong selectivity. It is mainly manifested in the difficulty in adsorbing highly volatile substances, and is most effective for thiophene.

Oxidation method: Hydrogen sulfide and carbon oxysulfide are oxidized by oxygen present in the gas.
H2S(g)+02=S(s)H20 2C0S 02==C02 2S

             
Catalytic method: Impregnate activated carbon with salts such as iron and copper to catalyze organic sulfur into hydrogen, which is then adsorbed and removed.
Desulfurizer regeneration includes superheated steam method and ammonium polysulfide method.

① The ammonium polysulfide method uses ammonium sulfide solution to extract sulfur from activated carbon multiple times. Sulfur reacts with ammonium sulfide to form ammonium polysulfide. The reaction formula is: (NH4)2S(n-1)S=(NH4)2sn

This method includes the steps of preparing ammonium sulfide solution, leaching sulfur on activated carbon with ammonium sulfide solution, regenerating activated carbon and decomposing ammonium polysulfide solution, and recovering sulfur and ammonium sulfide solution.

② Regeneration method with superheated steam or hot inert gas (hot nitrogen or coal combustion gas): Since these gases do not react with sulfur, they can be heated by a combustion furnace or an electric furnace, and the temperature can be adjusted to 350~450℃. After passing into the activated carbon desulfurizer, the sulfur on the activated carbon will sublime, and the sulfur vapor will be taken away by the hot gas.