Creation of active sites by impregnation of carbon fibers: application to the fixation of hydrogen sulfide

Experimental and simulation study of hydrogen sulfide adsorption on impregnated activated carbon under anaerobic conditions

“…In addition, the IAC has a higher efficiency for H 2 S adsorption, in comparison with AC under different relative humidity. These results support the hypothesis of that a basic environment is critical for dissolving and reaction of H 2 S [3][4][5][6]25,26], which is provided by the impregnation of Na 2 CO 3 in this study. By increasing the pH value of the carbon surface, Na 2 CO 3 causes an increase in the HS -ion concentration.…”

“…for removal of low concentration H 2 S, impregnated activated carbon is a better choice for more effective removal [16][17][18][19][20][21][22][23][24][25][26][27].…”

Role of Pore Structure of Activated Carbon Fibers in the Catalytic Oxidation of H2S

“…Four types of groups could be the active sites for the catalytic oxidation of H 2 S: nitrogen-containing groups, ,, impregnation agents, edge (or defect) carbon atoms, , and elemental sulfur (or polysulfides). ,, Nitrogen-containing groups might play an important role in the oxidation of H 2 S on original activated carbons, but according to the results obtained in this study, they do not have significant effects on impregnated ACFs. The role of alkali impregnants is widely accepted as promoting the dissolution and dissociation of H 2 S in water films through acid−base reactions rather than active sites for the oxidation of H 2 S. ,,, …”

“…Porous carbon materials have been widely used for H 2 S catalytic oxidation because of their unique pore structure and modifiable surface chemistry. , Although it has been reported that the sulfur capacity of unmodified activated carbons is significant for low-concentration H 2 S removal at a low space velocity of the gas stream, alkali-impregnated porous carbons are still the first choice for H 2 S removal because of their large sulfur capacities and fast kinetics of reaction. , …”

“…12,13 Porous carbon materials have been widely used for H 2 S catalytic oxidation because of their unique pore structure and modifiable surface chemistry. 14,15 Although it has been reported that the sulfur capacity of unmodified activated carbons is significant for low-concentration H 2 S removal at a low space velocity of the gas stream, 16 alkali-impregnated porous carbons are still the first choice for H 2 S removal because of their large sulfur capacities and fast kinetics of reaction. 17,18 For impregnated carbons, understanding the effect of pore structure on the performance of these materials for H 2 S removal is a scientifically and technologically important problem, which could enable the design of more efficient H 2 S oxidation catalysts.…”