Hydrogen Sulphide can be converted into Sulphur according to the following equation.
8H2S + 4 O2 ---> S8 + 8 H2O
Sulphur is adsorbed by physical adsorption in the pores of the carbon. The presence of at least the stoichiometric amount of oxygen is necessary for the propagation of the reaction. Moreover, the reaction is accelerated by the presence of water. Sulphur dioxide and hydrogen sulphate can be formed by further oxidation as by-products. In the presence of alkaline compounds further oxidation to salts of sulphate and thiosulphate takes place. The catalytically active compounds must accelerate the main reaction, the formation of Sulphur as S8. The formation of byproducts has to be suppressed. Byproducts take up more volume in the pores for storage of the same amount of Sulphur, may block the pores and can be corrosive. S8 is a relatively large molecule that fits in the larger pores, thus meso pores are necessary for a high storage capacity. Coal activated carbons contains large amount of meso pores to load elemental sulphur compounds. The macro pores present in the Coal activated carbons are important for fast transportation of reacting gas molecules to and from the active sites. Odour compounds, in the form of hydrocarbons, may also be present in the exhaust gas and they are adsorbed in the small micro pores. So, an optimum pore distribution is important for high removal efficiency. Coal carbons contain micro, meso and macro pores to facilitate the reaction kinetics.
The adsorption capacity of a carbon for hydrogen sulphide is given in g/cm3. The adsorption capacity is calculated with
conc(H2S) * flow * breakthrough time
Ads. Cap = ----------------------------------------
Carbon volume in tube
With Ads. Cap for H2S in g/cm3 act. carbon
conc(H2S) in g/NCM3 air
flow in Ncm3/min
breakthrough time in min
carbon volume in cm3
Pressure Drop Curves for 4mm Pellet Activated Carbon
| SI.No | Product Name | FILE |
|---|---|---|
| 1 | OilStic_IA_Brochure | DOWNLOAD |