Selective removal of h(2)s from biogas by a packed silica gel adsorber tower

The removal of hydrogen sulfide from biogas by silica gel was systematically studied. The results indicate that H(2)S could be selectively and completely removed from the biogas until the silica gel became saturated. When it became saturated, the color of silica gel changed from blue to black. The used silica gel could easily be regenerated and reused. The factors that affected the purification of biogas by silica gel were found to be the flow rate of biogas, the regeneration temperature, the degree of saturation of the silica gel, and the water content of silica gel. A mathematical model describing the operation of the adsorber was developed. The breakthrough curves and mass transfer coefficients of H(2)S were also obtained.