Biogas purification by using zeolite packing columns

Biogas is a product of anaerobic digestion, which consists of a mixture of methane (CH4), carbon dioxide (CO2), and some impurities such as hydrogen sulfide (H2S) and water. The contaminants, especially H2S, can cause metal corrosion, reduce the biogas calorific value, and are toxic to humans and the environment. The purpose of this study is to use natural materials such as zeolite to purify biogas, especially H2S removal. The specific surface area can be increased by physical or chemical activation, which helps increase adsorption capacity. It was found that zeolite with calcination has a high affinity for H2S. The bed height in the packed bed reactor and biogas flow rate have affected the efficiency of H2S removal. The highest adsorption capacity and removal efficiencies are obtained with the calcined zeolite with 20-30 mesh and 10 cm of packing column height with the saturated zeolite; the time is 160 minutes.