Adsorption of Hydrogen Sulfide at low temperature

From an ecological perspective is biogas an important source of energy. It is produced from fermentation of organic material, e.g. household waste and wastewater sludge. The composition of the gas depends on the raw material and varies between 65-85% methane, 15-35% carbon dioxide and small amounts of ammonia and hydrogen sulfide. To use the biogas it is important to purify it from hydrogen sulfide, because of the toxicity and corrosivity of hydrogen sulfide. This study aims to find an appropriate adsorbent for dry adsorption of hydrogen sulfide at the temperature of production, that is 30-60°C. The adsorbents tested are two iron oxides and one commercial adsorbent, SulfaTreat. The experiments were performed at 0, 40, 61, 81 and 100 % relative humidity. This to determine the influence of the relative humidity on the adsorption. The adsorption, for all three adsorbents, seemed to be only slightly depending on the relative humidity. The results indicates that the Fe3O4-adsorbent has the same and even somewhat better adsorption ability than the adsorbent SulfaTreat, which is on the market.