Abstract—Biogas should be purified before further application as a fuel for engine. Hidrogen Sulfide (H2S) is one the gas impurities that rising problem for the engine since will caused acidity to lubricant and corrosive to metal part of the engine. In this research, zinc obtained from used battery is utilized as desulfurizer. Two methods are introduced in this article for processing zinc as desulfurizer. First by immersing in the salt water to produce zinc oxide (ZnO) and secondly by galvanic coupling with iron in order to obtain ion Zn2+. It is found that both processing techniques having optimum result in reducing H2S impurity in the biogas.