Selection of better synthesis route of CeO2/NaOH/PSAC for hydrogen sulphide removal from biogas

Abstract

Biogas contains hydrogen sulphide (H2S), which is an acidic gas that would causes severe corrosion to the mechanical parts of combustion engines. Therefore, hydrogen sulphide must be separated from biogas prior to combustion. Among the conventional methods, the use of a cheap adsorbent appears to be one of the most promising methods for H2S removal. CeO2/NaOH/PSAC was successfully synthesized and used to remove H2S from a simulated biogas stream. A better synthesis method was found by applying a soaking method to impregnate cerium oxide into palm shell activated carbon (PSAC). Cerium oxide (CeO2) was obtained via a reaction between cerium nitrate hydrate (Ce(NO3)3·6H2O) and sodium hydroxide (NaOH). The calcination step was crucial for this synthetic route to enhance the H2S adsorption capacity of the adsorbent. Selected adsorbents were characterized using several techniques and provided further information about the surface properties, functional groups, morphologies/composition and chemical states of the selected adsorbents.