Valorization of MSWI bottom ash for biogas desulfurization: Influence of biogas water content

摘要

In this study an alternative valorization of Municipal Solid Waste Incineration (MSWI) Bottom Ash (BA) for H_2S elimination from landfill biogas was evaluated. Emphasis was given to the influence of water content in biogas on H_2S removal efficiency by BA. A small-scale pilot was developed and implemented in a landfill site located in France. A new biogas analyzer was used and allowed real-time continuous measurement of CH_4, CO_2, O_2, H_2S and H_2O in raw and treated biogas. The H_2S removal efficiency of bottom ash was evaluated for different inlet biogas humidities: from 4 to 24 g_(water)/m~3. The biogas water content was found to greatly affect bottom ash efficiency regarding H_2S removal. With humid inlet biogas the H_2S removal was almost 3 times higher than with a dry inlet biogas. Best removal capacity obtained was 56 g H_2S/kg dry BA. A humid inlet biogas allows to conserve the bottom ash moisture content for a maximum H_2S retention.