Dynamics of liquid-phase catalytic oxidation of hydrogen sulfide removal in rural biogas

Hydrogen sulfide in rural biogas was removed with liquid-phase catalytic oxidation.By using rare earth as catalyst,and sulfosalicylic acid as stabilizer,H2S purification efficiency could increase as high as 96%,and sulfur capacity of the composite solution was about 3 g/L.The results show that purification efficiency was affected by catalyst addition,pH,experimental temperature,and sulfur capacity.The parameters effects on catalytic oxidation were studied,and the optimized conditions were that Fe3+ concentration 0.08 mg/L,reaction temperature 70°C,pH 9.0,with a absorption solution volume of 50 mL,a gas flow rate 200 mL/min,and H2S mass concentration of 1.58-2.02 mg/m3.

Design Considerations of a Flexible Biogas Digester System for Use in Rural Communities of Developing Countries

Several challenges are associated with the development, adoption and deployment of biogas digesters in developing countries. Amongst these challenges is a comprehensive and systematic procedure for the design of digesters suitable for rural communities. This paper proposes the Flexible Biogas Digester System (FBDS) as a viable option for rural communities in developing countries and provides a detailed step-by-step procedure for its design. The biogas production process is a function of the digester operating factors which may be grouped into physical, process and performance parameters. The physical design parameters include the digester volume, the volume of the biogas storage tank, and the volume of the installation pit. The process parameters include total solid content of the slurry (TS), organic loading rate (OLR), digester operating temperatures, pH of the slurry inside the digester. The performance parameters include biogas production rate, biogas productivity and biogas quality. The Net Present Value and the Levelised Cost of Energy are presented for simple economic evaluation of the FBDS.