Microbial Removal of Hydrogen Sulfide from Biogas

Abstract

Biogas can contain 50–300 ppm of hydrogen sulfide, which is a highly corrosive and malodorous gas. It can be separated by several chemical techniques which are cost effective but the disposal of byproducts is another problem. Biological removal of H₂S from biogas is a low-cost technique and environmentally safe. For the removal of H₂S from biogas a packed bed biofilter is developed having wooden pellets as packing material for adhering each one of the microbial cultures such as T. thioparus, T. thioxidans, and T. novellus. Biogas passed through this biofilter column at different flow rates (0.003, 0.006, 0.075, 0.012, and 0.015 m³h⁻¹) with a spray of liquid medium of different microbial cultures (flow rate 12 Lh⁻¹) at different temperatures (25, 30, 35, and 40°C) separately in counter current action. It is observed that at a low flow rate 0.003 to 0.006 m³h⁻¹ 100% removal efficiency was observed for each of the mentioned microbial cultures. However, H₂S removal efficiency by T. thioparus is higher (47, 66.6, and 76.7%) at a high flow rate (0.003 and 0.006 ml/min⁻¹) as compared to the other two microbial cultures.

Keywords:

• biofilter
• biogas
• mixed culturea