Hydrogen sulfide removal from biogas using chemical absorption technique in packed column reactors.

Abstract

The toxicity and corrosion potential of hydrogen sulfide in raw biogas underlines\xa0the need for biogas purification. Several techniques available for removal of hydrogen sulfide from biogas are out of the reach for common end users due to lack of knowledge, higher running costs, and insufficient operational skills.\xa0The present experimental study aims to propagate hydrogen sulfide removal techniques amongst\xa0the end users by using a low-cost chemical absorption technique and packed column reactors.\xa0Commercial grade chemicals like monoethanolamine,\xa0sodium hydroxide, calcium hydroxide, granular activated carbon,\xa0and\xa0steel wool were used\xa0for biogas purification in packed column reactors of 1.2 liters capacity. Hydrogen sulfide removal efficiency up to 92.41%\xa0was achievable\xa0using single purification columns. The efficiency achieved by using multiple purification column was up to 96.84%.\xa0Hydrogen sulfide removal efficiency\xa0was calculated\xa0for experimental variants like the use of a dedicated purification column, multiple purification\xa0columns, flow variations\xa0and pressure\xa0variations\xa0of raw biogas. The data for the frequency of regeneration/replacement of different chemicals was also determined. The simplicity of operation and the use of low-cost reagents in the present study can enable the use of these methods amongst end users of biogas technology for minimizing health hazards and corrosion problems.