Function and limits of biofilters for the removal of methane in exhaust gases from the pig industry

The agricultural sector is responsible for an important part of Canadian greenhouse gas (GHG) emissions, 8 % of the 747 Mt eq. CO2 emitted each year. The pork industry, a key sector of the agrifood industry, has had a rapid growth in Canada since the middle 1980s. For this industry, slurry storage accounts for the major part of methane (CH4) emissions, a GHG 25 times higher than carbon dioxide (CO2) on a 100-year time horizon. Intending to reduce these emissions, biofiltration, a process effective to treat CH4 from landfills and coal mines, could be effective to treat CH4 from the pig industry. Biofiltration is a complex process that requires the understanding of the biological process of CH4 oxidation and a control of the engineering parameters (filter bed, temperature, etc.). Some biofiltration studies show that this technology could be used to treat CH4 at a relatively low cost and with a relatively high purification performance.