Reduction of Greenhouse Gas Emissions at Large Pig Farms in Fujian

  Objective   Reduction on greenhouse gas (GHG) emissions at large pig farms by treatment converting fecal waste to biogas for an environmentally friendly hog industry in Fujian was reviewed.

  Method  Based on the internationally accepted method for calculating GHG emission reduction and the 2010 and 2015 data, the amounts of manure and biogas production at large pig farms in the province were obtained for the analysis. The estimated benefits brought about by the emission reduction through the practice were discussed.

  Result  The total amount of excreta dry matters from the pig farms was 1.699 3 million tons in 2010 and 1.632 9 million tons in 2015 representing the production potentials of 714 million m³ and 686 million m³ biogas, respectively. If the biogas produced were to be used to replace firewood, it would have been 2.454 2 million t and 2.358 4 million t of firewood saved for the two years, respectively. And the resulting CO₂ emissions reduced would have amounted to 2.687 4 million t in 2010 and 2.582 5 million t in 2015. The same presumed biogas productions would translate to be 1 308 500 t and 1 257 400 t of coal, or 1 108 900 t and 1 065 600 t of CO₂ emissions for the years of 2010 and 2015, respectively. By converting pig manure to biogas, the CH₄ emissions could have been reduced by 35 900 t in 2010 and 34 500 t in 2015.

  Conclusion  Using biogas produced from livestock waste could conceivably generate a high quality fuel to replace the traditional energy sources and effectively reduce CO₂ emissions. Anaerobic digestion of the waste material also mitigated CH₄ emissions resulting in significant social, economic and environmental benefits.