Development of GHG Emission Factors for the Life Cycle of the Animal Manure Treatment Systems

Objectives:A whole process greenhouse gas emission factor was developed considering the direct greenhouse gas emission from the decomposition of livestock manure provided by the IPCC guidelines and the energy consumption of manure management systems.Methods:Greenhouse gas generated by animal manure management is divided into direct greenhouse gas emission by decomposition of manure and greenhouse gas effect in the entire process due to energy use by operating manure management systems. By obtaining and summing them, the whole process greenhouse gas emission factor for the livestock manure treatment system was calculated.Results and Discussion:Among the pig manure management systems, the greenhouse gas emission factors for composting, purification and liquefaction were calculated as 128 kgCO2-eq./ton, 123 kgCO2-eq./ton, 119 kgCO2-eq./ton, respectively. It was analyzed that 20.7% to 24.1% of greenhouse gas emissions generated in the process of managing manure were due to electricity use. As a result of analyzing the change in the emission factor according to the change in GHG emissions of the national electric power according to the 8th Basic Plan for Electricity Supply and Demand, a change in emission of about 6% was confirmed. Based on the results of this study and analysis of direct GHG emissions from manure management in three major Western European countries, France, Germany, and the Netherlands, based on the manure management emission factor in 2017, GHG emissions of 48.9% to 70% compared to this study in all countries.Conclusions:In the greenhouse gas emission factor for the pig manure management system, the greenhouse gas emission from energy used in the manure management system operation represents a contribution of more than 20%, so improvement of energy efficiency of the manure management system in the future can contribute to the reduction of greenhouse gas emission. As the GHG emissions of the pig manure management system are expected to change substantially according to the change in the power grid composition ratio according to the 8th Basic Plan for Electricity Supply and Demand, it is necessary to study the application plan in preparation for the implementation of product environmental footprint certification for livestock products in the future. As a result of comparing direct GHG emissions by manure management with major Western European countries, the difference in emissions was found to be large, suggesting the need to develop a Tier 2 emission factor suitable for the situation in Korea.