Challenges and strategies for biogas production in the circular agricultural waste utilization model: A case study in rural China

Abstract

As a renewable energy source, production and utilization of biogas is of great benefit to mitigation of greenhouse gas (GHG) emissions, reduction of the dependency on fossil fuels, and promotion of the utilization of livestock manure and crop straw. It has been widely popularized in rural China, yet the benefits and drawbacks of the operation of household biogas digesters (HBD) are not well-understood, resulting in the operation of HBD failing to live up to expectations. This study used propensity score matching (PSM) to estimate the true benefits of the HBD process, explored the drivers and barriers for households to continue using HBD with the logit model, and identified the determinants of HBD operation time by using the tobit model. Results showed that of the 1743 households interviewed, 42% had adopted HBD and the average biogas production time using HBD was 6.66 months per year. It was estimated that HBD owners could save 474 Chinese yuan (CNY) annually by using HBD and that the net present value of the HBD program would be generated after eight years of operation. However, lack of technical training and subsidies for HBD operation were the key barriers for households to carry on using HBD. Conversely, a warm local climate and HBD with larger size had positive effects on households deciding to continue using HBD. Thus, comprehensive policies addressing construction and operation of HBD, as well as new methods for a high-value supply chains to comprehensively utilize biogas products could solve dilemmas in HBD operation.