Performance analysis of biomass direct combustion heating and centralized biogas supply system for rural districts in China

•A new distributed energy system that only uses biomass as input is proposed.•A novel mode of energy system with biomass for rural districts far from city heat and gas pipelines.•Annual performance analysis of combined heat and biogas system with biomass.•The practicability to meeting the users' heat and biogas demands economically with biomass. With the rapid urbanization of China, many farmers are living in buildings and districts far from natural gas pipelines and heating pipe networks. Besides electricity, they urgently need a cheaper energy source for heating and cooking. In this paper, a novel mode of biomass direct combustion heating and centralized biogas supply system was put forward, and corresponding theritical model was developed and verified with a practical operation system in Nan'an community of Wuwei City, China. The energy conservation and loss mechanism, energy economy, thermodynamic performance, and environmental benefits of the system are analyzed and explored on the basis of the system's year-round operating conditions and the community’s dynamic load characteristics. The results show that it is possible to meet the users' heat and biogas demands economically with biomass; the dynamic investment payback period(DIPP)is 4.23 years;the average annual primary energy saving rate(PESR)is 21.82 %; and the annual treatment of agricultural and livestock waste is 8198.57 t.The results of the study demonstrate the value and significance of biomass direct combustion heating and centralized biogas supply systems for achieving China's “Double Carbon” goal.