Economic and environmental analysis of decentralized heating using biomass gasification gas and household biogas in rural areas

Abstract: With the rapid development of the economy and the significant improvement in people's living conditions, clean and convenient heating has gained attention due to being required by farmers in the northern rural areas of China. The centralized heating usually requires a long-distance transporting pipe network, thus it is not applicable to most rural villages. The decentralized heating is applicable by using biomass gasification gas coupled with a household gas-burning furnace and by digestion biogas coupled with a household gas-burning furnace. These two methods of heating are much cleaner and more convenient compared to the decentralized heating using coal, char, wood, etc. They potentially become the two main kinds of heating in rural villages in the near future. This paper presents the analysis for economic and greenhouse gas reduction referring to the Xiaoguta village in Tianjin. It goes into detail about all kinds of investments, such as the equipment cost, fuel cost, electricity charge, labor cost, and maintenance management cost. It also shows how greenhouse gas reductions, such as CO2 reduction and CH4 reduction, exist in the two decentralized heating. The results show that the initial investment in biogas heating is nearly 186% of gasification heating. Operation costs of biogas heating has many advantages compared to gasification when the byproduct of biogas (299 thousand RMB/a) is used. Fuel cost of the decentralized heating is 164 thousand RMB/a when using BG gas and 185 thousand RMB/a when using biogas. The electricity charge of the decentralized heating is 62.9 thousand RMB/a when using BG gas and 35 thousand RMB/a when using biogas. The labor cost of the decentralized heating using BG gas is 12 thousand RMB/a, while the decentralized heating using biogas has no labor cost. The maintenance management cost of the decentralized heating using biogas is 37.5 thousand RMB/a, while the decentralized heating using BG gas has no maintenance management cost. The greenhouse gas CO2 reduction of the two decentralized heating methods are also similar, i.e. reducing 561.18 t/a of CO2 in life cycle, when compared with coal-based heating. The CH4 reduction of decentralized heating using biogas is also equal to that of biomass gasification gas. The CH4 reduction of the two decentralized heating methods ranges from 1 328.4 to 2 120.3 kg/a. Overall, the economy of decentralized heating using BG gas has more advantages than using biogas. The advantages of decentralized heating using BG gas is especially more prominent in the low level management rural areas. Villages, such as those in the rural areas of suburbs in Tianjin, should use BG gas as a heating fuel when they need a lot of gas. The results appear valuable when guiding the rural heating modes to use local biomass resources.