The development and countermeasures of household biogas in northwest grain for green project areas of China

The Grain for Green Project (GGP) is an important ecological construction program in China from 2002. Household biogas plays an important role in the GGP of northwest of China. This article, according to the research results of the Clean Development Mechanism (CDM) project and previous relevant studies, discusses the development of household biogas in the northwest Grain for Green Project areas of China (NGGP), including its necessity, policies and laws and present situation. Furthermore, this article analyzes the constraints on household biogas development and suggests countermeasures to promote the development of household biogas in NGGP. After using household biogas in NGGP, the proportion of straw and firewood fuel decreases 60%-88%, 0.03-0.20 ha of the forest land area is protected per biogas user annually, the emission reduction of greenhouse gas is 1.23-1.34 t CO2 equivalent per biogas user annually, and the results of the GGP are promoted. There are several constraints for household biogas development in NGGP, including low-quality biogas construction, biogas education, imperfect service system, low biogas fermentation temperature in winter, low biogas, biogas slurry and biogas residue (three-biogas) utilization rate, low biogas digester utilization rate and improper policy support. Thus, biogas construction quality should be ensured, the biogas service system and comprehensive utilization of three-biogas should be improved, and biogas knowledge should be increased; additional research needs to be performed in low-temperature fermentation technology, straw fermentation technology and simple biogas technology and operation; the biogas policies and regulations of NGGP should be perfected to encourage the development of household biogas. The information presented in this article not only will provide a reference for the development of biogas and the improvement of policy in NGGP, but also will be helpful for household biogas development in other countries with similar situations. (C) 2015 Elsevier Ltd. All rights reserved.