中文摘要：

对现有的碳减排计算模型加以改进,对于关键参数的取值大部分参考我国学者的研究成果,以湖北省恩施州为例,从甲烷利用直接减排、化石能源替代减排、甲烷泄漏碳排放和甲烷燃烧碳排放4个方面,综合核算2000—2010年农村户用沼气项目的碳减排效益。结果表明,每口沼气池的碳减排量为1.10～1.29 t.a-1,碳减排量受沼气池规格（饲养生猪数量和类型）和地区气温变化等因素影响,每口沼气池的间接碳减排量（1.07 t.a-1）是直接碳减排量（0.22 t.a-1）的4.9倍。2000—2010年恩施州年碳减排效益整体随新建沼气池数量的增加而增加,碳减排量由2000年的3.97万t.a-1上升到2010年的70.93万t.a-1;2000—2010年恩施州户用沼气项目处理畜禽粪便导致的直接碳减排总量为157.44万t,沼气替代燃煤导致的间接碳减排总量为361.82万t,甲烷燃烧导致的碳排放量为13.12万t,甲烷泄漏导致的碳排放量为89.94万t,碳减排总效益为416.20万t。

英文摘要：

Based on the model recently modified for accounting of carbon mitigation and the research achievements of the scientists in China as reference for values of some key parameters, Enshi Prefecture of Hubei Province was selected for case study to evaluate effects of the popularization of rural household biogas projects in 2000-2010 on carbon mitigation from the following 4 aspects, direct carbon emission reduction by use of methane, substitution of fossil energy reducing carbon emission, carbon emission through leakage, and carbon emission from methane combustion. Results show that carbon reduction per unit （per biogas digestor） varied in the range of 1.10-1.29 tons per year, depending on specification of a digestor （ number of pigs in pen and type） and air temperature, and its indirect portion （ 1.07 t · a^-1 ） was 4. 9 times as much as its direct portion （0. 22 t · a-1 ）. The annual effect on carbon mitigation in the prefecture increased with the increasing number of biogas digestors in 2000-2010, and the reduction of carbon emission increased from 39 700 tons per year in 2000 to 709 300 tons per year in 2010. During this period, the use of biogas digestors treating livestock manures directly reduced carbon emission by 1. 574 4 million tons and the substitution of coal with biogas indirectly reduced carbon emission by 3.618 2 milhon tons, while the carbon emission from the combustion of methane increased by 0. 131 2 million tons and methane leakage by 0. 899 4 million tons. Balancing of the four factors shows that the total carbon mitigation benefit was 4. 162 0 million tons.