基于LCA的秸秆沼气集中供气工程环境影响评价  

Environment impact evaluation of straw biogas project for central gas supply based on LCA

作　　者：王红彦[1] 王亚静[1] 高春雨[1] 王道龙[1] 覃诚 毕于运[1] 

机构地区：[1]中国农业科学院农业资源与农业区划研究所,北京100081

出　　处：《农业工程学报》2017年第21期237-243,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金青年基金(41301626)

摘　　要：为进一步研究秸秆沼气工程生命周期的环境影响,采用生命周期评价方法对秸秆沼气集中供气利用模式的环境影响进行分析,系统比较沼气系统不同单元的环境影响。将秸秆沼气工程建设单元的物质和能量投入及其环境排放纳入生命周期边界,以河南省安阳县西街村秸秆沼气工程为例进行实证分析,对秸秆沼气集中供气工程建设单元、运行单元和产物利用单元进行清单分析和环境影响评价。结果表明,该沼气工程运行1 a产出13.60万m^3沼气,系统环境影响综合值为129.94标准人当量。从沼气系统各阶段看,沼气工程建设单元、运行单元和产物利用单元的环境影响潜值分别占沼气系统生命周期环境影响的65.62%、32.76%和1.62%。从能源替代角度看,该秸秆沼气集中供气工程替代煤炭的全球环境影响负荷为–132.48标准人当量。与煤炭作为炊事用能相比,该沼气工程的环境影响负荷可降低50.50%,秸秆沼气作为可再生的清洁能源可以有效替代煤炭燃烧从而改善环境质量。沼气工程建设阶段的环境影响对秸秆沼气集中供气系统总环境影响的贡献最大,而产物利用阶段环境排放影响最小。秸秆沼气工程运行单元的煤炭增温和电力消耗是影响沼气工程环境排放的重要因素,选择低碳环保的沼气增保温方式和降低工程运行电耗是未来秸秆沼气集中供气工程工艺改进的重要内容。Chinese government has been encouraging the use of crop straw as energy sources in the latest decades. Straw biogas project can not only provide clean energy for rural household, but also make full use of crop residue and reduce air pollution caused by straw open burning. Straw biogas industry has developed fast in the latest decades, with a total number of 458 projects by 2015. Crop straw biogas project is environmental-friendly, but pollutants emission will be caused during the biogas project construction, the crop straw transportation and pretreatment, the products utilization processes. The research on the environment performance of straw biogas is a hot topic with the straw biogas industry development of China. Life cycle assessment （LCA） can be used to calculate a product＆#39;s environment performance by building an integrated framework of processes. LCA is used to analyze overall inputs, outputs and potential synthetical environmental impacts throughout biogas＆#39;s lifetime. Some researchers have been studying the environmental impact of straw biogas system by the method of LCA. However, the pollutants emission and energy and material input of construction unit of biogas project were seldom considered in the boundary of the system. The straw biogas system was divided into construction unit, operation unit and product utilization unit during the inventory analysis. This paper analyzed the environment impact of each unit and the whole system of straw biogas project for central gas supply by the LCA method, and it started to focus on the environment performance of construction unit, which is different from previous studies. Taking the straw biogas project of Xijie Village in Anyang County, Henan Province as a case for empirical analysis, this paper made inventory analysis and impact assessment for life cycle of the biogas project including construction unit, project operation unit and product utilization unit. All the raw data were obtained by survey. Data of energy coefficient, emission factor, stan

关 键 词：秸秆 环境影响 温室气体 沼气集中供气工程 生命周期评价 

分 类 号：S216.4[农业科学—农业机械化工程]