我国正面临日益严峻的能源安全形势与碳减排压力，生物质能被认为是可再生能源战略选择的重要组成部分。但是原生的生物质能是一种分散的、低品质能源形态，其多元化综合利用需要投入大量的化石能源、厂房设备及劳动力等以提高其能量品质，继而引发新的能源消耗和碳排放负荷。因此,亟需建立一套针对我国当前技术经济条件下的生物质能源转换利用过程评价的方法体系，开展不同生物质能源系统的分析与成本收益考察。本研究将基于系统思维，建立EIO-LCA与PLCA耦合的混合生命周期分析模型，对生物质固体成型、气化与直燃发电等三种典型生物质转换利用过程中的可用能（Exergy）与碳排放进行系统分析，深入剖析生物质能源系统内部资源流动与转换机理以及外部能源替代利用的"可再生性"与"碳中性"程度，从而可明确我国不同生物质能源利用方式对化石燃料的替代能力与碳减排效益，为我国当前及未来生物质能源发展战略与碳减排政策等提供定量化依据。

In view of the increasing pressures associated with energy security and carbon emission abatement,the use of renewable energy sources including bioamss energy is often suggested to be a possible solution to lower the contribution to climate change and the dependency from fossil fuels. However, it is important to note that biomass energy is characterized with desperse distribution and low quality, whose comprehensive and commercialized utilizaiton needs large quantity of inputs of nonrenewable energy, facilities and labors,and leads to additional carbon emissions.Therefore, a systimatic evaluation methodology for different biomass energy alternatives with regard to the current economic and technical conditions of China is badly needed, to make cost-benefit analysis for different conversion and utilization systems of biomass energy.With respect to the life cycle and systematic viewpoint, this project aims to build a hybrid life cycle model, i.e.,combing Process based LCA(PLCA) and Economic input-output based LCA (EIO-LCA), by which to make a reliable and systematic accounting of energy and carbon emissions cost for differnent biomass energy alternavives. Three kinds of biomass energy conversion and utilizaiton systems in China are chosen as the cases to evaluate their renewability and carbon emission reduction potential, i.e., woody biomass pelleting,woody biogas gasification and biomass-fired power generation. This project would contribute to our better understanding of mechanism on resource flow and structure within biomass energy system,and clearifying the potentials of energy substitution and carbon emission reduction, which would definitely provide sound base for national biomass energy development choice and carbon emission reduction stragegy of China.