Evaluating Competing Uses of Biomass for Greenhouse Gas Mitigation

生物质（植物物质和有机废物）是世界上最大的可再生能源，约占全球一次能源供应的10%。对温室气体排放和矿物燃料耗竭的关注使人们对利用生物质作为能源和材料的兴趣日益浓厚。迄今为止，国家政策主要侧重于利用生物质生产运输燃料。这种狭隘的关注忽视了生物质的其他潜在用途，例如产生热量和电力，作为化学原料，航空燃料或碳储存介质。以前的研究表明，生物质资源虽然丰富，但可能不足以满足全球能源需求。因此，迫切需要确定生物质利用的优先次序，并使这些优先次序成为国家政策的基础。该项目将确定生物质的哪些用途在不影响其他环境目标的情况下，具有最大的减少温室气体排放的潜力。在生物质的不同用途之间进行优先排序由于可能的产品途径的绝对数量而变得复杂：可以使用各种各样的转化技术转化不同的生物质来源，以生产大量不同的最终产品。这项工作将对现有的关于生物质能源和产品对气候影响的文献进行批判性评估，并确定哪些生物基途径能够以最高的置信度实现温室气体减排。它将进一步解决这些不同途径的货币成本，并构建一个框架来评估这些途径对其他环境指标（如当地空气和水质）的影响。这项工作是在加拿大的关键时刻进行的，加拿大拥有世界上最大的生物质资源，但直到最近才开始制定关于生物质利用（生物经济）的国家战略。预计研究结果将指导政府和工业决策者制定更一致的生物质资源开发政策。

Biomass (plant matter and organic waste) is the world's largest renewable energy source, accounting for approximately 10% of global primary energy supply. Concern over greenhouse gas emissions and fossil fuel depletion has led to a growing interest in the use of biomass for both energy and materials. To date, national policies have focused primarily on using biomass to produce transportation fuels. This narrow focus overlooks other potential uses of biomass, such as to generate heat and electricity, as a chemical feedstock, aviation fuel, or carbon storage medium. Previous studies have shown that biomass resources, while substantial, will likely be insufficient to meet global energy demand. As a result, there is an urgent need to set priorities for biomass use, and for these priorities to form the basis of national policies. This program will establish which uses of biomass have the greatest potential to reduce greenhouse gas emissions, without compromising other environmental goals. Prioritizing among different uses of biomass is complicated by the sheer number of possible product pathways: difference sources of biomass can be transformed using a wide variety of conversion technologies to produce a large number of different end products. This work will provide a critical evaluation of existing literature surrounding the climate impact of biomass-based energy and products, and identify which bio-based pathways achieve greenhouse gas reductions with the highest level of confidence. It will further address the monetary costs of these different pathways, and construct a framework to evaluate the impact of these pathways on other environmental metrics such as local air and water quality. This work comes at a critical time for Canada, which has among the world's largest biomass resources, but has only recently begun developing a national strategy surrounding uses of biomass (the bioeconomy'). Results are expected to guide both government and industrial decision makers toward more coherent policies for the development of biomass resources.