Krogh Andreas, Junginger Martin, Shen Li, Grue Jeppe, Pedersen Thomas H
Department of Energy, Aalborg University, Pontoppidanstræde 111, 9220 Aalborg Ø, Denmark.
Copernicus Institute of Sustainable Development, Utrecht University, the Netherlands.
Sci Total Environ. 2024 Aug 25;940:173660. doi: 10.1016/j.scitotenv.2024.173660. Epub 2024 Jun 2.
The use of sustainable biomass can be a cost-effective way of reducing the greenhouse gas emissions in the maritime and aviation sectors. Biomass, however, is a limited resource, and therefore, it is important to use the biomass where it creates the highest value, not only economically, but also in terms of GHG reductions. This study comprehensively evaluates the GHG reduction potential of utilising forestry residue in different bioenergy technologies using a consequential LCA approach. Unlike previous studies that assess GHG impacts per unit of fuel produced, this research takes a feedstock-centric approach which enables comparisons across systems that yield diverse products and by-products. Three technologies-combined heat and power plant with carbon capture, hydrothermal liquefaction, and gasification-are assessed, while considering both carbon capture and storage (CCS) or carbon capture and utilisation (CCU). Through scenario analysis, the study addresses uncertainty, and assumptions in the LCA modelling. It explores the impact of energy systems, fuel substitution efficiency, renewable energy expansion, and the up/down stream supply chain. All technology pathways showed a potential for net emissions savings when including avoided emissions from substitution of products, with results varying from -111 to -1742 kgCO per tonne residue. When combining the bioenergy technologies with CCU the dependency on the energy system in which they are operated was a significantly higher compared to CCS. The breakpoint was found to be 44 kg CO/kWh electricity meaning that the marginal electricity mix has to be below this point for CCU to obtain lower GHG emissions. Furthermore, it is evident that the environmental performance of CCU technologies is highly sensitive to how it will affect the ongoing expansion of renewable electricity capacity.
使用可持续生物质能可能是减少海运和航空部门温室气体排放的一种经济有效的方式。然而，生物质是一种有限的资源，因此，重要的是在能创造最高价值的地方使用生物质，不仅在经济方面，而且在温室气体减排方面。本研究采用相应生命周期评价方法，全面评估了在不同生物能源技术中利用林业残余物的温室气体减排潜力。与以往评估每单位生产燃料的温室气体影响的研究不同，本研究采用以原料为中心的方法，能够对产生不同产品和副产品的系统进行比较。评估了三种技术——带碳捕获的热电联产厂、水热液化和气化——同时考虑了碳捕获与封存（CCS）或碳捕获与利用（CCU）。通过情景分析，该研究解决了生命周期评价建模中的不确定性和假设。它探讨了能源系统、燃料替代效率、可再生能源扩张以及上下游供应链的影响。当包括产品替代产生的避免排放时，所有技术途径都显示出净排放节省的潜力，结果从每吨残余物-111至-1742千克二氧化碳不等。当将生物能源技术与CCU相结合时，与CCS相比，它们对运行所在能源系统的依赖性显著更高。发现断点为44千克二氧化碳/千瓦时电力，这意味着边际电力组合必须低于这一点，CCU才能获得更低的温室气体排放。此外，很明显，CCU技术的环境性能对其将如何影响可再生电力容量的持续扩张高度敏感。
