Department of Agroecology, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark.
Department of Agroecology, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark.
Sci Total Environ. 2017 May 15;586:226-240. doi: 10.1016/j.scitotenv.2017.01.207. Epub 2017 Feb 8.
The current study aimed at evaluating potential environmental impacts for the production of willow, alfalfa and straw from spring barley as feedstocks for bioenergy or biorefinery systems. A method of Life Cycle Assessment was used to evaluate based on the following impact categories: Global Warming Potential (GWP), Eutrophication Potential (EP), Non-Renewable Energy (NRE) use, Agricultural Land Occupation (ALO), Potential Freshwater Ecotoxicity (PFWTox) and Soil quality. With regard to the methods, soil organic carbon (SOC) change related to the land occupation was calculated based on the net carbon input to the soil. Freshwater ecotoxicity was calculated using the comparative toxicity units of the active ingredients and their average emission distribution fractions to air and freshwater. Soil quality was based on the change in the SOC stock estimated during the land use transformation and land occupation. Environmental impacts for straw were economically allocated from the impacts obtained for spring barley. The results obtained per ton dry matter showed a lower carbon footprint for willow and alfalfa compared to straw. It was due to higher soil carbon sequestration and lower NO emissions. Likewise, willow and alfalfa had lower EP than straw. Straw had lowest NRE use compared to other biomasses. PFWTox was lower in willow and alfalfa compared to straw. A critical negative effect on soil quality was found with the spring barley production and hence for straw. Based on the energy output to input ratio, willow performed better than other biomasses. On the basis of carbohydrate content of straw, the equivalent dry matter of alfalfa and willow would be requiring higher. The environmental impacts of the selected biomasses in biorefinery therefore would differ based on the conversion efficiency, e.g. of the carbohydrates in the related biorefinery processes.
本研究旨在评估以春大麦为原料生产柳树、紫花苜蓿和秸秆作为生物能源或生物炼制系统原料的潜在环境影响。采用生命周期评估方法，根据以下影响类别进行评估：全球变暖潜势（GWP）、富营养化潜势（EP）、不可再生能源（NRE）使用、农业土地占用（ALO）、潜在淡水生态毒性（PFWTox）和土壤质量。关于方法，与土地占用相关的土壤有机碳（SOC）变化是根据土壤的净碳输入量计算的。淡水生态毒性是通过有效成分的比较毒性单位及其向空气和淡水的平均排放分布分数计算的。土壤质量基于土地利用转化和土地占用过程中 SOC 存量的变化。秸秆的环境影响是从春大麦获得的影响中经济分配的。每干物质吨的结果表明，与秸秆相比，柳树和紫花苜蓿的碳足迹更低。这是由于土壤碳固存较高和 NO 排放较低。同样，柳树和紫花苜蓿的 EP 低于秸秆。与其他生物质相比，秸秆的 NRE 使用量最低。与秸秆相比，柳树和紫花苜蓿的 PFWTox 较低。春大麦生产对土壤质量有负面影响，因此对秸秆也有负面影响。基于能量输出与输入的比值，柳树的性能优于其他生物质。基于秸秆的碳水化合物含量，相当于紫花苜蓿和柳树的干物质需要更高。因此，在生物炼制厂中，所选生物质的环境影响将根据相关生物炼制过程中碳水化合物的转化效率而有所不同。
