Abstract

This work conducts a life-cycle assessment (LCA) of ethanol production from sugarcane bagasse in the Indian context. A cradle-to-gate system boundary was considered, and a functional unit of 1 MJ of energy from ethanol was used. Eight pre-treatment technologies and four hydrolysis-fermentation technologies were considered, thereby comparing 32 process combinations. Process data were collected from various published studies, government reports and also personal communication, and were used to perform LCA. The ReCiPe and TRACI models were used to perform the impact assessment using OpenLCA 1.6.1. The results show that the dilute acid pre-treatment (DA) with simultaneous saccharification and fermentation (SSCF) processing route had lower impacts in most categories. The global warming potential for this combination was 0.132 kg CO₂ eq. per MJ, with 85% of the contribution due to steam generation. The impact can be reduced to 0.019 kg CO₂ eq. per MJ by using a natural gas for steam generation. Ammonia fiber explosion (AFEX) pre-treatment had the highest impact in many categories, primarily due to ammonia production, implying the importance of ammonia recycling. DA had a lower impact due to higher yields and lower biomass requirements. The water footprint ranged between 232 and 672 L/L of ethanol and was mostly dominated by agricultural water.

摘要

这项工作对印度甘蔗渣乙醇生产进行了生命周期评估 (LCA)。考虑了从摇篮到大门的系统边界，并使用了 1 MJ 乙醇能量的功能单位。考虑了八种预处理技术和四种水解-发酵技术，从而比较了 32 种工艺组合。过程数据是从各种已发表的研究、政府报告和个人交流中收集的，并用于执行 LCA。ReCiPe 和 TRACI 模型用于使用 OpenLCA 1.6.1 执行影响评估。结果表明，同时糖化发酵（SSCF）工艺路线的稀酸预处理（DA）对大多数类别的影响较小。这种组合的全球变暖潜能值为 0.132 kg CO₂当量 每 MJ，其中 85% 的贡献来自蒸汽产生。影响可降低至 0.019 kg CO ₂ eq。每 MJ 使用天然气产生蒸汽。氨纤维爆炸 (AFEX) 预处理在许多类别中的影响最大，主要是由于氨生产，这意味着氨回收的重要性。由于更高的产量和更低的生物量需求，DA 的影响较小。乙醇的水足迹在 232 到 672 L/L 之间，主要是农业用水。