Green house gases emissions in the production and use of ethanol from sugarcane in Brazil: The 2005/2006 averages and a prediction for 2020
Green house gases emissions in the production and use of ethanol from sugarcane in Brazil: The 2005/2006 averages and a prediction for 2020
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DOI：
10.1016/j.biombioe.2007.12.006
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发表时间：
2008-07-01
影响因子：
6
通讯作者：
Silva, Joao E. A. R.
中科院分区：
文献类型：
--
作者：
Macedo, Isaias C.;Seabra, Joaquim E. A.;Silva, Joao E. A. R.
这项工作评估了 2005/2006 年巴西甘蔗燃料乙醇生产和使用过程中的能源平衡和温室气体排放（以每年加工多达 1 亿吨甘蔗的工厂为样本），并针对 2020 年提出的保守情景。2005/2006 年化石能源比率为 9.3，如果采用已经商业化的技术，2020 年可能达到 11.6。对于无水乙醇生产，2005/2006 年温室气体排放总量为 436 kg CO2 eq m(-3) 乙醇，在 2020 年情景中减少至 345 kg CO2 eq m(-3)。避免的排放量取决于最终用途：巴西 E100 的使用量为（2005/2006 年）2181 kg CO2 eq m(-3) 乙醇，E25 的使用量为 2323 kg CO2 eq m(-3) 乙醇（无水）。在 2020 年假设的条件下，这两个值将增加约 26%，主要是由于剩余电力销售的大幅增加。已经进行了敏感性分析（使用 2005/2006 年的值），以调查整个巴西工厂一些重要参数的巨大变化对能源和排放平衡的影响。结果表明，甘蔗生产力和乙醇产量变化对这些平衡（以及平均甘蔗运输距离、土壤耕作水平等的影响）以及甘蔗渣和电力盈余对温室气体排放避免的影响很大。 (C) 2008 Elsevier Ltd. 保留所有权利。
This work presents the evaluation of energy balance and GHG emissions in the production and use of fuel ethanol from cane in Brazil for 2005/2006 (for a sample of mills processing up to 100 million tons of sugarcane per year), and for a conservative scenario proposed for 2020. Fossil energy ratio was 9.3 for 2005/2006 and may reach 11.6 in 2020 with technologies already commercial. For anhydrous ethanol production the total GHG emission was 436 kg CO2 eq m(-3) ethanol for 2005/2006, decreasing to 345 kg CO2 eq m(-3) in the 2020 scenario. Avoided emissions depend on the final use: for E100 use in Brazil they were (in 2005/2006) 2181 kg CO2 eq m(-3) ethanol, and for E25 they were 2323 kg CO2 eq m(-3) ethanol (anhydrous). Both values would increase about 26% for the conditions assumed for 2020 mostly due to the large increase in sales of electricity surpluses.A sensitivity analysis has been performed (with 2005/2006 values) to investigate the impacts of the huge variation of some important parameters throughout Brazilian mills on the energy and emissions balance. The results have shown the high impact of cane productivity and ethanol yield variation on these balances (and the impacts of average cane transportation distances, level of soil cultivation, and some others) and of bagasse and electricity surpluses on GHG emissions avoidance. (C) 2008 Elsevier Ltd. All rights reserved.