Chiriboga Gonzalo, De La Rosa Andrés, Molina Camila, Velarde Stefany, Carvajal C Ghem
Central University of Ecuador, Chemical Engineering Faculty, Jerónimo Ritter S/N and Bolivia Quito, Ecuador.
Heliyon. 2020 Jun 28;6(6):e04213. doi: 10.1016/j.heliyon.2020.e04213. eCollection 2020 Jun.
In Ecuador, the net energy contribution of biofuels is unknown or unnoticed. To address this issue, we determined the Energy Return on Investment (EROI) for bioethanol and biodiesel. The selection of raw materials relied on their productive capacity, export and import records, and historical yields. Consequently, the scope included three raw materials for ethanol (sugar cane, corn, and forest residues) and four for biodiesel (African palm, pinion, bovine fat, and swine fat). Using a method based on the Life Cycle Analysis (LCA) of each biofuel, we assessed the entire production chain through statistical processing of primary and secondary information. Then we calculated the calorific values in the laboratory, compared energy inputs/outputs, and finally obtained the energetic returns. EROIs for bioethanol were: 1.797 for sugarcane, 1.040 for corn, and 0.739 for wood. The results for biodiesel were: 3.052 for African palm, 2.743 for pinion, 2.187 for bovine fat, and 2.891 for swine fat. These values suggest feasibility only for sugarcane in the case of ethanol. In contrast, biodiesel has better prospects because all the feedstocks analyzed had EROIs higher than two. Nevertheless, biodiesel is not available for trading in Ecuador because energy policy has overlooked systems based on higher energy return. Future studies should consider more comprehensive variables such as climate change, land use, and water management.
在厄瓜多尔，生物燃料的净能源贡献尚不明确或未受到关注。为解决这一问题，我们确定了生物乙醇和生物柴油的能源投资回报率（EROI）。原材料的选择依据其生产能力、进出口记录以及历史产量。因此，范围涵盖了三种用于生产乙醇的原材料（甘蔗、玉米和森林残留物）以及四种用于生产生物柴油的原材料（非洲棕榈、小齿轮、牛脂和猪脂）。我们采用基于每种生物燃料生命周期分析（LCA）的方法，通过对一级和二级信息的统计处理来评估整个生产链。然后我们在实验室中计算热值，比较能源投入/产出，最终得出能源回报。生物乙醇的EROI分别为：甘蔗1.797、玉米1.040、木材0.739。生物柴油的结果为：非洲棕榈3.052、小齿轮2.743、牛脂2.187、猪脂2.891。这些数值表明，就乙醇而言，仅甘蔗具有可行性。相比之下，生物柴油前景更佳，因为所有分析的原料EROI均高于2。然而，由于能源政策忽视了基于更高能源回报的系统，生物柴油在厄瓜多尔无法进行交易。未来的研究应考虑更全面的变量，如气候变化、土地利用和水资源管理。
