玉米燃料乙醇生命周期净能量分析

玉米燃料乙醇作为化石燃料的替代品,能量效率(净能量或能量比)是评价其可持续性的一个重要标准.基于生命周期清单分析原理,建立了玉米燃料乙醇的净能量分析方法.以我国夏玉米燃料乙醇的生产条件为例,计算了玉米燃料乙醇整个生命周期的能量效率并对其影响因素进行了分析,讨论了乙醇汽油混合燃料的节能效果.研究表明:玉米燃料乙醇具有一定的能量效益,干法和湿法工艺的能量效率(能量比)分别为1.25和1.04.通过玉米燃料乙醇生命周期内的能量输入比较可知,玉米生产和乙醇转化过程的化石能输入占有最大的比例,因而玉米种植过程中的氮肥、电力、柴油消耗和乙醇生产过程中蒸馏和脱水过程的能耗是影响玉米燃料乙醇能量效益的主要因素.

Net Energy Analysis of Corn Fuel Ethanol Life Cycle

Energy efficiency(net energy gain or energy ratio) of corn-based ethanol as a substitute for fossil fuel is an important criteria for assessing its sustainability.The method of net energy analysis for fuel ethanol from corn was developed based on principles of life cycle inventory(LCI) analysis.For the production state of fuel ethanol from summer corn in China,energy efficiency of the corn fuel ethanol life cycle system was estimated and its main influence factors were identified,and energy saving effect of some ethanol blended gasoline fuels was discussed.Corn fuel ethanol has certain energy benefits.The energy ratios for dry and wet milling process were 1.25 and 1.04 respectively.Through comparison of energy inputs in corn fuel ethanol life cycle,fossil energy inputs of corn production and ethanol conversion processes were identified as the most important,and therefore nitrogen fertilizer,electivity and diesel used in corn farming and energy consumption of distillation and dehydration process in ethanol production could be known as the most influential factors for the energy benefit of corn fuel ethanol.