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要成为化石能源的有效替代品,生物燃料必须能提供净能量收益,能产生环境效益,具有经济效率,且在大量生产的情况下不引起粮食危机。麻疯树作为第二代生物柴油的重要原料作物,在国内得到大力推广,但实际效率尚不清楚。基于将麻疯树种子油与化石柴油直接混合使用的技术选择,利用生命周期评估法分析了麻疯树种子油生命周期的经济、环境和能量效率。结果表明:(1)在当前产量和生产技术水平下,生产和使用麻疯树种子油的财务净现值为负,要促进麻疯树种子油的生产,需要每年为种子生产者提供881.7元/hm2以上的补贴,为榨油厂商提供2.68元/L的补贴;(2)生产和使用每升麻疯树种子油可减少约13kgCO2当量的温室气体排放,固碳价值为补贴生产提供了部分经济依据,但是仅考虑种子油和固碳的价值时,生产和使用麻疯树种子油尚不具有经济可行性;(3)当仅考虑种子油的能量产出时,只有当种子产量达到795kg/hm2以上才具有能量效率;当把树枝和果壳等所包含的生物质能计算在内时,在较低种子产量的情况下,也具有显著的能量效率。敏感性分析表明,随着麻疯树种子产量的增加,财务净现值趋于下降,但是种子油的成本下降,减排温室气体的贡献和能量效率都增加。最后,基于麻疯树种子油的生命周期分析,提出了提高经济、环境和能量效率的途径。
To be an effective substitute for fossil fuels, biofuels must be able to provide net energy benefits, generate environmental benefits, are cost-effective and do not cause a food crisis in mass production. As an important raw material of second-generation biodiesel, Jatropha curcas is widely promoted in China, but the actual efficiency is not yet clear. Based on the technical selection of Jatropha curcas seed oil blended directly with fossil diesel, the economic, environmental and energy efficiency of Jatropha curcas seed oil life cycle was analyzed by life cycle assessment. The results show that: (1) under the current production and production technology levels, the net present value of the financial production and use of Jatropha curcas seed oil is negative. To promote the production of Jatropha curcas seed oil, seed producers need to provide 881.7 yuan / hm2 subsidy of 2.68 yuan / L for oil mill manufacturers; (2) Production and use of Jatropha curcas seed oil per liter can reduce about 13kgCO2 equivalent of greenhouse gas emissions, and the carbon sequestration value provides part of subsidy production Economic basis, but considering the value of seed oil and carbon sequestration, the production and use of Jatropha seed oil is not yet economically viable; (3) when considering only the energy output of seed oil, only when the seed yield reaches 795 kg / hm2 or more is energy efficient; when biomass energy contained in branches and husks is taken into account, there is also significant energy efficiency at lower seed yields. Sensitivity analysis showed that with the increase of Jatropha seed production, the financial net present value tends to decline, but the cost of seed oil decreased, the contribution of greenhouse gas emission reduction and energy efficiency increased. Finally, based on the life-cycle analysis of Jatropha seed oil, approaches to improve economic, environmental and energy efficiency are proposed.