酒糟厌氧发酵-气化耦合制备燃气环境影响评价

ENVIRONMENTAL IMPACT ASSESSMENT ON FUEL GAS PRODUCTION FROM DISTILLER’S GRAINS BY ANAEROBIC DIGESTION COUPLED WITH GASIFICATION

厌氧发酵-气化耦合技术是一种高效的生物质燃气化技术,具备显著的能源转化优势。为准确评估厌氧发酵程度对该耦合系统环境效益的影响,利用全生命周期分析方法,通过Gabi软件对所建立的不同厌氧发酵时间下酒糟厌氧发酵-气化耦合制备燃气模型进行环境影响评价。结果表明:厌氧发酵-气化梯度耦合反应系统基于能量流产生的环境正面影响可抵消基于物质流产生的环境负面影响,从而使系统获得正面的综合环境效益。厌氧发酵时间为8 d时系统环境影响结果最优,其环境影响潜值为-2.02×10^(-9)。对厌氧发酵-气化耦合系统的耦合程度进行控制,可在优化系统能量收益的同时产生最有利的环境影响,从而为耦合技术的应用提供理论指导。

As an efficient conversion pathway to produce biomass fuel gas,the integrated anaerobic digestion and gasification process shows significant advantages in energy conversion.To ascertain the effect of anaerobic digestion degree on the environmental benefits,a model of gradient-controlled anaerobic digestion and gasification integration process was built,and the distiller’s grains were treated with different anaerobic digestion times.The life cycle analysis method and Gabi software were used to conduct the environmental impact assessment.Results showed that the energy produced by the gradient-controlled coupled system can not only cover the drying of the biogas residue,but also achieve net energy output.And the positive environmental impacts based on energy flow can offset the negative environmental impacts based on material flow,so that the system can obtain positive comprehensive environmental impacts.The optimal total potential environmental impact of a 1000 kg distiller’s grains system was-2.02×10^(-9) with anaerobic digestion treatment lasting for 8 days.The control of the coupling degree of anaerobic digestion and gasification process makes the coupled system optimize its net energy output and have the most favorable environmental impact,so as to provide theoretical guidance for the application of the coupled process.