日本食品废物不同资源化技术下的碳排放比较研究

Comparative study on CO_(2) emissions under different recycling technologies for food waste in Japan

应用生命周期评价法(LCA),采用日本农林水产省和环境省的调查数据和统计数据,对不同资源化技术处理食品废物碳排放进行评价.10种资源化技术相比于3种非资源化(主要是焚烧)技术的结果表明,食品废物生命周期各阶段碳排放最多的是预处理+处理阶段,约占85%;最少的是回收阶段,可抵消部分排放.此外,全生命周期总排放,甲烷化(循环消化液)是最有利于温室气体减排的技术,可减排380.6kg CO_(2)e/t,通过调节参数核算日本城市生活垃圾的减排潜力每年约为5586万tCO_(2)e.甲烷化(单纯)、肥料化均减少温室气体排放,并且前者减排效果优于后者.而废物固形燃料(RDF)、甲烷化(与地下水混合)、饲料化(液化)、甲烷化(混合焚烧)、碳化、乙醇化、饲料化(额外干燥)与发电焚烧、无发电焚烧、焚烧可燃垃圾(无发电)依次增加了温室气体的排放.不考虑再生品的异地运输,则甲烷化(与地下水混发电焚烧合)相比饲料化(液化)产生更少的温室气体排放,其他次序按照技术的优劣性保持不变.

Based on life cycle assessment(LCA),survey data and statistical data from the Ministry of Agriculture,Forestry and Fisheries of Japan and Ministry of Environment of Japan were used to evaluate CO_(2) emissions of food waste under different recycling or non-recycling treatment systems.The research makes comparisons of CO_(2) emissions reduction caused by 10 kinds of recycling technology and 3non-recycling(mainly incineration)treatment technologies.The results show that,pretreatment and treatment stages combined accounts for almost 85%CO_(2) emissions,and the least is recycling stage,which can offset part of the emissions.As for the total emission,methanation(circulating digestive liquids)is the most favorable one with 380.6kg CO_(2)e/t reduction a year.In addition,it turns out that methanation(only)and fertilization can reduce CO_(2) emissions,while solidification of combustible waste(RDF),methanation(mixed with underground water),feed(liquefaction),methanation(mixed with incineration),carbonization,ethanol,feed(extra drying)and incineration(power generation),incineration(no power generation),incineration of combustible waste(no power generation)all increase the CO_(2) emission successively.While excluding recycling products transportation,methanation(mixed with underground water)will produce less CO_(2) emission than the feed(liquefaction),and the other order will remain the same according to the advantages and disadvantages of technologies.