户用沼气模式生命周期减排清单与环境效益分析

相对于传统农业活动,以沼气为纽带的生态农业生产具有清洁的能源生产和高度闭环的废物回收处置等明显优势,在全国范围内得到入户推广。本文综合考虑沼气工程建造、使用和综合利用等生命周期过程,分析了典型户用沼气池综合利用各阶段环境节能减排清单,并在此基础上评价其环境效益。结果表明,"猪-沼-稻-果"综合农业利用模式下单位沼气池节能减排效果明显,其中CO2、PM10、CH4和CO净减排量分别达3 060.700kg、19.820kg、12.960kg和75.590kg,总净节能达9 068.4MJ。其中,玉米秸秆、沼液沼渣的利用和燃煤替代对温室效应的减缓明显,畜禽粪便的利用和燃煤的替代减缓了环境酸化以及富营养化过程,而光化学氧化的减缓主要来自玉米秸秆的利用而减少的CO、VOC的排放,沼气工程对人体毒害的减缓主要是来自燃煤替代而减少的SO2和PM10排放。户用沼气利用对各种环境影响均有减缓作用,其中对光化学氧化、富营养化、环境酸化和温室效应的改善最为显著,对于降低能源耗竭、减缓对人体的毒性也起到了较好的作用。

Life-cycle Emission Mitigation Inventory and Environmental Benefit of Household Biogas Mode

Compared with traditional agricultural activities,the biogas-linked eco-agricultural production has obvious advantages such as clean energy production and closed-loop waste disposal,and thus has been promoted in many families across the country.Considering all the life-cycle stages in biogas construction,utilization and comprehensive utilization,this paper analyzed the emission mitigation inventory of a typical household biogas mode for all these stages based on which the pertinent environmental benefits are evaluated.The results show that in this biogas comprehensive utilization mode,the net decrease of CO2,CH4 and CO emissions are 3 060.700 kg,12.960 kg and 75.590 kg,respectively,while the total net energy saving is 9 068.4 MJ.The utilization of corn stalks,biogas slurry and residue has a significant mitigation effect on global warming,while manure utilization and burning coal replacement mitigate the acidification eutrophication process of the environment,and photochemical oxidation is alleviated through the reduced emissions of CO and VOC due to corn stalks utilization,and finally,biogas engineering ease human toxicity by decreasing emissions of SO2 and PM10 to the environment.The studied household biogas mode plays a role in the mitigations of all the environmental impacts,in which the mitigation effect of photochemical oxidation,eutrophication,acidification,global warming are most significant,while some extent of depressions in energy consumption and human toxicity are also found.