生物质气化合成-尾气发酵制备混合醇系统[火用]及环境影响分析

EXERGY AND LIFE CYCLE ENVIRONMENTAL ANALYSIS OF MIXED ALCOHOL PRODUCTION SYSTEM VIA PATHWAY OF BIOMASS GASIFICATION, CATALYTIC SYNTHESIS AND TAIL GAS FERMENTATION

以林业废弃木屑为原料,构建经气化、合成气催化合成、尾气发酵制乙醇的混合醇制备新工艺模型,对系统物质和能量流动、系统/子系统[火用]效率及损失来源进行分析。通过收集林业、收储运、制备和产品运输等不同阶段的资源能量消耗和排放清单,对包括全球变暖潜值、臭氧层耗竭潜值等9种环境影响类型开展分析。结果表明:尾气发酵子系统,可利用微生物菌株代谢尾气中CO和CO_(2)来制备乙醇,结合催化合成高级醇的高产率,使得耦合系统混合醇质量收率和[火用]效率分别达0.328 kg/kg木屑和43.8%。混合醇生命周期内,人体非致癌损害和陆地生态毒性是受影响较大的环境类型,分别来源于制备和收储运阶段。

A new process for mixed alcohol production via the pathway of gasification of forestry residue(wood chip),catalytic synthesis and tail gas fermentation was simulated in this study.The mass and energy flow of the system,the exergic efficiency of the system/subsystem and the source of exergic loss were analyzed.Through the collection of resource energy consumption and emission inventories at different stages of forestry,storage and transportation,preparation and product transportation,nine types of environmental impacts,including global warming potential and ozone depletion potential,were analyzed.The results show that the tail gas fermentation subsystem can use microbial strains to metabolize CO and CO2 in the tail gas to prepare ethanol and can obtain high yield of higher alcohols by catalyzed synthesis.The mixed alcohol yield and exergy efficiency can reach 0.328 kg/kg wood chips and 43.8%respectively.During the life cycle of mixed alcohol,non-carcinogenic damage to human body and terrestrial ecological toxicity are the most affected environmental types,which came from the preparation and storage and transportation stages respectively.