LCA of three thermal treatment methods of agricultural waste

Abstract

Biomass energy is becoming more and more popular, and agricultural waste has attracted attention. The “waste to energy” technology has good economic and market potential. The traditional treatment method of agricultural waste is to burn or discard directly on site, and a large amount of harmful substances are directly discharged into the atmosphere. It can cause global warming, eutrophication of water bodies, and damage to the ozone layer. In this study, three thermal treatment methods of direct incineration, pyrolysis and gasification are combined with three energy recovery methods (steam turbine, gas turbine and internal combustion engine) to form 7 treatment systems for comparison. The data involved is collected according to the four main processes of the system: pretreatment, thermal treatment, energy recovery and ash management. The pyrolysis-steam turbine system is the best because of its higher energy production and lower energy consumption. A sensitivity analysis of the efficiency of the treatment plant was conducted, and it was confirmed that the plant efficiency had a crucial impact on the thermal treatment system. It is to use high-efficiency energy conversion systems such as CCGT to improve efficiency. New technologies such as pyrolysis and gasification processes combined in one plant and indirect gasification methods are used to further process the products into higher value products. Optimizing the flue gas treatment system to effectively reduce the emissions of heavy metals, particulate matter and PCDD.