Biowaste Treatment and Waste-To-Energy—Environmental Benefits

Abstract

Biowaste represents a significant fraction of municipal solid waste (MSW). Its separate collection is considered as a useful measure to enhance waste management systems in both the developed and developing world. This paper aims to compare the environmental performance of three market-ready technologies currently used to treat biowaste—biowaste composting, fermentation, and biowaste incineration in waste-to-energy (WtE) plants as a component of residual municipal solid waste (RES). Global warming potential (GWP) was applied as an indicator and burdens related to the operation of facilities and credits obtained through the products were identified. The environmental performance of a WtE plant was investigated in detail using a model, implementing an approach similar to marginal-cost and revenues, which is a concept widely applied in economics. The results show that all of the treatment options offer an environmentally friendly treatment (their net GWP is negative). The environmental performance of a WtE plant is profoundly affected by its mode of its operation, i.e., type of energy exported. The concept producing environmental credits at the highest rate is co-incineration of biowaste in a strictly heat-oriented WtE plant. Anaerobic digestion plants treating biowaste by fermentation produce fewer credits, but approximately twice as more credits as WtE plants with power delivery only.