Life Cycle Assessment of Fuel Ethanol Production from Food Waste in Consideration of By-Product Utilization

In this paper, a life cycle assessment was used to evaluate fuel ethanol production from food waste with a capacity of 20 tons/day. The energy and pollution emissions during the whole process were recorded and compared by the method of electricity conversion to standard coal. Different indicators, such as GWP (global warming potential), ODP (ozone depletion potential), AP (acid potential), EP (possibility of eutrophication), POCP (photochemical oxidation potential), and DUST (dust), were used to perform an environmental impact analysis with and without by-product utilization. The result shows that the indicator sequence under the weighted factor sequence was AP > DUST > GWP > ODP > EP > POCP. The consideration of by-products decreased the values of GWP, AP, and DUST significantly; EP declined slightly; ODP and POCP increased; and the overall energy output was negative. The consideration of by-product utilization was determined to be environmentally friendly.