Feasibility of producing bio-ethanol from waste residues: A Canadian perspective: Feasibility of producing bio-ethanol from waste residues in Canada

Abstract

To date, the ethanol production industry in Canada is comprised mainly of small-scale plants producing ethanol primarily from agricultural crops as feedstocks. Research interests in the area of bio-ethanol production from organic waste materials emerged in the late 1980s. Significant advances in lignocellulosic material extraction and enzymatic hydrolysis have been reported in the last decade, however, continued research efforts are critical for the development of technically feasible and economically viable large-scale enzyme-based biomass-to-ethanol conversion processes which employ organic waste materials as alternative sources of feedstocks. The source of the lignocellulosic material, waste management practices and delignification procedures have a significant impact on the quantity and quality of delignified materials derived from these lignocellulosic feedstocks. The success of cellulose-to-ethanol conversion from lignocellulosic material feedstocks is generally a function of fibre pre-treatment, enzyme selection and operating conditions. These will differ depending on the source of the biomass feedstock. This paper illustrates the potential that Canada has to utilize its residual or waste biomass resources to provide a renewable and sustainable supply of bio-ethanol to help meet Canada's future energy needs. Canada could produce 5336 million L of bio-ethanol annually based on the recoverable fraction of crop residues generated in 2001. Based on bio-ethanol feasibility studies conducted on livestock manures and municipal biosolids and sludges, an estimated 6.22 Mt/year of sugar could be produced from this waste biomass for subsequent fermentation to bio-ethanol. The long-term benefits of using waste residues as lignocellulosic feedstocks will be to introduce a sustainable solid waste management strategy for a number of lignocellulosic waste materials; contribute to the mitigation in greenhouse gases through sustained carbon and nutrient recycling; reduce the potential for water, air, and soil contamination associated with the land application of organic waste materials; and to broaden the feedstock source of raw materials for the bio-ethanol production industry.