(553d) Municipal Solid Waste (MSW) to Liquid Fuels Synthesis: A Techno-Economic Evaluation of the Production of Mixed Alcohols

Municipal solid waste (MSW) is a potential gasifier feedstock that presents opportunity to produce alternative liquid fuels because of its availability in significant amounts at current landfills and because it is a predominantly biomass-derived material that, like conventional biomass feedstocks (such as wood), is a mostly renewable resource. The viability of MSW as a gasifier feedstock for liquid fuels synthesis depends on several factors. Foremost is the availability of MSW in sufficient quantities to meet the minimum process scale required for economic feasibility. That scale is identified, in this study, to be 3,300 short tons per day (as received) or more of MSW. A preliminary review of available information on the number and size of various landfill sites around the country identified 47 sites that meet the minimum scale identified for economic feasibility. Together these sites could potentially produce enough liquid fuel to meet approximately 1.4% of current transportation fuel demand (about 113 MM bbl/year of liquid fuel). A greater contribution could be attained if smaller scale facilities are found to be feasible due to latitude in the tipping fee charged to MSW producers. This work provides a preliminary techno-economic analysis for the production of mixed alcohols from MSW. This study investigates MSW, as it is processed into refuse derived fuel (RDF) and then gasified in a plant co-located with a landfill. The resulting syngas is then catalytically converted to mixed alcohols. At a scale of 2200 short tons per day of RDF, and using current technology, the minimum ethanol selling price at a 10% rate of return is approximately $1.85/gallon ethanol. Favorable economics are dependent upon the toxicity characteristics of the waste streams.