Municipal Solid Waste (MSW) to Liquid Fuels Synthesis, Volume 2: A Techno-economic Evaluation of the Production of Mixed Alcohols

Abstract

Biomass is a renewable energy resource that can be converted into liquid fuel suitable for transportation applications and thus help meet the Energy Independence and Security Act renewable energy goals (U.S. Congress 2007). However, biomass is not always available in sufficient quantity at a price compatible with fuels production. Municipal solid waste (MSW) on the other hand is readily available in large quantities in some communities and is considered a partially renewable feedstock. Furthermore, MSW may be available for little or no cost. This report provides a techno-economic analysis of the production of mixed alcohols from MSW and compares it to the costs for a wood based plant. In this analysis, MSW 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 2000 metric 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 (early 2008 $). However, favorable economics are dependent upon the toxicity characteristics of the waste streams and that a market exists for the by-product scrap metal recovered from the RDF process.

Life Cycle Greenhouse Gas Emissions and Costs of Production of Diesel and Jet Fuel from Municipal Solid Waste

“…Due to data limitations, we assess only the effect of different conversion efficiencies for the ATJ MD fuel pathway. The higher fuel yield is based on future projections by Mu et al and the lower fuel yield is based on a conservative estimate by Jones et al, which also forms the lower bound in the uncertainty assessment. These cases and other conversion efficiency scenarios are detailed in Tables S6–S8 in the SI.…”

“…Noncombustibles such as metals, glass, and other inorganics are sorted out, resulting in a higher heating value feedstock, which is then sized to meet the requirements of the gasifier. The preprocessing system is based on the Refuse Derived Fuel (RDF) facility model presented by Jones et al Assuming an average sorting efficiency of 90%, approximately 15% of the MSW feed is separated out during the preprocessing.…”

“…However, existing empirical evidence shows the emergence of long-term, zero-cost MSW feedstock contracts . We, therefore, follow Jones et al and assume zero feedstock cost for the baseline analysis but quantify the sensitivity of results to positive and negative feedstock costs. To quantify the costs of production of MD fuels produced from MSW, we calculate minimum selling prices (MSP) and net present value (NPV) of plant operation by adopting the discounted cash flow rate of return (DCFROR) model from Pearlson et al for a 20-year plant life .…”

“…Further financial assumptions are listed in Table S3. Facility capital cost estimates are obtained from the literature referenced for material and energy balances for each pathway. ,, In some cases, the estimates are supplemented with additional capital costs of the processes that are not modeled in the particular studies, such as MSW preprocessing, naphtha reforming to gasoline, and alcohol-to-jet conversion. The material and energy balances calculated for the LCA are carried over to the TEA to calculate operating costs and sales revenues.…”

Process synthesis and optimization of biorefinery configurations

“…Several articles have focused on the technoeconomic analysis and optimization of specific production pathways such as ethanol,23–27 biodiesel,28, 29 mixed alcohols and transportation fuels,30–32 and energy 33, 34. There is also research to establish processing routes with minimum energy consumption before establishing the optimal products 3, 35–37.…”