• No indirect greenhouse gas emissions result from land-use changes in the growing and harvesting of biomass.

  • The price of subbitumimous Illinois #6 coal is $42 per dry ton.

  • Electricity generated as a coproduct is valued at $80/MWh, absent any price placed on greenhouse gas emissions.

  • The biomass and co-fed coal/biomass conversion plants are sized for biomass feed rates of approximately 4000 dry tons per day.

  • The biomass feedstock is Miscanthus, a high-yield perennial grass costing $101 per dry ton.

Costs and CO2Emissions

The estimated 2020 supply function for biomass cost versus availability is shown in Figure 5.3. The costs of two of the feedstocks—corn grain and hay—are based on recent market prices. The corn price in particular is assumed to have dropped sharply from the 2008 high of $7.88 per bushel to $3.17 per bushel in 2020, corresponding to $130 per dry ton—a price more consistent with its historical levels. The price of hay is assumed to be $110 per dry ton, also similar to historical prices. The costs of most of the other feedstocks—corn stover, straw, high-yield grasses (such as Miscanthus), normal-yield grasses (such as native and mixed grasses and switchgrass), and woody biomass—are estimated from the growing, harvesting, transportation, and storage costs reported in the literature. Finally, the cost of using municipal solid wastes is based on a rough estimate of the costs of gathering, transporting, and storing them; although such costs can be highly variable, the committee assumes that they add up to $51 per dry ton.

The costs of producing alternative liquid fuels through the various pathways were estimated on the basis of the feedstock, capital, and operating costs, the conversion efficiencies, and the assumptions outlined above. Figure 5.4 shows the estimated gasoline-equivalent7 costs of alternative liquid fuels, without a CO2 price, produced from biomass, coal, or combined coal and biomass. Liquid fuels are produced using biochemical conversion—to make cellulosic ethanol from Miscanthus—or using thermochemical conversion via FT or MTG. For thermochemical conversion, FT and MTG are shown both with and without CCS. The cost of ethanol produced from corn grain is also included in Figure 5.4. For

7

Costs per barrel of ethanol are divided by 0.67 to put ethanol costs on an energy-equivalent basis with gasoline. For FT liquids, the conversion factor is 1.0.



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