An Assessment of Gasification-Based Biorefining at Kraft Pulp and Paper Mills in the United States, Part B: Results

Abstract

Commercialization of black liquor and biomass gasification technologies is anticipated in the 2010–2015 timeframe, and synthesis gas from gasifiers can be converted into liquid fuels using catalytic synthesis technol-ogies that are already commercially established today in the gas-to-liquids or coal-to-liquids industries. This set of two papers describes key results from a major assessment of the prospective energy, environmental, and financial performance of commercial gasification-based biorefineries integrated with kraft pulp and paper mills. Seven detailed biorefinery designs were developed for a reference mill in the southeastern United States, together with the associated mass/energy balances, air emissions estimates, and capital investment requirements. The biorefineries provide chemical recovery services and co-produce process steam for the mill, some electricity, and one of three liq-uid fuels: a Fischer-Tropsch synthetic crude oil (which could be refined to vehicle fuels at an existing petroleum refin-ery), dimethyl ether (a diesel engine fuel or propane substitute), or an ethanol-rich mixed-alcohol product. Compared with installing new Tomlinson power/recovery systems, biorefineries would require more capital investment and greater purchases of woody residues for energy use. However, because biorefineries would be more efficient, have lower air emissions, and produce a more diverse product slate, for nearly all cases examined, the internal rate of return (IRR) on the incremental capital investment lies between 14% and 18%, assuming a $50/bbl world oil price. The IRRs would more than double if plausible federal and state financial incentives were captured. Industry-wide adoption of such biorefining in the United States would provide significant energy and environmental benefits to the country.