Making Fischer−Tropsch Fuels and Electricity from Coal and Biomass: Performance and Cost Analysis

Abstract

Major challenges posed by crude-oil-derived transportation fuels are high current and prospective oil prices, insecurity of liquid fuel supplies, and climate change risks from the accumulation of fossil fuel CO2 and other greenhouse gases in the atmosphere. One option for addressing these challenges simultaneously involves producing ultraclean synthetic fuels from coal and lignocellulosic biomass with CO2 capture and storage. Detailed process simulations, lifecycle greenhouse gas emissions analyses, and cost analyses carried out in a comprehensive analytical framework are presented for 16 alternative system configurations that involve gasification-based coproduction of Fischer−Tropsch liquid (FTL) fuels and electricity from coal and/or biomass, with and without capture and storage of byproduct CO2. Systematic comparisons are made to cellulosic ethanol as an alternative low GHG-emitting liquid fuel and to alternative options for decarbonizing stand-alone fossil-fuel power plants. The analysis indicates that FTL fuels are typically less costly to produce when electricity is generated as a major coproduct than when producing mainly liquid fuel. Coproduction systems that utilize a cofeed of biomass and coal and incorporate CO2 capture and storage in the design offer attractive opportunities for decarbonizing liquid fuels and power generation simultaneously. Such coproduction systems considered as power generators can provide decarbonized electricity at lower costs than is feasible with stand-alone fossil-fuel power plant options under a wide range of conditions. At a plausible GHG emissions price under a future U.S. carbon mitigation policy ($50/t CO2eq), such a coproduction system built at a scale suitable for competing as a power generator would be able to provide low-GHG-emitting synthetic fuels at the same estimated unit cost as for coal synfuels characterized by ten times the GHG gas emission rate that are produced in a plant with CO2 capture and storage that does not provide electricity as a major coproduct having three times the synfuel output capacity and requiring twice the total capital investment. Moreover, the low GHG-emitting synfuels produced by such systems would be less costly to produce than cellulosic ethanol and require only half as much lignocellulosic biomass.

Cogasification of Coal and Biomass: A Review

“…Greenhouse emissions from coal gasification are higher than that from biomass gasification [45]. This could be due to the high carbon content and low volatile percentage in coal [14].…”

“…For measuring greenhouse emissions, the GHGI (greenhouse gas emission index) is used, which is defined as the lifecycle greenhouse gas emission associated with the energy products divided by the lifecycle greenhouse gas emissions associated with the fossil-fuel-derived products displaced [45]. In a study conducted to produce electricity and FT (Fisher Tropsch) liquids from coal and biomass, Lui et al [45] found that GHGI was 1.71 for coal gasification which came down to 0.96 when a mixture of 40% biomass-60% coal was used as feedstock. From these results, it can be concluded that using biomass with coal is beneficial for the environment in terms of greenhouse gas emissions.…”

Storage capacity assessment of liquid fuels production by solar gasification in a packed bed reactor using a dynamic process model

“…Two options to upgrade the syngas produced with the packed bed solar gasifier are, electricity generation (typically in a combined cycle gas turbine system) [23][24][25] and/or the production of synthetic crude oil by a Fischer-Tropsch process [23,[26][27][28][29][30] (see Fig. 2).…”

Ultraclean Fuels Production and Utilization for the Twenty-First Century: Advances toward Sustainable Transportation Fuels

“…2 On the other hand, because of its non-renewable nature, high consumption rates, and the limited reserves of petroleum, transportation fuels from non-petroleum resources have long been extensively explored. [3][4][5][6][7] Among the available choices, the mixture of carbon monoxide and hydrogen (syngas) derived from other carbon-based resources such as coal, natural gas, and biomass has been proven a versatile platform for the synthesis of liquid fuels and high-value added chemicals. [4][5][6][7] Changing environmental regulations in the U.S and abroad are also a major driving force for the production of ultraclean fuels.…”