Low-C power from fossil fuel and biomass with synthetic fuels coproduction

A novel approach is described for addressing simultaneously climate challenges for electricity generation and transportation fuels and energy insecurity challenges for transportation fuels. The approach involves: (i) coproducing electricity and liquid transportation fuels from biomass and a fossil fuel (coal or natural gas) with carbon capture and storage, and (ii) evaluating these systems as low-carbon (low-C) power generators as alternatives to new supercritical coal power plants that vent CO₂. Under a wide range of plausible future conditions, these systems could provide low-C electricity (and also low-C transportation fuels) at lower costs than could low-C stand-alone fossil-fuel power plant alternatives. One striking finding is that widespread deployment of coproduction systems could, via economic dispatch competition, drive natural gas combined cycle power plants out of baseload power markets at all GHG emission prices. There are five reasons for the prospective superior economic performances of coproduction plants compared to stand-alone power plants. Three hold without a C-mitigation policy: (i) the large credit for synfuel co-products at current or higher oil prices, (ii) the inherent low minimum dispatch cost of coproduction plants, and (iii) the energy efficiency gain offered by coproduction. The other two reasons are relevant only under a C-mitigation policy: (iv) the low CO₂ capture costs compared to capture costs for stand-alone power plants, and (v) levelized costs of electricity that decline sharply with greenhouse gas emission price at high (> 30%, HHV basis) biomass coprocessing rates. This approach represents not only an economically attractive way to decarbonize electricity and synfuels but also would provide an opportunity to make synfuels profitably at scales > 10,000 barrels per day in power-generation plant-scale applications that require only a modest fraction of the capital investment required for the 50,000 to 140,000 barrels per day facilities usually considered for making synfuels from coal or natural gas.