Techno-Economic Analysis of Synthetic Fuels Pathways Integrated with Light Water Reactors

Abstract

Synthetic fuels (synfuels) and chemicals (synchems) are produced by synthesis from chemical building blocks rather than by conventional petroleum refining. Synthesis gas or syngas (carbon monoxide and hydrogen) is a common intermediate building block in the production of synfuels and synchems. Syngas can be produced by many processes, including biomass or fossil fuel gasification and by co-electrolysis. In co-electrolysis, CO2 is reacted with water to roduce syngas. The CO2 can be sourced from processes that would otherwise eject the CO2 to the atmosphere, such as ethanol plants, including dozens of large plants in the United States that convert corn into ethanol that is being blended with the national gasoline, or fossil fuel processes, such as steam methane reforming or natural gas combined cycle (NGCC) power plants. CO2 is also emitted from biofuels gasification plants. Conversion of CO2, which would have otherwise been released to the atmosphere, to synfuels using nuclear energy is a potential avenue for adding value to existing light water reactor (LWR) facilities, while producing transportation fuels that are compatible with conventional fuels produced via petroleum refining. The cost of CO2 separation depends on the purity of the source. Valorization of CO2 is a critical complementary component of carbon capture and utilization (CCU) and an alternative to carbon capture and sequestration (CCS). The purpose of this work is to identify, model, perform techno-economic analysis, and compare two possible synfuel production routes utilizing CO2 as the feedstock. Heat from an LWR nuclear plant is integrated wherever possible to positively affect the economics of the LWR by converting power to fuels during times of low grid electricity demand. Process and economic modeling for a conceptual synfuel production plant co-located (or in near proximity) with an LWR is presented, including the cost of CO2 captured from an ethanol plant, compressed, and transported to the LWR hybrid plant, co-electrolysis of the CO2 with water in a solid oxide electrolyzing cell (SOEC) system to produce syngas, and thermocatalytic conversion of the syngas to transportation fuel. The hybrid LWR/synfuels plant is assumed to be located within 50–150 miles of an ethanol plant (e.g., located in the midwest region of the United States). Performance and nth-plant economics for the co-electrolysis-based processes are evaluated and compared with biomass-gasification-based technology for the synfuel routes considered. Sensitivity analysis around the price of CO2 and electricity, two of the major cost drivers, is presented for each case. Consideration of a carbon credit is also included in the sensitivity analysis.