Simulations have shown that it should be possible (within a relatively short time frame) to profitably synthesize high-purity carbon-neutral ethanol, gasoline, jet fuel, propylene, and many other hydrocarbons, in volumes that cannot be matched by any other renewable avenue, from captured CO2, water, and cheap off-peak low-carbon energy, notably form wind farms. The process, dubbed WindFuels, requires no biomass, and it is expected to solve the grid stability and energy storage challenges of wind energy. The process is based largely on the commercially proven technologies of wind energy, water electrolysis, and Fischer Tropsch Synthesis (FTS) chemistry. Wind energy is used to electrolyze water into hydrogen and oxygen. Some of the hydrogen is used in a process, the so-called reverse water gas shift (RWGS) reaction, that reduces CO2 to carbon monoxide (CO) and water. The CO and the balance of the hydrogen are fed into an FT reactor, similar to that commonly used to produce fuels and chemicals from coal or natural gas. Improved sub-processes have been simulated in detail, and key experiments will soon be carried out to help optimize process conditions. Conversion efficiencies (from input electrical to output chemical) are expected to approach 60%. Putting renewable hydrogen into liquid fuels solves the distribution and storage problems that have beset utilization of hydrogen in vehicles. Converting CO2 into fuels can eliminate the need for CO2 sequestration and reduce global CO2 emissions by 40% by mid-century. The amount of water needed for the renewable FTS (RFTS) process is an order of magnitude less than needed for biofuels. The atmosphere will eventually provide an unlimited source for CO2, though initially the CO2 would come from ammonia plants, biofuel refineries, cement factories, fossil power plants, and ore refineries. When the input energy is from off-peak wind and reasonable monetary credit is included for climate benefit, WindFuels could compete when petroleum is as low as $45/bbl.

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