LAUSR

Energy is required to convert CO2 into useful products. Thermodynamic arguments can be made to show that, if the energy for the conversion of CO2 is provided by combustion of fossil feedstock, it is not possible to consume more CO2 than is produced. Renewable energy, specifically renewable power, is generally assumed to be the energy source for CO2 utilization. Various options are available for using renewable power for mitigation of CO2 emissions, including electroreduction of CO2 to hydrocarbons, electrolysis of water to hydrogen, and power for battery electric vehicles. Thermodynamic and practical arguments can be used to rank the effectiveness of renewable power for CO2 mitigation for these options, using power for light duty transportation as an example. Renewable power used to reduce water to hydrogen, which is then used to convert CO2 into liquid fuels, is only one-fourth as effective at mitigating CO2 emissions compared to use of the renewable power in a battery electric vehicle. The direct electroreduction of CO2 to liquid fuels, even if achieved with 100% thermal efficiency, is only one-third as effective at mitigating CO2 compared to the battery electric vehicle.