Greenhouse Gas Emissions, Energy Efficiency, and Cost of Synthetic Fuel Production Using Electrochemical CO₂ Conversion and the Fischer–Tropsch Process

This study seeks to explore whether electrochemical reduction of CO₂ (using current US average and future low carbon electricity) will become a viable route for the reuse of CO₂ for producing synthetic fuel. This paper presents the results of a technical and economic analysis conducted for a pathway that converts CO₂ released from fossil fuel-burning power plants to diesel fuel via electrochemical reduction of CO₂ to CO and the Fischer–Tropsch process. Currently achievable performance levels for CO₂ electrolyzers and the Fischer–Tropsch process were used to compute key metrics, including (i) cost of the synthetic fuel, (ii) well-to-gate CO₂ emissions, and (iii) overall energy efficiency. An engineering and economic model framework was developed for the investigation. The discounted cash flow analysis method was employed to calculate the cost of diesel fuel using a 500 MW power plant as the CO₂ source. The model takes into account capital expenditures as well as operating costs for the reactors and auxiliaries. The final cost varies from 3.80 to 9.20 dollars per gallon in 2010 US dollars depending on the projected level of technology achieved. The WTG CO₂ emissions vary from 180% (nearly twice) to a reduction of 75% compared to that of the business as usual scenario without carbon sequestration. The well-to-gate energy efficiency varies from 41 to 65%

Nanoparticle Silver Catalysts That Show Enhanced Activity for Carbon Dioxide Electrolysis

Electrochemical conversion of CO₂ has been proposed both as a way to reduce CO₂ emissions and as a source of renewable fuels and chemicals, but conversion rates need improvement before the process will be practical. In this article, we show that the rate of CO₂ conversion per unit surface area is about 10 times higher on 5 nm silver nanoparticles than on bulk silver even though measurements on single crystal catalysts show much smaller variations in rate. The enhancement disappears on 1 nm particles. We attribute this effect to a volcano effect associated with changes of the binding energy of key intermediates as the particle size decreases. These results demonstrate that nanoparticle catalysts have unique properties for CO₂ conversion