Electrochemical production of syngas from CO₂at pressures up to 30 bar in electrolytes containing ionic liquid

Abstract

Electrochemical CO2reduction in a reactor that can operate up to 100 bar and 80 °C, with a configuration similar to that of an alkaline electrolyser, for hydrogen production suitable to be used industrially is reported for the first time.

Electrochemical conversion of pressurized CO2 at simple silver-based cathodes in undivided cells: study of the effect of pressure and other operative parameters

“…Indeed, this process may suffer of the potential formation of an explosive mixture of H 2 and O 2 and of a low CO 2 utilization rate; hence, further researches will be focused on this topic and various strategies will be tested, including: (i) the implementation of sacrificial anodes to avoid the O 2 evolution reaction; (ii) the utilization of higher-selective CO 3D-cathodes (mesh, perforated, foam) to suppress the H 2 production and improve the CO productivity at high pressure; (iii) the development of a novel reactor configuration operating in continuous mode, in order to prevent the mixing of potentially formed cathodic co-product, hydrogen, with the anodic product, oxygen and to increase the conversion rate. It is worth to mention that a similar alternative to the latter was successfully evaluated by some authors [36,55], which have estimated an improvement of the CO 2 conversion rate up to 26% and an enhancement of the selectivity towards CO using a divided semi-continuous mode system under pressurized conditions.…”

“…To enhance CO 2 solubility and its reduction rate to added value products, other researchers are focusing their attention on the utilization of pressurized CO 2 in aqueous electrolyte [37][38][39][40][41][42][43][44][45][46][47][48] or in ionic liquid-based electrolytes (ILs) [49][50][51][52][53][54][55]. Indeed, according to several authors, the pressure can affect the selectivity between CO 2 and water reduction, the distribution of the CO 2 reduction products and overpotentials need to drive the reaction [37][38][39][40][41][42][43][44][45][46].…”

Sunlight-driven CO2-to-fuel conversion: Exploring thermal and electrical coupling between photovoltaic and electrochemical systems for optimum solar-methane production

“…Usually high temperature and pressure facilitates the chemical reaction but require a more robust and less affordable apparatus. However, the higher costs of working at higher pressure may be compensated by increased energy efficiencies, due to minimization of intermediate compression steps and the direct coupling of downstream high pressure processes [16], [17]. The use of different electrodes and catalysts could influence both the overpotential of the process, sometimes making it more energetically consuming, and the pathway of the reaction, outputting different products such as methane (CH4), ethanol (CH3CH2OH), carbon monoxide (CO), hydrogen (H2) and other compounds (e.g.…”

“…For the Pressure rise calculations we apply Equation (17). Considering an initial pressure of 1 atm (output of EC cell) and final pressure of 30 atm we obtain a total cost of 1.96 kWhm -3 (0.33 kWhm -3 for 10 atm).…”

Carbon Materials as Cathode Constituents for Electrochemical CO2 Reduction—A Review

“…Liquid phase electrolysis needs further breakthroughs in terms of materials for electrodes, membranes and electrolytes that will allow the higher mass transfer limitations to be overcome, when compared with gas-phase electrolysis. However, this operation mode presents important advantages namely allowing the integration of CO 2 capture and conversion [51] and achieving higher conversions avoiding the costs of separating unreacted CO 2 from gaseous electrolysis products [95,96]. The development of cost-effective 3D materials with pore engineered structures that can be used directly as electrodes is an important nascent R&D avenue.…”