Integration of large scale electrochemical CO2 utilization with chlorine production using green elec

Publieke samenvatting / Public summary

The future is in renewable energy (RE) and to store it in platform molecules will be a critical part of the European energy and industry infrastructure. Conversion of CO2 to value added chemicals is of high interest; its use as a C1 feedstock offers the possibility to produce platform molecules such as CO and C2H4. Electrochemistry is a powerful method of synthesizing organic products. One example is the largest electrolytic chlor-alkali process to produce chlorine which is widely used for synthesis of chlorocarbon based intermediates. However, in most cases, the chemistry that occurs at the counter electrode yields a waste product, which holds little economic value (examples are the O2 from CO2 reduction process and HCl from chlor-alkali industry). To overcome this issue, we propose the concept of paired electrolysis, where useful products are produced at both electrodes without consuming more electricity. The concept involves the electro-oxidation of Cl- together with the electro-reduction of CO2, giving rise to valuable chemicals in a highly efficient manner from essentially waste materials.

The goal of this project is to develop a continuous electrochemical process (paired electrolysis) using waste materials (CO2 and HCl) to produce two valuable chemical products simultaneously by combining two large electrochemical processes: CO2 reduction to CO and chlorine production from HCl in one electrochemical reactor. This process is a breakthrough regarding higher electron efficiency (can be larger than 170%, compared to standard 70%) and lower capital costs (per product produced up to 50% lower compared to standard). This process will be demonstrated up to TRL4. Detailed techno-economic evaluation is part of the project.

Korte omschrijving
The main activities of this project comprise: • Investigation of performance of selected catalyst materials for anodic and cathodic reactions separately; • Optimization of reaction conditions (electrolyte, pH, temperature); • Integration of both reactions in a single electrochemical cell. Optimization of paired electrolysis; • Design of electrodes and continuous flow electrochemical reactor and auxiliaries including membrane design, mass-, heat-transfer and electrochemical reaction, for measurement validation and scale-up design calculations; • Construction of the reactor, optimization of continuous paired electrolysis and stability testing of the reactor and its components; • Demonstration of a bench scale continuous paired electrolysis of CO2 and Cl-; • Process concept; • System analysis to assess the potential of this technology for grid balancing and CO2 utilization and Cl2 production • Evaluation of economic impact;

The expected result is an operational continuous bench-scale electrochemical flow reactor for coproduction of CO and Cl2 including: - Experimentally validated key performance indicators; - Profitability of business case based on experimental results; - Technology development implementation plan for scale-up; - Dissemination through relevant fora.