A direct electrochemical substitution electrodialytic system for CO2 conversion into high value-added soda

The growth of CO2 emissions is a critical challenge to the global ecological system. Meanwhile, the rising use of evaporation units in industrial wastewater treatment plants has generated a large number of salts with low values for further valorization. In this study, a direct electrochemical substitution electrodialytic system is proposed for the conversion of CO2 and Na2SO4 into high value-added NaHCO3 and H2SO4. The CO2 is absorbed with poly-ethyleneimine and further metathesized with inorganic salts in an electrodialytic reactor. This unique system achieves soda preparation by avoiding the use of ammonia as a feedstock and demonstrates the ability to capture and convert CO2 at a specific energy consumption of 1.2 kWh/kg NaHCO3 and a current efficiency of 83%. This proof-of-concept study provides a highly effective technological pathway for the conversion of notorious wastes into valuable resources, creating possibilities for concurrent carbon reduction and wasted salt utilization.

Automated summary

A direct electrochemical substitution electrodialytic system is proposed to convert CO2 and Na2SO4 into high value-added NaHCO3 and H2SO4. The system achieves soda preparation without using ammonia as a feedstock, with a specific energy consumption of 1.2 kWh/kg NaHCO3 and a current efficiency of 83%. This proof-of-concept study offers an effective technological pathway for converting notorious wastes into valuable resources, enabling concurrent carbon reduction and wasted salt utilization.