Brines as autocatalytic reaction/separation platform to convert CO2 to organic carbonates: Integrating CO2 emissions and brines management

• First time integrating CO 2 conversion to organic compounds and brines management. • Experimental yields and kinetics insights comparable to other cyclic carbonate catalytic systems. • Competitive energy consumption of 1.87 kW/kg in comparison with reference processes. • Improved LCA impacts of 0.148 kg CO2 /kg and −0.144 m 3 water /kg derived against reference processes. • Universal platform extended to more hydrophobic cyclic carbonates by means of recycling byproducts. Several environmental issues are demanding urgent solutions to improve the sustainability of the future. In this work, two relevant and independent environmental issues, such as brines and CO 2 management are investigated together, trying to find technological solutions that can incorporate synergies in the search for carbon–water cycle optimization, decarbonization, waste management, and resource utilization. Inorganic salts presented in brines were shown to be effective catalysts to convert CO 2 to cyclic carbonates by cycloaddition to epoxides, whereas water is an ideal solvent to separate hydrophobic cyclic carbonates from inorganic salt catalysts with hydrophilic character. Although the hydrophobic character of epoxide reactant can impose some limitations in the reaction step, byproduct recycling can be an effective way to enable competitive catalytic activity and, thus, promote the widespread use of this innovative process. In addition, the purification of the cyclic carbonate is coupled with the isolation of a treated water stream, which is another product obtained. Although less desirable, the third product corresponds to the diol derived from the reaction of water with each epoxide, envisioning a coproduction scheme providing three valuable products (cyclic carbonate, diol, and water) from two wastes (brines and CO 2 ) and one epoxide. Preliminary kinetic study and calculated energy consumption (1.87 kWh/kg of products) show competitiveness when evaluating individual water separation from brines and cyclic carbonate and diol productions, demonstrating the viability of this new process. The work also opens a new horizon for sustainability since global warming potential (0.148 kgCO 2 /kg) and water depletion (−0.144 m 3 water/kg of products) improve reference individual technologies.