Supercritical water gasification of waste R410A refrigerant mixture for the resource utilization: ReaxFF reactive molecular dynamic simulation and density functional theory calculation study

Harmless treatment and resource utilization of the waste HFC refrigerants have gradually become the focus of attention. As a clean waste resource utilization technology, supercritical water gasification has good potential in converting waste refrigerant into high value-added chemicals and fuels. In this study, the supercritical water gasification mechanism of R410A, and the interaction mechanism between R125 and R32, and between H2O and R410A during the gasification process are investigated by using ReaxFF reactive molecular dynamic simulation and density functional theory calculation study. The results show that the main products obtained from the supercritical water gasification of R410A are HF, H-2, CO and CO2. More than 90 % of F atoms in R410A can be mineralized to form HF molecules. H-2 and CO are two important syngas products during the supercritical water gasification process. Hydrogen bonds are generated between R125 and H2O molecules and between R125 and R32 molecules, which leads to the decomposition of R125 molecules more easily, and the decomposition of R32 molecules more difficult. This work provides a possible way to convert waste HFC refrigerant mixture into high value-added chemicals and syngas.