Experimental and Theoretical Investigation of Thermal Decomposition Solvents for TOAHCl1

Abstract

In the pursuit of optimizing the reaction–extraction–crystallization-coupled mineralization process for carbon capture, utilization, and storage (CCUS) technology, this study presents a pioneering investigation into the solvent effects on the thermal decomposition of tri-n-octylamine hydrochloride (TOAHCl). Density functional theory (DFT) calculations have determined the structure parameters, solvation free energy, infrared spectrum, and charge distribution of TOAHCl in 41 solvents and obtained a universal law for the effects of solvents on the thermal decomposition process of TOAHCl, enabling the rapid screening of optimal solvents for experimental application. With the experiment results, the standout finding is the identification of n-undecane as the most favorable solvent, distinguished by its rapid thermal decomposition rate, high final conversion rate of 93.8%, minimal environmental impact, and cost-effectiveness. These attributes mark a significant advancement over solvents reported in existing literature. Furthermore, molecular dynamics (MD) simulations corroborate that n-undecane can enhance the decomposition process, underscoring their role in diluting reactants and products to facilitate mass transfer. This work not only sheds light on the solvent-mediated thermal decomposition pathways of TOAHCl but also provides a new idea for thermal decomposition solvent screening.