Vapor-Liquid Equilibrium Data Measurement of CO2 + Diisopropyl Ether, CO2 + Methyl tert-Butyl Ether, and CO2+1,2-Dimethoxy Ethane Binary Systems at 253.15 K

In order to achieve deep decarbonization for the purification process of coal-based syngas, developing efficient and clean solvents with strong CO2 absorption ability is essential. Considering this point, this work measured the vapor-liquid equilibrium (VLE) data of the CO2 + diisopropyl ether (DIPE), CO2 + methyl tert-butyl ether (MTBE), and CO2 + 1,2-dimethoxy ethane (1,2-DME) binary systems at 253.15 K, with an experimental pressure ranging from 0.30 to 1.85 MPa. From the experimental results, it can be seen that 1,2-DME has the strongest CO2 absorption capacity, followed by MTBE and DIPE. Meanwhile, it is found that the ether bonds can significantly improve the absorption ability of the solvent for CO2, whereas the increase in molecular weight can result in a negative impact. Finally, the Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), and perturbed-chain statistical associating fluid theory (PC-SAFT) models were used to correlate the VLE data and obtain the binary interaction parameters k(ij). From the results, it is found that PR and SRK models are more suitable to correlate the VLE data of the CO2 + ether system. This work not only can provide a crucial reference for the selection of solvents with stronger CO2 absorption capacity but also provides accurate basic data for process simulation and optimization in the purification process of raw syngas.