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A novel self-priming venturi mixer consists of a designed nozzle, and a conventional venturi mixer was proposed to enhance mixing quality by compressing the raw gas. Computational fluid dynamics technology was employed to study the flow characteristics of the fluid within the mixer, and the performance of the mixer under different structural parameters was evaluated by the entrained rate, pressure difference, and mixing quality. Besides, the relationship between the structural parameters of the mixer and the composition ratio at the outlet was clearly elucidated. The research results suggest that the energy loss is minimized when the nozzle outlet radius ranges from 0.8 to 1.2 cm. Furthermore, as the length-to-diameter ratio increases, the entrainment rate and pressure difference initially increase gradually and then stabilize. Additionally, a small length-to-diameter ratio and an excessively large diffusion angle may reduce the mixing uniformity of the venturi mixer.

The hydrophilic ionic liquid (IL) [EMIM][BF4] was adopted to absorb two chlorinated volatile organic compounds (CVOCs), named 1,2-dichloroethane and 1,1,2-trichloroethane. First, [EMIM][BF4] was screened out as the optimal absorbent from 69 IL candidates by the COSMO-RS model. Then, CVOC absorption experiments were conducted using [EMIM][BF4] and [EMIM][TF2N]. [EMIM][BF4] shows the highest absorption rate for both 1,2-dichloroethane (95.81%) and 1,1,2-trichloroethane (84.91%). Quantum chemical calculations show that both strong intermolecular electrostatic interaction and van der Waals interaction promote the absorption of CVOCs by [EMIM][BF4]. Subsequently, industrial-scale CVOC capture processes, simulation and optimization, were carried out with [EMIM][BF4] and TEG as absorbents, to attain the goal of reducing the concentration of CVOCs in the gas stream to 500 ppm (in mole fraction). The result shows that [EMIM][BF4] has a higher processing capacity and a lower heat duty under optimal operating conditions.

Ionic liquids (ILs) as green solvents were first used to capture 1,2-dimethoxyethane (DMET) from exhaust gas. The vapor liquid equilibrium (VLE) data of [EMIM][TF2N] + DMET and triethylene glycol (TEG) + DMET were measured. The results showed that the popular UNIFAC-Lei model is in good agreement with experimental data. The gas absorption experiment with [EMIM][TF2N] as absorbent was conducted. It demonstrates that the IL has good separation performance for capturing DMET, the absorption ratio being 87.32%. Then, the absorption capacities of 45 ILs for DMET were calculated by COSMO-RS model, while DMET removal mechanism was explored by σ-profiles analysis and molecular dynamics (MD) simulation. Finally, industrial scale process simulation using [EMIM][TF2N] and TEG as absorbents to capture DMET was made. Compared to the benchmark TEG process, the total operating cost and the total annual cost (TAC) in the IL process decrease by 24.06% and 17.15%, respectively. This further proves that ILs have great application potential for the condensable volatile organic compounds (VOCs) capture, especially in energy saving and improving economic benefits.

Predictive molecular thermodynamic models are significant for predicting basic thermodynamic properties, such as fluid phase equilibrium in chemical separation processes and the subsequent simulation and amplification of industrial processes. Considering that some group binary interaction parameters between ionic liquid (IL) groups and traditional substance groups in the original UNIFAC model are still missing, 18 pairs of parameters are obtained by collecting experimental data from the new literature. On the other hand, the remaining 1570 pairs of interaction parameters are expanded by the COSMO-UNIFAC model, with other parameters missing from the literature data. The prediction of gas–liquid equilibrium, liquid–liquid equilibrium, gas–liquid equilibrium, and infinite dilution activity coefficient is used to evaluate the prediction performance of the newly extended UNIFAC model for phase equilibria of systems containing ionic liquids.

The structure–property relationship between ionic liquids (ILs) and two chlorinated volatile organic compounds (CVOCs), dichloromethane (DCM) and 1,2-dichloroethane (DCE), was systematically investigated. The suitable IL was screened using the COSMO-RS model, and 1-ethyl-3-methylimidazolium acetate [EMIM][Ac] was considered the optimal absorbent to capture the two CVOCs. The vapor–liquid equilibrium experiment demonstrates that the addition of the IL significantly reduces the vapor pressures of the IL + DCM (or DCE) systems. The structure of ILs on the absorption performance was investigated by absorption capacity experiments. Then, the absorption mechanism was investigated through QC calculations and wavefunction analysis. The consistency between the experiments and the molecular mechanism reveals that the formation of the hydrogen bond between the IL and CVOC enhances the absorption process.

Ionic liquids (ILs) were developed to separate polycyclic aromatic hydrocarbons (PAHs) from real diesel from the molecular scale to the process system. Based on the liquid–liquid equilibrium data, the popular UNIFAC-Lei model was adopted and improved. A simulation comparison of real FCC diesel (including 712 components) with model oil (only n-hexadecane + 1-methylnaphthalene) indicates that the former is closer to experimental data, with the average relative deviation (ARD) being only 6.71%, showing the significance of considering all molecules in molecular refining.