Imidazolium Chloride Ionic Liquid Mixtures as Separating Agents: Fuel Processing and Azeotrope Breaking

Area of Science:

• Chemical Engineering
• Separation Science
• Materials Science

Background:

• Petrochemical and chemical industries require efficient separation techniques.
• Aromatic hydrocarbon removal, fuel desulfurization/denitrification, and azeotropic mixture separation are key industrial processes.
• Novel separation agents are needed to improve efficiency and sustainability.

Purpose of the Study:

• Investigate imidazolium chloride ionic liquid mixtures as potential separation agents.
• Evaluate the influence of cation alkyl chain length on separation performance.
• Explore the 'designer solvent' concept for tailored separation applications.

Main Methods:

• Calculated selectivities, capacities, and solvent performance indices.
• Determined activity coefficients at infinite dilution for organic solutes and water.
• Utilized imidazolium chloride ionic liquids: [C8mim]Cl, [C12mim]Cl, and an equimolar mixture of [C4mim]Cl and [C12mim]Cl.
• Applied the COSMO-RS thermodynamic model for qualitative screening.

Main Results:

• Imidazolium chloride ionic liquids can be tailored for specific separation needs.
• Increasing alkyl chain length on cations enhances affinity for organic solutes.
• The equimolar mixture showed performance comparable to the intermediary [C8mim]Cl, supporting the designer solvent concept.
• COSMO-RS model proved effective for rapid screening of potential ionic liquid separation agents.

Conclusions:

• Imidazolium chloride ionic liquids are versatile for targeted chemical separations.
• The study demonstrates the feasibility of designing ionic liquids for specific industrial separation challenges.
• Computational modeling (COSMO-RS) is a valuable tool for accelerating the discovery of new separation agents.