Abstract
Ionic liquids (ILs), which are regarded a new magical chemical owing to their unusual characteristics, offer a wide range of uses in the chemical sector. Electrolytes as batteries, lubricants, plasticizers, solvents and catalysis in synthesis, matrices for mass spectrometry, solvents for manufacturing nano-materials, extraction, gas absorption agents, etc are some of the applications. Their common characteristics of non-volatility and non-flammability provide materials an edge in a variety of applications. When combined with the ability to tune the physicochemical characteristics of ILs by altering the anion–cation combination, this common advantage provides a fantastic opportunity to create task-specific ILs for a wide range of applications. Many research have been published in the literature on the unique characteristics, preparation techniques, and various uses of ILs. The primary emphasis of this study, however, is on how ILs might be utilized in the chemical processing industry. Thus, the major application areas are investigated and fundamental applications such as fluid replacement, gas purification, homogeneous and chemical processing, biological response media, and metal ion removal are thoroughly addressed. Not only are the benefits of ILs discussed, but also the key obstacles and opportunities for utilizing ILs in the chemical sector. In many applications, ILs have replaced scCO2, and the majority of research in the literature have focused on the interplay of such two green solvents, ILs and scCO2. The chemistry of the ILs has indeed been discussed in a number of previous publications. As a result, the primary goal of this review article is to give an overview of the chemical and physical characteristics of ILs, as well as to look into the IL–scCO2 systems in more depth. Solute recovery from ILs with CO2, separation of ILs from organic solvents with CO2, phase behavior of IL–scCO2 systems, solubility of ILs in CO2 phase, and IL–scCO2 system interactions at the molecular level are all covered.