Green Solvents

Green solvents have emerged as a favorable alternative in both academia and industry because of the growing demand of solvents on sustainable energy and environment. Considering the demerits of conventional solvents, e.g., flammability, toxicity, high vapor pressure, and lower chemical, electrochemical, and thermal stability, greener or sustainable solvents have been developed during the past few decades. A significant number of organic solvents are also harmful to human health and the environment. Solvents, namely, ionic liquids, deep eutectic solvents, supercritical fluids, switchable solvents, liquid polymers, and renewable solvents have already marked their footprints in various chemical and pharmaceutical applications. Specifically, ionic liquids and deep eutectic solvents have been explored extensively for absorption, solvent extraction, and electrochemical energy storage. Due to their higher cost and viscosity, ionic liquids are progressively being replaced by deep eutectic solvents in most of the chemical engineering research. A variety of techno-economic and environmental factors should be considered to provide the current scenario of green solvent research and development. The proposed book chapter will focus on various types of green solvents useful for chemical and electrochemical applications and their process of synthesis. It will also discuss how several properties of these solvents can affect their performance and improvements required to overcome the limitations.