Chapter One examines the effect of water addition on some physicochemical properties of deep eutectic solvents through experimentation. Chapter Two deliberates on ionic liquids electrochemical behaviour for corrosion inhibition of different metals. Chapter Three presents the process and mechanism of electrochemical synthesis of DMC in ionic liquids. Chapter Four provides an overview of the applications of ionic liquids on the electrochemical reduction of CO2. Chapter Five studies the biocatalyst process for the esterification of dihydrocaffeic acid (DHCA) with different ionic liquids: 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, 1-butyl-3-methylimidazoliumhexafluorosphosphate, 1-hexyl-3-methylimidazoliumhexafluorosphosphate, 1-octyl-3-methyllidazoliumhexafluorosphosphate. Chaper Six continues with a study on predicting wine quality, with the suggestion that investors should further their knowledge on all aspects of winemaking. Chapter Seven reviews the advantages of ionic liquids in biorefinery processes.