Dealing with the surplus of glycerol production from biodiesel industry through catalytic upgrading to polyglycerols and other value-added products

An increase in glycerol production is expected because of the increasing use of fuel additives such as methyl esters. This increase can enhance the importance of glycerol as a cheap raw material for producing value-added products. Future scenarios for worldwide glycerol market will mostly be related to the supply and demand of glycerol and its application in other industries. Much research have been developed and continuously investigated to convert low-value glycerol using different strategies and approaches. Due to the unique structure of glycerol, properties and renewability feature of it, new opportunities for the transformation of glycerol into high-valued chemicals have merged in recent years. This paper provides a review on glycerol, global market of glycerol and conversion of glycerol to value-added products. Catalytic etherification of glycerol to value-added products such as polyglycerols is particularly reviewed.