Glycerol production and its applications as a raw material: A review

Glycerol is a valuable byproduct in biodiesel production by transesterification, soap manufacturing by saponification as well as hydrolysis reaction. The purity of glycerol obtained is low due to the presence of impurities such as remaining catalyst, water, soaps, salts and esters formed during the reaction. Purification of glycerol as well as the conversion of glycerol into valuable products has attained growing interest in recent years due to the dramatic growth of the biodiesel industry. This paper reviews different methods of producing crude glycerol as the major by-product. Purification of glycerol was reported as well as value-added products produced from glycerol. (C) 2013 Elsevier Ltd. All rights reserved.