Conversion Of Glycerol To 1,3-Dihydroxylacetone Via Indirect Oxidation

Recently, meeting the demand of renewable fuel, the production of so-called "biodiesel" break out worldwide. In the last several years, the conversion of biodiesel byproduct glycerol to other chemicals, such as diols and epoxides, becomes a research and industrial issue. 1, 3-Dihydroxyacetone (DHA), currently produced by microbial fermentation of glycerol over Gluconobacter Oxydans, is the main active ingredient in sunless tanning skincare preparations, medicine and the monomer of biodegradable polymer.In this work, we developed a convenient multi-step process to achieve a highly selective conversion of glycerol to DHA. This indirect oxidation (IDO) of glycerol avoids the complicated purification of the targeted product. The idea is to firstly protect the first and third hydroxyl groups of glycerol through acetalization with benzaldehyde to obtain 1, 3-benzylidene glycerol (HPD). The second step is to obtain 2-pheyl-1, 3-dioxan-5-one (PDO) by oxidizing the unprotected hydroxyl group of HPD into a carbonyl group. The purified PDO is then hydrolysized to release benzaldehyde and achieve 1, 3-dihydroxylacetone (DHA) with a high yield.At the end, based on the experimental results, we designed a process for DHA production, and briefly evaluated its cost.