Co-Production of 1,2-propandiol and Ethyl Lactate from the Conversion of Glycerol co-fed with Bio-Ethanol over Reduced Cu0.3Mg1.7Al LDH-derived Oxide Catalyst without External Hydrogen

Abstract

Usually, the hydrogenolysis of glycerol into 1,2-propandiol requires H₂ supply in the acetol hydrogenation step to 1,2-propandiol. However, in-situ hydrogen can be generated from glycerol dehydrogenation and glycerol reforming using metal catalysts. Moreover, ethanol can be co-fed as a hydrogen donor for this reaction and produce ethyl lactate via esterification with lactic acid which is by-product from glycerol conversion. In this study, the promotion effect of Cu partially-substituted Mg_1.7Al mixed oxide was investigated on the conversion of glycerol co-fed with bio-ethanol in a PARR-reactor at 180 ^oC for 4 h without hydrogen feeding. Then, the products were analyzed using GC-MS/TOF. The catalysts were characterized using BET, XRD, XPS, XRF, and TPDRO. As a result of the Mg₂AlO based catalyst, the glycerol can be converted to 1,2-propaniol, acetone, and acetaldehyde without ethyl lactate production at this condition. The reduced Cu_0.3Mg_1.7Al LDH-derived catalyst significantly enhanced the selectivity of 1,2-propandiol and ethyl lactate to 47.3 and 22.8 %. 1,2-Propandiol and ethyl lactate as specialty chemicals were found to be co-produced from co-feeding glycerol and bio-ethanol using the reduced Cu_0.3Mg_1.7Al LDH-derived catalyst.