Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia

OP-2-10BIODERIVED LACTIC ACID AND LACTATES AS ALTERNATIVESOURCES FOR PROPYLENE GLYCOL SYNTHESISSimonov M.N., Simakova I.L., Minyukova T.P., Khassin A.A.Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia, simakova@catalysis.ruPropylene glycol commercial production is currently petroleum-based andinvolves the high pressure and high temperature hydrolysis of propylene oxidemanufactured by either chlorohydrin’s process or the per-oxidation process. Acatalytic method starting from lactic acid obtained by fermentation of crude biomassis perspective way of propylene glycol synthesis. However it is well known thatcatalytic hydrogenation of carboxylic acid to corresponding alcohols is very difficultprocess, which requires high pressure and temperature. For example, thehydrogenation of lactic acid to propylene glycol over Ru-containing catalyst wascarried out at 145 bar and 423 K to reach necessary for noticeable lactic acidconversion and selectivity to propylene glycol [1]. According to [2] silica-supportedcopper prepared by incipient wetness impregnation is a high selective catalyst toconvert lactic acid carboxylic group to 1,2-propanediol hydroxyl one. To decrease thepressure the preliminary esterification may be used, because the hydrogenation ofcorresponding esters is usually conducted in milder conditions [3,4].The target of the present work is to elaborate vapour phase hydrogenation oflactic acid and hydrogenolysis of methyl- and butyl lactates in order to develop highselective catalytic process of propylene glycol synthesis in mild reaction conditionsover silica-supported copper catalysts.The main products of lactic acid hydrogenation were propylene glycol andpropanoic acid, while hydrogenolysis of alkyl lactates leads to propylene glycol,hydryxyacetone and corresponding alcohol, methanol or butanol. Also in reactionmixture were presented 1-propanol, 2-propanol, 2-hydroxypropanal in total amountless than 2 wt. %. To study the activity of Cu/SiO 2 catalysts the copper loading incatalyst was varied from 14.2 wt. % to 45.5 wt. %. Conversion of substrate ismonotone increasing with grow of copper content, while selectivity to propyleneglycol decreases slightly. Precursor of the catalyst 45.5 wt. % Cu/SiO 2 has astructure of mineral chrysocolla with Cu:Si atomic ratio of one to one. Reduction ofchrysocolla leads to formation of highly dispersed metallic copper particles, whichtake part in hydrogenation process. Further experiments were conducted over themost active 45.5 wt. % Cu/SiO 2 catalyst.52