The method of propylene glycol production from waste biomass generated in the sugar factory

Abstract

Propylene glycol (PG), one of the most important raw chemical materials, has many properties of interest to the industry like: low viscosity, negligible toxicity, odorlessness and low freezing point. Because of this, it is often used in food, pharmaceutical and cosmetic industries. A new way of PG obtaining was developed in Lodz University of Technology in cooperation with the Polish National Sugar Company Ltd. This method involves catalytic reduction of lactic acid (LA) obtained on the route of microbiological transformation of hydrolysates of sugar beet pulp. Sugar beet pulp, firstly in the enzymatic form hydrolyzed into hexose and pentose feedstocks, was used in the fermentation process. The obtained medium enriched with nutritients was fermented by selected lactic acid bacteria. After the removalof the biomass, broth was purified on active carbon and silica, and finally used as a substrate in catalytic hydrogenation to propylene glycol. Hydrogenation of LA was performed in a 50 ml autoclave at the temperature of 130˚C, under 3.5 MPa of H2 pressure. 5 % Ru/C catalyst was used with equal amounts (mcat = 0.5 g) in all reaction runs.

Keywords

• propylene glycol
• lactic acid
• sugar beet pulp
• hydrogenation