Simulation-based Analysis of Propylene Glycol Production from Lactic Acid

Propylene glycol is an intermediate molecule with wide applications in the chemical industry. Its most successful renewable production technology is based on hydrogenolysis of glycerol, subproduct of the biodiesel industry, which has been commercially produced since the early 2010s. The biodiesel market, however, is highly dependent on government incentives and raises the fuel versus food debate. Other renewable raw materials that can be obtained from lignocellulosic sources, such as cellulose and lactic acid, have been studied for propylene glycol production through similar technology but focusing on catalyst development. In that regard, this work developed a conceptual design and simulation using Aspen Plus® for propylene glycol production from lactic acid. To assess its potential as feedstock, mass and energy balances were compared with those reported in the literature for glycerol-based propylene glycol. The results demonstrate that there is room for improvement towards a competitive lactic-acid based biorefinery, especially in terms of energy consumption.