Towards sustainable production of bio-based ethylene glycol: Progress, perspective and challenges in catalytic conversion and purification

Ethylene glycol (EG) is one of the most sought-after industrial compounds. High global demand necessitates for a production of up to 28 million metric tons EG a year. Reaction pathway for fossil fuel derived EG may be relatively simpler, but it remains a finite resource and is notorious for greenhouse gas emission. The increasing awareness for sustainable development and security of raw material has prompted researchers to explore novel ideas for production of EG from renewable feedstock. The abundance of lignocellulosic raw material naturally positions it as a desirable substitute to its petrochemical counterpart. This paper reviews recent progress in valorization of biomass via catalytic conversion through a broader lens, encompassing the vital aspects for commercialization of process technology. An in-depth analysis of three critical inter-related subjects for sustainable EG production, namely the catalytic system performance, effects of impurities in biomass and catalyst reusability in the harsh hydrothermal reaction is presented. Probing further into post-reaction process, purification strategies of close boiling points polyol mixture product through this bio-route are assessed. Finally, the challenges and prospects of scaling-up the technology are appraised. © 2023 Elsevier B.V.