Bio-based acrylic acid from sugar via propylene glycol and allyl alcohol

Abstract

A new route for producing bio-based acrylic acid is proposed. It starts with the conversion of carbohydrates to propylene glycol, being main or by-product, and proceeds via a subsequent dehydration to allyl alcohol under gas-phase conditions over K-modified ZrO₂ and a final oxidation over MoWVO_x catalyst at atmospheric pressures. Although preliminary, this study shows the possibility to convert propylene glycol to allyl alcohol with ∼50 mol% selectivity (at ∼64 mol% conversion) and convert allyl alcohol to acrylic acid with ∼77 mol% selectivity (at ∼90 mol% conversion). The oxidation of unconverted propylene glycol or the by-products propanal and 1-propanol results in propionic acid under these conditions. A preliminary process flow scheme is proposed based on the distillation resistance of the reaction products.