Recycling Strategy for Bioaqueous Phase via Catalytic Wet Air Oxidation to Biobased Acetic Acid Solution

Abstract

The bioaqueous phase generated during biomass conversion to biofuel and biochemicals, e.g., fast pyrolysis and ex situ catalytic pyrolysis, contains a large number of organics, leading to a high chemical oxygen demand (COD) for its treatment. In this study, we demonstrate its catalytic conversion to bioacetic acid solution and propose a recycling strategy thereof. We found that the diluted bioaqueous phase (e.g., C content <0.5 wt %) can be selectively (>90%) converted to acetic acid with nondetectable impurities in solution. The solution contains 1.3-1.5 wt % acetic acid and can be directly used for demineralization of biomass in the biorefineries. This recycling strategy enhances the sustainability of the biobased economy and sheds light on production of biobased acetic acid, which has been recognized as a smart drop-in chemical.