Co-production of HMF and gluconic acid from sucrose by chemo-enzymatic method

Co-production of multi-products is one of the core principles of chemical industry, and it is also an important way to improve the atom economy. Herein, we proposed an approach to co-producing two valuable platform compounds, gluconic acid (GA) and 5-hydroxymethyl furfural (HMF), from sucrose by successive hydrolysis, oxidation and dehydration. In the enzymatic oxidation step, only glucose was oxidized to GA, meanwhile fructose was 100% retained. In the further biphasic dehydration system, only fructose was converted into HMF, whereas GA was maintained with over 95% recovery. After three reactions, the yields of HMF and GA were respectively 42.5% and 48% when the initial feedstock of sucrose was 200 g/L. Two products were easily separated because GA was completely existed in aqueous phase, and HMF was mainly in organic phase. In the whole process, only commercial enzymes and mineral acid were used instead of self-made catalysts.