Hydrothermal electrolysis: A new green technology EU-funded researchers have introduced an environmentally friendly and economically viable technique to convert biomass into value-added chemicals, improving upon hydrothermal electrolysis. Industrial Technologies Fundamental Research © Sylvie Bouchard, Shutterstock Under normal conditions, electrolysis of water produces hydrogen and oxygen. However, when electrolysis is carried out in sub-critical water – at temperatures exceeding the normal boiling point – the generation of oxygen can be controlled. Sub-critical water can safely be used as a reaction medium for electrolysis. Furthermore, it is non-toxic and readily available. Within the EU-funded project HYDELTECH (Synthesis of biomass sourced value added chemicals by hydrothermal electrolysis technique), researchers used biomass as feedstock. They wanted to develop a green technology for the production of chemicals such as glycols, levulinic acid, aspartic acid and many others under hydrothermal conditions. Research focused on the treatment of biomass to produce common chemicals and the conversion of these intermediates to other products. First, researchers designed hydrothermal electrolysis equipment to electrochemically decompose organic material into its building blocks using sub-critical water and without any organic solvent. Chemicals produced are subsequently used to synthesise value-added chemicals. To achieve the highest yield possible, the HYDELTECH team optimised the reaction conditions, including temperature, pressure and applied voltage. Moreover, they demonstrated the feasibility of scaling up the hydrochemical electrolysis system using computer simulations. Importantly, HYDELTECH technology is compatible and complementary with conventional oxidation processes. A patent application is being prepared to open the way to licencing the technology to companies that have already expressed interest. Keywords Hydrothermal electrolysis, green technology, biomass, sub-critical water, HYDELTECH
