Enzyme: Engineered Enzymatic Catalysts for In-flow CO2 Upcycling

Decarbonisation is critical to addressing climate change, a pressing global challenge affecting health, livelihoods and our environment. Advancing a sustainable future for everybody is the heart of Hitachi’s mission and it provides green mobility and green energy through its core UK business in Rail and Energy. To further realise the UK government’s target of net zero emissions by 2050, Hitachi aspires to be a climate change innovator to decarbonize adjacent industries such as electric vehicle fleets and the chemical industry. The concept of capturing and recycling carbon emissions into useful products presents an attractive opportunity to aid decarbonisation efforts, complementing many other measures aimed at reducing emissions. This is particularly relevant to the chemical sector as it simultaneously removes carbon from the atmosphere and decarbonises the chemical production process. Although a key bottleneck to carbon circularity is the high cost of CO2 capture, low-value compounds obtained such as methanol (MeOH) can be upcycled to higher-value products, making carbon-circular chemical production more economical. Despite the advances in catalyst design for CO2 conversion, inorganic catalysts frequently lack the necessary selectivity or are too costly for industrial production. This has sparked interest in biocatalytic systems, ranging from whole cell to catalytic proteins. Biocatalysts usually operate at nearly ambient temperatures and pressures in an aqueous environment, producing no toxic waste, which makes them suitable for sustainable production of biochemical components. Leveraging a longstanding collaboration between the University of Cambridge and Hitachi, the EngZyme partnership capitalizes on two years of joint research to engineer enzyme cascades for converting methanol into higher value chemical products. The proposed project focuses on two key reactions utilizing three enzymes to produce formaldehyde and dihydroxyacetone (DHA), which serve as precursors for a variety of industrially important molecules including sugars, amino acids, and pharmaceuticals. Towards design of efficient and affordable enzymatic cascades for MeOH conversion, we identified three main challenges that we aim to overcome through EngZyme Prosperity Partnership: Enzyme activity: early-stage enzymes in most upcycling cascades represent a rate limiting step. We will develop more efficient enzymes through enzyme engineering and design of nanostructured enzyme mimics ; Enzymes and co-factor stability: many enzymes and co-factors degrade rapidly. We will enhance the stability and recyclability of enzymatic catalyst through immobilisation within different scaffolds, and by replacing natural cofactors with cost-effective and stable cofactor-mimics. Integration into an industrial process: numerous convincing enzyme cascades have been demonstrated on a small lab-scale but these need to become a scalable and industrially viable upcycling process. We will design a modular flow reactor system for the on-demand production of desired compounds. If successful, EngZyme will help convince stakeholders within and around Hitachi and the UK to invest in realising large-scale industrial adoption of CO2 upcycling in the chemical industry by 2030 and beyond. Ultimately, this will put the UK and Hitachi in a better position to support the chemical industry in delivering net zero by 2050.