Evaluation of the technical and commercial feasibility of the manufacture of bio-based polyester from cellulose derived hydroxymethyl furfural

Aromatic chemicals are a crucial constituent of plastics and bioplastics, conveying functionality such as strength and flexibility. At present, these chemicals can only be sourced economically from fossil-oil. However, lignocellulose is a low-cost and renewable material available from plants from which aromatics can be obtained, both from lignin and indirectly from the cellulose portion. This project evaluates the commercial potential of novel work that has demonstrated high yielding and efficient conversion of a cellulose-derived chemical called HMF into a key novel building block (FDCA) for the synthesis of a biomass-derived bioplastic PBAF. The two- step enzyme process uses enzyme biocatalysts called oxidases which work at 37degC where water is the only by product. Hence the process has extremely green credentials. The project will evaluate sensitivity to the source and type of crude HMF used, improve reaction conditions and will be scaled up to produce gram quantities of FDCA. These will be converted into novel polymers and the properties of these materials tested. A techno-economic assessment of the holistic process will be carried out to evaluate the commercial potential in both the bioplastic and broader polyester markets.

Aromatic chemicals are a crucial constituent of plastics and bioplastics, conveying strength and flexibility. At present, these chemicals can only be sourced economically from fossil-oil. However, lignocellulose is a potential low-cost and renewable alternative input. This project will evaluate the commercial potential of novel work that has demonstrated a tandem bioconversion giving high yields (74% isolated, unoptimised) of the aromatic diacid, furan-2, 5-dicarboxylic acid (FDCA), from cellulose derived hydroxymethyl furfural (HMF), using isolated oxidase enzymes galactose oxidase M3-5 and E. coli aldehyde oxidase PaoABC. Both enzymes will be immobilised to compare performance with soluble enzymes. Loading efficiency, activity, re-use efficiency and product recovery will be optimised. This work will also provide important preliminary data for potential application in flow reactors. Reaction parameters, including pH control for HMF to FDCA in a two-step, one-pot conversion will be optimised. We will produce gram quantities of bio-derived FDCA with a target reaction concentration of 50g/L. We will also investigate a single stage process where both enzymes can be combined. This will require new GOase mutants that can convert the PaoABC by-product hydroxymethyl acid (HMFCA) to FDCA more effectively. If a suitable enzyme can be found we will substitute this for GOase M3-5 and thus potentially develop a combined GOase-PaoABC process. Biome will identify different sources of crude HMF and a process from a crude feed will be investigated. The FDCA produced will be converted into novel block co-polyesters/amides by Biome and the properties of these materials tested and compared with material made from commercially available FDCA and petrochemically-derived terephthalate analogue polymer PBAT. A techno-economic assessment of the holistic process will be carried out to evaluate the commercial potential in both the bioplastic and broader polyester markets.

As described in proposal submitted to INNOVATE UK