NGP2-biorefinery of RWTH has been retrofitted and commissioned for LVA production. Several campaigns in an integrated multi-reactor mode were successful. The LVA separation and purification strategy was developed. Systematic investigation of the critical steps led to the development of a process for the production of purified LVA at 50 kta scale with valorisation of solid residues.
In parallel, a second route for the transformation of furfural to LVA and esters and its consequent hydrogenation was examined. A successful heterogeneous gas-phase hydrogenation of ethyl levulinate to GVL has been performed in continuous mode from small scale to kg-scale.
For the homogeneous hydrogenation of LVA, molecular catalysts were evaluated. Consequently, tailored molecular catalyst systems enabled a selective hydrogenation. A scalable synthetic protocol for the preparation of selected catalyst has been developed and application testing has been performed. The comprehensive evaluation demonstrated favourable performance indicators for the 2-step process involving separation of metal-catalysed hydrogenation to GVL and MeBDO from the acid-catalysed cyclisation of MeBDO to 2-MTHF. To increase activity and stability of the utilised catalyst systems, structural variations of the recently established ligands were performed. The catalyst could be successfully recycled.
For application & development of hydrogenation intermediates, technical analysis indicated 2-MTHF as a replacement for fossil-based solvent THF. Further improvements in manufacturing of 2-MTHF led to high quality polymers that demonstrated a potential use in conventional polyurethane adhesives. In parallel, MeBDO polyesters were synthesised, screened, scaled up and tested for adhesive use. Results indicate promising novel bio-based materials with superior performance and properties compared to standard fossil-based alternatives. It is concluded that MeBDO can be beneficially utilised as building block for polyurethanes and specifically reactive polyurethane hotmelt adhesives (PURHM). A market start is promising for PURHM adhesives in high value adhesive markets. Reactive two component (2C) epoxy adhesives with the GVL-derivative have been developed.
For the risk and safety assessment of bio-based chemicals and their respective fossil-based benchmarks, extensive literature review and a stepwise test strategy was carried out to gather data on the physical-chemical properties, human toxicity, eco-toxicity (hazard assessment) and environmental fate (biodegradation, bioaccumulation). Life-cycle analysis indicated 30-80% reduction in global warming impacts with bio-based chemicals in comparison to their fossil-based counterparts in various scenarios.
Dissemination to target audiences including science and the general public took place via scientific publications, international conferences, seminars and workshops, a project website (www.GreenSolRes.eu) as well as social media channels like Linkedin. Exploitation first focussed on patenting the intellectual property before a stakeholder workshop was held in spring 2021 to present the achieved results to an industrial community and gain interest in further investments. Specific topics like low cost feedstock (waste wood, and residues from food industry) and the further investment in upscaling were focussed in interviews with representatives of industry. The finalized engineering concept including mass and energy balances of a 50 KT plant form the basis to proceed with industrial investors towards upscaling the process into a first commercial plant. The increase of production volumes will be a prerequisite to open markets for envisaged bio-based adhesives and solvents contributing to reduce emissions responsible for climate change and increase competitiveness of European industry.
