Feedstocks from forestry, agriculture, municipal waste and food-processing residues were analysed for their composition. Development of optimum pre-extraction conditions and subsequent valorization of fine chemicals was conducted. Biomass pre-extraction was successful at both the lab- and pilot-scale and produced a cleaner feedstock, enriched in lignocellulose.
Lab-scale fractionation was validated at pilot scale, showing excellent translation from lab-scale operation. Additionally, lignin was isolated in high yield and purity at TRL5 using a continuous falling film lignin precipitation process (LigniSep). The obtained lignin was converted to smaller lignin fragments using MetninTM technology. The sugars were fermented to obtain xylonic acid and acetone in high yields.
Lignin-based polyols with properties matching the requirements for PUR/PIR foam production were successfully produced by a new protocol that uses ethylene carbonate. This protocol has the advantage to be safer and easier to scale-up than the common protocol using oxypropylation. Lignin-based polyol replacement was successful at 20% substitution and the PUR foams complied with the industrial specifications.
The use of lignin to replace the SBS polymer for waterproofing membranes showed to be not a good alternative as the performance was limited compared to the industrial specifications, also after methylation. Lignin modification to increase hydrophobic moieties may better resemble the hydrophobic SBS polymer and provide more promising results.
The enzymatic conversion of glucose to fructose from UNRAVEL hydrolysates was performed to demonstrate an additional valorisation route. The glucose conversion was successful and expands the offering of the UNRAVEL biorefinery and strengthen its business case for potential investments.
The economic assessment concluded that the UNRAVEL concept has shown favorable prospects. The assessed scenarios indicate that a green premium of 15-40% would be needed for an attractive business-case and that potential further process intensification and integration could lower the green premium.
The sustainability assessment revealed the environmental burden of biorefinery processing can be reduced by introducing several successful innovations:
1. A new approach to pre-extraction of biomass to make underutilised residues available for lignocellulosic biorefineries
2. An improvement of the yield/quality of compounds obtained in the core fractionation process
3. Lignin modification with ethylene carbonate for use as a polyol in PUR/PIR insulation foams
Several project dissemination activities, networking events, press releases, policy briefs, fact sheets and online presence activities were held to build up the project visibility at the local, national and international level and to show how outcomes are relevant to the public. The project resulted in six peer-reviewed publications, one policy brief and two fact sheets.
