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REsidual soft WOod conversion to high characteristics drop-in bioFUELs

Periodic Reporting for period 2 - REWOFUEL (REsidual soft WOod conversion to high characteristics drop-in bioFUELs)

Reporting period: 2019-12-01 to 2022-06-30

Biomass is increasingly considered as an alternative to fossil oil to address the issues of climate change and resources depletion and independency in the EU. However, direct substitution is not possible and advanced processes are needed to efficiently convert biomass into drop-in intermediates and end products. Lignocellulosic sugars are an attractive resource for these processes and an evolution beyond traditional sugars as they can be produced from a wide variety of resources and do not compete with food or feed production.
The main technical challenges in the development of biomass to fuels technologies are the compatibility of biomass pre-treatment, fuel production technologies and of the produced biofuels with existing transport infrastructures, in particular in aviation. Moreover, public acceptance further challenges the deployment of biofuels.
The REWOFUEL project aimed at overcoming these challenges. The value chain was developed on residues from the forestry industry, an abundant resource regarded by the public as favorable for technological applications. The targeted fuels are bio-derived versions of existing and widely used high-performance gasoline and jetfuel constituents currently derived from fossil oil. The targeted fuels derive from a single biochemical intermediate, bio-isobutene (bio-IBN) which serves as a direct replacement of fossil isobutene (IBN), a commodity chemical.
The REWOFUEL approach of wood deconstruction followed by direct fermentation to isobutene, a gaseous hydrocarbon, and its final conversion into liquid fuel components was a true technological breakthrough that solved a number of technical and commercial issues throughout the value chain. Moreover, dedicated activities specifically assessed valorization opportunities of all side products and waste streams of the core processes to further improve the competitivity and environmental impact of the value chain. Valorization as energy, in materials (bitumen) and agriculture (animal nutrition and fertilizers) were investigated in detail.
The overall goal of the project was therefore to demonstrate the performance, the reliability and the environmental and socio-economic sustainability, of the entire value chain for the transformation of forestry residues into sustainable, high performance liquid fuels. The project was focused on renewable and sustainable gasoline and aviation fuel aiming to demonstrate that they can be produced efficiently and within specifications that are compliant with existing fuel norms and infrastructures. The project provided the backbone for a subsequent first of its kind flagship project converting around 350,000 tons of wood residues into fuels.
The REWOFUEL project successfully demonstrated its technology for the production of high-performance biofuel ingredients from wood residues at pre-industrial scale. Several ton-scale batches of bio-IBN were produced in Global Bioenergies specialized Demo scale IBN fermentation facilities using residual wood hydrolysate sugars provided by partners Sekab and Fibenol and benchmark sugars. Further the project allowed for the optimization of key process parameters which resulted in strong decreases in production costs, including reduced enzyme usage for wood to sugar conversion and improved sugar to IBN productivity and yield. In addition, the bio-IBN produced was found to be of excellent purity and quality thanks to its spontaneous extraction in the gas phase during fermentation, separating from impurities that remain in the liquid phase.
Subsequently, several tons of biofuel components isooctane, ETBE and jetfuels were generated. Concerning fuel characterization, gasoline formulations containing a high level of renewable components and compliant with the European standard were tested in engine trials showing improved performances compared to the fossil gasoline reference. On the aviation side, the REWOFUEL sustainable aviation fuel (SAF) component was evaluated by experts of the ASTM International standard organization, who reached the conclusion so far that the fuel showed good quality and did not require extensive phase 2 tests in order to be approved for use up to 50% in kerosene blends.
Overall the REWOFUEL project has been essential to further mature the wood-to-biofuel technology, from a TRL5-6 to a TRL 7.
Co-products of the wood hydrolysis and fermentation processes were also tested for valorization in various applications. In particular, lignin samples were shipped and used in the manufacture of bitumen which were successfully tested on road sections. Additional lignin valorization strategies with high potential were also identified including for the manufacture of plastics and resins. Fermentation derived microbial proteins were evaluated in animal nutrition trials, assessing tolerance, digestibility and performance.
Finally, process engineering studies allowed for the definition of a standalone integrated process solution which led to a site-specific case study. The socio-economic and public acceptance studies were also established. In particular key stakeholders were identified and classified and the major public acceptance issues were identified. A robust business plan was established to prepare for the deployment of the REWOFUEL technology.
Throughout the project, dissemination activities provided communication material (webinars, presentation video, website, visual identity, slides, roll-up, flyers and social media activity) and focused on presentation of the project at various conferences and in articles, public reports and press releases.
REWOFUEL has allowed for the optimization of high sugar yields from wood deconstruction with a lignin production showing good compatibility with bitumen blending. Highly concentrated hydrolysates, were then used in fermentation processes producing several tons of bio-IBN, by using novel strains optimized for bio-IBN production and efficient sugar consumption from wood hydrolysates.
Upscaling activities have shown a good compatibility of RWH with the bio-IBN production equipment, allowing a successful scale-up to the demonstration plant during the second reporting period. The co-produced lignin showed good compatibility with its use as a bitumen blend stock at targeted levels. Bio-IBN batches have shown good compatibility with catalysts used for its conversion into fuels which in turn displayed a promising impurities profile and characteristics allowing to achieve the targeted goals of easy-to-blend, high performance fuel components. Scale-up of the conversion of bio-IBN into high performance fuel components was a key activity of the second reporting period.
Overall, the project successfully demonstrated the feasibility of a new value chain for the conversion of residual wood feedstock into advanced liquid biofuels with increased yield and favorable energy and greenhouse gas balances. This work was performed with the clear objective of a first of its kind deployment in the EU thanks to the inclusion of industrial actors at each stage of the value chain and shall enable significant social and economic impacts in terms of job creation, economic growth and safe and affordable energy supply.
Sekab's Biorefinery Demo Plant located in Örnsköldsvik (Sweden)
Global Bioenergies's Laboratory, Pilot and Demo equipment for sugar to isobutene fermentation
Scheme of Oligomerization and Hydrogenation of bio-Isobutene to iso-Octance
Feed screw with wood chips from containers at the Biorefinery Demo Plant
Upgrading and detoxification at the Biorefinery Demo Plant