Periodic Reporting for period 1 - LIGFLOW (Valuable aromatics from stabilized lignins: towards an optimal and feasible continuous operation)
Période du rapport: 2022-01-01 au 2023-12-31
Environmental concerns linked to society’s dependence on fossil resources have spurred an unprecedented search for sustainable processes, not only for energy but also for manufacturing chemicals and materials. Unfortunately, the low efficiency of emerging technologies based on renewable resources often hinders their profitability. Bloom Biorenewables maximizes the utilization of non-edible biomass using a novel stabilization strategy that prevents undesired degradation pathways during biorefining. Pure fractions are stabilized, isolated and upgraded to products such as fragrances, textile fibres or bio-plastics. With a 10-fold yield increase compared to current solutions, lignin applications can drive rather than hinder the process’s techno-economic feasibility. Yet, catalytic lignin depolymerization for the production of high value molecules represents the main bottleneck for scale-up and is currently limiting the company’s ability to respond to the increasing demand for lignin products. LIGFLOW will develop an industry-compatible lignin depolymerization process that paves the way for a continuous operation demonstrator. The main objectives are: 1) Transfer from batch to flow reactor; 2) Enable solvent recycling >90% and perform in situ catalyst regeneration; 3) Isolate and purify targeted products for distribution to key industrial partners; 4) Perform process modelling and life cycle assessment to achieve a full techno-economic and sustainability analysis of the resulting process. LIGFLOW’s results will unlock more profitable and sustainable production routes for biomass-derived aromatics.
Bloom’s AAF-lignin was first depolymerized at 50 mL scale in batch mode, where the hydrogenolysis was evaluated using various metal-supported catalysts. Both the yields and distribution of monomers were tuneable by the catalyst choice, including carbon-supported catalysts in which the metal has a high hydrogenation activity, namely Ru/C and Pt/C. The use of Pd-based catalysts led to a higher proportion of oxygenated molecules. The results in batch served as base for designing the trials in continuous mode. The first continuous experiments were then performed in a trickle bed reactor located at a RISE (Research Institutes of Sweden) facility in Sodertalje – Sweden. The trials happened after throughout technical discussions and risk assessment by the RISE team together with the Bloom team. Four tests campaign were performed with selected catalyst by varying lignin residence time, catalyst quantity and packing. Finally, development of purification methods enabled, for the first time, to isolate relevant amounts of high purity 4-propylguaiacol and 4-propylsyringol from AAF-lignin. For instance, hundreds of grams of these compounds were isolated with purities up to 99% and recovery rates of >98%. They were both used for internal R&D projects targeting product development and send to industrial partners for applications as fine chemicals and surface-active ingredients (e.g. in flavour and fragrance industries, cosmetics, homecare).
The information and results obtained were very important for the scale-up of the technology (from g to kg) and led to substantial advances in product separation, purification and on the development of applications. Accordingly, a portfolio of lignin products was built and samples in the range of hundreds of grams/kg were delivered to industrial partners, and the results obtained were instrumental to develop the first version of Bloom´s process TEA and LCA and set base for the technology scale-up.