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Demonstration of solvent and resin production from lignocellulosic biomass via the platform chemical levulinic acid

Periodic Reporting for period 1 - GreenSolRes (Demonstration of solvent and resin production from lignocellulosic biomass via the platform chemical levulinic acid)

Reporting period: 2016-09-01 to 2018-02-28

The need to establish economically and environmentally sustainable large-scale systems for the conversion of biomass to building blocks for the chemical industry is becoming increasingly urgent regarding climate change and shrinking oil reservoirs. The overall objective of GreenSolRes is to demonstrate the competitiveness of the levulinic acid (LVA) value chain in terms of costs, environmental impact and technical performance. Lignocellulosic biomass is converted in a robust and low-impact process to platform chemical LVA, which is subsequently reduced to γ-valerolactone (GVL), 1-methyl-1,4-butanediol (MeBDO) and 2-methyltetrahydrofuran (2-MTHF). The LVA-derivates are applied as solvents or as building blocks in different polymers like polyurethanes, polyesters and polyether and then formulated to bio-based adhesives. These LVA derivates are applicable as well in the pharmaceutical sector. After successful demonstration, the project will prepare an optimized process design in full commercial scale enabling the planning of a first commercial plant. The bio-based chemicals are expected to have superior eco-toxicity and pharmacological properties compared to the established fossil-based solvents. Levulinic acid and related products compared to their fossil- based C4-counterparts will boost the bio-based market as they have a high greenhouse gas (GHG) avoidance of at least 70%. They provide an additional value to society via better health and safety properties.
The project work focussed on the hydrogenation of levulinic acid to GVL, 2-MTHF and MeBDO. In the comprehensive scientific approach, a collection of potential catalyst structures was initially established and the selected organometallic compounds were synthesized in lab scale quantities. The molecular catalysts were tested in dedicated high-pressure autoclaves in the homogeneous hydrogenation of LVA and GVL. A selection of the developed catalysts disclosed the envisaged key-performance indicators, paving the way to capable candidates for LVA hydrogenation. Consequently, the tailored molecular catalyst systems enabled a selective hydrogenation with a turnover number ≥250000 & a space time yield of ≥1000 kg/l/h. With that first milestone of the project has been achieved. The catalyst lead structure to be used in the LVA hydrogenation is defined. The work on the optimisation of the catalyst concerning productivity and recyclability as well as on kinetic studies is started. A scalable synthetic protocol for the preparation of selected catalyst has been developed. Application testing is performed for several batches of samples. Ligands are found to be equally active in catalysis as ligands earlier prepared in laboratory via a different route or acquired from commercial sources. The consecutive transformation of LVA to GVL, MeBDO and 2 MTHF can be either conducted in an integrated 1-step or a 2-step process. In the latter case, the metal-catalyzed hydrogenation to GVL and MeBDO is separated from the acid-catalyzed cyclization of MeBDO to 2-MTHF. In an interdisciplinary approach, the two possible process options were initially experimentally tested in lab scale reactions with the recently established molecular metal catalysts and then evaluated, based on a preliminary process simulation. The comprehensive evaluation demonstrated favourable performance indicators for the 2-step process, paving the way to two independent and dedicated process units with optimum characteristics. The engineering team has designed a continuous demonstration plant to hydrogenate levulinic acid into a mixture of GVL and MeBDO. A list of over 300 parameters was compiled, data gaps were identified and assigned an impact on the process design. In several iterations over the course of six month, the process design was updated with new data available. The design package of basis design, process and equipment design considerations as well as a process flow diagram of the demo-plant were provided to vendors. A basic design of the unit has been prepared by the selected vendor as well as a quotation for detailed design and construction is ready, construction start after optimisation of homogeneous catalyst. In application and development of hydrogenation intermediates, current focus is on polymers of 2-MTHF and MeBDO. The catalytic methods for the production of P2-MTHF as copolymers had been developed. One kilogram of the P2-MTHF was tested for use in adhesive formulations. Initial technical analysis indicates 2-MTHF as a replacement for fossil-based solvent THF in the production of industrial adhesives after some improvement in P2-MTHF. Manufacturing of high quality polymers is under process for a second round of technical investigations. Risk assessment of hydrogenation intermediates has been started as well. The missing toxicological data necessary to assess the carcinogenic and geno-toxic properties of 2-MTHF are identified. Some parameters on toxicity of 2-MTHF and biodegradation were estimated with selected computer models. A plan on exploitation and dissemination of results is drafted. The relevant project results are disseminated via project website as well at various events.
The tailoring of the catalysts’ lead structure in a way to feature only high-boiling components has expanded the limits of molecular catalysis towards the level of heterogeneous catalysis. Consequently, important preliminaries towards the establishment of molecular catalysis in modern sustainable industrial processes have been accomplished. Further optimization of catalyst converting LVA into desired products for demo plant is planned. The main objective is to develop the design of an efficient process at a commercial production scale at the end of the project. This will lead to generation of multiple jobs in future. HYBRID has scaled up the synthesis of several Triphos ligands by a factor of circa 50. It has now the capability to commercially produce such ligands at very short lead times. As these ligands are being used internationally by numerous institutes /companies, revenues could be generated in case HYBRID is granted freedom to operate. LIKAT’s technologies for the preparation of the as yet unknown polymers from levulinic acid-derived renewables (GVL, MeBDO and 2-MTHF) will become available. These polymers will be applied by HENKEL for the preparation of adhesives on ton-scale. This in turn will create a market for bio-based levulinic acid of sufficient size to allow GFBiochemicals to start large scale production. For HENKEL hydrogenation products of LVA are very attractive as they can be applied as substitutes of their fossil-based C-4 counterparts in solvent applications and give potential to new polymers with improved product properties. 2-MTHF is a replacement of THF in its solvent as well as building block applications. GVL may be a replacement for GBL as solvent and building block. The approach is that HENKEL e.g. selects the most appropriate, THF-containing standard adhesives to test replacement with 2-MTHF. 2-MTHF based polymers still need to be optimized with regards to purity and reactivity. Nevertheless, HENKEL and LIKAT are both convinced that adhesives of a much higher quality can be produced from polyethers that do not contain (so far detected) cyclic oligomers. Hence LIKAT is currently producing improved versions of a polymer. This will lead to a high performance component for the new bio-based adhesives.