Z2-9200

Process development for upgrading furfural from biomass to higher value-added chemicals
Project leader: dr. Miha Grilc
Brief project description
In the scope of the project, biomass derived furfural was transformed into value-added chemicals. Furfural is an important basic chemical, which is exclusively produced by hydrolysis of hemicellulose. As prior research, found in literature is often not comparable and narrowly studied, we have designed an extensive experimental and in-silico study. Numerous experimental tests were performed, by using various supports, monometallic and bimetallic catalysts. Different solvents were also tested. Promising catalysts were further thoroughly studied at varying operating conditions. A reaction pathway and a microkinetic model was developed and compared to first‑principle calculations. The developed model can be further used for process optimization.
Basic co-funding information
Project is financed by ARRS with 1700 annual hours of price category B for a period of 2 years. Funding started on July 1st, 2018.
Project team with links to SICRIS
Person contributing to the project:
34522 | Dr. Grilc Miha |
Project results
In the scope of the project, we have made numerous publications in respected journals. We have tested a variety of catalysts and optimized the kinetics for furfural and its derivatives transformation into value-added products. During catalytic testing, we have identified, quantified and developed a reaction pathway for promising catalysts. The results were supported by thorough characterization, microkinetic modelling and by using first principle calculations. Only a handful of such extensive studies can be found in the literature. [1]

Figure 1. Various multiscale modelling scales; from quantum mechanics to industrial process simulation. [1]
Palladium on carbon was found to be one of the most promising monometallic catalysts for selective tetrahydrofurfuryl alcohol production. A microkinetic model was developed, which can be used for production process optimization. [2]

Figure 2. Proposed reaction scheme for hydrogenation of furfural over Pd/C catalyst. [2]
Various doped nickel-based catalysts were prepared and their catalytic activity and selectivity was tested. Partial or total hydrogenation and deoxygenation can be selectively controlled by varying operation conditions and by using dopants, such as lanthanum and niobium. The results were supported by using thorough characterization and microkinetic modeling. [3]

Figure 3. TEM images of reduced a) NiLa, b) reduced NiNb, c) reduced Ni, and d) used Ni. [3]
Hydrogenation, hydrodeoxygenation, and esterification of furfural over various MoOx catalysts were studied through experimental testing, microkinetic modeling and theoretical (DFT) calculations. Isopropyl levulinate was produced as the main product by using isopropanol in the absence of hydrogen gas. The reaction mechanism on the catalyst surface was developed and studied. [4]

Figure 4. Wulff construction for exposed surfaces present on A) MoO2 and B) MoO3. [4]
Bimetallic catalysts, such as ruthenium nanoparticles on iron showed promising results. Faster Ru3+ cation reduction was achieved by using magnetic heating compared to conventional heating. High activity, selectivity and stability of furfural hydrogenation towards furfuryl alcohol, which is an important monomer for numerous syntheses, were achieved. [5] Promising results for furfural transformation towards furfuryl alcohol in a slurry reactor were also obtained by using a magnetic catalyst, consisting of ruthenium with iron oxide on alumina. Such a catalyst has a hierarchical structure, offering a large active surface area. [6]

Figure 5. Schematic representation of hydrolysis and synthesis of boehmite and magnetic nanoparticles. [6]
As an alternative catalyst, we tested enzymatic conversion of 5-hydroxymethyl furfural, which has comparable properties and structure to furfural. Depending on the choice of enzyme, high selectivity towards a desired product can be achieved. [7]
We have additionally studied the use of more ecological and sustainable solvents, such as deep eutectic solvents. Such sustainable and ecological solvents can be used for environmentally friendly production of furfural and similar compounds. The choice of solvent also effects the complexity of reactions, catalysis and process simplicity. [8]
High throughput screening methodology and first principle methods were also expended to other lignocellulosic biomass derivatives, such as adipic acid production. We have proven a wide use of concepts, which were developed in the scope of this project. [9]
Hydrogen solubility in furfural and furfuryl alcohol, as a common furfural derivative was thoroughly studied. This data is fundamental for estimating hydrogen mass transport rate, which is often an important factor, influencing reaction rates and selectivity. [10]

Figure 6. Comparison of experimental and model values of hydrogen solubility under different operating conditions. [10]
Bibliographic references, which were produced in the scope of this project
[1] R. Šivec*, M. Grilc, M. Huš, B. Likozar, Multiscale Modeling of (Hemi)cellulose Hydrolysis and Cascade Hydrotreatment of 5-Hydroxymethylfurfural, Furfural, and Levulinic Acid, Ind. Eng. Chem. Res. 58 (2019) 16018–16032. doi.org/10.1021/acs.iecr.9b00898.
[2] R. Šivec*, B. Likozar, M. Grilc, Surface kinetics and transport phenomena modelling for furfural hydrotreatment over Pd/C in isopropanol and tetrahydrofuran, Appl. Surf. Sci. (2020) 148485. doi.org/10.1016/j.apsusc.2020.148485.
[3] B. Pomeroy*, M. Grilc, S. Gyergyek, B. Likozar, Catalyst structure-based hydroxymethylfurfural (HMF) hydrogenation mechanisms, activity and selectivity over Ni, Chem. Eng. J. (2020) 127553. doi.org/10.1016/j.cej.2020.127553.
[4] A. Kojčinović*, Ž. Kovačič, M. Huš, B. Likozar, M. Grilc, Furfural hydrogenation, hydrodeoxygenation and etherification over MoO2 and MoO3: a combined experimental and theoretical study, Appl. Surf. Sci. (2020) 148836. doi.org/10.1016/j.apsusc.2020.148836.
[5] S. Gyergyek*, D. Lisjak, M. Beković, M. Grilc, B. Likozar, M. Nečemer, D. Makovec, Magnetic Heating of Nanoparticles Applied in the Synthesis of a Magnetically Recyclable Hydrogenation Nanocatalyst, Nanomaterials. 10 (2020) 1142. doi.org/10.3390/nano10061142.
[6] S. Gyergyek*, A. Kocjan, M. Grilc, B. Likozar, B. Hočevar, D. Makovec, A hierarchical Ru-bearing alumina/magnetic iron-oxide composite for the magnetically heated hydrogenation of furfural, Green Chem. 22 (2020) 5978–5983. doi.org/10.1039/d0gc00966k.
[7] M.M. Cajnko*, U. Novak, M. Grilc, B. Likozar, Enzymatic conversion reactions of 5-hydroxymethylfurfural (HMF) to bio-based 2,5-diformylfuran (DFF) and 2,5-furandicarboxylic acid (FDCA) with air: Mechanisms, pathways and synthesis selectivity, Biotechnol. Biofuels. 13 (2020) 66. doi.org/10.1186/s13068-020-01705-z.
[8] A. Bjelić*, B. Hočevar, M. Grilc, U. Novak, B. Likozar, A review of sustainable lignocellulose biorefining applying (natural) deep eutectic solvents (DESs) for separations, catalysis and enzymatic biotransformation processes, Rev. Chem. Eng. 1 (2020). doi.org/10.1515/revce-2019-0077.
[9] B. Hočevar*, A. Prašnikar, M. Huš, M. Grilc, B. Likozar, H 2 ‐Free Re‐Based Catalytic Dehydroxylation of Aldaric Acid to Muconic and Adipic Acid Esters, Angew. Chem., Int. Ed. (2020) anie.202010035. doi.org/10.1002/anie.202010035.
[10] G. Ivaniš*, L. Fele Žilnik, B. Likozar, M. Grilc, Hydrogen solubility in bio-based furfural and furfuryl alcohol at elevated temperatures and pressures relevant for hydrodeoxygenation, Fuel. 290 (2021) 120021. doi.org/10.1016/j.fuel.2020.120021.
[11] R. Šivec*, M. Huš, B. Likozar, M. Grilc, Furfural Hydrogenation over Cu, Ni, Pd, Pt, Re, Rh and Ru Catalysts: ab initio Modelling of Adsorption, Desorption and Reaction Micro-kinetics, Chem. Eng. J. 436 (2022), 135070. doi.org/10.1016/j.cej.2022.135070
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