Catalyst Design for the Valorisation of Biomass-derived Furans into Aromatics
Licentiate thesis, 2023

Anno 2023, mankind must strive towards a more sustainable chemical industry; one that does not solely rely on fossil fuels but also utilises renewable feedstocks such as biomass. Biomass can be catalytically converted into commodity chemicals such as aromatics, through intermediates like furans. Aromatics serve as building blocks for everyday materials.

In this work, the conversion of one type of furans, 2,5-dimethylfuran, was studied at elevated temperatures in a flow reactor by using a selection of microporous, acidic catalysts. The effluent gas stream was analysed with Fourier-transform infrared spectroscopy and mass spectrometry. Zeolitic catalysts with the MFI-framework were synthesised bottom-up through hydrothermal synthesis, with aluminium or gallium substituted in their framework. Structural analysis was performed comprising X-ray fluorescence, X-ray diffraction, physisorption, thermogravimetric analysis, scanning electron microscopy, and acidity analysis by NH3-TPD. 

Both aluminium and gallium-substituted zeolites were active for converting 2,5-dimethylfuran into aromatics, of which Ga-MFI displayed superior benzene production and catalyst lifetime. Catalyst deactivation was caused by the loss of strong and extra-framework acid sites due to the coking. After deactivation towards aromatics, the intermediate products formed on weak acid sites such as 2,4-dimethylfuran, were detected as the main products.

It was found that an increase in gallium content increases catalytic activity until a limit of Si/Ga=13 was reached, at which the synthesis of the catalyst also yielded an inactive, amorphous phase. Increasing the crystallisation duration enabled approaching this limit and forming phase-pure MFI zeolite with a Si/Ga ratio of Si/Ga=17.

Mesopores were introduced to the catalyst to improve the mass transfer of reactants and products. Even though the total production of aromatics and the catalyst lifetime remained unchanged, its number of acid sites was halved implying that each acid site was able to produce twice as many aromatics.

aromatics

2,5-dimethylfuran

gallium

biomass

furans

production of aromatics

zeolites

biomass conversion

catalysis

KC-salen, Kemigården 4, Chalmers
Opponent: Prof. Jerker Mårtensson, Department of Chemistry and Biochemistry, Chalmers University of Technology, Sweden



Author

Guido J.L. de Reijer

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

C. Sauer, G.J.L. de Reijer, B. Wilfinger, A. Hellman, and P.-A. Carlsson, Continuous isomerisation of 2,5-dimethylfuran to 2,4-dimethylfuran over Ga-silicate

Green Commodity Chemicals

Swedish Energy Agency (2019-006746), 2020-01-01 -- 2024-12-31.

Subject Categories

Inorganic Chemistry

Chemical Process Engineering

Materials Chemistry

Environmental Sciences

Organic Chemistry

Infrastructure

Chalmers Materials Analysis Laboratory

Areas of Advance

Materials Science

Publisher

Chalmers

KC-salen, Kemigården 4, Chalmers

Online

Opponent: Prof. Jerker Mårtensson, Department of Chemistry and Biochemistry, Chalmers University of Technology, Sweden

More information

Latest update

1/26/2024