Aromatisation of bio-derivable isobutyraldehyde over HZSM-5 zeolite catalysts. Issue 7 (8th March 2019)

• Record Type: Journal Article
• Authors: Deischter, Jeff; Schute, Kai; Neves, Dario S.; Ebert, Brigitta E.; Blank, Lars M.; Palkovits, Regina
• Is Part Of: Green chemistry. Volume 21:Issue 7(2019)
• Page Start: 1710
• Page End: 1717
• Publication Date: 2019-03-08
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c9gc00483a
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : A novel efficient route to obtain aromatic products based on biomass feedstock was successfully demonstrated with high BTX yields. Abstract : An efficient route to obtain aromatic products based on biomass feedstock is a challenge for future biorefineries. Isobutyraldehyde is a promising feedstock available via biotechnological routes based on both carbohydrates and the direct bioconversion of CO2 . Herein, we report an efficient process for the aromatisation of isobutyraldehyde over zeolite catalysts in a continuous fixed bed reactor to provide value-added aromatic compounds with a yield of 93%. Benzene, toluene and xylenes are the major compounds formed with 79% yield and a productivity of 65 mmol gcat −1 h −1 . Zeolite Y, Beta and Mordenite and ZSM-5 of different modules were studied. Comprehensive catalyst characterisation using XRD, NH3 -TPD, N2 -physisorption, and ICP-OES enabled establishing structure–performance relationships with a major role of zeolite structure, density of strong acid sites and mesoporosity, respectively. HZSM-5 with Si/Al ratios of 15 to 49 proved effective at the aromatisation possessing a comparable density of strong acid sites of 0.37–0.52 mmol g −1 . Superior stability was observed for HZSM-5 zeolites with higher mesopore volumes. The reaction is suggested to mainly proceed via catalytic cracking to C1 –C4 alkanes/alkenes, which undergo further oligomerisation, cyclisation, and aromatisation to form the observed alkyl-aromatics. Emphasizing the potential of the concept, long term continuous operation was carried out by alternating 10 hours time on steam operation and catalyst regeneration via in situ calcination.