Propylene synthesis via isomerization–metathesis of 1-hexene and FCC olefins. Issue 18 (12th August 2021)

• Record Type: Journal Article
• Authors: Novodárszki, Gyula; Szabó, Blanka; Auer, Róbert; Tóth, Katalin; Leveles, László; Barthos, Róbert; Turczel, Gábor; Pászti, Zoltán; Valyon, József; Mihályi, Magdolna R.; Tuba, Róbert
• Is Part Of: Catalysis science & technology. Volume 11:Issue 18(2021)
• Page Start: 6257
• Page End: 6270
• Publication Date: 2021-08-12
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d1cy00269d
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Highly efficient conversion of 1-hexene and FCC mixture to propylene via isomerization–metathesis (ISOMET) catalyzed by a HBEA–MoO x /Al2 O3 system. Abstract : Conversion of 1-hexene or olefins obtained by fluid catalytic cracking (FCC) to propylene via isomerization–metathesis (ISOMET) was investigated using ethylene as a cross-coupling agent. Zeolite H-beta (HBEA) was applied as an isomerization catalyst. The olefin metathesis (OM) catalysts were about 12 wt% molybdena, supported on zeolite beta (MoO3 /HBEA), and γ-alumina (MoO3 /Al2 O3 ). HBEA-supported catalyst with a lower molybdena content (6 wt%) was also investigated. The catalysts were characterized by X-ray diffractometry (XRD), H2 -temperature-programmed reduction (H2 -TPR), and Fourier transform infrared (FT-IR), visible Raman, in situ ultraviolet-visible (UV/VIS) and XPS spectroscopy. It was shown that HBEA is a highly active and robust catalyst of double-bond isomerization. Applying a physical mixture of HBEA and 12MoO3 /Al2 O3 catalyst at 150 °C and 3 bar ethylene pressure, 60% conversion of 1-hexene to propylene was attained. Interestingly, quantitative conversion to propylene was achieved after reactivation of the deactivated catalyst in an argon atmosphere at 550 °C. It was found that the pre-treatment of the catalyst with olefins such as ethylene before inert gas activation resulted in significant catalyst activity improvement. This suggests that the adsorbed olefins may play a key role in the formation of active metal centers during the catalyst reactivation process. The catalyst mixture also had good performance in the conversion of FCC olefins to propylene. The MoO3 /HBEA catalysts have rendered reasonable activity; however, the catalysts showed a significantly shorter lifetime than the alumina-containing catalyst mixture.