Deactivation pathways in zeolite-catalyzed isobutane/butene alkylation

Molecular elucidating of an unusual growth mechanism for polycyclic aromatic hydrocarbons in confined space

“…However, given the diverse isomers of each specified mass, accurate molecular structures are rather difficult to be fingerprinted, and their structural confirmation normally necessitates reference standards or predetermined/published UV spectra 19,21 . Noticeably, among these MS techniques, matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry (MALDI FT-ICR MS) (that was traditionally applied for deciphering the structure of biological molecules) has emerged as a powerful tool for coke structural identification in zeolitecatalyzed reactions with the advantage of soft ionization thus minimizing the fragmentation 22 . Only few studies are available to date that used MALDI FT-ICR MS to identify the nature of coke species over HBEA 23 , HMOR 24 , and HZSM-5 17 , but this tool alone was unable to address the complexity of isomerspecific measurements.…”

Mechanism of byproducts formation in the isobutane/butene alkylation on HY zeolites

“…9 Formation routes of target compound TMP and primary oligomers in isobutane/butene alkylation over zeolites. 21,31 Fig . 10 Formation routes of alkylation byproducts.…”

“…In order to increase the selectivity of desirable alkylate trimethylpentane (TMP), considerable research has been carried out to understand the formation mechanism of C8. [21][22][23][24] However, the formation pathways of the byproducts were discussed roughly. It is expected that the C5-C7 hydrocarbon species are derived from the cracking of higher hydrocarbons by b-scission, and the C9+ hydrocarbon species are formed via butene oligomerization.…”

Perspectives of Ionic Liquids Applications for Clean Oilfield Technologies

“…The fluoride anion is highly toxic and ecological problems are generated when fluoride is not completely removed after the alkylation reaction (Weitkamp & Traa, 1999). Many efforts have been made to introduce new developments relating to established technologies and properly new technologies (Hommeltoft, 2001) and other catalysts have been evaluated as alternative for this process, such as solid materials like zeolites and Lewis and Brønsted acid in different solid supports (Feller et al, 2003, Platon & Thomson, 2005, Thompson & Ginosar, 2005, Guzmán et al, 2006, heteropolyacids (Zhao et al, 2000) and Nafion silica nanocomposite , a-b. Shen et al, 2010 (Chauvin et al, 1994), but after this first effort several paper describing the application of supported and non-supported ILs catalysts have been published , Yoo et al, 2004 Figure 11) in a ratio 22:1 of HF:pyridine can be advantageously applied in alkylation process representing environmentally benign and safer conditions readily adaptable to the existing refinery alkylation units (Olah et al, 2005).…”