540-84-1Relevant articles and documents
Isobutane/2-Butene Alkylation on Ultrastable Y Zeolites: Influence of Zeolite Unite Cell Size
Corma, A.,Martinez, A.,Martinez, C.
, p. 185 - 192 (1994)
The alkylation reaction of isobutane with trans-2-butene has been carried out on a series of steam-dealuminated Y zeolites with unit cell sizes ranging from 2.450 to 2.426 nm.A fixed-bed reactor connected to an automatized multiloop sampling system allowed us to make differential product analysis from very short (1 min or less) to longer times on stream.A maximum in the initial 2-butene conversion was found on samples with unit cell sizes between 2.435 and 2.450 nm.However, the TMP/DMH ratio, i.e., the alkylation-to-oligomerization ratio, continuously increased withzeolite unit cell size.The concentration of reactants in the pores, the strength distribution of Broensted acid sites, and the extent of hydrogen transfer reactions, which in turn depend on the framework Si/Al ratio of a given zeolite, were seen to affect activity and product distribution of the catalysts.Finally, the influence of these factors on the aging characteristics of the samples was also discussed.
Hybrid Catalysts Based on Sulfated Zirconium Dioxide and H-beta Zeolite for Alkylation of Isobutane with Isobutylene
Yuferova,Devyatkov, S. Yu.,Fedorov,Semikin,Sladkovskii,Kuzichkin
, p. 1605 - 1613 (2017)
Physicochemical properties of new hybrid catalysts based on sulfated zirconium oxide supported by zeolite of the Beta structural type were investigated. The acid-base characteristics of the catalysts were determined by the amount of the supported component, the maximum concentration of Br?nsted acid centers (277 Μmol/g) was achieved upon deposition of 1.7 wt.% sulfated zirconium oxide. The texture characteristics of the final catalyst were determined by the starting support. Tests of the catalysts in the reaction of isobutane alkylation with isobutylene demonstrated their advantage in selectivity and stability over the classical bulk sulfated zirconium oxide. The variation of the surface acidity is correlated with the amount of the deposited sulfated zirconium dioxide and has an extremum point at around 4 wt.%. Hybrid catalysts based on H-Beta zeolite with supported sulfated zirconium dioxide are more stable and exhibited a higher selectivity with respect to C8 hydrocarbons and trimethylpentanes, compared with bulk sulfated zirconium dioxide.
Eidus,Nefedow
, (1960)
MxOy/SO42--/dealuminated zeolite β (M=Ti, Fe) as novel catalysts for alkylation of isobutane with 1-butene
Sun, Mingxing,Sun, Jianwei,Li, Quanzhi
, p. 519 - 520 (1998)
A new kind of MxOy/SO42--/H-form dealuminated β (DHβ) catalysts prepared here were applied to alkylation of isobutane with 1-butene. The group of MxCy/SO42-/DHβ (M = Ti, Fe) catalysts has a lower rate of deactivation and higher selectivity of this alkylation than other group of Hβ and DHβ. It is proposed that the strong acid sites corresponding to the active sites for this alkylation can be formed by the interaction among DHβ, MxOy, and SO42-.
Ionic liquid-catalyzed alkylation of isobutane with 2-butene
Yoo, Kyesang,Namboodiri, Vasudevan V.,Varma, Rajender S.,Smirniotis, Panagiotis G.
, p. 511 - 519 (2004)
A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides-aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions, respectively. The emphasis has been to delineate the role of both cations and anions in this reaction. The ionic liquids bearing a larger alkyl group on their cation ([C8mim]) displayed relatively higher activity than a smaller one ([C6 or C4mim]) with the same anionic composition, due to the high solubility of reactants in the former. Among the ionic liquids with different halide groups, bromides ([C8mim]Br-AlCl3) showed outstanding activity, because of the higher inherent acidity relative to others. From the 27Al NMR study, a major peak at ~99.5 ppm corresponding to [AlCl3Br]- (~99.5 ppm) was observed. Moreover, the anion showed a strong acidity based on FT-IR characterization; the largest peak related to acidity (1570 cm-1) was detected. Under various composition conditions, catalytic activity and amount of TMPs increased with concentration of anion. This is mainly attributed to a higher amount of strong acid ions [Al2Cl6Br]- which can react with hydrogen atoms at the 2-position of an imidazolium ion to form Bronsted acid. However, the ionic liquid with strong acidity (X=0.58) deactivated rapidly due to a higher sensitivity to moisture, causing decomposition. Under various reaction temperature conditions, optimum catalytic activity was observed at 80°C. The result is also attributed to the effect of anion composition. The strong acidic anion increased with temperature. However, at higher reaction temperatures (120°C), the ionic liquid showed a lower activity and TMP selectivity, since the solubility and Bronsted acid sites were reduced by decomposition of imidazolium ions. The selected ionic liquid sample ([C8mim]Br-AlCl3) was compared with one of the standard commercial catalysts, sulfuric acid. Under optimum experimental conditions, it was observed that both catalysts showed comparable catalytic behavior. However, ionic liquid showed higher activity, and lower TMP selectivity due to a more acidic nature and a lower amount of Bronsted acid sites, respectively.
A Polymer-Supported Organotin Hydride and Its Multipurpose Application in Radical Organic Synthesis
Gerlach, Martin,Joerdens, Frank,Kuhn, Heiko,Neumann, Wilhelm P.,Peterseim, Markus
, p. 5971 - 5972 (1991)
The multipurpose application of a polystyrene-supported, regenerable organotin hydride for radical organic syntheses is demonstrated using 10 examples taken from dehalogenation of bulky or multifunctional halides, dehydroxylation of secondary alcohols, and deamination of secondary or tertiary amines.
HYDROTHERMAL PRODUCTION OF ALKANES
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Paragraph 0022; 0035-0036, (2021/04/17)
Synthesizing an alkane includes heating a mixture including an alkene and water at or above the water vapor saturation pressure in the presence of a catalyst and one or both of hydrogen and a reductant, thereby hydrogenating the alkene to yield an alkane and water, and separating the alkane from the water to yield the alkane. The reductant includes a first metal and the catalyst includes a second metal.
PROCESS OF MAKING OLEFINS OR ALKYLATE BY REACTION OF METHANOL AND/OR DME OR BY REACTION OF METHANOL AND/OR DME AND BUTANE
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Page/Page column 15; 25; 26; 31; 32, (2017/05/10)
Methods of simultaneously converting butanes and methanol to olefins over Ti-containing zeolite catalysts are described. The exothermicity of the alcohols to olefins reaction is matched by endothermicity of dehydrogenation reaction of butane(s) to light olefins resulting in a thermo- neutral process. The Ti-containing zeolites provide excellent selectivity to light olefins as well as exceptionally high hydrothermal stability. The coupled reaction may advantageously be conducted in a staged reactor with methanol/DME conversion zones alternating with zones for butane(s) dehydrogenation. The resulting light olefins can then be reacted with iso-butane to produce high-octane alkylate. The net result is a highly efficient and low cost method for converting methanol and butanes to alkylate.