- Ionic liquid and solid HF equivalent amine-poly(hydrogen fluoride) complexes effecting efficient environmentally friendly isobutane-isobutylene alkylation
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Isoparaffin-olefin alkylation was investigated using liquid as well as solid onium poly(hydrogen fluoride) catalysts. These new immobilized anhydrous HF catalysts contain varied amines and nitrogen-containing polymers as complexing agents. The liquid poly(hydrogen fluoride) complexes of amines are typical ionic liquids, which are convenient media and serve as HF equivalent catalysts with decreased volatility for isoparaffin-olefin alkylation. Polymeric solid amine:poly(hydrogen fluoride) complexes are excellent solid HF equivalents for similar alkylation acid catalysis. Isobutane-isobutylene or 2-butene alkylation gave excellent yields of high octane alkylates (up to RON = 94). Apart from their excellent catalytic performance, the new catalyst systems significantly reduce environmental hazards due to the low volatility of complexed HF. They represent a new, green class of catalyst systems for alkylation reactions, maintaining activity of HF while minimizing its environmental hazards.
- Olah, George A.,Mathew, Thomas,Goeppert, Alain,Toeroek, Bela,Bucsi, Imre,Li, Xing-Ya,Wang, Qi,Marinez, Eric R.,Batamack, Patrice,Aniszfeld, Robert,Surya Prakash
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- Effects of catalyst composition on the ionic liquid catalyzed isobutane/2-butene alkylation
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Ionic liquid catalyzed isobutane/2-butene alkylation modified with metal compounds was studied. The effect of catalyst composition on the alkylation selectivity was investigated. 27Al NMR, ESI-MS, and FTIR spectra reveal that the catalytic selectivity of the modified ionic liquid is probably determined by the catalyst composition rather than by the acid strength. The complexation of transition metal with 2-butene can increase the internal isobutane-to-olefin ratio of feed during the alkylation reaction, which results in the better selectivity of the modified ionic liquid. The best ionic liquid catalysts were those containing CuAlCl4 complexes, giving the alkylate with 87.5 wt% trimethylpentanes and a calculated research octane number (RON) of 100.5.
- Liu, Ying,Li, Rui,Sun, Hongjuan,Hu, Ruisheng
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p. 133 - 139
(2015/02/19)
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- Liquid-phase isobutane/butene-alkylation using promoted Lewis-acidic IL-catalysts
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The effect of different promoters on activity and selectivity of Lewis-acidic chloroaluminate ionic liquid catalysts was studied for isobutane/2-butene alkylation. When tert-butyl halides are used as promoters, the active species of the alkylation reaction, which is the tert-butyl cation, is directly generated whereas upon catalysis with Bronsted-acid supported ionic liquids, this species is indirectly provided through a hydride shift between protonated 2-butene and isobutane. Experimental results both from batch and continuously operated liquid phase alkylation reactors indicate, that tert-butyl halides are able to speed up the reaction rate significantly and shift the C8-selectivity towards the desired high-octane trimethylpentanes (TMPs). However, secondary reactions like oligomerization and cracking could not be suppressed by the use of this additives and high deactivation rates in continuous opperation were observed. Suggestions are made, how the product composition is effected by the additive and how the promoted IL-catalyst system is deactivated with time on stream.
- Aschauer, Stephan,Schilder, Lisa,Korth, Wolfgang,Fritschi, Susanne,Jess, Andreas
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body text
p. 1405 - 1419
(2012/06/18)
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- Paraffin alkylation
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A liquid acid process is disclosed in which a hydrocarbon component containing an olefin, an olefin precursor or mixture and an isoalkane and a liquid acid catalyst is fed to a downflow reaction zone containing a disperser, under conditions to induce pulse flow at or near the outlet to react the isoalkane and olefin to produce a reaction product and feeding the reaction product to a vaporization zone containing a disperser under conditions to induce pulse flow at or near the outlet of the vaporization zone. A pressure drop across the disperser in the vaporization zone causes partial vaporization of the hydrocarbon which quench es the heat reaction and cooling the unvaporized portion of said reaction product, which is recovered and allowed to separate into an acid phase and hydrocarbon phase containing the alkylate. The acid catalyst and hydrocarbons may be fractally fed to the reaction zone.
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Page/Page column 7
(2008/06/13)
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- Alkylation process with recontacting in settler
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A system and/or process for decreasing the level of at least one organic fluoride present in a hydrocarbon phase contained in an alkylation settler by contacting the hydrocarbon phase with an HF containing stream, containing greater than about 80 wt. % and less than about 94 wt. % HF, in the intermediate portion of the settler which contains at least one tray system, with each tray system comprising a perforated tray defining a plurality of perforations and a layer of packing below the perforated tray, are disclosed.
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Page/Page column 3-5
(2008/06/13)
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- Catalyst and process for contacting a hydrocarbon and ethylene
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A process of contacting at least one feed hydrocarbon, containing three to about seven carbon atoms per molecule, and ethylene in a hydrocarbon-containing fluid in the presence of a catalyst composition to provide at least one product hydrocarbon isomer containing about four to about nine carbon atoms per molecule is provided. The at least one feed hydrocarbon can be selected from paraffins, isoparaffins, and the like and combinations thereof. The catalyst composition contains a hydrogen halide component, a sulfone component, and a metal halide component.
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- Alkene oligomerization process
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A process for oligomerising alkenes having from 3 to 6 carbon atoms which comprises contacting a feedstock comprising a) one or several alkenes having x carbon atoms, and, b) optionally, one or several alkenes having y carbon atoms, x and y being different, with a catalyst containing a zeolite of the MFS structure type, under conditions to obtain selectively oligomeric product containing predominant amounts of certain oligomers. The process is carried out at a temperature comprised between 125 and 175° C. when the feedstock contains only alkenes with 3 carbon atoms and between 140 and 240° C., preferably between 140 and 200° C. when the feedstock contains comprises at least one alkene with 4 or more carbon atoms.
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- Complexation of a Singlet Carbene by a Fluoroalkane. Modification of 1:CHCO2Et Selectivity in Perfluorohexane Solution and ab Initio Calculations
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We have compared product distribution from reactions of 1:CH2 with 2,5-dimethylhexane and 1:CHCO2Et with 2,3-dimethylbutane in alkane vs 1:1 pentane-perfluorohexane solution.A solvent effect was observed in the reaction of 1:CHCO2Et, but not 1:CH2.The preference for tertiary/primary C-H insertion by 1:CHCO2Et is 3.97 +/- 0.04 in 2,3-dimethylbutane solution and 4.48 +/- 0.09 in 1:1 pentane-perfluorohexane solution.There is no change in the stereospecificity of 1:CHCO2Et addition to cis-2-pentene in pentane vs 1:1 pentane-perfluorohexane solution, indicating that the observed change in selectivity is probably not due to intersystem crossing to 3:CHCO2Et.Ab initio calculations provide evidence for a possible origin of the solvent effect via formation of carbene-fluoroalkane complexes.At the RHF/3-21G level, 1:CHCO2Me forms bound complexes with CH3F and CF4 with binding energies ranging from 5.7-19.6 kcal/mol.These complexes are 1.3-1.7 times more strongly bound than complexes formed between 1:CH2 and the same fluoroalkanes.
- Swanson, Judith M.,Dvorak, Curt A.,DeLuca, JoAnn, P.,Standard, Jean M.
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p. 3026 - 3032
(2007/10/02)
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- A solvent effect in reactions of singlet methylene
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The effect of several solvents on the selectivity of singlet methylene (1:CH2) was investigated. It was found that product ratios from reactions in pentane, ethyl ether and cyclohexene solutions were identical; however, product ratios from reactions carried out in benzene were slightly different.
- Neugebauer,DeLuca
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p. 7169 - 7172
(2007/10/02)
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- Mechanisms of 1,5-Dehydrocyclisation and Isomerisation of Alkanes on Iridium, Rhodium, Palladium and Platinum Films
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Deuterium tracer studies with a combined gas-liquid chromatography and mass spectrometry analysis of products and using 2,2,4,4-tetramethylpentane (TMP) as a model reactant establish clearly that the selective cyclisation (SCM) of five-carbon chain alkanes on Ir, Rh, Pd and Pt is by the heterogeneous counterpart of reductive elimination of alkyls in organometallic chemistry.A comparison of cyclisation of TMP, 3,3-dimethylpentane and n-pentane on films of the same series of metals and an extended study of cyclisation of 3,3-dimethylpentane and of n-pentane on a series of Pt-Cu alloy films with variation of hydrogen partial pressure show that more than one mechanism of non-selective cyclisation (NSCM) takes place.The isotopic studies show clearly that a monoadsorbed intermediate is sufficient for bond-shift rearrangement of TMP to 2,2,5-trimethylhexane on Ir, Rh, Pd or Pt.An important major conclusion to be derived from the present work is that one surface metal atom comprises the active centre of the catalytic site for a variety of reactions in addition to simple hydrogenation-dehydrogenation.
- Finlayson, Odilla E.,Clarke, John K. A.,Rooney, John J.
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p. 191 - 210
(2007/10/02)
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- Selective Formation of Solute Radicals in the Radiolysis of Neopentane-Cyclopentane Mixtures at 4 and 77 K as Studied by Capillary Gas Chromatography and ESR Spectroscopy
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The dimer yields in the radiolysis of the neo-C5H12-cyclo-C5H11 (1 molpercent) mixtures at 77 and 4 K have been measured by capillary gas chromatography.Analysis of the results indicates that cyclopentyl radicals are produced selectively at 77K, while their selective formation is suppressed at 4K.This result coincides well with the data obtained by ESR spectroscopy.
- Tilquin, Bernard,Gourdin-Serveniere, Catherine,Miyazaki, Tetsuo,Fueki, Kenji
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p. 2029 - 2030
(2007/10/02)
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- The Mechanisms of Cyclisation and 1,2-Bond-shift Rearrangements of 2,2,4,4-Tetramethylpentane on Transition Metal Films
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The cyclisation/rearrangement products of 2,2,4,4-tetramethylpentane in deuterium on sintered films of Ir, Rh, Pd, and Pt, analysed by combined gas-liquid chromatography/mass spectrometry, show that chemisorbed carbene and carbyne species are not responsi
- Clarke, John K. A.,Finlayson, Odilla E.,Rooney, John J.
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p. 1277 - 1279
(2007/10/02)
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