The Experts below are selected from a list of 16581 Experts worldwide ranked by ideXlab platform
Kunio Arai - One of the best experts on this subject based on the ideXlab platform.
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A new two-stage process for supercritical fluid extraction of coal with Tetralin pretreatment
Fuel, 1996Co-Authors: Tadafumi Adschiri, Shun-ichi Tanaka, Shinji Abe, Kunio AraiAbstract:Abstract A new two-stage process for supercritical toluene extraction of coal is proposed that achieves conversion of 60 wt% and a liquid yield of 45 wt%. The first stage consists of pretreatment of the coal with Tetralin liquid and vapour with a prescribed temperature-pressure-solvent programme (TPSP). In this stage, coal is pretreated with liquid Tetralin up to 460 K and Tetralin vapour from 460 to 653 K. In the second stage, the coal is extracted with supercritical toluene at 653 K and 20 MPa. Extractions were compared with other TPSPs including toluene-Tetralin (70 : 30 w/w) mixtures and it was found that the new process could achieve similar conversions and liquid yield but with much less Tetralin. The pretreatment TPSP is explained in terms of coal swelling during liquid Tetralin pretreatment and inhibition of radical recombination in the pyrolysis during Tetralin vapour pretreatment.
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Co-solvent effect of Tetralin or ethanol on supercritical toluene extraction of coal
Fuel, 1991Co-Authors: Masahiro Shishido, Takahiro Mashiko, Kunio AraiAbstract:Abstract The co-solvent effect of Tetralin and ethanol on supercritical toluene extraction of coal has been investigated. Eleven coals were extracted with three solvents: toluene, toluene-Tetralin and toluene-ethanol mixtures. Addition of Tetralin or ethanol to toluene increased the conversion of these 11 coals. Stabilization of radical fragments by hydrogen transfer from Tetralin inhibits the recombination of radicals with coal and the degradation of extracts. Thus the addition of Tetralin increased the conversion and the coal liquid yield. Ethanol attacks the coal structure and a considerable amount of coal liquid is produced by this attack, although its solvent power is lower than toluene. The solvent power of the toluene-ethanol mixture decreased as the ethanol content increases. The conversion and liquid yield increased to a maximum and then decreased with increasing ethanol content in the solvent.
Gerald D. Holder - One of the best experts on this subject based on the ideXlab platform.
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Vapor-liquid equilibria in the systems of n-decane/Tetralin, n-hexadecane/Tetralin, n-decane/1-methylnaphthalene, and 1-methylnaphthalene/Tetralin
Journal of Chemical & Engineering Data, 1992Co-Authors: Dennis M. Dempsey, Rahoma S. Mohamed, Gerald D. HolderAbstract:Vapor-liquid equilibrium data for the binary systems of n-decane/Tetralin, n-hexadecane/Tetralin, n-decane/1-methyinaphthalene, and 1-methyinaphthalene/Tetralin were measured at a low to moderate pressure (0 - 1123 kPa) by using a static equilibrium cell. The binary P-x data were isothermally correlated using the modified Peng-Robinson equation of state to describe both vapor and liquid phases at 473.15, 533.15, and 573.15 K. In this paper interaction parameters for density-dependent mixing rules are reported at each isotherm.
Daniel E. Resasco - One of the best experts on this subject based on the ideXlab platform.
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comparative study of the hydrogenation of Tetralin on supported ni pt and pd catalysts
Catalysis Today, 2007Co-Authors: Siraprapha Dokjampa, Siriporn Jongpatiwut, Thirasak Rirksomboon, Somchai Osuwan, Daniel E. ResascoAbstract:ThehydrogenationofTetralininthevaporphasehasbeeninvestigatedoverNi,Pt,andPdcatalyststodeterminetheevolutionofthetrans-andcisdecalin products as a function of conversion over the different catalysts. The concentration of each isomer in the product may be important in subsequentring openingstepsif cetane number improvementis desired.Thecis-decalin isomer is preferredto open the naphthenicring ina selective wayinsteadofmultiplecracking.However,thermodynamically,thisisomeristheleastfavored;so,kineticcontrolistheonlysolution.Byselectingthe proper catalyst and operating conditions, one could keep the trans/cis-decalin ratio low. In this study, we have prepared a series of supported metal catalysts and tested them in a flow reactor at 3540 kPa and 548 K. Kinetic parameters for the hydrogenation of Tetralin and the cis-to-trans-decalin isomerization over the various catalysts investigated were obtained by fitting the data with a generalized Langmuir‐Hinshelwood model. The kinetic analysis revealed that the relative rates of Tetralin hydrogenation, as well as the cis-to-trans isomerization are greatly affected by adsorption site competition of decalin and Tetralin, which in turn has different magnitudes overthe different catalysts. At Tetralin conversions above 30%, the Ni catalyst yields the lowest trans/cis-decalin ratio. In contrast, the trans/cis ratio on Pd catalyst remains constant at all conversion levels and is highest at low Tetralin conversion. It is concluded that the trans/cis ratio is a combination of the intrinsic selectivity of each isomer and the isomerization reaction. # 2007 Elsevier B.V. All rights reserved.
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Gas-phase kinetic studies of Tetralin hydrogenation on Pt/alumina
Industrial & Engineering Chemistry Research, 2005Co-Authors: Roberto C. Santana, Siriporn Jongpatiwut, Walter E. Alvarez, Daniel E. ResascoAbstract:The hydrogenation of aromatic compounds is a reaction of relevance in the improvement of diesel fuel quality. In this work, the kinetics of Tetralin (1,2,3,4-tetrahydronaphthalene) hydrogenation over Pt/Al2O3 catalysts have been studied in an integral fixed bed reactor at 500 psig in the temperature range 553−573 K. A semiempirical Langmuir−Hinshelwood equation has been used to model the kinetics. The values of the kinetic parameters were determined by a nonlinear fitting, while the heats of adsorption for the hydrocarbons involved (Tetralin and cis- and trans-decalin) were experimentally obtained by temperature-programmed desorption. The adsorption competition between Tetralin and the hydrogenated products (cis- and trans-decalin) for surface active sites can be quantitatively traced to the higher heat of adsorption of Tetralin compared to those of cis- and trans-decalins. As a result, while the activation energy for the cis−trans isomerization is significantly lower than the one for Tetralin hydrogenati...
Guo Can-cheng - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of α-Tetralone from Tetralin by Metalloporphyrin and Transition Metal Salt Tandem Catalysis and the Reaction Mechanism
Chinese Journal of Catalysis, 2008Co-Authors: Guo Can-chengAbstract:An efficient two-step preparation of α-tetralone from Tetralin was studied.First,Tetralin was oxidized to α-Tetralin hydroperoxide with air in the presence of a metalloporphyrin catalyst.Second,a catalytic amount of either water-soluble iron salts or copper salts was added to the resultant α-Tetralin hydroperoxide solution to convert α-Tetralin hydroperoxide into α-tetralone.The major product of oxidation catalyzed by metalloporphyrin was α-Tetralin hydroperoxide,and only a minor amount of α-tetralone and trace of α-tetralol were formed.Simple salts such as CuⅠand FeⅡcould efficiently decompose α-Tetralin hydroperoxide to α-tetralone,and best result was obtained with ferrous ion.The influence of the metal ions,catalyst amount,and reaction temperature on both the Tetralin aerobic oxidation and the decomposition of α-Tetralin hydroperoxide was studied.Possible mechanisms for the oxidation of Tetralin and the decomposition of α-Tetralin hydroperoxide were proposed.
D.h.l. Prasad - One of the best experts on this subject based on the ideXlab platform.
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vapor liquid equilibrium in the binary systems formed by phenol and ortho cresol with Tetralin at 101 1 and 26 6 kpa
Fluid Phase Equilibria, 1997Co-Authors: S M Ashraf, T Vittal E Prasad, M Ramakrishna, D.h.l. PrasadAbstract:Abstract Isobaric vapor-liquid equilibria of: phenol(1) + Tetralin(2) and ortho -cresol(1) + Tetralin(2) binary mixtures measured at 101.1 and 26.6 kPa are reported. Activity coefficients are evaluated and correlated by using the Wilson equation.
