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Catalyst-transfer

Thus the ECCU always operates in complete heat balance at any desired hydrocarbon feed rate and reactor temperature this heat balance is achieved in units such as the one shown in Eigure 1 by varying the catalyst circulation rate. Catalyst flow is controlled by a sHde valve located in the catalyst transfer line from the regenerator to the reactor and in the catalyst return line from the reactor to the regenerator. In some older style units of the Exxon Model IV-type, where catalyst flow is controlled by pressure balance between the reactor and regenerator, the heat-balance control is more often achieved by changing the temperature of the hydrocarbon feed entering the riser. [Pg.208]

In the modern unit design, the main vessel elevations and catalyst transfer lines are typically set to achieve optimum pressure differentials because the process favors high regenerator pressure, to enhance power recovery from the flue gas and coke-burning kinetics, and low reactor pressure to enhance product yields and selectivities. [Pg.216]

Erosion. The abrasive is likely to be gas borne (as in catalytic cracking units), liquid borne (as in abrasive slurries), or gravity pulled (as in catalyst transfer lines). Because of the association of velocity and kinetic energy, the severity of erosion may increase as some power (usually up to the 3d) of the velocity. The angle of impingement also influences severity. At supersonic speeds, even water droplets can be seriously erosive. There is some evidence that the response of resisting metals is influenced by whether they are ductile or brittle. Probably most abrasion involved with hydrocarbon processing is of the erosive type. [Pg.269]

Concept Phase transfer catalysis (PTC)111 is now a convenient and useful tool in chemistry, especially in preparative organic chemistry. In general, compounds (reactants) located in different phases of a reaction mixture such as water and benzene sluggishly react each other even by harsh stirring the mixture because the reactants can not easily contact together. Phase transfer catalysts transfer between different phases, become highly active species, and catalytically medi-... [Pg.123]

A catalytic asymmetric [4+2]-cydoaddition of a vinylallene with butadiene has been achieved successfully, in which a palladium complex modified by a ferrocene-derived chiral monophosphine ligand proved to be a superior catalyst transferring chirality to the product (Scheme 16.80) [90],... [Pg.958]

Scanning electron micrographs of typical NSTF catalysts as fabricated on a microstructured catalyst transfer substrate, seen (top) in cross section with original magnification of xl0,000 and (bottom) in-plane view with original magnification of x50,000. A dotted scale bar is shown in each micrograph. (Reproduced from Debe, M. K. et al. Journal of Power Sources 2006 161 1002-1011. With permission from Elsevier.)... [Pg.78]

The pilot plant employed intermittent rather than continuous catalyst transfer, because of the difficulties involved on this scale in circulating the small flows of catalyst required. [Pg.52]

Weigh and dilute catalyst Transfer to reactor vessel... [Pg.76]

After the development of catalyst-transfer condensation polymerization of polythiophene, the block copolymer of polythiophene and PMA could be prepared more easily. As mentioned above, the vinyl-terminated polythiophene was first prepared. The vinyl group was converted to the 2-hydroxyethyl group by hydroboration, followed by esterification with 2-bromopropionyl bromide to give a macroinitiator for ATRP (Scheme 101)... [Pg.65]

It is important to clarify whether catalyst-transfer condensation polymerization is specific to polythiophene, or whether it is generally applicable to the synthesis of well-defined it-conjugated polymers. We investigated the synthesis of poly(p-phenylene), to see whether a monomer 28 containing no heteroatom in the aromatic ring would undergo catalyst-transfer polymerization. However, all polymers obtained in the polymerization with Ni(dppp)Cl2, Ni(dppe)Cl2, or Ni(dppf)Cl2 possessed low molecular weights and broad polydispersities. Nevertheless, we found that LiCl was necessary for opti-... [Pg.66]

Zhou and Hirao showed that a low-valent catalyst generated from CP2VCI2 or VC12 and zinc in the presence of chlorotrimethylsilane is active in tandem reductive dimerization/Thorpe-Ziegler-type cyclizations of arylidenemalononitriles 96 (Fig. 29) [188]. The low-valent catalyst transfers an electron to 96 and the thus generated radical anion 96A adds to another molecule of 96. The resulting distonic... [Pg.150]

In biological photosystems (whole cells, thylakoids or isolated PSI) a simple redox catalyst transfers electrons from the terminal acceptor of PSI to oxygen, the light-transducing system being the natural photosynthetic apparatus itself. In artificial model systems, by contrast, it is a redox photocatalyst (flavin or Ru (II)-tris(2, 2 -bipyridine)) who promotes the light-driven transfer of electrons from appropriate electron donors to molecular oxygen. [Pg.183]

An interesting option (Monsanto, Du Pont) involves the use of a riser reaction as shown in Fig. 2.22. The configuration is analogous to a modern FCC unit (see Fig. 2.3). In the riser reactor the (oxidized) catalyst transfers oxygen to the butane substrate giving maleic anhydride. The catalyst is separated from the product in... [Pg.57]

Description The process consists of a reactor section, continuous catalyst regeneration section (CCR) and product recovery section. Stacked radial flow reactors (1) facilitate catalyst transfer to and from the CCR catalyst regeneration section (2). A charge heater and interheaters (3) are used to achieve optimum conversion and selectivity for the endothermic reaction. [Pg.36]

Description The process consists of a reactor section, continuous catalyst regeneration (CCR) section and product-recovery section. Stacked radial-flow reactors (1) facilitate catalyst transfer to and from the CCR catalyst regeneration section (2). A charge heater and interheaters (3) achieve optimum conversion and selectivity for the endothermic reaction. Reactor effluent is separated into liquid and vapor products (4). The liquid product is sent to a stripper column (5) to remove light saturates from the C6 aromatic product. Vapor from the separator is compressed and sent to a gas recovery unit (6). The compressed vapor is then separated into a 95% pure hydrogen coproduct, a fuel-gas stream containing light byproducts and a recycled stream of unconverted LPG. [Pg.37]

Description This new process consists of a reactor section, a continuous catalyst regeneration section and product recovery section. One or more fluidized-bed reactors (1) are used with continuous catalyst transfer to and from the continuous catalyst regenerator (2). The robust regenerable MTO-lOO catalyst is based on a nonzeolitic molecular sieve. Raw (nondewatered) methanol is fed to the low-pressure reactor (1), which offers very high (99%+) conversion of the... [Pg.77]

The transalkylation and isomerization reactions can be satisfactorily explained by the Streitwieser mechanism( ). This mechanism proposes a 1,1-diphenylethane-type intermediate. For example, para-diethylbenzene. (Figure 3) Such an intermolecular mechanism is consistent with the experimental data and does not require the assumption of a sequence of intramolecular 1,2 shifts. The decay of the polyethylbenzenes towards equilibrium is consecutive and not concurrent. The catalyst seems to be associated with the most basic center and when it reaches steady-state, the catalyst transfers to the next most basic one. There is also a concurrent intramolecular isomerization such as 1,2,4 triethylbenzene going to 1,3,5 triethylbenzene. There is hence a movement towards isomer equilibrium as well as product equilibrium. [Pg.347]

A cyclone outside the moving-bed catalytic colnmn serves to sort only catalyst particles of a desired size among the catalyst particles dropped to the lower portion. A nickel-molybdenum catalyst regenerator with an air injector serves to regenerate the catalyst transferred from the cyclone and the regenerated catalyst is then returned to the moving-bed catalytic cracker [29],... [Pg.424]

About half of the flue gas from the regenerator is used for transporting the catalyst, about 5 % is diverted to an elutriator for removal of catalyst fines, and the remainder is vented directly to the atmosphere. The portion used for catalyst transfer passes through a pressure controller into the... [Pg.312]

The hydrogens Ha and Hb in NADH are diastereotopic, and in the presence of an. enzymic catalyst, transfer of Ha. or Hb depending on the reaction, takes place exclusively in reductions. [Pg.145]

A catalyst transfer system using gas lift to carry the catalyst from one reactor to the next and finally to the regenerator. [Pg.402]

Long-term material testing was performed to confirm material selection for equipment, catalyst transfer piping and control valves. [Pg.277]


See other pages where Catalyst-transfer is mentioned: [Pg.18]    [Pg.352]    [Pg.299]    [Pg.494]    [Pg.189]    [Pg.52]    [Pg.63]    [Pg.64]    [Pg.64]    [Pg.67]    [Pg.410]    [Pg.14]    [Pg.245]    [Pg.122]    [Pg.299]    [Pg.18]    [Pg.1007]    [Pg.320]    [Pg.328]    [Pg.356]    [Pg.172]    [Pg.225]    [Pg.63]    [Pg.1098]    [Pg.3]    [Pg.2560]   
See also in sourсe #XX -- [ Pg.63 ]

See also in sourсe #XX -- [ Pg.91 , Pg.92 ]




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Activity of phase-transfer catalysts

Acyl-transfer catalysts

Alcohol catalysts chain transfer catalyzed

Aldol phase-transfer-catalysts

Aliquat 336 as phase transfer catalyst

Aliquat 336, phase-transfer catalyst

Alkaloid Derivatives as Asymmetric Phase-transfer Catalysts

Alkaloids as phase-transfer-catalysts

Alternative phase transfer catalysts

Amine Salts as Phase-Transfer Catalysts

Amino acid-derived catalysts asymmetric hydrogen transfer

Ammonium salts as phase transfer catalysts

And phase transfer catalysts

As phase transfer catalysts

Assumptions in SO2 oxidation calculations no heat transfer to catalyst

Asymmetric Cycloaddition Catalyzed by Cinchona-Based Phase-Transfer Catalysts

Asymmetric phase-transfer catalysts

Asymmetric transfer hydrogenation (ATH) catalysts

Asymmetric transfer hydrogenation catalysts

Atom transfer radical catalyst

Atom transfer radical various catalysts

Atom-transfer catalysts

Aziridination of Enones Using Cinchona-Based Chiral Phase-Transfer Catalyst

Benzyltriethylammonium chloride phase-transfer catalyst

Benzyltriethylammonium chloride, as phase transfer catalyst

Catalyst Preparation and Transfer

Catalyst chain transfer polymerization

Catalyst chain transfer polymerization technique

Catalyst decal transfer

Catalyst for transfer hydrogenation

Catalyst hydrogen transfer reaction

Catalyst layer charge-transfer resistivity

Catalyst transfer hydrogenation

Catalyst-transfer Suzuki-Miyaura coupling

Catalyst-transfer polycondensation

Catalyst-transfer polymerization

Catalysts coupled heat/mass transfer

Catalysts electron transfer processes

Catalysts mass transfer with reaction

Catalysts reaction, mass transfer

Catalysts, phase transfer type

Catalysts, phase transfer, with

Catalysts, transfer constants

Catalytic chain transfer catalysts

Chemical synthesis phase-transfer catalyst

Chiral Anion Phase-Transfer Catalysts

Chiral Cation Phase-Transfer Catalysts

Chiral compounds phase-transfer catalysts

Chiral phase-transfer catalysis catalysts

Chiral phase-transfer catalysts alkylations

Chiral phase-transfer catalysts conjugate additions

Cinchona phase transfer catalysts

Cinchona-Derived Chiral Phase-Transfer Catalysts for Other Asymmetric Synthesis

Cinchona-Derived Chiral Poly(Phase-Transfer Catalysts) for Asymmetric Synthesis

Cinchona-based phase-transfer catalysts

Copper catalysts atom/group-transfer reactions

Corey phase-transfer catalyst

Coupled heat/mass transfer porous catalysts

Crown ethers as phase transfer catalysts

Crown phase-transfer-catalysts

Cyclodextrins, as phase-transfer catalysts

Dendritic phase transfer catalysts

Deprotonation phase-transfer catalysts

Derived Chiral Phase-Transfer Catalysts for Amino Acid Synthesis

Design of Chiral Phase-transfer Catalysts

Dibenzo-18-crown-6 ether phase transfer catalyst

Diynes phase-transfer catalysts

Dual-catalyst systems, reversible chain transfer

Effects of Mass Transfer Around and within Catalyst or Enzymatic Particles on the Apparent Reaction Rates

Electron transfer catalyst

Enone epoxidation, phase transfer catalyst

Ethers as Chiral Phase-Transfer Catalysts

Ethers, Taddol, Nobin and Metal(salen) Complexes as Chiral Phase-Transfer Catalysts for Asymmetric Synthesis

Flowsheets heat transfers after catalyst beds

Fluidized catalyst beds mass transfer

Fluidized catalyst beds wall heat transfer

Graft polymerization phase transfer catalysts

Growth Catalyst-Transfer Polycondensations

Heat Transfer Between the Bulk Fluid and External Surfaces of Solid Catalysts

Heat and Mass Transfer Coefficients for Flow around Catalyst Particles

Heat and Mass Transfer in Fluidized Catalyst Beds

Heat transfer in porous catalyst

Heat transfers between catalyst beds

Heck reaction phase-transfer catalysts

Homogeneous charge-transfer catalyst

Hydride transfer transition metal catalyst

Hydrogen transfer catalyst

Hydrogen transfer iridium catalysts

Hydrogenation, transfer palladium catalyst preparation

Hydrogenations Mediated by Phase-transfer Catalysts

Iminium catalysts transfer hydrogenation

Immobilized phase transfer catalyst

Inverse phase-transfer catalysts

Iridium chloride, transfer hydrogenation catalyst

Isomerization phase-transfer catalysts

Kumada catalyst-transfer polycondensation

Kumada catalyst-transfer polycondensation KCTP)

Lactones transfer catalysts

Mass and Heat Transfer in Porous Catalysts

Mass transfer and chemical reaction in a catalyst pellet

Mass transfer catalyst particles

Mass transfer in porous catalyst

Metal-free reduction of imines enantioselective Br0nsted acid-catalyzed transfer hydrogenation using chiral BINOL-phosphates as catalysts

Metallocene catalysts chain transfer

Metallocene catalysts chain transfer reactions

Michael enantioselective phase-transfer catalyst

Monolithic catalysts heat transfer coefficient

Organocatalytic phase-transfer catalysts

Other Chiral Phase-Transfer Catalysts for Asymmetric Synthesis

Other Two-Center Chiral Phase-Transfer Catalysts

PEG as Phase-Transfer Catalyst

PTC = phase-transfer catalysts

PTC—See Phase transfer catalysts

Palladium acetate phase-transfer catalyst

Partial wetting/mass transfer/catalyst

Phase transfer catalysis catalysts

Phase transfer catalysis cinchona-based catalysts

Phase transfer catalysis quaternary ammonium catalysts

Phase transfer catalysis triphase catalysts

Phase transfer catalyst activity evaluation

Phase transfer catalyst asymmetric selection

Phase transfer catalyst benzyltriethyl ammonium

Phase transfer catalyst phenol

Phase transfer catalyst polymerization

Phase transfer catalyst preparation

Phase transfer catalyst, chiral

Phase transfer catalysts ammonium salts

Phase transfer catalysts crown ethers

Phase transfer catalysts cryptands

Phase transfer catalysts description

Phase transfer catalysts onium salts

Phase transfer catalysts poly used

Phase transfer catalysts soluble polyethers

Phase transfer catalysts sulfate

Phase transfer catalysts sulfur ylide reactions

Phase transfer catalysts tetrabutylammonium bromide

Phase transfer catalysts tetrabutylammonium chloride

Phase transfer catalysts using tris amine

Phase transfer catalysts, chiral polymer-based

Phase transfer catalysts, chiral polymeric

Phase transfer catalysts, chiral solid

Phase transfer catalysts, laboratory

Phase transfer catalysts, laboratory experiments

Phase transfer triphase catalysts

Phase-transfer catalysis catalyst improvements

Phase-transfer catalysis conditions cinchona alkaloid-derived catalyst

Phase-transfer catalysis polymer-supported catalysts

Phase-transfer catalysis supported catalysts

Phase-transfer catalysis usual catalysts

Phase-transfer catalysis, copper catalysts

Phase-transfer catalyst future research

Phase-transfer catalyst reaction

Phase-transfer catalyst, for

Phase-transfer catalyst, role

Phase-transfer catalysts

Phase-transfer catalysts Adogen

Phase-transfer catalysts Methyltrioctylammonium chloride

Phase-transfer catalysts Polyethylene glycol

Phase-transfer catalysts Tris amine

Phase-transfer catalysts alkylation

Phase-transfer catalysts matrix

Phase-transfer catalysts multisite

Phase-transfer catalysts substitution reactions

Phase-transfer catalysts, functional group

Phase-transfer catalysts, functional group tolerance

Phase-transfer catalysts, heterocyclic

Phase-transfer catalysts, phosphonium salts

Phase-transfer catalysts, requirements

Photoelectron transfer catalysts

Poly phase transfer catalyst

Polyethylene glycol phosphonium salts phase-transfer catalysts

Polyethylene supported phase-transfer catalysts

Polymer phase-transfer catalyst

Polymer-supported phase transfer catalyst stability

Polymer-supported phase-transfer catalysts

Purely organic catalysts phase-transfer reactions

Quaternary Ammonium compounds phase-transfer catalysts

Quaternary ammonium salts as phase transfer catalysts

Quaternary ammonium salts phase-transfer catalysts

Reaction and Mass Transfer in Porous Catalyst Structures

Reaction-controlled phase-transfer catalyst

Ruthenium catalysts asymmetric transfer hydrogenation

Ruthenium catalysts atom/group transfer reactions

SOULA Phase transfer catalyst

SOX transfer catalysts

Soluble phase-transfer catalysts

Stable catalysts for phase transfer

Sulfonium salts phase transfer catalysts

Tetraalkylammonium Salts as Phase-Transfer Catalysts

Tetrabutylammonium as phase transfer catalyst

Tetrabutylammonium hydrogen sulfate phase transfer catalyst

Tetrabutylammonium iodide phase transfer catalyst

Thermoregulated Inverse Phase-Transfer Catalysts

Transfer DPEN catalysts

Transfer Effects in Poisoned Catalysts

Transfer Hydrogenation Using Heterogeneous Catalysts

Transfer Hydrogenation using Homogeneous Catalysts

Transfer hydrogenation active catalyst

Transfer hydrogenation active catalyst species

Transfer of Catalyst

Transition metal catalysts atom/group-transfer reactions

Two-Center Chiral Phase-Transfer Catalyst Derived from BINOL

Two-Center Chiral Phase-Transfer Catalysts for Asymmetric Synthesis

Use of Crown Ether as Phase-Transfer Catalyst

Use of Nobin and Related Species as Asymmetric Phase-Transfer Catalysts

Wittig reactions phase transfer catalysts

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