摘要:
Hydrocarbons are alkylated in a fluidized riser-reactor using a solid catalyst which is regenerated within the process by contact with hydrogen. The alkylation and regeneration steps are separated to prevent the admixture of hydrogen and any olefins present in the process. Two separate modes of regeneration are performed simultaneously: a mild liquid-phase washing and a vapor-phase hot hydrogen stripping operation.
摘要:
A catalytic reforming process comprises a prereactor which provides an intermediate stream to a riser reactor with multiple catalyst injection points to obtain high aromatics yields from a naphtha feedstock. Product from the riser reactor typically is discharged into a fluidized-bed reforming reactor, in which the reforming reaction is completed and catalyst is separated from hydrogen and hydrocarbons. Hydrocarbons from the reactor are separated to recover an aromatized product. Catalyst is regenerated to remove coke and reduced for reuse in the reforming process.
摘要:
A process for the continuous isomerization of an alkane to produce an isomerized product through contacting the alkane with a simulated moving bed acting as a catalyst for isomerization and an adsorbent for the alkanes has been developed. The alkane may be n-butane and the isomerized product 2-methylpropane, the alkane may be n-pentane and the isomerized product 2-methylbutane or 2,2-dimethylpropane, the alkane may have from 6 up to about 8 carbon atoms with no more than one methyl branch and the isomerized product having the same number of carbon atoms and at least two methyl branches, or the reactant may be a mixture of the foregoing alkanes with the corresponding isomerized products being formed. In a zone of the simulated moving bed, the alkanes are catalytically isomerized to form the isomerized products. The unreacted alkanes are adsorbed, and the isomerized products are collected. In a subsequent zone of the simulated moving bed, the unreacted alkanes are desorbed using a desorbent and may be catalytically isomerized to form additional isomerized products which are also separated and collected. The catalyst used in the simulated moving bed may be platinum on tungstated zirconia, and the adsorbent used in the simulated moving bed may be EU-1, ZSM-12, SAPO-5, Y-82, faujasite, erionite, zeolite beta exchanged with sodium, lithium, potassium, barium, calcium, strontium or combinations thereof, zeolite X exchanged with calcium and strontium, mordenite exchanged with sodium, lithium, potassium, barium, calcium, strontium, or combinations thereof.
摘要:
A process for the efficient production of diisopropyl ether where catalytic distillation is used to increase the yield of product beyond thermodynamic equilibrium limitations has been developed. In a hydration zone the propylene in a feedstock is reacted with water in the presence of a catalyst to effect hydration to produce an effluent stream containing at least water, unreacted propylene, and isopropyl alcohol, and then, in an etherification zone, at least a portion of the effluent stream is further reacted by catalytic distillation in the presence of a catalyst to effect reaction of propylene and isopropyl alcohol to form diisopropyl ether while concurrently separating an organic portion containing the diisopropyl ether and an aqueous portion, and collecting the organic portion containing the diisopropyl ether.
摘要:
A two-stage process for effecting a chemical reaction has been developed. The reactants are contacted with a first stage fixed catalyst bed containing a solid catalyst or mixture of catalysts effective to catalyze the reaction and form a mixture of reactants and products. This reaction mixture and a desorbent are then contacted with a second stage simulated moving bed containing a solid or a mixture of solids effective to catalyze the reaction and to selectively adsorb at least one component from the reaction mixture. At least one product-containing stream is formed and collected. The process may be conducted in the liquid phase or in the vapor phase.
摘要:
Hydrocarbons such as isobutane and benzenes are alkylated using a solid catalyst in a process which simulates the cocurrent movement of the catalyst bed versus the reactants. This has been found to greatly reduce the rate of catalyst deactivation compared to simulated countercurrent flow. The process may be performed using five or more beds of catalyst, with two undergoing regeneration at any one time. One bed is subjected to a short term liquid-phase regeneration while the other is subjected to long term vapor-phase regeneration. The catalyst preferably contains a metal hydrogenation function effective to selectively hydrogenate C.sub.6 -plus materials trapped on the used catalyst.
摘要:
A process for the continuous production of methanol through contacting at least one feed stream containing at least carbon monoxide and hydrogen, and optionally carbon dioxide, with a simulated moving bed acting as a catalyst for methanol synthesis and an adsorbent for the methanol formed has been developed. The carbon monoxide and hydrogen are catalytically reacted to form methanol which is separated from the carbon monoxide and hydrogen by concurrent adsorption. The methanol is desorbed using a carbon dioxide or hydrogen desorbent and collected. A specific embodiment is one where the feed stream is introduced to the simulated moving bed at a temperature from about 210.degree. to about 270.degree. C. and the desorbent is introduced to the simulated moving bed at a temperature of about 150.degree. to about 250.degree. C.
摘要:
A process to separate multimethyl-branched alkanes from a mixture of multimethyl-branched alkanes, monomethyl-branched alkanes, and normal alkanes has been developed. The mixture is introduced to a simulated moving bed of solid adsorbent particles having the selectivity normal alkanes>monomethyl-branched alkanes>multimethyl-branched alkanes. The adsorbent may be silicalite, ferrierite, zeolite Beta, MAPO-31, SAPO-31, SAPO-11, zeolite X ion exchanged with alkaline cations, alkaline earth cations, or a mixture thereof, and zeolite Y ion exchanged with alkaline cations, alkaline earth cations, or a mixture thereof. A raffinate stream enriched in multimethyl-branched alkanes is removed from the simulated moving bed. The monomethyl-branched alkanes are desorbed from the solid adsorbent particles using a first desorbent capable of desorbing the monomethyl-branched alkanes but incapable of desorbing the normal alkanes and first extract stream enriched in the desorbed monomethyl-branched alkanes is removed from the simulated moving bed. The normal alkanes are desorbed from the solid adsorbent particles using a second desorbent, and a second extract stream enriched in the desorbed normal alkanes is removed from the simulated moving bed. The process may be incorporated into an isomerization flowscheme.
摘要:
A process for isomerizing a mixture of alkanes containing pentanes and at least one alkane having from 6 to about 8 carbon atoms and no more than one methyl branch has been developed. The process includes: 1) separating the mixture in a first separation zone to produce two streams, a stream enriched in alkanes having from 6 to about 8 carbon atoms and a stream enriched in pentanes; 2) separating the stream enriched in pentanes in a second separation zone to produce two streams, a stream predominately comprising n-pentane and a stream predominately comprising branched pentanes; 3) passing the stream enriched in alkanes having from 6 to about 8 carbon atoms and the stream enriched in n-pentane to an isomerization zone of a simulated moving bed to produce two streams, a stream containing branched pentanes, n-pentane, and multi-methyl-branched alkanes having from 6 to about 8 carbon atoms, and a stream containing branched pentanes and n-pentane; 4) separating the stream containing branched pentanes, n-pentane, and multi-methyl-branched alkanes having from 6 to about 8 carbon atoms in a third separation zone to produce two streams, a stream enriched in multi-methyl-branched alkanes having from 6 to about 8 carbon atoms and a stream enriched in branched pentanes and n-pentane; and 5) collecting the stream predominately comprising branched pentanes from the second separation zone and the stream enriched in multi-methyl-branched alkanes having from 6 to about 8 carbon atoms from the third separation zone. The catalyst used in the simulated moving bed may be platinum on tungstated zirconia and the adsorbent used in the simulated moving bed may be one or more of the following adsorbents, zeolite beta exchanged with sodium, lithium, potassium, barium, calcium, strontium or combinations thereof, zeolite X exchanged with calcium and strontium, mordenite exchanged with sodium, lithium, potassium, barium, calcium, strontium, or combinations thereof, EU-1, ZSM-12, SAPO-5, Y-82, faujasite and erionite.
摘要:
Hydrocarbons are alkylated in a fluidized riser-reactor using a solid catalyst which is regenerated within the process by contact with hydrogen. The alkylation and regeneration steps are separated to prevent the admixture of hydrogen and any olefins present in the process. Two separate modes of regeneration are performed simultaneously: a mild liquid-phase washing and a vapor-phase hot hydrogen stripping operation.