Patents by Inventor Hemant W. Dandekar

Hemant W. Dandekar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6180846
    Abstract: A process and apparatus for indirectly heating an endothermic reaction by combustion of reactants or products from the endothermic reaction using a plate heat exchange arrangement in a highly efficient manner. This invention is particularly suited for processes such as the production of styrene or synthesis gas. When producing synthesis gas, oxidizing reactants in a secondary reforming step generates heat for a primary reforming step and the process improves selectivity and yield with a highly efficient heat exchange step that uses narrow channel for indirect heat exchange. The narrow channels are preferably defined by corrugated plates. The primary reaction channels will contain a catalyst for the promotion of the primary reaction such as steam reforming or ethylbenzene dehydrogenation.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: January 30, 2001
    Assignee: UOP LLC
    Inventors: Hemant W. Dandekar, Robert C. Mulvaney, III
  • Patent number: 6159358
    Abstract: A process and apparatus produces reaction products by indirectly preheating and heating reactants by indirect heat exchange. The use of the preheating step simplifies the reaction zone design by eliminating the need for external exchangers and is particularly suited for an arrangement of plates that defines narrow channels for indirect heat exchange. The narrow channels are preferably defined by corrugated plates. The primary reaction channels will contain a catalyst for the promotion of the desired reaction product from the principal reactants. The heating fluid passes through adjacent heating channels defined by shared partition plates to provide indirect heating. At least a portion of the heating channels exchange heat with a non-catalytic portion of the reaction channels to preheat the reactants ahead of a catalytic section of the reaction channels. Catalytic combustion within the heating channels may provide in-situ heat input for the heating medium.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: December 12, 2000
    Assignee: UOP LLC
    Inventors: Robert C. Mulvaney, III, Hemant W. Dandekar
  • Patent number: 6069289
    Abstract: 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.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: May 30, 2000
    Assignee: UOP LLC
    Inventors: Hemant W. Dandekar, Gregory A. Funk, Herman A. Zinnen
  • Patent number: 5811630
    Abstract: A process is disclosed for the production of a high octane product from a feed mixture comprising C.sub.5 -C.sub.6 normal paraffins in which an equilibrium reaction to produce mono and dimethyl branched paraffins is achieved by conducting the reaction and the product separation in a pressure swing adsorption and reaction zone containing a uniformly distributed adsorbent for the selective adsorption of normal paraffins and a catalyst for the equilibrium conversion of normal paraffins to mono and dimethyl branched paraffins. More specifically, the process achieves the isomerization of the normal paraffins by the reaction of the normal paraffins in the presence of hydrogen with the simultaneous removal of the mono and dimethyl branched paraffin product at the same temperature and pressure. In one embodiment, the passing of the feed mixture to the bed is terminated and the bed is purged with one of the reactants which in turn further reacts to displace heavier paraffin and enhance the overall product octane.
    Type: Grant
    Filed: April 29, 1996
    Date of Patent: September 22, 1998
    Assignee: UOP LLC
    Inventors: Hemant W. Dandekar, Gregory A. Funk
  • Patent number: 5763730
    Abstract: 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.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: June 9, 1998
    Assignee: UOP
    Inventors: Hemant W. Dandekar, Gregory A. Funk, Ralph D. Gillespie, Herman A. Zinnen, Charles P. McGonegal, Masami Kojima, Simon H. Hobbs
  • Patent number: 5744683
    Abstract: 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.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: April 28, 1998
    Assignee: UOP
    Inventors: Hemant W. Dandekar, Gregory A. Funk, Simon H. Hobbs, Masami Kojima, Ralph D. Gillespie, Herman A. Zinnen, Charles P. McGonegal
  • Patent number: 5744684
    Abstract: 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.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: April 28, 1998
    Assignee: UOP
    Inventors: Herman A. Zinnen, Charles P. McGonegal, Hemant W. Dandekar, Gregory A. Funk, Ralph D. Gillespie
  • Patent number: 5618972
    Abstract: 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.
    Type: Grant
    Filed: February 27, 1995
    Date of Patent: April 8, 1997
    Assignee: UOP
    Inventors: Gregory A. Funk, Hemant W. Dandekar, Simon H. Hobbs
  • Patent number: 5530173
    Abstract: 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.
    Type: Grant
    Filed: November 3, 1994
    Date of Patent: June 25, 1996
    Inventors: Gregory A. Funk, Hemant W. Dandekar
  • Patent number: 5523326
    Abstract: A process is disclosed for the production of methanol from a synthesis gas stream comprising hydrogen and carbon dioxide in which an equilibrium reaction to methanol is achieved by conducting the reaction and the product separation in a pressure swing adsorption and reaction zone containing a uniformly distributed adsorbent for the selective adsorption of methanol and a catalyst for the equilibrium conversion of the synthesis gas to methanol. More specifically, the process achieves the production of methanol by the reaction of the hydrogen and the carbon oxide with the simultaneous adsorption of the product at the same temperature and pressure. The passing of the synthesis stream to the bed is terminated and the bed is purged and depressurized to desorb the methanol product. In one embodiment, the bed is cocurrently purged with at least a portion of an effluent stream prior to depressurizing the bed.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: June 4, 1996
    Assignee: UOP
    Inventors: Hemant W. Dandekar, Gregory A. Funk, John D. Swift, Richard T. Maurer
  • Patent number: 5502248
    Abstract: A process for the continuous hydrolysis of esters containing from 2 to about 16 carbon atoms to form at least one alcohol and at least one carboxylic acid and the concurrent separation of the hydrolysis products has been developed. The process uses a solid bed which acts as a catalyst for hydrolysis and as an adsorbent for at least one class of the products. The process operates in the simulated moving bed mode. A specific embodiment of the invention is one where the simulated moving bed is a homogeneous mixture of at least one solid effective as a hydrolysis catalyst and at least one solid effective as an alcohol or carboxylic acid adsorbent. Another specific embodiment is one where the simulated moving bed is a strongly acidic macroreticular polymeric resin effective both as a hydrolysis catalyst and as an adsorbent for at least one hydrolysis product.
    Type: Grant
    Filed: February 27, 1995
    Date of Patent: March 26, 1996
    Assignee: UOP
    Inventors: Gregory A. Funk, Hemant W. Dandekar, Simon H. Hobbs
  • Patent number: 5478787
    Abstract: This invention presents a novel MgAPSO molecular sieve, containing a critical range of magnesium: in the sieve framework and having a small crystallite size, which is particularly active for hydrocarbon conversion. The sieve advantageously is incorporated, along with a platinum-group metal, into a catalyst formulation which is useful for isomerization. When utilized in a process for isomerizing a non-equilibrium mixture of xylenes containing ethylbenzene, a greater yield of para-xylene is obtained compared to prior-art processes.
    Type: Grant
    Filed: February 28, 1994
    Date of Patent: December 26, 1995
    Assignee: UOP
    Inventors: Hemant W. Dandekar, David A. Lesch, Thomas M. Reynolds, Robert L. Patton, Stephen T. Wilson, Gregory J. Gajda
  • Patent number: 5449696
    Abstract: 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.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: September 12, 1995
    Assignee: UOP
    Inventors: Hemant W. Dandekar, Gregory A. Funk