Patents by Inventor Ravindra K. Mariwala

Ravindra K. Mariwala 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).

  • CMS/SiO.sub.2 /Al.sub.2 O.sub.3 catalysts for improved selectivity in the synthesis of amines from methanol and/or dimethyl ether and ammonia
    Patent number: 5482909
    Abstract: The present invention relates to an improved catalyst for the selective synthesis of monomethylamine (MMA) and dimethylamine (DMA) at the expense of trimethylamine (TMA) for a starting feed of methanol and/or dimethyl ether and ammonia. The current industrial catalyst for this process is a standard SiO.sub.2 /Al.sub.2 O.sub.3 material. The present invention combines this standard catalyst with microporous carbon molecular sieves (CMS) to form a composite material (i.e., a CMS/SiO.sub.2 /Al.sub.2 O.sub.3 material) with higher selectivity for the desired products MMA and DMA. The invention also relates to methods of making the improved catalyst and a process of using the improved catalyst material in the production of MMA and DMA.
    Type: Grant
    Filed: July 21, 1994
    Date of Patent: January 9, 1996
    Assignees: University of Delaware, E. I. Du Pont de Nemours & Co., Inc.
    Inventors: Henry C. Foley, George C. Sonnichsen, Loren D. Brake, Ravindra K. Mariwala, Davis S. Lafyatis
  • CMS/SiO.sub.2 /Al.sub.2 O.sub.3 catalysts for improved selectivity in the synthesis of amines from methanol and/or dimethyl ether and ammonia
    Patent number: 5470814
    Abstract: The present invention relates to an improved catalyst for the selective synthesis of monomethylamine (MMA) and dimethylamine (DMA) at the expense of trimethylamine (TMA) for a starting feed of methanol and/or dimethyl ether and ammonia. The current industrial catalyst for this process is a standard SiO.sub.2 /Al.sub.2 O.sub.3 material. The present invention combines this standard catalyst with microporous carbon molecular sieves (CMS) to form a composite material (i.e., a CMS/SiO.sub.2 /Al.sub.2 O.sub.3 material) with higher selectivity for the desired products MMA and DMA. The invention also relates to methods of making the improved catalyst and a process of using the improved catalyst material in the production of MMA and DMA.
    Type: Grant
    Filed: July 21, 1994
    Date of Patent: November 28, 1995
    Assignees: University of Delaware, E. I. Du Pont de Nemours & Co., Inc.
    Inventors: Henry C. Foley, George C. Sonnichsen, Loren D. Brake, Ravindra K. Mariwala, David S. Lafyatis
  • CMS/SiO.sub.2 /Al.sub.2 O.sub.3 catalysts for improved selectivity in the synthesis of amines from methanol and/or dimethyl ether and ammonia
    Patent number: 5354893
    Abstract: The present invention relates to an improved catalyst for the selective synthesis of monomethylamine (MMA) and dimethylamine (DMA) at the expense of trimethylamine (TMA) for a starting feed of methanol and/or dimethyl ether and ammonia. The current industrial catalyst for this process is a standard SiO.sub.2 /Al.sub.2 O.sub.3 material. The present invention combines this standard catalyst with microporous carbon molecular sieves (CMS) to form a composite material (i.e., a CMS/SiO.sub.2 /Al.sub.2 O.sub.3 material) with higher selectivity for the desired products MMA and DMA. The invention also relates to methods of making the improved catalyst and a process of using the improved catalyst material in the production of MMA and DMA.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: October 11, 1994
    Assignees: The University of Delaware, E. I. Du Pont de Nemours Company, Inc.
    Inventors: Henry C. Foley, George C. Sonnichsen, Loren D. Brake, Ravindra K. Mariwala, David S. Lafyatis
  • Carbon molecular sieve for the kinetic separation of acid gases and fluorocarbons
    Patent number: 5261948
    Abstract: A method for the preparation of a carbon molecular sieve capable of separating acid gases and fluorocarbons of the formula C.sub.a H.sub.b X.sub.c F.sub.d, wherein a is from 1 to about 6, b is from 0 to about 13, c is from 0 to about 13, d is from 1 to about 14, and X is a halogen; on the basis of shape selectivity and size exclusion. A precursor resin is heated at about 0.2.degree. C. per minute to about 500.degree. C. Then the resin is soaked at about 500.degree. C. for about 6 hours in flowing inert gas.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: November 16, 1993
    Assignees: University of Delaware, E. I. Du Pont de Nemours Co.
    Inventors: Henry C. Foley, Ravindra K. Mariwala, Leo Manzer