Patents by Inventor Vishnu D. Singh
Vishnu D. Singh 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: 10287241Abstract: Methods and systems for producing urea are provided. Ammonia, carbon dioxide, and a carbamate solution can be combined in a pressurized mixer to produce a carbamate reaction mixture. The carbamate reaction mixture can be transferred from the pressurized mixer to a reactor. The carbamate reaction mixture can be heated in the reactor to produce a urea reaction mixture that can include urea, water, ammonia, carbon dioxide, and ammonium carbamate. The urea reaction mixture can be contacted to a membrane to separate an aqueous filtrate and a urea concentrate that can include urea, ammonia, carbon dioxide, and ammonium carbamate. The urea concentrate can be transferred from the reactor to a urea purification system that can include one or more separators and one or more decomposers. The urea concentrate can flow through the urea purification system to produce one or more urea products and one or more carbamate solutions.Type: GrantFiled: May 11, 2017Date of Patent: May 14, 2019Assignee: KELLOGG BROWN & ROOT LLCInventors: Vishnu D. Singh, Robert K. Collins
-
Publication number: 20170327461Abstract: Methods and systems for producing urea are provided. Ammonia, carbon dioxide, and a carbamate solution can be combined in a pressurized mixer to produce a carbamate reaction mixture. The carbamate reaction mixture can be transferred from the pressurized mixer to a reactor. The carbamate reaction mixture can be heated in the reactor to produce a urea reaction mixture that can include urea, water, ammonia, carbon dioxide, and ammonium carbamate. The urea reaction mixture can be contacted to a membrane to separate an aqueous filtrate and a urea concentrate that can include urea, ammonia, carbon dioxide, and ammonium carbamate. The urea concentrate can be transferred from the reactor to a urea purification system that can include one or more separators and one or more decomposers. The urea concentrate can flow through the urea purification system to produce one or more urea products and one or more carbamate solutions.Type: ApplicationFiled: May 11, 2017Publication date: November 16, 2017Inventors: VISHNU D. SINGH, ROBERT K. COLLINS
-
Patent number: 8481786Abstract: Methods for producing urea are provided. A method for producing urea can include exchanging heat from a syngas comprising hydrogen and carbon dioxide to a urea solution comprising urea and ammonium carbamate. The heat transferred can be sufficient to decompose at least a portion of the ammonium carbamate. In one or more embodiments, the syngas can be reacted with liquid ammonia to provide a carbon dioxide lean syngas and an ammonium carbamate solution. The ammonium carbamate solution can be heated to a temperature of about 180 C. or more. At least a portion of the ammonium carbamate in the heated ammonium carbamate solution can be dehydrated to provide the urea solution.Type: GrantFiled: November 30, 2009Date of Patent: July 9, 2013Assignee: Kellogg Brown & Root LLCInventor: Vishnu D. Singh
-
Patent number: 7687041Abstract: Apparatus and methods for producing urea are provided. In one or more embodiments, an apparatus for producing urea can include a first zone, which can include a first flow channel in fluid communication with a first tube disposed about a first end of a plurality of trays, a second flow channel in fluid communication with a second tube disposed about the first end of the trays and a second end of the trays, and a third flow channel in fluid communication with a third tube disposed about the first and second ends of the trays. The apparatus can include a second zone, which can include a fixed bed comprising one or more inert packing materials disposed therein to provide additional surface area. The apparatus can include a third zone, which can include a plurality of tubes disposed therein. The second zone can be disposed between the first and third zones.Type: GrantFiled: February 27, 2008Date of Patent: March 30, 2010Assignee: Kellogg Brown & Root LLCInventor: Vishnu D. Singh
-
Publication number: 20100076222Abstract: Methods for producing urea are provided. A method for producing urea can include exchanging heat from a syngas comprising hydrogen and carbon dioxide to a urea solution comprising urea and ammonium carbamate. The heat transferred can be sufficient to decompose at least a portion of the ammonium carbamate. In one or more embodiments, the syngas can be reacted with liquid ammonia to provide a carbon dioxide lean syngas and an ammonium carbamate solution. The ammonium carbamate solution can be heated to a temperature of about 180 C or more. At least a portion of the ammonium carbamate in the heated ammonium carbamate solution can be dehydrated to provide the urea solution.Type: ApplicationFiled: November 30, 2009Publication date: March 25, 2010Applicant: KELLOGG BROWN & ROOT LLCInventor: Vishnu D. Singh
-
Publication number: 20100016635Abstract: Systems and methods for producing urea are provided. A method for producing urea can include exchanging heat from a syngas comprising hydrogen and carbon dioxide to a urea solution comprising urea and ammonium carbamate. The heat transferred can be sufficient to decompose at least a portion of the ammonium carbamate. In one or more embodiments, the syngas can be reacted with liquid ammonia to provide a carbon dioxide lean syngas and an ammonium carbamate solution. The ammonium carbamate solution can be heated to a temperature of about 180° C. or more. At least a portion of the ammonium carbamate in the heated ammonium carbamate solution can be dehydrated to provide the urea solution.Type: ApplicationFiled: July 21, 2008Publication date: January 21, 2010Applicant: KELLOGG BROWN & ROOT LLCInventor: Vishnu D. Singh
-
Patent number: 7642377Abstract: Systems and methods for producing urea are provided. A method for producing urea can include exchanging heat from a syngas comprising hydrogen and carbon dioxide to a urea solution comprising urea and ammonium carbamate. The heat transferred can be sufficient to decompose at least a portion of the ammonium carbamate. In one or more embodiments, the syngas can be reacted with liquid ammonia to provide a carbon dioxide lean syngas and an ammonium carbamate solution. The ammonium carbamate solution can be heated to a temperature of about 180° C. or more. At least a portion of the ammonium carbamate in the heated ammonium carbamate solution can be dehydrated to provide the urea solution.Type: GrantFiled: July 21, 2008Date of Patent: January 5, 2010Assignee: Kellogg Brown & Root LLCInventor: Vishnu D. Singh
-
Publication number: 20090216045Abstract: Apparatus and methods for producing urea are provided. In one or more embodiments, an apparatus for producing urea can include a first zone, which can include a first flow channel in fluid communication with a first tube disposed about a first end of a plurality of trays, a second flow channel in fluid communication with a second tube disposed about the first end of the trays and a second end of the trays, and a third flow channel in fluid communication with a third tube disposed about the first and second ends of the trays. The apparatus can include a second zone, which can include a fixed bed comprising one or more inert packing materials disposed therein to provide additional surface area. The apparatus can include a third zone, which can include a plurality of tubes disposed therein. The second zone can be disposed between the first and third zones.Type: ApplicationFiled: February 27, 2008Publication date: August 27, 2009Inventor: VISHNU D. SINGH
-
Patent number: 5523483Abstract: An integrated ammonia/urea process and a plant for carrying out the same. The process comprises recycling a high pressure purge stream made up mostly of air from the urea synthesis cycle to the autothermal reformer in a syngas production unit of the ammonia process. In such a manner, compression energy required for ammonia synthesis can be reduced since a portion of the high pressure air feed to the autothermal reactor is supplied by the urea purge stream recycle. In addition, the equipment needed to clean up the urea purge stream is largely eliminated.Type: GrantFiled: June 16, 1995Date of Patent: June 4, 1996Assignee: The M. W. Kellogg CompanyInventors: Vishnu D. Singh, Meghji N. Shah, Richard B. Strait