Patents by Inventor Persefoni E. Kechagia
Persefoni E. Kechagia 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).
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Publication number: 20230352746Abstract: A carbon-based additive for negative active materials includes carbon nanostructures free of a fiber substrate, carbon nanostructures fused to a fiber substrate or any combination thereof. In many cases, the carbon-based additive further includes carbon black. The additive is used to prepare electrode compositions for lead acid batteries. Batteries that include such electrode compositions are characterized by improved dynamic charge acceptance and lead utilization, typically at acceptable water loss levels. Some of the batteries described herein exhibit a negligible memory effect.Type: ApplicationFiled: August 20, 2021Publication date: November 2, 2023Inventors: Yu-Hua Kao, Agathagelos Kyrlidis, Persefoni E. Kechagia, Paolina Atanassova, Tushar Shah
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Patent number: 9772139Abstract: The invention relates to a process for removing oxygen from liquid argon using a TSA (temperature swing adsorption) cyclical process that includes cooling an adsorbent bed to sustain argon in a liquid phase; supplying the adsorbent bed with a liquid argon feed that is contaminated with oxygen and purifying the liquid argon thereby producing an argon product with less oxygen contaminant than is in the initial liquid argon feed; draining the purified residual liquid argon product and sending purified argon out of the adsorbent bed. Regeneration of specially prepared adsorbent allows the adsorbent bed to warm up to temperatures that preclude the use of requiring either vacuum or evacuation of adsorbent from the bed.Type: GrantFiled: November 23, 2015Date of Patent: September 26, 2017Assignee: Praxair Technology, Inc.Inventors: Persefoni E. Kechagia, Neil A. Stephenson, Philip A. Barrett, Hai Du, Steven J. Pontonio
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Patent number: 9759482Abstract: A method and apparatus for producing a purified liquid argon product in which liquid argon having oxygen impurities is produced in a cryogenic air separation plant by separating argon from oxygen within an argon column. An impure liquid argon stream, composed of part of the liquid argon, is purified in an adsorbent bed by adsorbing the oxygen impurities in an adsorbent to produce a purified liquid argon stream that constitutes the purified liquid argon product. During adsorption, the adsorbent bed is maintained at a reduced temperature with a coolant to prevent vaporization of the liquid argon. The bed is then regenerated by draining residual liquid argon from the adsorbent bed, introducing the residual liquid argon back into the air separation plant and then desorbing the oxygen impurities with a regeneration gas. After regeneration, the adsorbent bed is refilled with purified liquid argon prior to being brought back on-line.Type: GrantFiled: March 24, 2017Date of Patent: September 12, 2017Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Henry E. Howard, Persefoni E. Kechagia, Philip A. Barrett, James R. Handley
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Publication number: 20170198968Abstract: A method and apparatus for producing a purified liquid argon product in which liquid argon having oxygen impurities is produced in a cryogenic air separation plant by separating argon from oxygen within an argon column. An impure liquid argon stream, composed of part of the liquid argon, is purified in an adsorbent bed by adsorbing the oxygen impurities in an adsorbent to produce a purified liquid argon stream that constitutes the purified liquid argon product. During adsorption, the adsorbent bed is maintained at a reduced temperature with a coolant to prevent vaporization of the liquid argon. The bed is then regenerated by draining residual liquid argon from the adsorbent bed, introducing the residual liquid argon back into the air separation plant and then desorbing the oxygen impurities with a regeneration gas. After regeneration, the adsorbent bed is refilled with purified liquid argon prior to being brought back on-line.Type: ApplicationFiled: March 24, 2017Publication date: July 13, 2017Inventors: Henry E. Howard, Persefoni E. Kechagia, Philip A. Barrett, James R. Handley
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Patent number: 9644890Abstract: A method and apparatus for producing a purified liquid argon product in which liquid argon having oxygen impurities is produced in a cryogenic air separation plant by separating argon from oxygen within an argon column. An impure liquid argon stream, composed of part of the liquid argon, is purified in an adsorbent bed by adsorbing the oxygen impurities in an adsorbent to produce a purified liquid argon stream that constitutes the purified liquid argon product. During adsorption, the adsorbent bed is maintained at a reduced temperature with a coolant to prevent vaporization of the liquid argon. The bed is then regenerated by draining residual liquid argon from the adsorbent bed, introducing the residual liquid argon back into the air separation plant and then desorbing the oxygen impurities with a regeneration gas. After regeneration, the adsorbent bed is refilled with purified liquid argon prior to being brought back on-line.Type: GrantFiled: February 27, 2014Date of Patent: May 9, 2017Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Henry E. Howard, Persefoni E. Kechagia, Philip A. Barrett, James R. Handley
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Patent number: 9457337Abstract: An optimal material composition that allows for the purification of at least one feed component from a fluid feed stream such that the adsorbent has an oxygen capacity of at least 10 weight percent is described. More specifically, the material is an adsorbent for purification of a fluid feed stream having an oxygen to argon selectivity greater than or equal to a ratio of 3:1 and an oxygen capacity of greater than or equal to 10 weight percent, wherein the oxygen capacity is measured at a pressure in the range of about 9-10 Torr and a temperature of 77 degrees Kelvin after 4 hours of equilibration time and wherein the oxygen to argon selectivity is obtained by dividing the oxygen capacity by the argon capacity of the adsorbent measured at a pressure in the range of about 697-700 Torr and a temperature of 87 degrees Kelvin after 8 hours of equilibration time. The adsorption capacities are measured on a pure component basis.Type: GrantFiled: March 1, 2013Date of Patent: October 4, 2016Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Philip A. Barrett, Steven J. Pontonio, Neil A. Stephenson, Persefoni E. Kechagia
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Publication number: 20160084571Abstract: The invention relates to a process for removing oxygen from liquid argon using a TSA (temperature swing adsorption) cyclical process that includes cooling an adsorbent bed to sustain argon in a liquid phase; supplying the adsorbent bed with a liquid argon feed that is contaminated with oxygen and purifying the liquid argon thereby producing an argon product with less oxygen contaminant than is in the initial liquid argon feed; draining the purified residual liquid argon product and sending purified argon out of the adsorbent bed. Regeneration of specially prepared adsorbent allows the adsorbent bed to warm up to temperatures that preclude the use of requiring either vacuum or evacuation of adsorbent from the bed.Type: ApplicationFiled: November 23, 2015Publication date: March 24, 2016Inventors: PERSEFONI E. KECHAGIA, Neil A. Stephenson, Philip A. Barrett, Hai Du, Steven J. Pontonio
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Patent number: 9222727Abstract: The invention relates to a process for removing oxygen from liquid argon using a TSA (temperature swing adsorption) cyclical process that includes cooling an adsorbent bed to sustain argon in a liquid phase; supplying the adsorbent bed with a liquid argon feed that is contaminated with oxygen and purifying the liquid argon thereby producing an argon product with less oxygen contaminant than is in the initial liquid argon feed; draining the purified residual liquid argon product and sending purified argon out of the adsorbent bed. Regeneration of specially prepared adsorbent allows the adsorbent bed to warm up to temperatures that preclude the use of requiring either vacuum or evacuation of adsorbent from the bed.Type: GrantFiled: March 1, 2013Date of Patent: December 29, 2015Assignee: Praxair Technology, Inc.Inventors: Persefoni E. Kechagia, Neil A. Stephenson, Philip A. Barrett, Hai Du, Steven J. Pontonio
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Publication number: 20140245781Abstract: The invention relates to a process for removing oxygen from liquid argon using a TSA (temperature swing adsorption) cyclical process that includes cooling an adsorbent bed to sustain argon in a liquid phase; supplying the adsorbent bed with a liquid argon feed that is contaminated with oxygen and purifying the liquid argon thereby producing an argon product with less oxygen contaminant than is in the initial liquid argon feed; draining the purified residual liquid argon product and sending purified argon out of the adsorbent bed. Regeneration of specially prepared adsorbent allows the adsorbent bed to warm up to temperatures that preclude the use of requiring either vacuum or evacuation of adsorbent from the bed.Type: ApplicationFiled: March 1, 2013Publication date: September 4, 2014Inventors: Persefoni E. Kechagia, Neil A. Stephenson, Philip A. Barrett, Hai Du, Steven J. Pontonio
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Publication number: 20140249023Abstract: An optimal material composition that allows for the purification of at least one feed component from a fluid feed stream such that the adsorbent has an oxygen capacity of at least 10 weight percent is described. More specifically, the material is an adsorbent for purification of a fluid feed stream having an oxygen to argon selectivity greater than or equal to a ratio of 3:1 and an oxygen capacity of greater than or equal to 10 weight percent, wherein the oxygen capacity is measured at a pressure in the range of about 9-10 Torr and a temperature of 77 degrees Kelvin after 4 hours of equilibration time and wherein the oxygen to argon selectivity is obtained by dividing the oxygen capacity by the argon capacity of the adsorbent measured at a pressure in the range of about 697-700 Torr and a temperature of 87 degrees Kelvin after 8 hours of equilibration time. The adsorption capacities are measured on a pure component basis.Type: ApplicationFiled: March 1, 2013Publication date: September 4, 2014Inventors: Philip A. Barrett, Steven J. Pontonio, Neil A. Stephenson, Persefoni E. Kechagia
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Publication number: 20140245782Abstract: A method and apparatus for producing a purified liquid argon product in which liquid argon having oxygen impurities is produced in a cryogenic air separation plant by separating argon from oxygen within an argon column. An impure liquid argon stream, composed of part of the liquid argon, is purified in an adsorbent bed by adsorbing the oxygen impurities in an adsorbent to produce a purified liquid argon stream that constitutes the purified liquid argon product. During adsorption, the adsorbent bed is maintained at a reduced temperature with a coolant to prevent vaporization of the liquid argon. The bed is then regenerated by draining residual liquid argon from the adsorbent bed, introducing the residual liquid argon back into the air separation plant and then desorbing the oxygen impurities with a regeneration gas. After regeneration, the adsorbent bed is refilled with purified liquid argon prior to being brought back on-line.Type: ApplicationFiled: February 27, 2014Publication date: September 4, 2014Inventors: Henry E. Howard, Persefoni E. Kechagia, Philip A. Barrett, James R. Handley