Instituto Mexicano Del Petroleo

Fidencio Hernandez Perez

Maria Del Carmen Martinez Guerrero

Federico Jesus Jimenez Cruz

Marco Antonio Dominguez Aguilar

Florentino Rafael Murrieta Guevara

Liliana Alejandra Astudillo Lopez Lena

Arturo Trejo Rodriguez

Jose Luis Garcia Gutierrez

Alberto Cabrales Torres

Jose Francisco Gaspar Silva Sanchez

Georgina Cecilia Laredo Sanchez

J Jesus Castillo Munguia

Ricardo Saint Martin Castanon

Obet Marroquin De La Rosa

Jose Luis Cano Dominguez

Laura Olivia Aleman Vazquez

Maria Teresa Mares Gallardo

Maria Del Martinez Guerrero

The present invention relates to a process for the manufacture of microporous carbon materials to perform selective separations of nitrogen in gas mixtures such as hydrogen sulfide, carbon dioxide, methane and C, Cand Chydrocarbons, with high efficiency, shaped of microspheres or cylinders from copolymers of poly (vinylidene chloride-co-methyl acrylate) with density of 1.3 to 1.85 g/cm.sup.3 or poly (vinylidene chloride-co-vinyl chloride) with density of 1.3 to 1.85 g/cm.sup.3, using two stages. The first stage consists of a surface passivation of the material by chemical attack in a highly alkaline alcohol solution, with the aim of effecting a precarbonization on the surface of the copolymer that during the pyrolysis process is not deformed and gradually develops microporosity. The material of the first stage presents, in the layer, percentages between 55% to 85% carbon, between 5% to 20% oxygen, and between 10% to 40% chlorine. The interior of the material presents lower percentages of carbon, between 30% to 65%, oxygen in the amount of between 2% to 6%, and chlorine in the amount of between 30% to 60%. The second stage consists of the gradual pyrolysis of the passivated copolymer, with the aim of developing microporosity and high surface area values; as well as during the melting and gas dehydrohalogenation stages thereof, the deformation of the material is avoided. The morphology of the copolymers are microspheres of 125 to 225 micrometers, or cylinders of 4 mm in height and 3 mm in diameter, which after pyrolysis reduce its size by 35% with respect to the initial one. The material of the second stage, which is already microporous carbon material, presents in the layer percentages between 90% to 100% carbon and between 10% to 0% oxygen.

Microporous carbon materials to separate nitrogen in associated and non-associated natural gas streams

The present invention relates to a process for the manufacture of microporous carbon materials to perform selective separations of nitrogen in gas mixtures such as hydrogen sulfide, carbon dioxide, methane and C, Cand Chydrocarbons, with high efficiency, shaped of microspheres or cylinders from copolymers of poly (vinylidene chloride-co-methyl acrylate) with density of 1.3 to 1.85 g/cmor poly (vinylidene chloride-co-vinyl chloride) with density of 1.3 to 1.85 g/cm, using two stages. The first stage consists of a surface passivation of the material by chemical attack in a highly alkaline alcohol solution, with the aim of effecting a precarbonization on the surface of the copolymer that during the pyrolysis process is not deformed and gradually develops microporosity. The material of the first stage presents, in the layer, percentages between 55% to 85% carbon, between 5% to 20% oxygen, and between 10% to 40% chlorine. The interior of the material presents lower percentages of carbon, between 30% to 65%, oxygen in the amount of between 2% to 6%, and chlorine in the amount of between 30% to 60%. The second stage consists of the gradual pyrolysis of the passivated copolymer, with the aim of developing microporosity and high surface area values; as well as during the melting and gas dehydrohalogenation stages thereof, the deformation of the material is avoided. The morphology of the copolymers are microspheres of 125 to 225 micrometers, or cylinders of 4 mm in height and 3 mm in diameter, which after pyrolysis reduce its size by 35% with respect to the initial one. The material of the second stage, which is already microporous carbon material, presents in the layer percentages between 90% to 100% carbon and between 10% to 0% oxygen.

The present invention is related with the application of an adsorbent material of microporous carbon (MCA), prepared from the direct pyrolysis of copolymers generically known as Saran, in adsorption processes to reduce the benzene content in naphtha boiling range hydrocarbon streams, between 27 and 191&#xb0; C., in which is preferable to perform a first separation by distillation of the C6's fraction, and a further separation of Benzene by adsorption through an adsorbent material bed, obtaining the fraction of C6's free of Benzene and an adsorbent with Benzene, which is further regenerated by pressure or temperature swing desorption or by displacement using a desorbent such as an inert gas at high temperature or by passing a desorbent which after the process, the desorbent and Benzene are separated by distillation. The fraction of C6's free of Benzene is reintegrated to the hydrocarbon stream and providing a gasoline with a Benzene content less than 1 volume %. Besides, the application of the MCA in this type of process allows obtaining Benzene with a minimum purity of 99.8 weight % and a maximum toluene content of 0.1 weight %, satisfying the specifications of ASTM D-2359-02 for Refined Benzene-535.

Process for reducing benzene content of hydrocarbon stream using microporous carbon adsorbent

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Mexico City, Mexico

Fidencio Hernandez Perez