MICROPOROUS CARBON MATERIALS TO SEPARATE NITROGEN IN ASSOCIATED AND NON-ASSOCIATED NATURAL GAS STREAMS

• Main Authors: SILVA SANCHEZ, JOSE FRANCISCO GASPAR, MARTINEZ GUERRERO, MARIA DEL CARMEN, HERNANDEZ PEREZ, FIDENCIO, MURRIETA GUEVARA, FLORENTINO RAFAEL, ASTUDILLO LOPEZ LENA, LILIANA ALEJANDRA, CABRALES TORRES, ALBERTO, DOMINGUEZ AGUILAR, MARCO ANTONIO, GARCIA GUTIERREZ, JOSE LUIS, JIMENEZ CRUZ, FEDERICO JESUS, TREJO RODRIGUEZ, ARTURO
• Format: Patent
• Language: English; French
• Published: 29.03.2019
• Subjects: CHEMISTRY; COMPOUNDS THEREOF; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING

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 C2, C3 and C4+ hydrocarbons, 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/cm3 or poly (vinylidene chloride-co-vinyl chloride) with density of 1.3 to 1.85 g/cm3, using two stages. The first 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, so that during the pyrolysis process it does not deform and gradually develop the microporosity. The material of the first stage presents in the crust, percentages between 55 to 85 % carbon, between 5 to 20% oxygen and between 10 to 40 % chlorine, while in the interior of the material presents lower percentages of carbon between 30 to 65 %, oxygen between 2 to 6 % and chlorine of 30 to 60 %. The second consists of the gradual pyrolysis of the chemically 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 their size by 35 % with respect to the initial one. The material of the second stage, which is already microporous carbon material, has percentages in the crust between 90 to 100 % carbon and between 10 to 0 % oxygen. This microporous carbon material has the highly feasible quality of performing the chromatographic separation of nitrogen in mixtures with gases such as hydrogen sulfide, carbon dioxide, methane and C2, C3 and C4+ hydrocarbons, which allows to take as a basis to develop separation technologies of these components through adsorption-desorption processes. The microporous carbon materials of the present invention can separate and desorb mixtures of nitrogen with carbon dioxide and hydrogen sulfide at temperatures below 175 °C as well as depending on the way to perform stage 1 (chemical treatment) can have materials microporous carbon that retains very important carbon dioxide and hydrogen sulfide.