Carbon dioxide gas in a high-pressure gas to be treated is stably separated using a separation membrane. Upon separating carbon dioxide gas in a high-pressure gas to be treated using a separation membrane module including a separation membrane, a preliminary boosted gas is supplied to the separation membrane module before the supply of natural gas is started to boost a pressure on a primary side of the separation membrane to a preliminary pressure between a stand-by pressure and an operating pressure. Thus, when the supply of a high-pressure gas to be treated is started to increase the pressure of the separation membrane module to an operating pressure, an abrupt decrease in temperature of the gas to be treated can be suppressed.

The invention relates to a method for membrane permeation of a gas flow including methane and carbon dioxide, wherein said gas flow is cooled to a temperature of 0° C. to −60° C. before being fed into a membrane separation unit.

A catalyst system comprising a combination of: 1) one or more catalyst compounds comprising at least one oxygen linkage, such as a phenoxide transition metal compound; 2) a support comprising an organosilica material, which may be a mesoporous organosilica material; and 3) an optional activator. Useful catalysts include biphenyl phenol catalysts (BPP). The organosilica material may be a polymer of at least one monomer of Formula [Z.sup.1OZ.sup.2SiCH.sub.2].sub.3 (I), where Z.sup.1 represents a hydrogen atom, a C.sub.1-C.sub.4 alkyl group, or a bond to a silicon atom of another monomer and Z.sup.2 represents a hydroxyl group, a C.sub.1-C.sub.4 alkoxy group, a C.sub.1-C.sub.6 alkyl group, or an oxygen atom bonded to a silicon atom of another monomer. This invention further relates to processes to polymerize olefins comprising contacting one or more olefins with the above catalyst system.

The present disclosure pertains to materials for CO.sub.2 adsorption at pressures above 1 bar, where the materials include a porous material with a surface area of at least 2,800 m.sup.2/g, and a total pore volume of at least 1.35 cm.sup.3/g, where a majority of pores of the porous material have diameters of less than 2 nm as measured from N.sub.2 sorption isotherms using the BET (Brunauer-Emmett-Teller) method. The present disclosure also pertains to materials for separation of CO.sub.2 from natural gas at partial pressures of either component above 1 bar, where the materials include a porous material with a surface area of at least 2,200 m.sup.2/g, and a total pore volume of at least 1.00 cm.sup.3/g, where a majority of pores of the porous material have diameters of greater than 1 nm and less than 2 nm as measured from N.sub.2 sorption isotherms using the BET method.

A carbon molecular sieve (CMS) membrane is made by pyrolyzing a polymeric precursor membrane in a pyrolysis atmosphere containing a sulfur-containing compound.

A pretreatment system and method for a floating liquid natural gas (“FLNG”) facility are presented. The inlet natural gas stream flows through a membrane system to remove carbon dioxide and a heat exchanger, producing first and second cooled CO.sub.2-depleted non-permeate streams. The first cooled CO.sub.2-depleted non-permeate stream is routed to additional pretreatment equipment, while the second cooled CO.sub.2-depleted non-permeate stream is routed directly to a LNG train. Alternatively, the inlet natural gas stream may flow through a membrane system to produce a single cooled CO.sub.2-depleted non-permeate stream that is routed to the LNG train after sweetening and dehydration. Because the pretreatment system delivers the incoming gas stream to the LNG train at a lower temperature than conventional systems, less energy is needed to convert the gas stream to LNG. In addition, the pretreatment system has a smaller footprint than conventional pretreatment systems.

A separation membrane structure comprises a porous support, a first separation membrane formed on the porous support, and a second separation membrane formed on the first separation membrane. The first separation membrane has an average pore diameter of greater than or equal to 0.32 nm and less than or equal to 0.44 nm. The second separation membrane includes addition of at least one of a metal cation or a metal complex that tends to adsorb nitrogen in comparison to methane.

A fuel cell system including a hydrocarbon fuel stream including a sulfur compound; a passive sorbent bed including a selective sulfur sorbent configured to remove the sulfur compound from the hydrocarbon fuel stream; a SCSO reactor, and an active sorbent bed comprising a sulfur oxide sorbent, wherein the active sorbet bed is configured to receive an effluent stream from the SCSO reactor and remove at least a portion of the sulfur oxides via the sulfur oxide sorbent. During start-up of the fuel cell system, the hydrocarbon fuel stream may be directed along a first flow pathway through the passive sorbent bed to remove the sulfur compound from the fuel stream during a first time period and then directed along a second flow pathway during a second time period that does not pass through the passive sorbent bed, e.g., once the SCSO reactor/active sorbent bed have reached operating temperature.

Disclosed in certain embodiments are sorbents for capturing heavy hydrocarbons via thermal swing adsorption processes.

A pretreatment system and method for a floating liquid natural gas (“FLNG”) facility are presented. The inlet natural gas stream flows through a membrane system to remove carbon dioxide and a heat exchanger, producing first and second cooled CO.sub.2-depleted non-permeate streams. The first cooled CO.sub.2-depleted non-permeate stream is routed to additional pretreatment equipment, while the second cooled CO.sub.2-depleted non-permeate stream is routed directly to a LNG train. Alternatively, the inlet natural gas stream may flow through a membrane system to produce a single cooled CO.sub.2-depleted non-permeate stream that is routed to the LNG train after sweetening and dehydration. Because the pretreatment system delivers the incoming gas stream to the LNG train at a lower temperature than conventional systems, less energy is needed to convert the gas stream to LNG. In addition, the pretreatment system has a smaller footprint than conventional pretreatment systems.