A method for separating a raw feed gas stream using a plurality of membrane module stages. The raw feed gas stream may be from a biogas process. Off-gas from another unit process in the system, such as a temperature swing adsorption unit or liquefaction unit, may be used as a low pressure sweep gas on the low pressure side of at least one of the membrane module stages. In one example, the sweep gas is used in a first membrane module stage. In another example, a stripping membrane module stage is provided and the sweep gas is used in the stripping membrane module stage. Optionally, portions of the off-gas could be directed to other streams in the system for the purpose of balancing compressor power requirements.

A method for separating a raw feed gas stream using a plurality of membrane module stages. The raw feed gas stream may be from a biogas process. Off-gas from another unit process in the system, such as a temperature swing adsorption unit or liquefaction unit, may be used as a low pressure sweep gas on the low pressure side of at least one of the membrane module stages. In one example, the sweep gas is used in a first membrane module stage. In another example, a stripping membrane module stage is provided and the sweep gas is used in the stripping membrane module stage. Optionally, portions of the off-gas could be directed to other streams in the system for the purpose of balancing compressor power requirements.

Disclosed is a method for preparing a solid material including manganese, the method including the following steps: a. bringing into contact an aqueous effluent including manganese, for example at least 5 mg/L, typically at least 5 to 50 mg/L, and preferably 7 to 25 mg/L of manganese, with an oxidizing agent, manganese, preferably at a temperature between 10° C. and 50° C., and obtaining an oxidized aqueous solution; b. adding a base to the oxidized aqueous solution obtained at the end of step a) until a pH of between 8 and 12, preferably greater than 9, and preferably from 9 to 10.5, and obtaining a solution including a precipitate; c. filtration of the solution obtained at the end of step b); and d. obtaining a solid material including manganese, and especially manganese (IV) and/or Mn (III).

Disclosed is a method for preparing a solid material including manganese, the method including the following steps: a. bringing into contact an aqueous effluent including manganese, for example at least 5 mg/L, typically at least 5 to 50 mg/L, and preferably 7 to 25 mg/L of manganese, with an oxidizing agent, manganese, preferably at a temperature between 10° C. and 50° C., and obtaining an oxidized aqueous solution; b. adding a base to the oxidized aqueous solution obtained at the end of step a) until a pH of between 8 and 12, preferably greater than 9, and preferably from 9 to 10.5, and obtaining a solution including a precipitate; c. filtration of the solution obtained at the end of step b); and d. obtaining a solid material including manganese, and especially manganese (IV) and/or Mn (III).

Catalyst compositions are prepared by contacting a palladium source and 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane and a methoxyocta-diene compound, in a primary aliphatic alcohol, under suitable conditions including a ratio of equivalents of palladium to equivalents of 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane ranging from greater than 1:1 to 1:1.3. The result is a complex of palladium, a 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaada-mantane ligand, and a ligand selected from a methoxyoctadiene ligand, an octadienyl ligand, or a protonated octadienyl. Such complexes may, in solution, exhibit surprising solubility and storage stability and are useful in the telomerization of butadiene, which is a step in the production of 1-octene.

To provide a method for producing cyclohexylbenzene, which is capable of obtaining cyclohexylbenzene at a high selectivity, and a cyclohexylbenzene composition obtained with the method. A method for producing cyclohexylbenzene, comprising a step of bringing a raw material containing benzene and cyclohexene or cyclohexanol into contact with a solid acid catalyst to thereby perform alkylation reaction, wherein the solid acid catalyst is a silica-alumina catalyst or an MTW-type zeolite catalyst.

Apparatus and process for converting aromatic compounds, comprising/using: a fractionating train (4-7) suitable for extracting at least one benzene-comprising fraction (22), one toluene-comprising fraction (23) and one fraction (24) comprising xylenes and ethylbenzene from the feedstock (2); a xylene separating unit (10) suitable for treating the fraction comprising xylenes and ethylbenzene and producing a para-xylene-comprising extract (39) and a raffinate (40) comprising ortho-xylene, meta-xylene and ethylbenzene; an isomerizing unit (11) for treating the raffinate and producing a para-xylene-enriched isomerizate (42), which is sent to the fractionated train; and an alkylating reaction section (13) for treating at least part of the benzene-comprising fraction with an ethanol source (30) and producing an alkylation effluent (31) comprising ethylbenzene, which is sent to the isomerizing unit.

A mixed oxide catalyst for the oxidative coupling of methane can include a catalyst with the formula A.sub.aB.sub.bC.sub.cD.sub.dO.sub.x, wherein: element A is selected from alkaline earth metals; elements B and C are selected from rare earth metals, and wherein elements B and C are different rare earth metals; the oxide of at least one of A, B, C, and D has basic properties; the oxide of at least one of A, B, C, and D has redox properties; and elements A, B, C, and D are selected to create a synergistic effect whereby the catalytic material provides a methane conversion of greater than or equal to 15% and a C.sub.2.sup.+ selectivity of greater than or equal to 70%. Systems and methods can include contacting the catalyst with methane and oxygen and purifying or collecting C.sub.2.sup.+ products.

A process for treating mixtures containing polyalkylaromatic hydrocarbons, intended for transalkylation processes, includes a mild reduction with hydrogen in the presence of a suitable hydrogenation catalyst. The process also relates to a transalkylation process of polyalkylaromatic hydrocarbons having the treatment.

Disclosed herein is a system and method capable of producing butadiene from a product stream.