Provided are a reusable polymeric material for removing siloxane compounds in biogas, a method for removing siloxane using the same, and an apparatus therefor, and more particularly, a polyacrylate-based polymer absorbent for removing siloxane compounds in biogas and a method for removing siloxane compounds in biogas. The method for removing siloxane compounds in biogas includes (a) providing the biogas, and b) absorbing the siloxane compounds in a polymer absorbent by passing the biogas through the polymer absorbent according to any one of claims 1 to 5.

A process for the separation of a natural gas stream is provided. The process includes receiving an effluent gas flow from a first fractionator operating at a first pressure, splitting the effluent gas flow into a first stream and a second stream, and passing the first stream through a heat exchanger thereby causing a phase change of at least a portion of the first stream from a gaseous state to a liquid state. The process includes inserting the first stream into an upper portion of a second fractionator operating at a second pressure. The second pressure is lower than the first pressure. The process includes inserting the second stream into a lower portion of the second fractionator, and diverting liquids from a lower portion of the second fractionator to the first fractionator.

The methods apparatuses described herein involve recovering of glycol from an aqueous phase to form a stream of recovered glycol and a glycol recovery system. The aqueous phase is fed to the top of a lower theoretical stage in a distillation column. An overhead vapor stream is drawn from the distillation column overhead of an upper theoretical stage, and a bottom stream comprising a stream of regenerated glycol is drawn from the distillation column via a bottom outlet configured below the lower theoretical stage. The stream of recovered glycol comprises the regenerated glycol. In addition, a first middle theoretical stage is situated within the distillation column gravitationally above the lower theoretical stage and below the upper theoretical stage. A side stream of liquid water is drawn from the bottom of the upper theoretical stage in the distillation column.

The present techniques are directed to a system and method for generating power and recovering methane from methane hydrates. The system includes a low emissions power plant configured to generate power, wherein an exhaust gas from the low emissions power plant provides a gas mixture including nitrogen and carbon dioxide. The system also includes a methane recovery system configured to recover methane from methane hydrates by injecting the nitrogen and the carbon dioxide from the gas mixture into the methane hydrates.

Rich natural gas is first compressed, and then cooled by a series of heat exchangers and an ambient air cooler. The cooled mixture of natural gas, natural gas liquid (NGL), and water is first separated in a high-pressure three-phase separator. NGL flows through a depressurization valve and NGL is separated from gas in a second separator for storage and transport such as in a conventional propane tank. A resulting lean natural gas is suitably conditioned for internal combustion, compressed natural gas processing, or liquid fuel processing.

Compressed rich natural gas is divided into a cooling gas stream and a fuel gas stream. The cooling gas stream is depressurized. The cooling gas and the fuel gas are then heat exchanged to provide a first cooling step to the fuel gas. The cooled fuel gas continues into a second cooling step in a second heat exchanger, and then flows into a separator vessel where liquids are removed from the bottom of the separator and conditioned fuel gas exits the top of the separator. The conditioned fuel gas from the separator and produced from its influent is depressurized and heat exchanged to provide the second cooling fluid for the second heat exchanger.

An absorbent for selective removal of hydrogen sulfide over carbon dioxide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I) ##STR00001##
in which R.sub.1 and R.sub.2 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl, with the proviso that at least one R.sub.4 and/or R.sub.5 radical on the carbon atom bonded directly to the nitrogen atom is C.sub.1-4-alkyl or C.sub.1-4-hydroxyalkyl when R.sub.3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol. The absorbent allows a defined H.sub.2S selectivity to be set at pressures of the kind typical in natural gas processing.

Described herein are catalysts and methods for converting waste biogas (e.g., a mixture of carbon dioxide and methane) into useful products. In some embodiments, the biogas is converted into a highly purified methane, that can be further processed to generate fuel products, including recycled natural gas (RNG) and liquid fuels. The described catalysts and methods may be advantageous over conventional methods, including by reducing catalyst costs, decreasing temperature requirements and/or providing higher purity products by reducing carbon dioxide and carbon monoxide in product streams.

A system for recovering natural gas liquid from a gas source, comprising compression means (206) for increasing the temperature and pressure of the fluid from the gas source, cooling means (230) for cooling the fluid from the compression means, a gas/gas heat exchanger (204), fluid from the gas source flowing from a first inlet to a first outlet; at least one separator (208) for receiving the fluid from the first outlet of the gas/gas heat exchanger (204) and separating liquid from the gas, the gas from the separator being directed to expansion means (206) for reducing the temperature and pressure of the gas, the aqueous part of the liquid from the separator and/or the gas from the expansion means being directed to the gas/gas heat exchanger (204) where it flows therethrough from a second inlet to a second outlet for cooling the fluid flowing between the first inlet and first outlet, wherein injection means are provided between the cooling means and the gas/gas heat exchanger for saturating the gas with a liquid agent, wherein the liquid agent comprises an evaporant and an antifreeze agent; and a recovery vessel (240) is provided downstream of the second outlet, the antifreeze agent being recovered therein for injection into the fluid from the gas source upstream of the first inlet.

The present invention is directed to the removal of mercury in a gas dehydration process using thermally table chemical additives.