Refining assemblies and methods for refining rich natural gas containing a first methane gas and other hydrocarbons that are heavier than methane gas are disclosed. In some embodiments, the assemblies may include a methane-producing assembly configured to receive at least one liquid-containing feed stream that includes water and rich natural gas and to produce an output stream therefrom by (a) converting at least a substantial portion of the other hydrocarbons of the rich natural gas with the water to a second methane gas, a lesser portion of the water, and other gases, and (b) allowing at least a substantial portion of the first methane gas from the rich natural gas to pass through the methane-producing assembly unconverted. The assemblies may additionally include a purification assembly configured to receive the output stream and to produce a methane-rich stream therefrom having a greater methane concentration than the output stream.

A gas pressurized separation system strips a product gas from a stream yielding a high pressure gaseous effluent containing the product gas such as may be used to capture CO.sub.2 from coal fired post combustion flue gas capture and to purify natural gas, syngas and EOR recycle gas. The system comprises a gas pressurized stripping column allowing flow of one or more raw streams in a first direction and allowing flow of one or more high pressure gas streams in a second direction, to strip the product gas into the high pressure gas stream and yield a high pressure gaseous effluent that contains the product gas. The process can further comprise a final separation process to further purify the product gas from the GPS column. For CO.sub.2 product, a preferred energy efficient final separation process, compound compression and refrigeration process, is also introduced.

A method for production of renewable natural gas (RNG) from biogases containing volatile organic compounds (VOCs) combines temperature swing adsorption (TSA) for removal of VOCs, a form of pressure swing adsorption (PSA) for nitrogen separation, and membrane gas separation technology for carbon dioxide removal. TSA systems may improve removal of VOCs relative to PSA systems, may reduce RNG plant operating costs, and may simplify RNG plant operation. Methane recovery may be improved by using equilibrium PSA systems instead of dynamic PSA systems for methane separation.

An adsorbent separates methanol and other alcohols from gas and liquid oxygenates and hydrocarbon streams with a low silica faujasite (LSX) in a mono-, bi, or tri-cation alkali and/or alkaline-earth metal forms. The LSX has silicon to aluminum ratio from about 0.9 to about 1.15 and an ion exchange degree for each alkali or alkaline-earth metal in the range of about 10 to about 99.9% equiv. The gas streams for treatment include natural gas, individual hydrocarbons, or vaporized alkyl esters of carboxylic acids, or methyl tert-alkyl ethers and their mixtures with hydrocarbons. The liquid streams include liquefied natural gas (LNG), liquefied petroleum gas (LPG), natural gas liquid (NGL), individual hydrocarbons C.sub.3-C.sub.5, and monomers, alkyl esters of carboxylic acids including methyl acetate, methyl, ethyl, butyl acrylates and methacrylate, methyl tert-alkyl ethers including methyl tert-butyl ether (MTBE) and methyl tert-amyl ether (TAME). The adsorbent is especially suited for temperature swing or pressure swing adsorption processes.

The present disclosure provides a method of dehydrating a feed stream processed in a distillation tower. The method may include (a) introducing a feed stream comprising a first contaminant stream into a distillation tower; (b) forming a solid from the feed stream in a controlled freeze zone section of the distillation tower; (c) feeding a second contaminant stream into the feed stream outside the distillation tower; and (d) removing water from the feed stream with a second contaminant stream by feeding the second contaminant stream.

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.

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.

The present disclosure provides a method for separating a feed stream in a distillation tower. The method includes operating a controlled freeze zone section in a distillation tower that separates a feed stream at a temperature and pressure at which the feed stream forms a solid in the controlled freeze zone section, wherein the feed stream includes a first contaminant; maintaining a melt tray assembly in the controlled freeze zone section; introducing the feed stream to the controlled freeze zone section; and accumulating a liquid in the melt tray assembly until the liquid is at a predetermined liquid level in the controlled freeze zone section, by: feeding a second contaminant to the controlled freeze zone section; and adding the second contaminant to the melt tray assembly, wherein the liquid comprises the second contaminant.

A system for heating water for an oil and gas well treatment system utilizing raw natural gas from an oil and gas well. The system includes a separation assembly to remove liquids from the raw natural gas, wherein at least a portion of heated water from a frac water heater is passed through the separation assembly to prevent freezing therein.