Process for efficiently operating a natural gas liquefaction system with integrated heavies removal/natural gas liquids recovery to produce liquefied natural gas (LNG) and/or natural gas liquids (NGL) products with varying characteristics, such as, for example higher heating value (HHV) and/or propane content. Resulting LNG and/or NGL products are capable of meeting the significantly different specifications of two or more markets.

A process for producing liquefied natural gas and liquid carbon dioxide from a natural gas feed gas comprising at least the following steps: Separation of a natural gas feed gas into a CO.sub.2-enriched gas stream and a natural gas stream; Cooling of said natural gas in a heat exchanger; Purification of the in step 1 from compounds containing at least six carbon atoms; At least partial condensation of said gas stream resulting from step 3 to form a two-phase stream; Separation of said two-phase stream resulting from step 4 to form a gas stream and a liquid stream; Condensation of the gas stream resulting from step 5 to form a liquefied gas containing less than 5 ppm by volume of compounds containing at least six carbon atoms; Liquefaction of the CO.sub.2-enriched gas stream resulting from step 1 with a portion of the liquid stream resulting from step 5.

A method and system for liquefying a natural gas feed stream and removing nitrogen therefrom.

A system for removing acid gases from a raw gas stream is provided. The system includes a cryogenic distillation column. The cryogenic distillation column receives a dehydrated and chilled sour gas stream, and separates the sour gas stream into an overhead gas stream comprised primarily of methane, and a bottom acid gas stream comprised primarily of carbon dioxide. The system also includes a series of co-current contactors. The co-current contactors may be placed in series to receive the bottom acid gas stream and recapture any entrained methane gas. Alternatively or in addition, the co-current contactors may be placed in series to receive the overhead gas stream, and sweeten it using a reflux liquid such as methane. In this instance, the sweetened gas is optionally liquefied and delivered for commercial sale, or is used as fuel gas on-site.

The present disclosure provides a method for separating a feed stream in a distillation tower. The method may include forming solids in a controlled freeze zone section of the distillation tower; emitting radiation from a first radiation source in the controlled freeze zone section while the controlled freeze zone section forms no solids; detecting radiation emitted by the first radiation source as a first radiation level; detecting radiation emitted by the first radiation source as a second radiation level after detecting the first radiation level; and determining whether the solids adhered to at least one of on and around a first mechanical component included in the controlled freeze zone section based on the first radiation level and the second radiation level.

A method of constructing a plate fin heat exchanger includes joining a first side bar formed from a nickel-iron alloy to a first end of a fin element formed from a nickel-iron alloy through a first nickel-iron alloy bond, and joining a second side bar formed from a nickel-iron alloy to a second end of the fin element through a second nickel-iron alloy bond to create a first layer of the plate fin heat exchanger. The fin element defines a fluid passage.

The invention relates to an integrated process and apparatus for liquefaction of natural gas and recovery of natural gas liquids. In particular, the improved process and apparatus reduces the energy consumption of a Liquefied Natural Gas (LNG) unit by using a portion of the already cooled overhead vapor from a fractionation column from an NGL (natural gas liquefaction) unit to, depending upon composition, provide, for example, reflux for fractionation in the NGL unit and/or a cold feed for the LNG unit, or by cooling, within the NGL unit, a residue gas originating from a fractionation column of the NGL unit and using the resultant cooled residue gas to, depending upon composition, provide, for example, reflux/feed for fractionation in the NGL and/or a cold feed for the LNG unit, thereby reducing the energy consumption of the LNG unit and rendering the process more energy-efficient.

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.

Integrated systems are provided for the production of higher hydrocarbon compositions, for example liquid hydrocarbon compositions, from methane using an oxidative coupling of methane system to convert methane to ethylene, followed by conversion of ethylene to selectable higher hydrocarbon products. Integrated systems and processes are provided that process methane through to these higher hydrocarbon products.

A method of designing, constructing, and operating a hydrocarbon gas treatment plant is disclosed. A target hydrocarbon production range for a hydrocarbon gas meeting a required product specification is established. A cryogenic distillation column is designed and constructed with a vapor capacity to meet the target hydrocarbon production range. A variable feed refrigeration system is incorporated to cool an inlet feed of the hydrocarbon gas. The variable feed refrigeration system is designed to handle the target hydrocarbon production range and a wide range of contaminant concentrations in the inlet feed. A variable bottoms heating system is incorporated to handle heating duties associated with the wide range of contaminant concentrations in the inlet feed. A variable bottoms pumping system is incorporated to handle liquid flows associated with the wide range of contaminant concentrations in the inlet feed.