摘要:
A process is described for separating off a nitrogen-rich fraction from a feed fraction containing essentially nitrogen and hydrocarbons, wherein the feed fraction is separated by rectification into a nitrogen-rich fraction and a methane-rich fraction and wherein the methane-rich fraction for the purpose of cold generation is vaporized and superheated at a pressure as high as possible against the feed fraction which is to be cooled.According to the invention the still liquid or partially vaporized methane-rich fraction (5′) is fed to a circulation vessel (D), only the liquid fraction of the methane-rich fraction (5′) occurring in the circulation vessel (D) is completely vaporized, preferably in natural circulation, and the top product (7) of the circulation vessel (D) is superheated (E1).
摘要:
A process for separating off a nitrogen-rich fraction from a feed fraction containing essentially nitrogen and hydrocarbons, wherein the feed fraction is separated by rectification a nitrogen-rich fraction and a methane-rich fraction, is described.According to the invention, during an interruption of the supply of the feed fraction, at least temporarily, the nitrogen-rich fraction (4″) and the methane-rich fraction (5″) are compressed and jointly supplied to the process as feed fraction, wherein the compression of the nitrogen-rich fraction (4″) and the methane-rich fraction (5″) can be performed separately and/or jointly.
摘要:
A process is described for removing a nitrogen-rich fraction from a feed fraction containing essentially nitrogen and hydrocarbons, wherein the feed fraction is partially condensed and fractionated by rectification into a nitrogen-rich fraction and a methane-rich fraction.According to the invention during an interruption in the supply of the feed fraction, the separation column(s) (T1/T2) used for the fractionation by rectification and also the heat exchangers used for the partial condensation (E1) of the feed fraction and the cooling and warming of process streams occurring in the fractionation by rectification (E2) are kept by means of one or more differing cooling media (6-11) at temperature levels which correspond essentially to the temperature levels during standard operation of the separation column(s) (T1/T2) and the heat exchangers (E1, E2).
摘要:
A process is described for removing a nitrogen-rich fraction from a feed fraction containing essentially nitrogen and hydrocarbons, wherein the feed fraction is partially condensed and fractionated by rectification into a nitrogen-rich fraction and a methane-rich fraction.According to the invention during an interruption in the supply of the feed fraction, the separation column(s) (T1/T2) used for the fractionation by rectification and also the heat exchangers used for the partial condensation (E1) of the feed fraction and the cooling and warming of process streams occurring in the fractionation by rectification (E2) are kept by means of one or more differing cooling media (6-11) at temperature levels which correspond essentially to the temperature levels during standard operation of the separation column(s) (T1/T2) and the heat exchangers (E1, E2).
摘要:
A process and apparatus for separating a fraction rich in C2+ from liquefied natural gas (LNG) is disclosed. In an embodiment, partial evaporation of the liquefied natural gas occurs in a heat exchanger. The partially evaporated natural gas is separated into a first gas fraction rich in C1 and a first liquid fraction rich in C2+. In a separation column, rectification separation of the first liquid fraction rich in C2+ into a second gas fraction rich in C1 and a second liquid fraction rich in C2+ occurs. The first gas fraction rich in C1 is re-liquefied in the heat exchanger. At least one sub-stream of the re-liquefied gas fraction rich in C1 is fed as a reflux to the rectification separation.
摘要:
A process for the separation of C.sub.2+ hydrocarbons from natural gas under pressure wherein the natural gas is cooled (2, 6), partially condensed, and separated (9) into a liquid fraction and a gaseous fraction. The liquid fraction (10) is subcooled (11) and then expanded into the upper zone of a rectifying column (7). The gaseous fraction (23), after engine expansion (25), is also introduced into the rectifying column (7). During rectification, a product stream (37) containing essentially C.sub.2+ hydrocarbons and a residual gas stream (22) containing predominantly lower-boiling components are obtained. The residual gas stream (22) is initially heated by heat exchange (11) with the liquid fraction (10) and then heated by heat exchange (21) with the gaseous fraction obtained after partial condensation. The residual gas stream is then further heated (6, 2) by heat exchange with the feed stream of natural gas to be partially condensed. The heated residual gas is then engine expanded (28) and reheated again by heat exchange with the feed stream of natural gas to be partially condensed (2).
摘要:
A method of liquefying a hydrocarbon-rich gas, wherein the gas flows through a cascade of three refrigeration stages, each stage comprising a refrigerant circuit and a compressor, wherein at least part of the flow of refrigerant from the second circuit is used for the pre-cooling of the hydrocarbon rich gas in the first refrigeration stage. This balances the load on each of the compressors. By standardizing the drive units and compressors of the three coolant circuits, it is possible to maximize the attainable liquefaction capacity of the liquefaction process using tried-and-trusted drive units and compressors respectively. This method can be applied to mixed refrigerant cascades and circuits with a carbon dioxide pre-cooling circuit. This latter option has benefits for offshore use where large amounts of hydrocarbons are undesirable.
摘要:
The invention relates to a process for separating off C2+-hydrocarbons from a feed fraction containing essentially nitrogen and hydrocarbons, wherein a) the feed fraction (1, 20) is partially condensed (E1, E1′, E3) and separated by rectification (T) into a C2+-hydrocarbon-rich fraction (11) and a C2+-hydrocarbon-depleted fraction (2), b) the C2+-hydrocarbon-depleted fraction (2) is partially condensed (E2) and separated into a liquid fraction which forms at least in part the reflux (3) for the separation by rectification (T), and a C2+-hydrocarbon-depleted gas fraction (4), and c) the C2+-hydrocarbon-depleted gas fraction (4) is separated in a double-column process (N) into a nitrogen-rich fraction (8′) and a methane-rich fraction (7″). According to the invention, the liquid fraction obtained in process step b) is fed (10) at least in part likewise to the double-column process (N) and separated therein into a nitrogen-rich fraction (8′) and a methane-rich fraction (7″).
摘要:
The invention relates to a process for liquefying a hydrocarbon-rich, nitrogen-containing feed fraction, preferably natural gas, wherein: a) the feed fraction (1) is liquefied (E1, E2), b) is separated by rectification (T1) into a nitrogen-enriched fraction (9), the methane content of which is a max. of 1% by volume, and a hydrocarbon-rich, nitrogen-depleted fraction (4), c) the hydrocarbon-rich, nitrogen-depleted fraction (4) is subcooled (E3) and expanded (b), d) the expanded hydrocarbon-rich, nitrogen-depleted fraction (5) is separated (D1) into a hydrocarbon-rich fraction (6), the nitrogen content of which is a max. of 1% by volume, and a nitrogen-rich fraction (7), and e) the nitrogen-rich fraction (7) is added to the feed fraction (1).
摘要:
A method for liquefying a hydrocarbon-rich stream, in particular a natural gas stream, is disclosed. A liquefaction of the hydrocarbon-rich stream takes place countercurrent to a refrigerant mixture cycle cascade consisting of two or three refrigerant mixture cycles. No additional process steps are involved in the heat exchange between the hydrocarbon-rich stream which is to be precooled and the refrigerant mixture of the first refrigerant mixture cycle.