Abstract: Described herein is a method for separating C2+-hydrocarbons or C3+-hydrocarbons from a hydrocarbon-rich fraction is described, whereby the separation is carried out in a rectification fractionation. The rectification fractionation is provided with at least three heating circuits via which intermediate fractions are drawn off from rectification fractionation, partially evaporated and fed back again to rectification fractionation. In the method, removal of the intermediate fraction circulating in the heating circuit located at the highest temperature level is at least temporarily interrupted. During this interruption, a partial stream of a bottom fraction from the rectification fractionation is partially evaporated against an external medium and is fed as a bottom heating to the rectification fractionation.

Abstract: Disclosed is a method for separating heavy hydrocarbons, in particular C6+ hydrocarbons and/or aromatic hydrocarbons, such as benzene, from a hydrocarbon-rich fraction to be liquefied, in particular from natural gas, the hydrocarbon-rich fraction being precooled prior to separation of the heavy hydrocarbons. One or a plurality of C5 hydrocarbon-rich fractions are mixed into the hydrocarbon-rich fraction prior to the pre-cooling thereof and/or into the separation column used for separating the heavy hydrocarbons at least in such a quantity, preferably in liquid form, that freezing of the heavy hydrocarbons to be separated is prevented.

Abstract: A method for the liquefaction of a hydrocarbon-rich fraction is described, wherein the hydrocarbon-rich fraction is liquefied against an open expander refrigeration circuit. According to the invention, that partial stream (6-14) of the hydrocarbon-rich fraction (3) to be liquefied which circulates in the expander refrigeration circuit is expanded in two stages so as to perform work (X1, X2), wherein the partial stream (9) expanded in the first expansion stage (X1) is cooled (E) and subsequently supplied (10) to the second expansion stage (X2).

Abstract: Described herein is a method for separating C2+-hydrocarbons from a hydrocarbon-rich fraction comprising partially condensing a hydrocarbon-rich fraction, and separating the hydrocarbon-rich fraction into a gaseous fraction and a liquid fraction. These fractions are subjected to a rectification fractionation to obtain a methane-rich fraction and a C2+-hydrocarbon-rich fraction. The methane-rich fraction is compressed, and a partial stream of the compressed methane-rich fraction is condensed is fed as reflux to rectification fractionation. In addition, before rectification fractionation, the liquid fraction is separated into two partial streams. The first partial stream is partially evaporated and then is fed to rectification fractionation. The second partial stream is undercooled and then is fed as additional reflux to rectification fractionation.

Abstract: Described herein is a method for separating C2+-hydrocarbons or C3+-hydrocarbons from a hydrocarbon-rich fraction is described, whereby the separation is carried out in a rectification fractionation. The rectification fractionation is provided with at least three heating circuits via which intermediate fractions are drawn off from rectification fractionation, partially evaporated and fed back again to rectification fractionation. In the method, removal of the intermediate fraction circulating in the heating circuit located at the highest temperature level is at least temporarily interrupted. During this interruption, a partial stream of a bottom fraction from the rectification fractionation is partially evaporated against an external medium and is fed as a bottom heating to the rectification fractionation.

Abstract: 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).

Abstract: The invention relates to a method for converting heat energy into mechanical energy by means of a Rankine cycle. In the Rankine cycle the circulating working fluid is pumped to a pressure above its critical pressure prior to heat exchange with an external medium. During the heat exchange with the external medium, the working fluid is heated to a temperature above its critical temperature and sufficiently high for the working fluid to expand without partial condensation. The working fluid is then expanded and condensed. The maximum pressure of the working fluid is controlled by means of an expander controllable with regard to the mass flow rate of the working fluid and/or a pump controllable with regard to the mass flow rate of the working fluid.

Abstract: 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).

Abstract: 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.

Abstract: 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).

Abstract: 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).

Abstract: 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?).

Abstract: 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.

Abstract: 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.

Abstract: A method of evaporating a process stream is disclosed. In an embodiment, a process stream to be cooled is provided to a heat exchanger. A process stream to be evaporated is provided to the heat exchanger. A gas and/or a liquid is admixed with the process stream to be evaporated only when an amount of gas generated during evaporation of the process stream cannot entrain a liquid portion of the process stream to be evaporated. A gas is generated by the admixing.

Abstract: 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.

Abstract: 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.

Abstract: A process for the separation of CO.sub.2 from gases containing light hydrocarbons and a relatively high proportion of CO.sub.2 comprises a two stage fractionation procedure. In a first fractionating stage, the entire amount of C.sub.1 and C.sub.2 hydrocarbons are separated from the gaseous mixture; the resultant bottoms fraction, which contains the C.sub.3+ hydrocarbons and CO.sub.2, is pumped to a higher pressure and further distilled in a second fractionating stage. During this process, the head cooling of the second fractionating stage is coupled with the bottoms heating of the first fractionating stage.

Abstract: The separation of C.sub.3+ hydrocarbons from natural gas and the like comprises subjecting the gas under pressure to partial condensation under cooling, separating the uncondensed gaseous phase and engine expanding same while the condensed liquid fraction is subjected to rectification. Additional C.sub.3+ hydrocarbons are separated from the engine expanded gaseous fraction by scrubbing and then fed to the rectification column. The resultant scrubbed gaseous fraction, whose pressure preferably is above the rectification pressure, can be delivered as C.sub.2- product stream.

Abstract: For the separation of CO.sub.2 from a gaseous mixture containing CO.sub.2 and C.sub.1 -C.sub.6 hydrocarbons, the gaseous mixture to be fractionated is separated in a first fractionating stage into an overhead fraction containing substantially all of the C.sub.1 and C.sub.2 hydrocarbons as well as CO.sub.2 in a molar ratio CO.sub.2 /C.sub.2 of 2:1 to 3.5:1, and into a bottoms fraction containing the remainder of CO.sub.2 and the C.sub.3+ hydrocarbons. The fraction containing CO.sub.2 /C.sub.3+ hydrocarbons is further fractionated, preferably in two serially connected rectification columns, into CO.sub.2 and C.sub.3+ hydrocarbon fractions.