Abstract: A method is provided for separating off acid gases, in particular CO2 and H2S, from a hydrocarbon-rich fraction, in particular natural gas. The hydrocarbon-rich fraction is cooled and partially condensed. The resultant CO2-enriched liquid fraction is separated by rectification into a CO2-rich liquid fraction and a CO2-depleted gas fraction. The hydrocarbon-rich fraction is cooled close to the temperature of the CO2 triple point by means of a closed multistage refrigeration circuit. The refrigerant is a CO2 fraction of greater than 99.5% by volume. The rectification column is operated at a pressure between 40 and 65 bar. The reboiler of the rectification column is heated by means of a condensing refrigerant substream of the refrigeration circuit that is at a suitable pressure level.

Abstract: A process for cooling a hydrocarbon-rich fraction, in particular natural gas, against a refrigerant circuit. In this process, the compressed refrigerant is divided into three refrigerant substreams. Whereas the first substream is work-producingly expanded in a warm expander and the second substream is work-producingly expanded in a cold expander, the third substream is work-producingly expanded at the lowest temperature level. The result therefrom is that the operating point of the cold expander is shifted in such a manner that the refrigeration output of the two expanders is situated in a ratio between 40/60 and 60/40.

Abstract: A process for cooling a hydrocarbon-rich fraction, in particular natural gas, against a refrigerant circuit. In this process, the compressed refrigerant is divided into three refrigerant substreams. Whereas the first substream is work-producingly expanded in a warm expander and the second substream is work-producingly expanded in a cold expander, the third substream is work-producingly expanded at the lowest temperature level. The result therefrom is that the operating point of the cold expander is shifted in such a manner that the refrigeration output of the two expanders is situated in a ratio between 40/60 and 60/40.

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 is provided for separating off acid gases, in particular CO2 and H2S, from a hydrocarbon-rich fraction, in particular natural gas. The hydrocarbon-rich fraction is cooled and partially condensed. The resultant CO2-enriched liquid fraction is separated by rectification into a CO2-rich liquid fraction and a CO2-depleted gas fraction. The hydrocarbon-rich fraction is cooled close to the temperature of the CO2 triple point by means of a closed multistage refrigeration circuit. The refrigerant is a CO2 fraction of greater than 99.5% by volume. The rectification column is operated at a pressure between 40 and 65 bar. The reboiler of the rectification column is heated by means of a condensing refrigerant substream of the refrigeration circuit that is at a suitable pressure level.

Abstract: Described herein is a process for liquefying a hydrocarbon-rich fraction, in particular natural gas, is described, in which the hydrocarbon-rich fraction that is to be liquefied is cooled in indirect heat exchange against a multistage precooling circuit, the refrigerant of the precooling circuit is at least 95% by volume carbon dioxide, the cooled hydrocarbon-rich fraction is liquefied and subcooled in indirect heat exchange against a mixed cycle, and the mixed refrigerant of the mixed cycle comprises exclusively the component(s) nitrogen, methane and/or ethane.