Abstract: Disclosed is a method for liquefying a hydrocarbon-rich stream, in particular a natural gas stream, by indirectly exchanging hear with the coolant mixture of a coolant mixture circuit. In said method, the coolant mixture is condensed in two or more stages, is divided into at least one lower-boiling and at least one higher-boiling coolant mixture fraction, and the coolant mixture fractions are evaporated at different temperature levels against the hydrocarbon-rich stream that is to be cooled and liquefied and are then combined before being condensed once again. The coolant mixture fractions are not entirely evaporated during normal operation and are preferably not superheated. Preferably, at least 1 to 10 percent by weight of the total amount of the coolant mixture are not evaporated.

Abstract: In the liquefaction of a hydrocarbon by indirect heat exchange with the refrigerant mixture of a refrigerant mixture cycle, the refrigerant mixture being compressed in multiple stages, the compressed refrigerant mixture (23) is at least partially condensed (E4) downstream of the penultimate compressor stage and is fractionated (D4) into a higher-boiling liquid fraction (26) and a lower-boiling gas fraction (24). The lower-boiling gas fraction (24) is compressed to the final pressure, partially condensed (E5) and fractionated (D5) into a lower-boiling gas fraction (10) and a higher-boiling liquid fraction (27). The higher-boiling liquid fraction (27) is added to the partially condensed refrigerant mixture stream (23), and the gas fraction (10) forms the lower-boiling refrigerant mixture fraction and the liquid fraction (26) forms the higher boiling refrigerant mixture fraction of the refrigerant mixture cycle.

Abstract: The invention relates to a method for liquefying a stream rich in hydrocarbons, especially a stream of natural gas, by the indirect exchange of heat with the refrigerants in a closed-circuit cascade of mixed refrigerants. According to the invention, said closed-circuit cascade of mixed refrigerants consists of at least 3 circuits of mixed refrigerants, with each circuit comprising different refrigerants. The first of the three mixed refrigerant circuits is used for pre-cooling (E1), the second for liquefying E2), and the third for super-cooling (E3) the hydrocarbon-rich stream (1) to be liquefied. The method provided for in the invention reduces specific energy consumption and investment costs since the three circuits of mixed refrigerants are or can be optimally adjusted to the enthalpy temperature curves of the hydrocarbon-rich stream to be liquefied and the refrigerant mixtures.

Abstract: The invention relates to a process for the removal of HCN from gas mixtures that contain at least HCN and sulfur compounds, especially from gas mixtures that are obtained by partial oxidation of hydrocarbons, by catalytic decomposition of HCN, as well as a catalyst for the decomposition of HCN. According to the invention, the gas mixture is brought into contact with a catalyst which decomposes the HCN by hydrogenation and/or by hydrolysis and COS that is contained in the gas mixture is decomposed at least partially in this catalyst by hydrolysis. Advantageously, a catalyst that is based on titanium oxide and/or zirconium oxide as a vehicle and that contains chromium oxide as an active component is used. Advantageously, the catalyst is reduced during catalyst production or before use with H.sub.2 and/or a reducing gas at temperatures above the operating temperature of catalytic decomposition.

Abstract: To recover liquid methane from a feed gas mixture (1) essentially consisting of methane, C.sub.2+ hydrocarbons, carbon dioxide and nitrogen, the feed gas mixture (1) is fed first to an adsorption unit (E) and freed from water; dried feed gas mixture (2) is fed to a membrane separating unit (F), wherein the carbon dioxide is separated down to a residual content less than 2% by volume (9) and resultant gas mixture (3) now essentially consisting of methane, C.sub.2+ hydrocarbons and nitrogen is fed to a low-temperature distillation (A) wherein the C.sub.2+ hydrocarbons as well as the residual content of carbon dioxide are separated by distillation.

Abstract: In a process for the rectification of a raw gaseous mixture under superatmospheric pressure and containing at least three components, e.g. natural gas wherein the gaseous mixture is fractionated in a first rectifying column into a head product largely freed of at least one higher-boiling component and into a bottoms product largely freed of at least one lower-boiling component, the improvement which comprises compressing the liquid bottoms product of the first rectifying column; passing resultant compressed bottoms product in indirect heat exchange relationship with the gaseous mixture to at least partially vaporize said bottoms product; engine-expanding resultant vaporized compressed bottoms product to form a liquid which is then passed as reflux into a second rectifying column; and fractionating resultant expanded bottoms product in said second rectifying column to form a top product containing lower-boiling components and into a sump product containing higher-boiling components.

Abstract: Process for the liquefaction of natural gas by heat exchange, initially with a first multicomponent mixture and thereafter with a second multicomponent mixture, each of these mixtures, respectively in a closed refrigeration cycle, being compressed, at least partially liquefied, and expanded, characterized in that the first multicomponent mixture, after the partial liquefaction thereof, is subjected to a phase separation; that the thus-obtained liquid fraction, after its expansion, is at least partially evaporated in heat exchange with media to be cooled comprising the natural gas, the gaseous fraction obtained during the phase separation, and the second multicomponent mixture; and that the gaseous fraction, liquefied in heat exchange with the expanded liquid fraction, is expanded and at least partially evaporated in heat exchange with the natural gas and with the second multicomponent mixture, which latter is at least partially liquefied during this heat exchange.

Abstract: Process for the at least partial liquefaction of a low-boiling gaseous mixture, which is under pressure, wherein the gaseous mixture is precooled in heat exchange with a vaporizing refrigerant, purified during the course of the precooling step, and, after the precooling step, is subjected to a preliminary separation, characterized in that the at least partial liquefaction of the gaseous fraction obtained during the preliminary separation is carried out in heat exchange with a vaporizing multicomponent gas, the partial liquefaction of which takes place by precooling, and the completed liquefaction and subcooling of which takes place in one stage against itself.