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:
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.
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 method of separating off an N2-rich fraction from a liquefied hydrocarbon-rich fraction is described, in particular from liquefied natural gas, wherein the liquefied hydrocarbon-rich fraction, after its liquefaction and subcooling, is fed to a stripping column which serves for separating off the N2-rich fraction.According to the invention, a first substream of the liquefied hydrocarbon-rich fraction (2, 2′) is applied to the stripping column (S) as reflux, whereas a second substream of the liquefied hydrocarbon-rich fraction (3, 3′) is fed to the bottom of the stripping column (S), wherein the second substream of the liquefied hydrocarbon-rich fraction (3, 3′) has a higher temperature than the first substream of the liquefied hydrocarbon-rich fraction (2, 2′).