Abstract A process for the liquefaction of gas mixtures by at least two open partial cycles with different boiling points includes premixing the gas mixture with the cycle media and by means of a compressor bringing it to an elevated pressure and subjecting it to a fractional condensation where the cycle media and the more difficulty boiling mixture constituents are precipitated as liquid fractions in separators. The liquid fraction of the first separator is divided into two partial streams. The first stream, which forms the first partial cycle, after expansion to an average pressure gives off coolness from cycle gas and gas mixture to be liquefied to the mixture streaming to the first separator and again conducts back to the compressor. The second stream is deep-cooled, expanded to about atmospheric pressure and admixed to the last cycle medium streaming back to the compressor. Furthermore, it is proceeded with the compressor of the subsequent separator accordingly, the expansion of the first partial streams occurring at average pressure until finally the liquid precipitating in the last separator after cooling of itself and expanding to about atmospheric pressure, gives off coolness to the gas mixture to be liquefied and to the other separated cycle media and is again conducted to the compressor.
A process according to claim 1 wherein each first partial stream is greater than its second partial stream.
Claim 2
Dependent Claim
39 words
A process according to claim 2, characterized in that from at least one of the first partial streams formed from the liquid fractions, a partial amount is branched off, deep-cooled, expanded, and again admixed to the liquefied gas mixture.
Claim 3
Dependent Claim
27 words
A process according to claim 3, characterized in that the gas mixture to be liquefied is natural gas and the cycle media consist preponderantly of high-boiling hydrocarbons.
Claim 4
Dependent Claim
59 words
A process according to claim 4, whereby nitrogen is to be removed from the natural gas, characterized in that the gaseous fraction drawn off from the last separator after further cooling and partial liquefaction is subjected to a predecomposition in an additional separator for the purpose of nitrogen separation, and before further cooling is expanded in the nitrogen column.
Claim 5
Dependent Claim
19 words
A process according to claim 5, characterized in that only two refrigeration cycles are used with two appropriate separators.
Claim 6
Dependent Claim
27 words
A process according to claim 1, characterized in that the gas mixture to be liquefied is natural gas and the cycle media consist preponderantly of high-boiling hydrocarbons.