Method and apparatus for separation of a gas mixture with emergency operation

The method and device are used for the separation of a gas mixture in a separation plant. A feed gas (18) in a compressor system (6, 16) and then introduced into the separation plant. In case of failure or partial failure of the compressor system (6, 16) of the first feed gas compressor (6), a first auxiliary power (91, 92) which has approximately the composition of the first product stream or approximately the composition of the feed gas, such as compressed the first pressure at least on (78, 89) and recirculated to the separation plant.