A compressed vaporous discharge stream is de-superheated in a de-superheater system. The de-superheater system comprises a de-superheater heat exchanger configured to bring at least a portion of the compressed vaporous discharge stream in indirect heat exchanging contact with an ambient stream. A de-superheater bypass line comprising an temperature-controlled valve is configured to selectively bypass the de-superheater heat exchanger. A combiner is configured downstream of the de-superheater heat exchanger for rejoining the bypass portion with the portion of the compressed vaporous discharge stream that has passed through the de-superheater heat exchanger. A mixer is configured downstream of said combiner, to receive and mix the rejoined stream, and discharge the rejoined stream into a de-superheater discharge conduit as a de-superheated stream.