摘要 |
A method is described for cooling a hydrocarbon-rich fraction, in particular of natural gas, wherein the hydrocarbon-rich fraction (1) is cooled against at least one coolant circuit (10-15), the coolant has at least nitrogen, carbon dioxide, methane and/or C2+ hydrocarbons, the coolant is compressed by means of at least one turbocompressor (C1) having one or more gas-lubricated sliding-ring seals, and as primary seal gas, a substream of the coolant and/or an external gas or gas mixture having substantially nitrogen and/or methane is fed to the turbocompressor (C1), and as secondary seal gas, nitrogen is fed. According to the invention, at least one nitrogen-rich stream (21) is withdrawn at least at times from the coolant circuit (10-15). |