| abstract |
A method for cooling a natural gas stream (CxHy) and separating the cooled gas stream into various fractions having different boiling points, such as methane, ethane, propane, butane and condensates, comprises: cooling the gas stream (1,2); and separating the cooled gas stream in an inlet separation tank (4); a fractionating column (7) in which a methane lean rich fluid fraction (CH4) is separated from a methane lean fluid fravction (C2+Hz); feeding at least part of the methane enriched fluid fraction from the inlet separation tank (4) into a cyclonic expansion and separation device (8), which preferably has an isentropic efficiency of expansion of at least 80%, such as a supersonic or transonic cyclone; and feeding the methane depleted fluid fraction from the cyclonic expansion and separation device (8) into the fractionating column (7) for further separation. |