A turbine with a supersonic separator disposed upstream of the turbine. The supersonic separator imparts a swirl on a vapor stream to remove any heavier components. A superheated vapor stream from the supersonic separator is passed through the turbine to reduce the pressure of the vapor stream. At the same time, electricity is generated by the superheated vapor stream via a turbine wheel. The turbine and the supersonic separator can be integrally formed, or they can be discrete components.