Patent ID: 6318119
Filing Date: 2001-11-20
Classification: C10L,F25J

Abstract:
A process allowing to fractionate a gas comprising constituents referred to as heavy constituents and constituents referred to as light constituents, the gas being at a temperature T.sub.0 initially and at a pressure P.sub.0, characterized in that it comprises in combination at least the following stages:a) cooling the gas from T.sub.0 to a temperature T.sub.1,b) separating a first gas phase from a first liquid phase obtained during cooling stage a),c) sending at least part of the first gas phase from separate stage b) to a first expansion stage so as to obtain a first mixed phase at a temperature T.sub.2 and at a pressure P.sub.2,d) sending the first mixed phase to a heat exchange stage (stage g) wherein it serves as a cooling agent, after which it is reheated,e) sending the first liquid L.sub.1 to a second expansion stage,f) sending the heated mixed phase and the expanded liquid phase to a separation stage so as to obtain a gas phase and a liquid phase,g) fractionating the gas phase by distillation performed by means of continuous heat exchange with the first mixed phase, extracting the light constituents as gas and the heavy constituents as condensates, the fractionating stage being carried out after the stage of expansion of the first mixed phase.