Patent ID: 8236179

Claim:
A separation method, including: performing a separating operation in a separation device, with the separation device receiving a product and feeding into an eluent that includes a supercritical fluid, routed via a first pumping operation, and a modifier, routed via at least one second pumping operation, collecting at least one fraction of the product downstream of the separation device, recycling the supercritical fluid mixed with a residual quantity of modifier, following after the collecting operation and preceding the first pumping operation, with the first pumping operation being used to pump at least the supercritical fluid mixed with a residual quantity of modifier, and performing a condensing operation following after the collecting operation and preceding the first pumping operation, the method being characterised in that it further includes: downstream of the collecting operation and upstream of the separating operation, determining at least one magnitude associated with the level of modifier mixed with the recycled supercritical fluid, and if necessary correcting the flow in the first pumping operation and the flow in the second pumping operation, in order to limit the variations, during execution of the method, of the modifier level in the eluent at the input to the separation device, in a direction that is suitable for meeting a first setpoint, determined beforehand, for the total flow.