Device and method for processing a fluid by two-phase compression and fractionation

DETAILED DESCRIPTION The present invention consists in using a compression device allowing to mix and to dissolve the type A fraction(s) in a solvent phase while increasing the pressure level of the compressed fluids.
The invention is notably applied in cases where the fluid is a natural gas comprising acid gases to be removed, such as hydrogen sulfide H.
sub.
2 S and/or carbon dioxide CO.
sub.
2, the acid gases representing fraction A.
In the description hereafter, the term "solvent" or the expression "solvent phase" both designate the same product capable of collecting constituents to be separated from a fluid, and which can be a physical or a chemical solvent.
Similarly, the term "fluid" refers to liquids, gases or to a mixture of liquid and gas.
The present invention relates to a device for processing a fluid F comprising at least one fraction A to be separated, the fraction to be separated being at least soluble in a solvent phase.
The device comprises at least one line for delivering the fluid F to be processed, at least one line for delivering the solvent phase, at least one two-phase compression device permitting the different phases of the fluid F and the solvent phase to homogenize so as to dissolve most of the fraction A in the solvent phase and to produce a mixture made up of a solution F1 consisting of the solvent phase and of the fraction A dissolved in the solvent phase, and of a fluid F2 depleted in at least most of fraction A, at least one line for discharging the mixture, a separation device provided with lines for discharging respectively solution F1 consisting of the solvent phase and of fraction A, and fluid F2.
The delivery line(s) can comprise compression and/or pumping devices and the discharge line can be fitted with a cooling device.
The device can comprise a means located upstream from the two-phase compression device, which "mixes" the fluid to be processed and the solvent phase prior to feeding it into a line.
The compression device comprises for example at least two sections, a first section providing a mixture Mi with a pressure level Pi and a second section providing, from mixture Mi, a mixture Ms with a pressure level Ps, a line for discharging mixture Mi and a line for feeding a fluid Mi into the second part, the two sections being separated by a seal and the hydraulics of the two sections being mounted "back to back" for minimizing axial thrust stresses