METHOD AND APPARATUS FOR SWEETENING AND/OR DEHYDRATING A HYDROCARBON GAS, IN PARTICULAR A NATURAL GAS

摘要

A method for removing acidity and/or moisture from a hydrocarbon gas, in particular from a natural gas, a refinery gas or a syngas, by ab¬ sorption into a sweetening liquid and into a dehydration liquid, that are adapted to extract acid compounds or water from the gas, respec¬ tively. The method provides a step of prearranging a vertical elongat¬ ed container (150) comprising at least one inner partition wall (168) that defines at least two treatment chambers within said container (151,152), a step of feeding a treatment liquid from the above into at least one of the two chambers (251,252) and feeding the gas to be treated from below into at least one same treatment chamber. It is also provided a step of selecting a treatment mode, wherein the gas flows along the two treatment chambers in a parallel or in a se¬ ries arrangement, or one chamber being excluded; in particular the series-mode or the exclusion mode is actuated when the flowrate of the gas decreases below a minimum threshold value, while the paral¬ lel-mode is actuated when the flowrate of the gas rises above a max¬ imum threshold value. An apparatus comprising at least such a con¬ tainer and a gas convey selective convey means (44', 44") for actuat¬ ing said treatment modes, in particular responsive to a flowrate of the gas, is also described. The apparatus and the method allow to main¬ tain the sweetening and/or dehydration efficiency, in particular in the case of a progressive reduction of the flowrate of natural gas that can be obtained from a well or gasfield.