Method and an apparatus for sweetening and dehydrating a hydrocarbon gas, in particular a natural gas

Abstract

A method and an apparatus for removing acid compounds (sweetening) and moisture (dehydration) from a hydrocarbon gas, in particular from a natural gas or from a refinery gas fraction or a gas of synthesis, by subsequent absorption operations using a sweetening liquid and a dehydration liquid. The method comprises a step of prearranging a sweetening chamber () and a dehydration chamber () within a vertical elongated container (), each chamber defined by an inner partition wall () of said vertical elongated container (), is wherein a gas transfer passageway () is provided between an upper outlet port of the sweetening chamber () and an inlet port of the dehydration chamber (); the method also comprises steps of feeding the absorption liquid from the above into the two chambers and of feeding the gas from below into the sweetening chamber. The apparatus and the method according to the invention make it possible to reduce the overall dimensions of the treatment unit with respect to the prior art units, which is particularly relevant for off-shore installations.