TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The feed gas stream is a natural gas stream in which the gaseous contaminants are carbon dioxide and/or hydrogen sulfide, preferably in which the natural gas stream comprises 1-90 (preferably 5-80) vol.% of carbon dioxide and/or 0.1-60 (preferably 20-40) vol.% of hydrogen sulfide. The feed gas stream comprises 20-80 vol.% of methane.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The gas/liquid separator used in step (C) comprises: a gas/liquid inlet at an intermediate level, a liquid outlet arranged below the gas/liquid inlet and a gas outlet arranged above the gas/liquid inlet, in which vessel a normally horizontal coalescer is present above the gas/liquid inlet and over the whole cross-section of the vessel and in which vessel a centrifugal liquid separator is arranged above the coalescer and over the whole cross-section of the vessel, where the liquid separator comprises at least one swirl tube; or a centrifugal separator which comprises a bundle of parallel channels that are arranged within a spinning tube parallel to an axis of rotation of the spinning tube, preferably in which the centrifugal separator is spinned by introducing a swirling gas stream into the spinning tube; or a housing with a gas inlet for contaminated gas at one end of the vessel, a separating body, a gas outlet for purified gas at the opposite end of the housing and a contaminants outlet downstream of the separating body or upstream and downstream of the separating body, where the separating body comprises several ducts over a part of the length of the axis of the housing, which ducts have been arranged around a central axis of rotation, in which apparatus the separating body has been composed of several perforated discs, where the perforations of the discs form the ducts; or a housing comprising a first, second and third separation section for separating liquid from the mixture, where the second separation section is arranged below the first separation section and above the third separation section, the respective separation sections are in communication with each other, and the second separation section comprises a rotating coalescer element, tangentially arranged inlet units to introduce the mixture into the first separation section, units to remove liquid from the first separation section, units to remove liquid from the third separation section, and units to remove a gaseous stream, lean in liquid, from the third separation section.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: In the process (P1), the feed gas stream in step (A) has a temperature of -20 to 150 (preferably -10 to 70) degrees C, and a pressure of 10-150 (preferably 80-120) bara. The cooling in step (B) is done by isenthalpic expansion, preferably isenthalpic expansion over an orifice or a valve, especially a Joule-Thomson valve, or in which the cooling is done by nearly isentropic expansion, especially by an expander, preferably a turbo expander or a laval nozzle, preferably in which the feed gas stream is pre-cooled to a temperature of 15 to -35 (preferably 10 to -20) degrees C, before expansion. The expansion is done using at least two expansion devices and the operating parameters of the expansion devices are chosen such that the liquefied acidic contaminants have a certain droplet size distribution. The feed gas stream is cooled in step (B) to a temperature of -30 to -80 (preferably -40 to -65) degrees C. The methane enriched gaseous phase obtained in step (C) is recompressed in one more compression step before it is subjected to the distillation treatment in step (D), preferably in which energy that is recovered in step (B) is used for at least one compression step. The methane enriched gaseous phase obtained in step (C) or the recompressed methane enriched gaseous phase obtained in the at least one compression step is cooled in a cooling step to a temperature at which liquid phase contaminant is formed as well as a methane enriched gaseous phase, and the methane enriched gaseous phase so obtained is subjected to the distillation treatment in step (D). The cooling between steps (C) and (D) is at least partly done by an external refrigerant, preferably in which the external refrigerant has a higher molecular weight than the methane enriched gaseous phase to be cooled, more preferably in which the external refrigerant comprises a propane cycle, ethane/propane mixed refrigerant or an ethane/propane cascade. The bottom temperature of the distillation section is 0-30 degrees C, or in which the top temperature of the distillation section is -20 to -90 degrees C. EXAMPLE - No suitable example given.