TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The porous material and the activated carbon are packed in a sequential fashion of porous material preceding the activated carbon in a single column (the column). The porous material comprises molecular sieves. The relative quantities of molecular sieves to activated carbon is selected so that regeneration of the molecular sieves is required at the same or similar time to the activated carbon. The wet scrubbing step involves: a water scrubbing process in a water scrubber.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Apparatus: The apparatus includes two identical columns arranged in parallel, allowing one column to be on line whilst the other column is regenerated. In the apparatus, there is a device to separate a fraction of the upgraded biogas exiting the on-line column, heating of that fraction of gas, and device for passage of that fraction of gas in a counter current direction through the column being regenerated. Preferred Components: In the apparatus, the wet scrubber is a water scrubber.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: In the method (M1), the removal step is immediately after the drying step. The drying step involves: passage of the upgraded biogas stream through a porous material capable of removing water from the gas. The removal step involves: passage of the upgraded biogas stream through activated carbon (where the porous material and the activated carbon are located in a single vessel and the drying and H2S removal steps are carried out by passage of the upgraded biogas through this vessel). The step iia) is at elevated pressure. The step iva) involves passage through activated carbon. The step iiia) involves passage through a molecular sieve. The steps iiia) and iva) are performed by a passage through a same vessel; or in sequence in a single vessel of a bank of at least two such vessels and the stream is diverted from one to the other as the content of a vessel degrades in use (e.g. by reference to the dew point of the output gas stream). Preferred Components: The upgraded biogas stream exiting the water scrubber is at temperature of 2-10 degrees C. The upgraded biogas entering the column is at a temperature of 2-10 degrees C upon entry. In the method (M1), upon exiting the column the H2S levels of the upgraded biogas are in parts per billion; upon exiting the column the produced bio-methane meets a Swedish standard for biogas SS155438. The produced bio-methane meets the Swedish standard for biogas SS155438, either Standard A or Standard B. EXAMPLE - No suitable example given.