TWO STAGE PROCESS FOR PRODUCING PURIFIED GAS
The present invention provides a process for producing purified gas from a feed gas stream comprising methane and gaseous contaminants, the process comprising the steps of : 1) providing the feed gas stream; 2) cooling the feed gas stream to a temperature at which at least part of the feed gas stream is present in the liquid phase; 3) separating the cooled feed gas stream by means of cryogenic distillation into a bottom stream rich in contaminants and lean in methane, and into a top stream rich in methane and lean in gaseous contaminants, in which the bottom stream contains between 0.5 and 15 % of the methane present in the feed gas stream; 4) cooling the stream rich in methane to a temperature at which solid and/or liquid phase contaminants are formed; 5) introducing the cooled stream of step 4) into a gas/liquid/solids separation vessel, and 6) removing from the gas/liquid/solids separation vessel the purified gas and a stream rich in contaminants.