NOVELTY - The method involves feeding a feed gas (402) into a port of a sleeve (407) arranged around a portion of a periphery of a column (400) such that the sleeve comprises a space between an outer wall of the column and an inner wall of the column. The sleeve is configured such that the feed gas is released into the column through an opening arranged at an opposite end of the sleeve from the port. The feed gas comprises a carbon dioxide concentration of less than about 16%. The sleeve is located in a zone of the column that is configured to freeze one component of the feed gas.    USE - Method of controlling temperature in column for separating acid gas component and impurities such as ethane, propane, and butane from raw material gas such as methane used for domestic heating and cooking purposes and vehicle.    ADVANTAGE - The freezing of the carbon dioxide on the walls is prevented, as the feed gas is injected into an upper region of a hollow area positioned around the perimeter of the freezing zone. The system power requirement is reduced, since the low-carbon dioxide raw feed stream is injected into the controlled freeze zone, which contains the carbon dioxide concentration similar to that of the raw feed stream. Re-vaporizing the carbon dioxide is reduced, the power efficiency is improved and the power consumption is reduced, by introducing the feed gas above the melt tray. The efficient separation is performed to purify the raw gas stream by removing carbon dioxide to produce purified methane for use as a valuable energy source.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a method of separating an acid gas component from a raw natural gas stream in a column; and    (2) a column for a separation of a feed gas.    DESCRIPTION OF DRAWING(S) - The drawing shows an explanatory view explaining the feeding process of the low-carbon dioxide content feed gas into the controlled freeze zone section of the column.    Column (400)    Feed gas (402)    Sleeve (407)    Liquid (422)    Vapor (434)