Gases (petroleum), naphtha steam cracking high-pressure residual; Refinery gas; [A complex combination obtained as a reaction mass of the non-condensable portions from the product of a naphtha steam cracking process as well as residual gases obtained during the preparation of subsequent products. It consists predominantly of hydrogen and paraffinic and olefinic hydrocarbons having carbon numbers predominantly in the range of C1 through C5 with which natural gas may also be mixed.]