Abstract: Hydrocarbons are subjected to hydrogenation, pressure reduction and separation into liquid and gaseous fractions. The gaseous fractions are purified and desulfurized. Hydrogen-rich components of the gaseous fraction are returned to the hydrogenation stage. Hydrocarbon-rich components of the gaseous fraction and components of the liquid fraction are cracked and fractionated. Residue is partially oxidized with oxygen and steam. Gas produced by the partial oxidation is desulfurized and separated, and hydrogen is returned to the hydrogenation stage. A polymer free fraction of the residue is returned to the feed stock and to the hydrogenation stage, a heavy residue component of the initial liquid fraction is partially oxidized with the residue.

Abstract: A tube furnace for the cracking of organic feed stock, e.g. naphtha to ethylene, comprises a chamber traversed by at least one conduit system for the organic feed stock. The conduit system in the region of the inlet comprises a plurality of pipes which are united at an intermediate location and communicate jointly with a single pipe forming the discharge portion of the duct system. Preferably the flow cross section of the duct system increases from the inlet to the outlet end. Burners are provided in the wall of the chamber.

Abstract: A tube furnace for the cracking of organic feed stock, e.g. naphtha to ethylene, comprises a chamber traversed by at least one conduit system for the organic feed stock. The conduit system in the region of the inlet comprises a plurality of pipes which are united at an intermediate location and communicate jointly with a single pipe forming the discharge portion of the duct system. Preferably the flow cross section of the duct system increases from the inlet to the outlet end. Burners are provided in the wall of the chamber.

Abstract: A tube furnace, especially for the cracking of hydrocarbons, comprises a heat and combustion chamber in which the hydrocarbons are passed through a plurality of tube coils lying in planes parallel to the walls of the chamber and having predominantly vertical stretches. Preferably, a plurality of tube coils is provided and lies along respective walls of the vessel with each pair of tube coils communicating with a common tube coil of larger cross section extending into the interior of the chamber.