Method and apparatus for dehydrogenating aliphatic hydrocarbons to olefinic hydrocarbons

A method of producing olefinic hydrocarbons from a charge comprising aliphatic hydrocarbons with 2 to 6 carbon atoms, by dehydrogenation in at least one reaction chamber, the chamber having a plurality of substantially parallel reaction tubes arranged in rows, each tube containing a fixed bed of catalyst, wherein said method comprises:

• a) reacting said charge by circulating said charge, optionally preheated, in the tubes containing the fixed beds of catalyst under dehydrogenation conditions at 500-800° C. and collecting an effluent rich in olefinic hydrocarbons;
• b) purging the tubes with at least one inert gas, after reaction phase a), and collecting a purge effluent;
• c) regenerating the catalyst in the tubes of said at least one reaction chamber under regenerating conditions, to remove coke deposited on said catalyst during reaction phase a), and recovering a regeneration effluent;
• and
• d) purging the tubes with at least one inert gas, after regeneration phase c);
• wherein the tubes are heated during reaction phase a) by a plurality of radiant ceramic fiber matrix burners arranged at the periphery of the tubes in layers which are substantially parallel, independent of one another, and substantially perpendicular to the tubes,
• whereby said burners heat a first part of the tubes, representing 1% to 40% of the length of the tubes, with a heat flow equal to 120% to 300% of the mean heat flow of the reaction chamber, and heat the remaining part of the tubes with a heat flow equal to 20% to 85% of the mean heat flow, so that a constant temperature of the catalyst is substantially maintained, and
• wherein any combustion fumes emanating from said burners is eventually discharged from the chamber.