Method of producing aromatic hydrocarbons in a chamber heated by radiant heating means with a variable heat flow

A process is described for production of aromatic hydrocarbons from a charge of aliphatic hydrocarbons containing 2 to 12 carbon atoms, in an enclosure 1 comprising a plurality of pipes 3 which are filled with a catalyst and which are parallel and arranged in rows. A stage called reaction stage and a regeneration stage of the catalyst in the pipes of the enclosure are carried out. Heating of the pipes is produced by suitable radiant heating means 6, situated between two successive rows and arranged in sheets which are substantially perpendicular to the pipes. These sheets heat a first part of the pipes (feed side) with a heat flow greater than the mean heat flow of the heating means and a subsequent second part with a mean flow no greater than the mean heat flow, so that the isothermal condition (isothermicity) of the catalyst is substantially maintained, by virtue of suitable control means. Application to the production of benzene, toluene and xylenes.