Patent ID: 6875338

Claim:
A process for converting hydrocarbons using at least one globally endothermic chemical reaction, comprising: successively traversing a hydrocarbon feed through at least two reaction zones, each containing at least one solid catalyst and an intermediate reheating step, in a non catalytic zone, for reheating the stream (ST) from the first of the two reaction zones prior to its introduction into said second reaction zone, wherein said reheating step is between said reaction zones wherein said reheating is carried out in a heat exchanger, in which heat transfer is performed essentially by convection using a thermal fluid TF with a coking sensitivity index CS that is less than that of the stream ST, and heating said thermal fluid TF in a furnace upstream of the heat exchanger, and wherein the difference in temperature ΔT between the temperature of the thermal fluid TF at the inlet to the exchanger and the temperature of the stream ST at the heat exchanger outlet is less than 250° C., and said thermal fluid TF is selected from: a hydrogen-rich gaseous stream, a stream of recycle gas, and a gaseous stream containing hydrocarbons from the feed circulating upstream of the first reaction zone.