Multi-zone fixed-bed or moving-bed reactor with an integrated heat exchanger

A reactor system comprising a source of fresh or regenerated catalyst reactor of elongated shape along an essentially vertical axis, said reactor comprising a cylindrical shell and several vertically-staged catalytic reaction zones in said cylindrical shell, whereby said reactor is adapted to the axial circulation of a reaction fluid serially in each of said zones and comprises means (100) for introducing and means (101) for evacuating said reaction fluid, means (102) connected to said source of fresh or regenerated catalyst for intake of fresh or regenerated catalyst at the top of the reactor, and means (105) for evacuating spent catalyst in the lower portion of the reactor, said reactor comprising:

• an upper reaction zone (3a) filled with granular catalyst, at least a section of zone (3a) being vertical and diametrically coextensive to that of the cylindrical shell on a portion of its height, directly connected via a constriction zone to a reaction zone (3b) that is also filled with granular catalyst at least a section of zone (3b) being vertical and diametrically coextensive to that of the cylindrical shell on a portion of its height, located just below the upper reaction zone (3a), whereby said reaction zones (3a) and (3b) are two successive reaction zones that are directly connected by a reaction effluent path, and by a catalyst path from zone (3a) to zone (3b) through said constriction zone, whereby zone (3a) is connected at its upper portion, directly or indirectly, to said fluid means (102) for feeding fresh or regenerated catalyst, whereby zone (3b) is connected at its lower portion, directly or indirectly, to said means (105) for evacuating spent catalyst, whereby the reactor, placed at the constriction zone between this constriction zone and the cylindrical shell of the reactor, also comprises a heat exchanger (8) for heating or cooling reaction fluid circulating between zones (3a) and (3b), and means for transporting fresh and/or regenerated catalyst to said reactor.