FIELD: methods of performing chemical reactions. SUBSTANCE: device includes axially elongated reactor 1 having square or rectangular section; at one end, reactor has at least one unit loading at least one reagent and at opposite end, it has at least one unit for removal of effluents. Reactor has many heat exchange device 3 is first zone (on side of first end) which are practically parallel relative to one another and are arranged in practically parallel layers which are perpendicular relative to reactor axis forming clearances or passages between these devices and/or layers formed by them for circulation of reagent or reagents and/or effluents. Heat exchanger devices 3 are adaptable for heat exchange in passages due to successive transversal sections which are independent and practically perpendicular to reactor axis. At least several heat exchange devices 3 include tube formed by at least one envelope which is loaded with gas or gaseous mixture for heat exchange and provided with at least one device for removal of gas or gaseous mixture subjected to heat exchange with reagent or reagents and/or effluents circulating on the outside of heat exchange device 3. EFFECT: enhanced efficiency. 16 cl, 4 dwg
