FIELD: method and reactors for heterogeneous exothermic synthesis of formaldehyde. SUBSTANCE: method of heterogeneous exothermic synthesis of formaldehyde in reactor with several successively connected adiabatic layers of catalyst provides for supply into reactor of gaseous reagents containing methanol and excessive amount of oxygen, and passage of gaseous reagents through adiabatic layers to partially oxidized methanol. In this case, methanol supplied to reactor is separated into several parts. The first part comprising the larger part amounting to about 82% of total quantity of methanol supplied to synthesis reactor is supplied to the first catalytic bed and, at least, the second part is supplied to the second catalytic bed located behind the first catalytic bed. Reactor (its versions) is offered for embodiment of claimed method. EFFECT: higher process efficiency, reduced possibility of reagent explosion, simplified design of reactor. 17 cl, 2 dwg, 3 ex
