Fixed-bed tubular reactor

A fixed-bed tubular reactor which extends, according to a longitudinal axis, between a first end and a second end, said reactor comprises a catalytic powder bed confined in an annular space delimited by an inner wall of a hollow tube and an outer wall of a hollow insert disposed coaxially in the hollow tube,

• the hollow insert comprises at least one distribution chamber and at least one collection chamber, separated from one another by at least one first partition wall, the at least one distribution chamber comprising a plurality of distribution compartments separated from one another by one or more second partition wall(s), each distribution compartment and the at least one collection chamber comprising, respectively, a gas intake opening at the first end and a gas discharge opening at the second end,
• the inner wall comprises distributing openings and at least one collecting opening, which extend over a length, each distributing opening enabling the distribution of a gas capable of being admitted through an intake opening into a distribution compartment towards the annular space and the collecting opening enabling the collection of the gas distributed in the annular space by the collection chamber.