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, called first wall, of a hollow tube and an outer wall, called second 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 each other by at least one partition wall, and comprising, respectively, a gas intake opening at the first end and a gas discharge opening at the second end,
• the at least one distribution chamber is provided with a plurality of distributing openings whereas the at least one collection chamber is provided with a collecting opening, the plurality of distributing openings and the collecting opening of each collection chamber are formed at the second wall and extend parallel to the longitudinal axis, the distributing openings of a distribution chamber enabling the distribution of a gas capable of being admitted through the intake opening from said distribution chamber towards the annular space and the collecting opening enabling the collection of the gas distributed in the annular space by the collection chamber.