Method for separating gas in a fluidized gas/solid mixture

A process for separating gases from a fluidized gas/solid mixture contained in a reactor, characterized in that the process comprises at least one step of injecting gas and at least one step of discharging gas, and optionally at least one step of injecting solids and at least one step of discharging solids, and further comprises a step of separating the solids entrained by the gas by passing the fluidized gas/solid mixture along an internal placed parallel to a free cross-sectional area of the reactor in a portion of the fluidized gas/solid mixture where a voidage is greater than 0.7, a cross section of the internal occupying less than 10% of the free cross-sectional area of the reactor and the internal comprising at least one unitary internal which comprises at least a first layer and a second layer of deflectors, and a ratio of a projected surface area of the internal to the free cross-sectional area of the reactor is greater than 0.75, wherein each of the deflectors comprises at least one plate, and wherein each of the first and second layers of deflectors comprises a plurality of deflectors such that the deflectors of the first layer are inclined in an opposite direction to the deflectors of the second layer, and wherein a lower edge of each of the plurality of deflectors of the first layer is immediately above an upper edge of each of the plurality of deflectors of the second layer.