Process and apparatus for effecting three-phase catalytic reactions

Claim 1

A process for reacting a gas with a liquid in the presence of a dispersed solid catalyst, wherein a mixture of said liquid and said gas is circulated upwardly at reaction conditions of said gas with said liquid in general counter-current to the dispersed catalyst throughout a reaction zone comprising a plurality of superposed chambers separated by common walls, each chamber containing a catalyst at least partially dispersed in the circulated liquid, each chamber also communicating with the next upper or lower chamber or both through a number of low section openings giving passage to the liquid and the gas and not to the catalyst under operation conditions, said openings being arranged in the concerned common wall and located on the direct path of the liquid and the gas, and through at least one catalyst transfer duct external to said direct path, the lower portion of the transfer duct forming a relatively quiet zone where the catalyst may accumulate, the liquid and the gas are circulated upwardly in sequence throughout the superposed chambers and the low section openings of the corresponding common walls, fresh catalyst is fed to the upper chamber of the reaction zone, the catalyst particles are moved downwardly from one chamber to a lower chamber through said duct external to the direct path of the liquid and the gas, catalyst is discharged from the lower chamber of the reaction zone and the liquid reaction product and the residual gas are discharged from the upper chamber, so characterized that the rate of flow of the catalyst from a chamber to the immediately lower chamber is controlled by sweeping along the catalyst accumulated at the bottom of a transfer duct towards said immediately lower chamber by means of an adjustable secondary liquid and/or gas stream injected into said transfer duct, said secondary stream of liquid and/or gas being delivered in the vicinity of the opening at the lower portion of the catalyst transfer duct within said lower chamber, in the direction of said opening.