Process for improving the gas distribution in air-lift loop reactors

Claim 1

A process for improving the gas distribution in air-lift loop reactors of the type in which gas is supplied to a reactor vessel through multiple-outlet gas nozzle means disposed in a lower portion of the vessel and having a predetermined plurality of gas outlets, and a guide device disposed above the gas nozzle means separates liquid in the vessel into an upflow space in which gassed liquid rises to a degassing zone and a downflow space in which partially degassed liquid flows down to below the guide device, the guide device defining a free cross section for the rising gassed liquid in the upflow space; comprising the steps of damming said free cross section of said upflow space with damming means at the location of said gas nozzle means; providing a corresponding predetermined plurality of apertures in said damming means to define part streams at said damming means flowing therethrough into said upflow space, said liquid entering said upflow space only through said apertures with each aperture being associated with a respective one of said gas outlets disposed thereat, and the part streams having cross sections such that the sum of the cross sections of the part streams is less than the free cross section of the upflow space; and introducing gas through said gas outlets into said part streams.