Countercurrent catalytic contact of a reactant stream in a multi-stage process and the apparatus therefor

Claim 1

A unitary, multiple-stage reaction system for countercurrently contacting a fluid reactant stream with catalyst particles movable through said system via gravity-flow, which system comprises, in combination: a. a tubular-form, vertically-disposed reaction chamber; b. at least two reaction zones withiN said chamber, each of said zones having coaxially-disposed inner and outer tubular form, catalyst-retaining screens forming (i) an annular-form catalyst holding section therebetween, (ii) an annular-form void volume between the outer screen and the interior wall of said chamber and, (iii) a center reactant conduit, said reaction zones spaced apart to form a mixing zone therebetween; c. a lower, imperforate transverse partition connected to said inner and outer screens, and to the interior wall of said chamber, said lower partition terminating at said inner catalyst-retaining screen, whereby at least one of said center reactant conduits is in open communication, at its lower extremity, with a mixing zone; d. an upper, imperforate transverse partition, across said reactant conduit, connected to said inner and outer catalyst-retaining screens, said upper partition terminating at said outer screen, whereby at least one of said annular-form void volumes is in open communication, at its upper extremity, with said mixing zone; e. catalyst-transfer conduits connecting a catalyst-holding section with the next succeeding lower catalyst-holding section, and catalyst-withdrawal conduits in the lowermost of said catalyst-holding sections, said withdrawal conduits extending downwardly through the lower extremity of said chamber, whereby catalyst particles flow via gravity from one catalyst-holding section to a lower catalyst-holding section and out of said reaction chamber; f. a reactant stream inlet port in the bottom of said reaction chamber, in open communication with the lowermost center reactant conduit; g. a catalyst inlet port in the upper end of said chamber, in open communication, via catalyst-transfer conduits, with the uppermost catalyst-holding section; h. a reaction product outlet port in the upper end of said chamber, in open communication with the uppermost annular-form void volume; and, i. a heat exchange fluid inlet conduit between said reaction zones, said inlet conduit terminating within the mixing zone therebetween and being positioned to discharge upwardly into said center reactant conduit.