Reaction method and reactor therefor

Claim 1

In a reactor having a cylindrical, upright outer shell having a top wall and a bottom wall, in which a catalytic reaction can be effected, in the presence of a granular catalyst, under conditions effective to maintain both the reactants and the product in a gaseous state at the temperatures and pressures of the reaction, the improvement which comprises: (a) a gas-permeable, cylindrical, outer catalyst retaining wall positioned within said outer shell and spaced from the inner wall of said outer shell, thereby defining an outer, first, annular, intercylinder space between the inner surface of said outer shell, the outer surface of said catalyst retaining wall and said top and bottom walls; (b) a gas-permeable, cylindrical, inner catalyst retaining wall positional coaxial with, iinside of and spaced from said outer catalyst retaining wall, thereby defining a second, annular, intercylinder space between said outer catalyst retaining wall, said inner catalyst retaining wall and said top and bottom walls, said inner catalyst retaining wall further defining an internal zone therewithin; (c) at least two vertical partition walls extending in respectively different radial directions between said outer catalyst retaining wall and said inner catalyst retaining wall so as to divide said second intercylinder space into a plurality of separate chambers which have the shapes of segments of an annulus in horizontal cross section, at least two of which chambers define at least two separate reaction chambers when said granular catalyst is packed therein; (d) a first heat exchange means comprising a plurality of heat exchange tubes which extend vertically through at least one of said reaction chambers, said tubes being arranged in partially cylindrical groups wherein said groups are concentric with the common axis of both of said outer and inner catalyst retaining walls, with the tubes in each of said groups being spaced substantially the same radial distance from said common axis and being circumferentially spaced from each other, the respective groups of tubes being spaced different radial distances from said common axis; (e) at least one collecting header and at least one distributing header provided respectively at opposite vertical ends of each of said reaction chambers having said heat exchange tubes therein, said headers being connected to the opposite ends of said heat exchange tubes extending through the corresponding reaction chamber in order to collect or distribute, respectively, heat exchange fluid which passes through said heat exchange tubes; (f) at least one fluid outlet and at least one fluid inlet which communicate with said collecting header and said distributing header respectively; (g) at least one catalyst charging inlet and at least one catalyst discharging outlet provided to each of said reaction chambers; (h) one or more radially extending, vertical, dividing walls provided in at least one of (i) said first intercylinder space and (ii) said internal zone within said inner catalyst retaining wall, said dividing walls being located so as to define the flow path of a reaction gas stream so that said stream is caused to flow in series through at least two of said reaction chambers in radial directions alternately radially inwardly and outwardly and said stream is caused to flow circumferentially through a circumferential flow path in at least one of (i) said first intercylinder space and (ii) said internal zone within said inner catalyst retaining wall as its flows from a first one of said reaction chambers to the next, the direction of the flow in the first chamber being radially outwardly when said stream is introduced at the radially inward end of said chamber, and the flow direction in said first chamber being radially inwardly when said stream is introduced at the radially outward end thereof; (i) at least one vertical, radially extending, perforated plate in the circumferential flow path between said one of said reaction chambers and the next reaction chamber, which perforated plate causes said stream to flow in the circumferential directions through the orifices defined by the perforations thereof, said perforated plate constituting a radial extension of one of said vertical partition walls; and (j) at least one reaction gas inlet and at least one product gas outlet provided in communication with said chambers.