Patent GB-342854-A (GB)
Title: Process and apparatus for catalytic gaseous reactions
IPC: C01C1/04
Filed: 1929-12-31
Abstract: The heat required for the initiation of gaseous exothermic catalytic reactions which are carried out under pressure and at high temperatures e.g. 450 DEG -500 DEG  C., is derived from an auxiliary catalytic exothermic reaction involving the gases in question, other gases being added temporarily if desired, which is carried out under such conditions that the heat evolved is available for heating the incoming gases, the apparatus and the catalyst for the main reaction. This "priming" reaction may be effected before the gases contact with the main catalyst, the heat being conveyed thereto by the gas stream and also by the priming catalyst being in heat-exchange relation to the main catalyst, or alternatively it may be effected after the gases have passed through the main catalyst, the hot gases from the priming reaction being subjected to <PICT:0342854/III/1> heat-exchange with the cold gases entering the apparatus.  This arrangement obviates the possible contamination of the main catalyst by the products of the initial reaction, or by substances carried over from the priming catalyst.  In the apparatus shown, the gases are led at a low temperature through the inlet F to the priming catalyst E, then through the main catalyst D, and are discharged through the orifices N and outlet J.  When the catalyst D has attained the necessary temperature, the heating chamber is byepassed by closing valve G and opening valve M, thus allowing the gases to reach the main catalyst via annular passage C, heat exchanger P and conduit L.  While traversing passage C, the gases are warmed by heat-exchange with the catalyst, and also protect the outer pressure-sustaining wall A.  The products pass through orifices N into the heat-exchange compartment O, where they are cooled sufficiently to handle in conduits outside the apparatus, and any unconverted gases may be re-treated.  Also, by passing part of the gases over a priming catalyst and main catalyst as described above, and another portion directly to the main catalyst, the temperature of the reaction may be regulated by varying the two gas streams relatively to each other.  According to examples, in the production of the higher homologues of methanol from a mixture of carbon monoxide and hydrogen at pressures exceeding 200 atmospheres, and at temperatures of 450 DEG -500 DEG  C., a catalyst such as a reduced mixture of the precipitated oxides of copper, manganese and magnesium, which will initiate the formation of methanol from the above gas mixture at temperatures as low as 250 DEG  C., is used as a priming catalyst. Alternatively, if methanol alone is desired as the product, a more rugged catalyst may be used as the main catalyst, and the reaction started by the above priming catalyst, or an active methane forming catalyst e.g. a reduced mixture of the precipitated oxides of cobalt and magnesium may be used.  In the production of ammonia from a nitrogen-hydrogen mixture derived from water gas the amount of carbon monoxide purification may be reduced and the gases passed over a low temperature methane forming catalyst to initiate the ammonia synthesis.ALSO:<PICT:0342854/IV/1> The heat required for the initiation of gaseous exothermic catalytic reactions which are carried out under pressure and at high temperatures, e.g. 450 DEG -500 DEG  C., is derived from an auxiliary catalytic exothermic reaction involving the gases in question, other gases being added temporarily if desired, which is carried out under such conditions that the heat evolved is available for heating the incoming gases, the apparatus and the catalyst for the main reaction.  This "priming" reaction may be effected before the gases contact with the main catalyst, the heat being conveyed thereto by the gas stream and also by the priming catalyst being in heat exchange relation to the main catalyst, or alternatively it may be effected after the gases have passed through the main catalyst, the hot gases from the primary reaction being subjected to heat exchange with the cold gases entering the apparatus.  This arrangement obviates the possible contamination of the main catalyst by the products of the initial reaction, or by substances carried over from the priming catalyst. In the apparatus shown, the gases are led at a low temperature through the inlet F to the priming catalyst E, then through the main catalyst D, and are discharged through the orifices N and outlet J. When the catalyst D has attained the necessary temperature, the heating chamber is bye-passed by closing valve G and opening valve M, thus allowing the gases to reach the main catalyst via annular passage C, heat exchanger P and conduit L.  While traversing passage C, the gases are warmed by heat-exchange with the catalyst, and also protect the outer pressure-sustaining wall A.  The products pass through orifices N into the heat-exchange compartment O where they are cooled sufficiently to handle in conduits outside the apparatus and any unconverted gases may be re-treated.  Also by passing part of the gases over a priming catalyst and main catalyst as described above, and another portion directly to the main catalyst, the temperature of the reaction may be regulated by varying the two gas streams relatively to each other.  According to examples, in the production of the higher homologues of methanol from a mixture of carbon monoxide and hydrogen at pressures exceeding 200 atmospheres, and at temperatures of 450 DEG -500 DEG  C., a catalyst such as a reduced mixture of the precipitated oxides of copper, manganese and magnesium which will initiate the formation of methanol from the above gas mixture at temperatures as low as 250 DEG  C., is used as a priming catalyst.  Alternatively, if methanol alone is desired as the product, a more rugged catalyst may be used as the main catalyst, and the reaction started by the above priming catalyst, or an active methane forming catalyst, e.g. a reduced mixture of the precipitated oxides of cobalt and magnesium may be used.