Abstract In an ammonia oxidation process wherein ammonia and an oxidizing gas are contacted with a multilayer pad of platinum metal catalyst, a method is provided for reducing the amount of platinum metal catalyst required. The optimum amount of catalyst needed for a 95 percent ammonia conversion is reduced by replacement of a significant fraction of the gauze with a nonprecious metal corrosion resistant foraminous structure which simulates the flow resistance of the fraction of catalyst gauze removed from the optimum pad. The resulting catalyst pack comprising platinum metal gauze and foraminous structure is equivalent in ammonia conversion to the optimum pad and the volatilization of the platinum metal gauze is materially reduced.
A process in accordance with claim 1 wherein the foraminous structure is fabricated from Inconel or Nichrome wires.
Claim 2
Dependent Claim
26 words
A process in accordance with claim 2 wherein the foraminous structure is made of knitted metal mesh compressed to form a pad of randomly oriented metal.
Claim 3
Dependent Claim
57 words
A process in accordance with claim 1 wherein the reaction product is used as a step in the production of nitric acid and wherein the platinum group metal catalyst is present in said catalyst pack in an amount of 0.5 to 1.5 troy ounces, calculated on the basis of metal per ton of daily nitric acid production.
Claim 4
Dependent Claim
16 words
A process in accordance with claim 1 wherein the foraminous structure is a compressed metal pad.