Question

Why is Platinum catalyst gauze used for ammonia oxidation in the production of nitric acid? What are the safety requirements or percussion for this catalyst?

Answer 1

Demonstration a coiled platinum wire impetus is utilized to catalyze the oxidation of alkali. Comparative heterogeneous impetuses are utilized broadly in industry since they are powerful at high temperatures, which takes into consideration an extensive variety of working conditions. An extra advantage is there are no additional means required to isolate the impetus from the item. Ordinarily, vaporous reactants enter a rounded reactor toward one side, disregard a bolstered impetus and the items are gathered at the opposite end. Exhaust systems used to oxidize carbon monoxide and hydrocarbons, and decrease nitrous oxides in vehicle debilitate vapor depend on a similar straightforward structure.

Safety percussion :- All parts of the exhibit must be done in a smoke organizer. Wear goggles and gloves. Concentrated smelling salts arrangement is destructive and can consume the skin. Alkali is lethal by inward breath and, similar to nitrogen oxides, disturbing to the respiratory framework and eyes. Discard all items down a sink in the smoke cabinet with a lot of water .

Answer 2

Answer:

The State Institute for the Nitrogen Industry is one of the oldest industrial branches of the research and engineering institutes in Russia and the former U.S.S.R., and in 1991 the Institute celebrated its sixtieth anniversary. This paper gives a brief overview of the main results of work carried out by GIAP alone and in co-operation with other organisations over the past 50 years on the optimisation of the production of non-concentrated nitric acid. In particular developments to reduce the amounts of platinum group metals used in ammonia oxidation and waste gas cleaing, and ways to reduce platinum group metal losses are discussed.

At present the states of the former U.S.S.R. (CIS) produce about half of the total world output of non-concentrated nitric acid, and have in use at all times approximately 6 tonnes of platinum-rhodium-palladium alloys as catalysts for the conversion of ammonia to nitrous oxide, and about 8 tonnes of palladium in catalysts for the removal of residual nitrogen oxide from the waste gas. Annually the non-recoverable loss of platinum-rhodium-palladium alloys amounts to over 1 tonne. Nitric acid plants use the greatest quantities of the platinum group metals of all the plants developed and engineered by GIAP. All these nitric acid plants developed by GIAP utilise equipment manufactured by Russian and Ukrainian enterprises. Over 70 per cent of the total nitric acid output is produced by modern large scale UKL-7 and AK-72 type plants, which produce 355 and 1150 tonnes of nitric acid/day, respectively. The temperatures of the catalytic gauzes in the ammonia oxidation reactors in UKL-7 and AK-72 units are 900 and 840°C, respectively, and the pressures are 0.7 and 0.4 MPa, respectively (1). In this process, the ammonia conversion stage critically determines the specific consumption of both ammonia and of the platinum-rhodium-palladium catalyst per tonne of the final product. The approximate metal losses per tonne of acid produced in UKL-7 and AK-72 are 0.135 and 0.12 g, respectively. About 85 per cent of the manufacturing cost of nitric acid comes from the cost of the ammonia and the platinum metals catalysts.This paper reviews briefly the main results of work on the optimisation of platinum group metals based catalytic systems for the production of non-concentrated nitric acid. It should be noted that the technical approaches reported below for ammonia conversion can also be used to advantage for the manufacture of hydroxylamine sulphate, prussic acid and other chemical processes which have a catalytic ammonia processing stage as part of their production.