Process for the manufacture of nitric oxide
AssigneeThe BOC Group, Inc.
InventorLien-Lung Sheu
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Abstract
Nitric oxide is produced by reacting aqueous nitric acid with gaseous sulfur dioxide in a gas-liquid contact reactor. The reaction is conducted in the presence of a stoichiometric excess of nitric acid to minimize the production of byproduct nitrous oxide and nitrogen. The nitric oxide product gas is chilled sufficiently to freeze most of the water and byproduct nitrogen dioxide contained in the nitric oxide product gas. Residual nitrogen dioxide can be removed by adsorptive separation using an adsorbent which preferentially adsorbs nitrogen dioxide.
Claims9
In a process for the production of nitric oxide comprising contacting aqueous nitric acid solution with gaseous sulfur dioxide in a gas-liquid contact zone thereby producing a product gas comprising nitric oxide, the improvement wherein the nitric acid and sulfur dioxide are introduced into the contact zone at a nitric acid to sulfur dioxide molar ratio of at least 0.7:1 and contacted therein at temperature in the range of about 50.degree. to about 120.degree. C., thereby producing a nitrous oxide- and nitrogen-depleted nitric oxide product gas.
Dependencies are inferred from the claim text.