Process for the purification of nitric oxide
AssigneeThe BOC Group, Inc.
InventorsLien-Lung Sheu, Ramakrishnan Ramachandran, Theodore R. Galica
Life of this patent
Estimating the term…
Abstract
A gas mixture comprised of nitric oxide and, optionally an inert gas, and containing small amounts of nitrogen dioxide, and perhaps moisture and sulfur dioxide, is purified by passing the gas stream through a bed of metal cation-free silica, alumina, or zeolite. The concentration of nitrogen dioxide, sulfur dioxide and moisture in the gas stream are significantly reduced as the gas mixture passes through the bed of adsorbent.
Claims25
A process for purifying an oxygen-free nitric oxide gas stream containing nitrogen dioxide comprising passing said gas stream through a bed of metal cation-free adsorbent selected from silica, alumina, zeolites and mixtures of these, thereby depleting said gas stream of nitrogen dioxide.
A method of removing nitrogen dioxide from a gas stream containing nitric oxide and at least about 10 ppm nitrogen dioxide comprising passing said gas stream through a bed of metal cation-free adsorbent selected from silica, alumina, zeolite A, zeolite X, zeolite Y and mixtures of these, thereby producing a nitrogen dioxide-depleted gas containing not more than about 5 ppm nitrogen dioxide.
A process for preparing an inert gas-nitric oxide gaseous product containing about 5 to about 5000 ppm nitric oxide comprising passing a gas stream containing nitric oxide and nitrogen dioxide through a bed of metal cation-free adsorbent selected from silica, alumina, zeolite A, zeolite X, zeolite Y and mixtures of these, thereby producing a nitrogen dioxide-depleted gas, and diluting the nitrogen dioxide-depleted gas with an inert gas.
A process for preparing an inert gas-nitric oxide gaseous product comprising blending a gas stream containing nitric oxide and nitrogen dioxide with sufficient inert gas to reduce the concentration of nitric oxide in the gas stream to about 5 to about 5000 ppm, and passing said gas stream through a bed of metal cation-free adsorbent selected from silica, alumina, zeolite A, zeolite X, zeolite Y or mixtures of these, thereby producing a nitrogen dioxide-depleted gas stream.
Dependencies are inferred from the claim text.