Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B21/00—Nitrogen; Compounds thereof
  • C01B21/20—Nitrogen oxides; Oxyacids of nitrogen; Salts thereof

Definitions

• Patented Dec. 31 1929 UNITED STATES PATENT OFFICE.
• nitric acid far less cooling, or application of pressure, is needed than in the absence of such addition, in order to recover a given amount of liquid nitrogen oxids from a gaseous mixture with a given content of oxids of nitrogen, or in the case of undiluted nitrogen oxids'the liquefaction may be effected by cooling alone.
• Small amounts of nitric acid for instance about 4 per cent calculated on the amount of nitgrogen oxids to be separated are suificient for the said purpose.
• the said process may be carri d out by adding nitric acid in proportion as the nitrogen oxids separate out from the mixture.
• Nitric acid may however also be provided, for example, in the condensing vessel, and this acid, after saturationwith nitrogen oxids, gradually becomes completely dissolved in the layer of liquid nitrogen oxids first formed, so that, finally the condensed nitrogen oxids assume the condition of a homogeneous liquid containing a little nitric acid in solution.
• the nitric acid to be so added is referably saturated with nitrogen oxids be orehand, as for 1928, Serial No. 299,102, and lnGermany August 18, 1927.
• T e nitric acid lowering the vapor tension may also be introduced, in the form of vapor, into the gaseous mixture prior to cooling to low temperatures so that it condenses, with the desired concentration, the nitrogen oxids, and finally, such a de gree of humidity and oxygen content may be imparted to the gaseous mixture of nitrogen oxids, which is to be cooled, that the desired amount of nitric acid is formed during the process of condensation itself.
• the concentration of the nitric acid t erein' may be arranged to be high or low, but in order to obtain the greatest possible reduction of the vapor tension, a high concentration of nitric acid a proaching the saturation point is of specidl tage.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7741400

Family Applications (1)

Country Status (3)

• 0
  • BE BE352073D patent/BE352073A/xx unknown
• 1928
  • 1928-06-11 FR FR655578D patent/FR655578A/fr not_active Expired
  • 1928-08-11 US US299102A patent/US1741906A/en not_active Expired - Lifetime

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