Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
  • C01C3/00—Cyanogen; Compounds thereof
  • C01C3/02—Preparation, separation or purification of hydrogen cyanide
  • C01C3/0208—Preparation in gaseous phase
  • C01C3/0212—Preparation in gaseous phase from hydrocarbons and ammonia in the presence of oxygen, e.g. the Andrussow-process
  • C01C3/0216—Preparation in gaseous phase from hydrocarbons and ammonia in the presence of oxygen, e.g. the Andrussow-process characterised by the catalyst used

Definitions

• This invention relates to the production of hydrogen cyanide.
• hydrocyanic acid It is known to produce hydrocyanic acid by passing a gaseous mixture containing ammonia, hydrocarbons, especially methane, and oxygen at elevated temperature over catalysts, especially those which favour the oxidation of ammonia.
• catalysts especially those which favour the oxidation of ammonia.
• noble metals such as platinum metals or gold or silver or alloys of these metals with each other, or also other metallic or oxidic catalysts are proposed.
• the catalysts consisting of platinum metals or their alloys with each other, which are especially active, have the drawback that by the action of the reaction gases they gradually undergo a 'marked change in structure whereby their mechanical resistance is impaired.
• alloys of platinum and iridium containing from a few tenths of one per cent, say one half per cent, to about 15 per cent, preferably from 1 per cent to 10 per cent of iridium can be employed with advantage for the said process, although iridium hasa comparatively high volatility at the high temperatures concerned, by bringing the said alloys into the form of gauze from wires the thickness of which is at least 0.1 millimetre; a thickness of about 0.15 millimetre is very suitable. It is preferable to work at temperatures of from about 950 to 1100 C. Under the said conditions, not only are excellent yields of hydrogen cyanide obtained,
• the catalyst also has a very good stability in spite of the high working temperature and remains active as well as mechanically resistant over several months. This effect is contrary to expectation inasmuch as alloys of platinum and iridium, when exposed to temperatures of the said order, are about four times as volatile as platinum and-about six times as volatile as a corresponding alloy from platinum and rhodium.
• Example A gas mixture consisting of 11 per cent of ammonia, 11.5 per cent oi! methane, 15 per cent of oxygen, 2 per cent of hydrogen and the remainder of nitrogen is led at about 1050' C. at a speed 01 500 cubic metres per hour through four nets, arranged closely behind each other having 500 meshes per square centimetre and prepared from wire of a thickness of 0.15 millimetre and preover catalysts the use oi alloys of platinum and Application November 22, 1935, 51,074. In Germany November 29.
• hydrocyanic acid by passing a gaseous mixture consisting oi 11 per cent of ammonia, 11.5 per cent of methane, 15 per cent of oxygen, 2 per cent of hydrogen andthe remainder of nitrogen at about 1050 C. over nets having 500 meshes per square centimetre and prepared from wire of a thickness 01' 0.15 millimetre and prepared from an alloy of platinum and iridium containing 3 per cent of irid-

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Inorganic Chemistry (AREA)
• Catalysts (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7985195

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Cited By (4)

• 1935
  • 1935-11-22 US US51074A patent/US2105831A/en not_active Expired - Lifetime
  • 1935-11-28 FR FR798371D patent/FR798371A/fr not_active Expired

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