RU2000101819A - METHOD OF EPOXIDATION WITH THE APPLICATION OF A SILVER CATALYST ON A MEDIA TREATED BY ORGANIC CHLORESETTING CONNECTION - Google Patents

Claims (20)

1. The method of carrying out the process of epoxidation of propylene, including
(a) contacting a silver catalyst on a carrier with a conditioning stream containing in the vapor phase an organic chlorine-containing compound C ₁ -C ₁₀ and molecular oxygen, at a temperature of 150–350 ^o C for a time sufficient to turn the chlorine-containing compound into a silver catalyst on a carrier with obtaining a chlorine-containing catalyst, in which the silver catalyst on the carrier contains (i) an inert refractory solid carrier, (ii) a catalytically effective amount of silver and (iii) a promoter amount of a linear promoter derived from a potassium salt containing a potassium cation and a nitric oxide anion or its precursor; and
(b) contacting the chlorine-containing catalyst with an incoming stream containing propylene and molecular oxygen, but practically free of organic chlorine-containing compound C ₁ -C ₁₀ , for a time and at a temperature sufficient to form propylene oxide.  2. The method according to claim 1, in which the inert refractory solid carrier contains a carbonate of alkaline earth metal. 3. The method according to claim 1, in which the conditioning flow contains from 25 parts per million to 2000 parts per million organic chlorine-containing compounds With ₁ -C ₁₀ .  4. The method according to claim 1, in which the silver catalyst on the carrier further comprises a promoting amount of a metal selected from the group consisting of molybdenum, rhenium, tungsten, and mixtures thereof.  5. The method according to claim 1, in which the conditioning flow contains almost no propylene.  6. The method according to claim 1, in which the input stream further comprises nitrogen oxide. 7. The method according to claim 1, wherein after step (a) and before step (b) the chlorine-containing catalyst is brought into contact with a carbon dioxide stream containing carbon dioxide at a temperature of 150 ^° -350 ^° C.  8. The method according to claim 7, in which the carbon dioxide stream further comprises molecular oxygen.  9. The method according to claim 1, wherein the potassium salt is selected from the group consisting of potassium carbonate, potassium bicarbonate, potassium nitrate, potassium nitrite, and mixtures thereof.  10. The method according to claim 1, comprising the additional step of repeating step (a) after step (b).  11. The method according to claim 1, in which the chlorine-containing catalyst contains at least 0.5 wt.% Chlorine. 12. The method according to claim 1, wherein the organic chlorine-containing compound C ₁ -C ₁₀ is ethyl chloride. 13. The method of carrying out the process of epoxidation of propylene, including
(a) contacting a silver catalyst on a carrier with a conditioning stream containing in the vapor phase from 25 parts per million to 2000 parts per million of organic chlorine-containing compound C ₁ -C ₄ and molecular oxygen, at a temperature of 220–280 ^o C over time sufficient to include a chlorine-containing compound in a supported silver catalyst to obtain a chlorine-containing catalyst with a chlorine content of at least 0.1 wt.%, in which the supported silver catalyst contains (i) an inert refractory solid carrier, containing alkaline earth metal carbonate, (ii) 10 to 60 wt.% silver and (iii) a promoter amount of a potassium promoter derived from a potassium salt selected from the group consisting of potassium nitrate, potassium nitrite, potassium carbonate, potassium bicarbonate, and mixtures thereof; and
(b) contacting the chlorine-containing catalyst with the incoming stream containing propylene and molecular oxygen, but practically not containing the organic chlorine-containing compound C ₁ -C ₄ , at a temperature of 220-280 ^o C for a time sufficient to form propylene oxide.  14. The method according to claim 13, wherein the conditioning stream is substantially free of propylene.  15. The method according to claim 13, wherein the silver catalyst on the carrier further comprises 0.2 to 2.5% by weight of a metal promoter selected from the group consisting of molybdenum, rhenium, tungsten, and mixtures thereof. 16. The method according to claim 13, wherein after stage (a) and before stage (b) the chlorine-containing catalyst is brought into contact with a gas stream containing 5 to 60% by volume of carbon dioxide at a temperature of 220-280 ^o C.  17. The method of claim 16, wherein said gas stream further comprises 1 to 10% by volume of molecular oxygen.  18. The method according to claim 13, comprising the additional step of repeating step (a) after step (b).  19. The method according to claim 13, wherein the alkaline earth metal carbonate is calcium carbonate. 20. The method according to p. 13, in which the organic chlorine-containing compound C ₁ -C ₄ is ethyl chloride.