Title of Invention

A PROCESS OF PREPARING AN OLEFIN OXIDE AND A METHOD OF PREPARING A CATALYST COMPOSITION

Abstract

A process and catalyst for the direct oxidation of an olefin having three or more carbon atoms, such as propylene, by oxygen to the corresponding olefin oxide, such as propylene oxide. The process involves contacting the olefin with oxygen under reaction conditions in the presence of hydrogen and in the presence of a catalyst. The catalyst comprises gold on a titanosilicate, preferably a microporous or mesoporous titanosilicate, such as, TS-1, TS-2, Ti-beta, Ti-ZSM-48, or Ti-MCM-41. Selectivity to the olefin oxide is high at good conversions of the olefin. The catalyst is readily regenerated, and the time between catalyst regenerations is long.

Full Text

an overhead stirrer. After one-half of the TPAOH had been added, the TEOS solution was cloudy and began to thicken. Within five minutes the solution froze completely. At this point the remainder of the TPAOH was added, the gel was broken up with a spatula, and stirring was resumed. Deionized water (354 g) was added, and the solution was warmed to room temperature. After 5 hr the solids had largely dissolved, and an additional quantity of deionized water (708 g) was added. Stirring was continued overnight yielding a clear yellow synthesis gel containing no solids. The synthesis gel was poured into a 1 gallon (3.785 liters) stainless steel autoclave and sealed. The autoclave was heated to 120°C and then gradually to 160°C where it was kept for 6 days. The reactor contents were stirred at all times. At the end of the reaction period, the autoclave was cooled and a milky white suspension was recovered. The solids were recovered, washed, centrifuged, and resuspended in deionized water. The solids were filtered, dried at room temperature, heated slowly to 550°C, and calcined thereat for 8 hr. The solid was identified as having an MFI structure, as determined by XRD. Raman spectra did not reveal any known crystalline titania phase. A Si/Ti atomic ratio of 100 was found, as measured by X-ray fluorescence (XRF). Yield of titanium silicalite-1: 106 g. Accordingly, the present invention provides a process of preparing an olefin oxide comprising contacting an olefin having at least three carbon atoms with oxygen in the presence of hydrogen and an optional diluent, and in the presence of a catalyst comprising gold on a titanosilicate, wherein the contacting occurs at a temperature greater than 20°C and less than 250°C sufficient to produce the olefin oxide. Accordingly, the present invention provides a method of preparing a catalyst composition comprising gold on a titanosilicate, the method comprising contacting the titanosilicate with a solution containing a gold compound, wherein the pH of the solution is between 5 and 11, at a temperature between 20°C and 80°C; and thereafter recovering the solids and calcining the solids under air or under a reducing atmosphere or heating the solids in an inert atmosphere at a temperature between 250°C and 800°C. Example 1. Preparation of Epoxidation Catalyst Titanium silicalite TS-1 (10.042 g) having a SiyHTi atomic ratio of 100, prepared as described hereinabove, was added to an aqueous solution of chloroauric acid, HAuCI/3H20 (0.4829 g in 50 ml water). The pH was adjusted to between 7 and 8 by adding sodium carbonate. Magnesium nitrate, Mg(N03)26H20 (1.97 g), was added as was more sodium carbonate until the pH was between 7 and 8. The total amount of sodium carbonate used was 0.62 g. The mixture was stirred overnight. A solid product was filtered, and the filtercake was washed 3 times with 150 ml of water. The wet filtercake was dried at 100°C for 2 hr. The dried solid was heated over an 8 hr period to 400°C and then calcined under air at 400°C for 5 hr to yield an epoxidation catalyst comprising gold on TS-1. Catalyst composition as determined by neutron activation analysis (NAA) was the following: Au, 1.07, Si 41.0, Ti 0.77, Mg 0.21, and Na 0.31 percent. The average gold particle size was 35 A, as determined by TEM. Example 2. Oxidation of Propylene to Propylene Oxide The epoxidation catalyst of Example 1 was tested in the direct oxidation of propylene to propylene oxide. The catalyst (5 cc) was loaded into a 10 cc fixed-bed, continuous flow reactor with flows of helium, oxygen, hydrogen, and propylene. Total flow rate was 150 cc/min (or GHSV 1,800 hr'1). Feedstream composition was 5.0 mole percent hydrogen, 10.5 mole percent oxygen, and 53.6 mole percent propylene, the balance being helium. Propylene, oxygen and helium were used as pure streams; hydrogen was mixed with helium in a 20 H/80 He (v/v) mixture. Pressure was atmospheric; reactor temperature ranged from 50°C to 165°C. Products were analyzed using an on-line gas chromatograph (Chrompack™ Poraplot™ S column, 25 m) with the results shown in Table 1. WE CLAIM: 1. A process of preparing an olefin oxide comprising contacting an olefin having at least three carbon atoms with oxygen in the presence of hydrogen and an optional diluent, and in the presence of a catalyst comprising gold on a titanosilicate, wherein the contacting occurs at a temperature greater than 20°C and less than 250°C sufficient to produce the olefin oxide. 2. The process as claimed in claim 1 wherein the olefin is a C3.12 olefin. 3. The process as claimed in claim 2 wherein the olefin is propylene. 4. The process as claimed in claim 1 wherein the olefin is selected from butadiene, cyclopentadiene, dicyclopentadiene, styrene, a-methylstyrene, divinylbenzene, allyl chloride, allyl alcohol, allyl ether, allyl ethyl ether, allyl butyrate, allyl acetate, allyl benzene, allyl phenyl ether, allyl propyl ether, and allyl anisole. 5. The process as claimed in claim 1 wherein the olefin is used in a quantity greater than 1 and less than 99 mole percent, based on the total moles of olefin, oxygen, hydrogen, and optional diluent. 6. The process as claimed in claim 1 wherein the oxygen is used in a quantity greater than 0.01 and less than 30 mole percent, based on the total moles of olefin, oxygen, hydrogen, and optional diluent. 7. The process as claimed in claim 1 wherein the hydrogen is used in a quantity greater than 0.01 and less than 50 mole percent, based on the total moles of olefin, oxygen, hydrogen, and optional diluent. 8. The process as claimed in claim 1 wherein a diluent is employed. 9. The process as claimed in claim 8 wherein when the process is conducted in a vapor phase, the diluent is selected from the group consisting of helium, nitrogen, argon, methane, carbon dioxide, steam, and mixtures thereof; and wherein when the process is conducted in a liquid phase, the diluent is selected from chlorinated benzenes, CMO aliphatic alcohols, chlorinated CMO alkanols, and liquid polyethers, polyalcohols, and polyesters. 10. The process as claimed in claim 1 wherein the diluent is used in a quantity greater than 0 and less than 90 mole percent, based on the total moles of olefin, oxygen, hydrogen, and optional diluent. 11. The process as claimed in claim 1 wherein the gold has an average particle size of 10 A or greater. 12. The process as claimed in claim 11 wherein the average gold particle size is greater than 12 A and less than 500 A. 13. The process as claimed in claim 1 wherein the gold is loaded onto the titanosilicate in an amount greater than 0.01 and less than 20 weight percent. 14. The process as claimed in claim 1 wherein the titanosilicate has a Si/Ti atomic ratio ranging from equal to or greater than 5/1 to equal to or less than 200/1. 15. The process as claimed in claim 1 wherein the titanosilicate is amorphous. 16. The process as claimed in claim 1 wherein the titanosilicate is crystalline. 17. The process as claimed in claim 16 wherein the titanosilicate is a crystalline porous titanosilicate. 18. The process as claimed in claim 17 wherein the crystalline porous titanosilicate has pores ranging in size from 4 A to 200 A. 19. The process as claimed in claim 18 wherein the crystalline porous titanosilicate is selected from TS-1, TS-2, Ti-beta, Ti-ZSM-12, Ti-ZSM-48, and Ti-MCM-41. 20. The process as claimed in claim 1 wherein the catalyst is substantially free of the anatase phase of titanium dioxide. 21. The process as claimed in claim 20 wherein Raman spectroscopy is used to analyze for the presence of the anatase phase, and the Raman spectrum exhibits essentially no peak at about 147 cm-1. 22. The process as claimed in claim 1 wherein the catalyst is substantially free of titanium dioxide. 23. The process as claimed in claim 22 wherein Raman spectroscopy is used to analyze for the presence of crystalline titanium dioxide, and the Raman spectrum exhibits essentially no peaks at about 147 cm"1, 155 cm-1, 448 cm*1, and 612 cm-1. 24. The process as claimed in claim 1 wherein the catalyst is essentially free of palladium. 25. The process as claimed in claim 1 wherein the catalyst is essentially free of a Group VIII metal. 26. The process as claimed in claim 1 wherein the catalyst is bound to a support. 27. The process as claimed in claim 1 wherein the support is selected from silicas, aluminosilicates, titania, magnesia, carbon, and mixtures thereof. 28. The process as claimed in claim 1 wherein the process is conducted in a gaseous phase at a gas hourly space velocity of the olefin greater than 10 hr'1 and less than 50,000 hr"1. 29. The process as claimed in claim 1 wherein the process is conducted in a liquid phase at a weight hourly space velocity of the olefin greater than 0.01 hr"1 and less than 100 hr-1. 30. The process as claimed in claim 1 wherein the process is conducted in a reactor selected from batch, fixed bed, transport bed, moving bed, fluidized bed, trickle bed. shell and tube, continuous flow, intermittent flow, and swing reactors. 31. The process as claimed in claim 1 wherein the process exhibits an olefin conversion of greater than 0.05 mole percent and a selectivity to olefin oxide of greater than 50 mole percent. 32. The process as claimed in claim 1 wherein the process exhibits an olefin conversion of greater than 0.2 mole percent and a selectivity to olefin oxide of greater than 90 mole percent. 33. The process as claimed in claim 1 wherein the catalyst is operated for at least 100 hours. 34. A process of preparing propylene oxide comprising contacting propylene with oxygen in a gas phase in the presence of hydrogen and an optional diluent and in the presence of a catalyst comprising gold having an average particle size greater than 10 A and less than 200 A on a porous titanosilicate having pores ranging in size from 4 A to 200 A; the contacting being conducted at a temperature greater than 70°C and less than 225°C. 35. The process as claimed in claim 34 wherein the quantity of propylene is greater than 20 and less than 70 mole percent, based on the total moles of propylene, oxygen, hydrogen, and optional diluent. 36. The process as claimed in claim 34 wherein the quantity of oxygen is greater than 5 and less than 20 mole percent, based on the total moles of propylene, oxygen, hydrogen, and optional diluent. 37. The process as claimed in claim 34 wherein the quantity of hydrogen is greater than 3 and less than 20 mole percent, based on the total moles of propylene, oxygen, hydrogen, and optional diluent. 38. The process as claimed in claim 34 wherein the quantity of diluent is greater than 15 and less than 70 mole percent, based on the total moles of propylene, oxygen, hydrogen, and optional diluent. 39. The process as claimed in claim 34 wherein the process achieves a selectivity to propylene oxide of greater than 90 mole percent. 40. The process as claimed in claim 34 wherein the process achieves a propylene conversion of greater than 0.2 mole percent. 41. The process as claimed in claim 34 wherein the catalyst is essentially free of a Group VIII metal. 42. A method of preparing a catalyst composition comprising gold on a titanosilicate, the method comprising contacting the titanosilicate with a solution containing a gold compound, wherein the pH of the solution is between 5 and 11, at a temperature between 20°C and 80°C; and thereafter recovering the solids and calcining the solids under air or under a reducing atmosphere or heating the solids in an inert atmosphere at a temperature between 250°C and 800°C. 43. The method as claimed in claim 42 wherein the titanosilicate is amorphous. 44. The method as claimed in claim 42 wherein the titanosilicate is crystalline. 45. The method as claimed in claim 42 wherein the titanosilicate has pores ranging in size from 4 A to about 200 A in diameter. 46. The method as claimed in claim 42 wherein the titanosilicate is a crystalline porous titanosilicate selected from TS-1, TS-2, Ti-beta, Ti-ZSM-12, Ti-ZSM-48,andTi-MCM-41. 47. The method as claimed in claim 42 wherein the gold in the catalyst composition is present as particles having an average size of 10 A or greater. 48. The method as claimed in claim 47 wherein the gold in the catalyst composition is present as particles having an average size of greater than 10 A and less than 500 A. 49. The method as claimed in claim 42 wherein the gold in the catalyst composition is present in an amount greater than 0.01 and less than 20 weight percent. 50. The method as claimed in claim 42 wherein the catalyst composition is essentially free of the anatase phase of titanium dioxide. 51. The method as claimed in claim 50 wherein Raman spectroscopy is used to determine the presence of the anatase phase, and the Raman spectrum exhibits essentially no peak at about 147 cm-1. 52. The method as claimed in claim 42 wherein the catalyst composition is substantially free of titanium dioxide. 53. The method as claimed in claim 52 wherein Raman spectroscopy if used to determine the presence of crystalline titanium dioxide, and the Raman spectrum exhibits essentially no peaks at about 147 cm" , 155 cm" , 448 cm" , and 612 cm-1. 54. The method as claimed in claim 42 wherein the catalyst composition is essentially free of a Group VIII metal. 55. The method as claimed in claim 54 wherein the Group VIII metal is palladium. 56. The method as claimed in claim 42 wherein the composition after preparation is bound to or supported on a support. 57. The method as claimed in claim 56 wherein the support is selected from silicas, aluminas, aluminosilicates, magnesia, titania, carbon and mixtures thereof. 58. The method as claimed in claim 42 wherein the soluble gold compound is selected from chloroauric acid, sodium chloroaurate, potassium chloroaurate, gold cyanide, potassium gold cyanide, and diethylamine auric acid trichloride. 59. The method as claimed in claim 42 wherein the pH is adjusted with a base. 60. The method as claimed in claim 59 wherein the base is selected from sodium hydroxide, sodium carbonate, potassium carbonate, cesium hydroxide, and cesium carbonate. 61. The method as claimed in claim 42 wherein the reducing atmosphere is hydrogen. 62. A process of preparing an olefin oxide substantially as herein described and exemplified. 63. A method of preparing a catalyst composition substantially as herein described and exemplified.

Documents:

3000-mas-1997- abstract.pdf

3000-mas-1997- assignment.pdf

3000-mas-1997- calims duplicate.pdf

3000-mas-1997- calims original.pdf

3000-mas-1997- correspondence others.pdf

3000-mas-1997- correspondence po.pdf

3000-mas-1997- descripition complete duplicate.pdf

3000-mas-1997- descripition complete original.pdf

3000-mas-1997- form 1.pdf

3000-mas-1997- form 26.pdf

3000-mas-1997- form 3.pdf

3000-mas-1997- form 4.pdf