Patent EA-005078-B1 (EA)
Title: Process for the production of olefins
Inventor: GRIFFITHS DAVID CHARLES
IPC: C07C5/333
Filed: 2001-07-04
Abstract: 1. A process for the production of an olefin, said process comprising: partially combusting in a reaction zone a mixture of a hydrocarbon and an oxygen-containing gas in the presence of a catalyst which is capable of supporting combustion beyond the fuel rich limit of flammability to produce the olefin, wherein the superficial feed velocity of said mixture is at least 250 cmxc<-1> at standard temperature and operating pressure with the proviso that where the catalyst is an unsupported catalyst, the superficial feed velocity of said mixture is at least 300 cmxc<-1> standard temperature and operating pressure. 2. A process according to claim 1 wherein the superficial feed velocity of the hydrocarbon and oxygen-containing gas mixture is in the range 300 to 5000 cm/s. 3. A process according to claim 1 or claim 2 wherein the hydrocarbon is a paraffin containing hydrocarbon feed having at least two carbon atoms. 4. A process according to claim 3 in which the hydrocarbon is selected from the group consisting of ethane, propane, butane, naphtha, gas oil, vacuum gas oil and mixtures thereof. 5. A process according to any one of claims 1 to 4 wherein the molar ratio of hydrocarbon to the oxygen-containing gas is 5 to 16 times the stoichiometric ratio of hydrocarbon to oxygen-containing gas required for complete combustion to carbon dioxide and water. 6. A process according to any one of claims 1 to 5 in which hydrogen is co-fed into the reaction zone. 7. A process according to claim 6 in which the molar ratio of hydrogen to oxygen containing gas is in the range 0.2 to 4. 8. A process according to any one of claims 1 to 7 wherein the process is conducted at a gas hourly space velocity of greater than 10,000/h. 9. A process according to any one of claims 1 to8 in which the catalyst comprises a Group VIII metal. 10. A process according to claim 9 wherein the Group VIII metal is selected from rhodium, platinum, palladium and mixtures thereof. 11. A process according to claim 9 or claim 10 in which the Group VIII metal catalyst comprises at least one promoter. 12. A process according to claim 11 wherein the at least one promoter is selected from the group consisting of elements of Groups IIIA, IVA, VA of the Periodic Table and mixtures thereof and a transition metal which is a different metal to the Group VIII metal employed as catalyst. 13. A process according to claim 12 wherein the promoter is selected from tin and copper. 14. A process according to claim 11 wherein the Group VIII metal is platinum and the promoter is selected from tin and copper. 15. A process according to claim 11 wherein the atomic ratio of Group VIII metal to promoter is in the range 1: 0.1-50.0. 16. A process according to any one of claims 1 to 14 wherein the catalyst is supported. 17. A process according to claim 16 wherein the support is a ceramic support. 18. A process according to claim 17 wherein the support is in the form of a monolith or particles. 19. A process according to claim 18 wherein the monolith is a foam or a fibre. 20. A process according to any one of claims 1 to 19 in which the hydrocarbon and oxygen-containing gas mixture is preheated to a temperature below the auto-ignition temperature of the mixture.