Process for olefin production
(19)AUSTRALIAN PATENT OFFICE (54) Title Process for olefin production (51)6 International Patent Classification(s) C07C 001/20 C07C 004/06 (21) Application No: 2003295941 (22) Application Date: 2003 .11.21 (87) WIPO No: WO04/048299 (30) Priority Data (31) Number (32) Date (33) Country 10/302,258 2002.11.21 US (43) Publication Date : 2004.06.18 (43) Publication Journal Date : 2004 .07.22 (71) Applicant(s) UOP LLC (72) Inventor(s) Vora, Bipin V.; Puiado, Peter R. (-1-1) Application NoAU2003295941 A8(19)AUSTRALIAN PATENT OFFICE (54) Title Process for olefin production (51)6 International Patent Classification(s) C07C 001/20 C07C 004/06 (21) Application No: 2003295941 (22) Application Date: 2003 .11.21 (87) WIPO No: WO04/048299 (30) Priority Data (31) Number (32) Date (33) Country 10/302,258 2002.11.21 US (43) Publication Date : 2004.06.18 (43) Publication Journal Date : 2004 .07.22 (71) Applicant(s) UOP LLC (72) Inventor(s) Vora, Bipin V.; Puiado, Peter R. -1- The present invention relates to a process for the production of light weight olefins comprising olefins having from 2 to 3 carbon atoms per molecule from an oxygenate feedstock. The process comprises passing the oxygenate feedstock to an oxygenate conversion zone containing a metal alumino phosphate catalyst to produce a light weight olefin stream. A propylene stream and/or mixed butylene is fractionated from said light weight olefin stream and a medium weight C<SUB>4 </SUB>to C<SUB>7 </SUB>stream is cracked in a separate olefin cracking reactor to enhance the yield of ethylene and propylene products. CLAIMS : 1. A process for increasing the yield of ethylene and propylene from an oxygenate to olefins reactor comprising sending an initial stream comprising medium weight olefins comprising C4 to C7 olefins to an olefin cracking reactor, contacting the medium weight olefins with an olefin cracking catalyst, within the olefin cracking reactor to produce a mixture comprising ethylene, propylene, remaining medium weight olefins, heavy weight olefins and other products and separating the mixture into separate streams comprising at least one light weight olefin stream comprising one or more of ethylene and propylene, a medium weight stream comprising at least a portion of the remaining medium weight olefins and other products and a heavy weight olefin stream,STDC0274 wherein at least a portion of the remaining medium weight olefin stream is returned to the olefin cracking reactor and a portion of the remaining medium weight olefin stream or a portion of the medium weight olefins in the initial stream is purged.
2. The process of claim 1 wherein the mixture produced in the olefin cracking reactor is sent to a separation zone to be separated into the separate streams and wherein reactor effluent from the oxygenate to olefin reactor is sent to the separation zone.
3. The process of claim 1 wherein the mixture produced in the olefin cracking reactor is sent to a different separation zone than the reactor effluent from the oxygenate to olefins reactor.
4. The process of any of claims 1-3 wherein the olefin cracking catalyst comprises a crystalline silicate of the MFI family or the MEL family 5. The process of any of claim 4 wherein the olefin cracking catalyst is selected from the group consisting of ZSM-5, silicalite, ZSM-1 I and Boralite D.
6. The process of any of claims 1-3 wherein the olefin cracking reactor increases ethylene and propylene yield by 5 to 15% relative to the carbon content of the oxygenate feed to the methanol to olefins reactor. <Desc/Clms Page number 23> 7. The process of any of claims 1-3 wherein the olefin cracking reactor is operated at an inlet temperature of 450 to 600 C and preferably at an inlet temperature of 540 to 580 C.
8. The process of any of claims 1-3 wherein 1 to 5% of the remaining medium weight olefin stream is purged.
9. The process of any of claims 1-3 wherein 1 to 5% of the medium weight olefins in the initial stream are purged.
10. The process of any of claims 1-3 wherein the medium weight olefin stream is produced by separating an olefin rich feedstock comprising C2 to C8 olefins and the olefin rich feedstock comprising C2 to C8 olefins is produced in the oxygenate to olefins reactor by the contact of an oxygenate feedstock in the reaction zone that contains an aluminophosphate molecular sieve catalyst at conditions effective to convert the oxygenate-containing feedstock to light weight olefins comprising ethylene, propylene and butylenes and heavier products.