CA2174045C - C8 aromatics isomerization using catalyst containing modified silicoaluminophosphate molecular sieve - Google Patents
C8 aromatics isomerization using catalyst containing modified silicoaluminophosphate molecular sieve Download PDFInfo
- Publication number
- CA2174045C CA2174045C CA002174045A CA2174045A CA2174045C CA 2174045 C CA2174045 C CA 2174045C CA 002174045 A CA002174045 A CA 002174045A CA 2174045 A CA2174045 A CA 2174045A CA 2174045 C CA2174045 C CA 2174045C
- Authority
- CA
- Canada
- Prior art keywords
- xylene
- catalyst
- isomerization
- platinum
- molecular sieve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 63
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 title claims abstract description 22
- 239000002808 molecular sieve Substances 0.000 title claims abstract description 21
- 238000006317 isomerization reaction Methods 0.000 title claims description 33
- 239000000203 mixture Substances 0.000 claims abstract description 40
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 claims abstract description 31
- 238000000034 method Methods 0.000 claims abstract description 28
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 21
- 239000001257 hydrogen Substances 0.000 claims abstract description 12
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 12
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 11
- YNQLUTRBYVCPMQ-UHFFFAOYSA-N Ethylbenzene Chemical compound CCC1=CC=CC=C1 YNQLUTRBYVCPMQ-UHFFFAOYSA-N 0.000 claims description 36
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 31
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 26
- 239000002131 composite material Substances 0.000 claims description 23
- 229910052751 metal Inorganic materials 0.000 claims description 22
- 239000002184 metal Substances 0.000 claims description 22
- 229930195733 hydrocarbon Natural products 0.000 claims description 19
- 150000002430 hydrocarbons Chemical class 0.000 claims description 19
- 239000008096 xylene Substances 0.000 claims description 16
- 239000011230 binding agent Substances 0.000 claims description 14
- 239000004215 Carbon black (E152) Substances 0.000 claims description 13
- 229910052697 platinum Inorganic materials 0.000 claims description 11
- 150000003738 xylenes Chemical class 0.000 claims description 11
- 239000000377 silicon dioxide Substances 0.000 claims description 9
- 229910052809 inorganic oxide Inorganic materials 0.000 claims description 7
- 125000003118 aryl group Chemical group 0.000 claims description 5
- 230000003197 catalytic effect Effects 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 2
- 239000010703 silicon Substances 0.000 abstract description 6
- 229910052710 silicon Inorganic materials 0.000 abstract description 6
- 230000002378 acidificating effect Effects 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 22
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 21
- 239000000047 product Substances 0.000 description 11
- 230000000694 effects Effects 0.000 description 10
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 9
- 229910052736 halogen Inorganic materials 0.000 description 8
- 150000002367 halogens Chemical class 0.000 description 8
- IVSZLXZYQVIEFR-UHFFFAOYSA-N m-xylene Chemical group CC1=CC=CC(C)=C1 IVSZLXZYQVIEFR-UHFFFAOYSA-N 0.000 description 8
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 238000000926 separation method Methods 0.000 description 6
- 238000001354 calcination Methods 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- 239000003921 oil Substances 0.000 description 5
- AGGKEGLBGGJEBZ-UHFFFAOYSA-N tetramethylenedisulfotetramine Chemical compound C1N(S2(=O)=O)CN3S(=O)(=O)N1CN2C3 AGGKEGLBGGJEBZ-UHFFFAOYSA-N 0.000 description 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000001179 sorption measurement Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000010457 zeolite Substances 0.000 description 4
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910000323 aluminium silicate Inorganic materials 0.000 description 3
- 238000005194 fractionation Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 241000894007 species Species 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- -1 chromic Chemical compound 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 2
- 230000008034 disappearance Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000000017 hydrogel Substances 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000003607 modifier Substances 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 239000011541 reaction mixture Substances 0.000 description 2
- 229960001866 silicon dioxide Drugs 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- 239000012808 vapor phase Substances 0.000 description 2
- VIDOPANCAUPXNH-UHFFFAOYSA-N 1,2,3-triethylbenzene Chemical class CCC1=CC=CC(CC)=C1CC VIDOPANCAUPXNH-UHFFFAOYSA-N 0.000 description 1
- OKIRBHVFJGXOIS-UHFFFAOYSA-N 1,2-di(propan-2-yl)benzene Chemical class CC(C)C1=CC=CC=C1C(C)C OKIRBHVFJGXOIS-UHFFFAOYSA-N 0.000 description 1
- KVNYFPKFSJIPBJ-UHFFFAOYSA-N 1,2-diethylbenzene Chemical class CCC1=CC=CC=C1CC KVNYFPKFSJIPBJ-UHFFFAOYSA-N 0.000 description 1
- YQZBFMJOASEONC-UHFFFAOYSA-N 1-Methyl-2-propylbenzene Chemical class CCCC1=CC=CC=C1C YQZBFMJOASEONC-UHFFFAOYSA-N 0.000 description 1
- DMUVQFCRCMDZPW-UHFFFAOYSA-N 1-ethyl-2-propylbenzene Chemical class CCCC1=CC=CC=C1CC DMUVQFCRCMDZPW-UHFFFAOYSA-N 0.000 description 1
- VBWYZPGRKYRKNV-UHFFFAOYSA-N 3-propanoyl-1,3-benzoxazol-2-one Chemical compound C1=CC=C2OC(=O)N(C(=O)CC)C2=C1 VBWYZPGRKYRKNV-UHFFFAOYSA-N 0.000 description 1
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- ZZBAGJPKGRJIJH-UHFFFAOYSA-N 7h-purine-2-carbaldehyde Chemical compound O=CC1=NC=C2NC=NC2=N1 ZZBAGJPKGRJIJH-UHFFFAOYSA-N 0.000 description 1
- 239000005995 Aluminium silicate Substances 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- 241000640882 Condea Species 0.000 description 1
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000005909 Kieselgur Substances 0.000 description 1
- YVDLTVYVLJZLLS-UHFFFAOYSA-J O.Cl[Pt](Cl)(Cl)Cl Chemical compound O.Cl[Pt](Cl)(Cl)Cl YVDLTVYVLJZLLS-UHFFFAOYSA-J 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- FCUFAHVIZMPWGD-UHFFFAOYSA-N [O-][N+](=O)[Pt](N)(N)[N+]([O-])=O Chemical compound [O-][N+](=O)[Pt](N)(N)[N+]([O-])=O FCUFAHVIZMPWGD-UHFFFAOYSA-N 0.000 description 1
- 230000000274 adsorptive effect Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000010685 alcohol synthesis reaction Methods 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- VXAUWWUXCIMFIM-UHFFFAOYSA-M aluminum;oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Al+3] VXAUWWUXCIMFIM-UHFFFAOYSA-M 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007900 aqueous suspension Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 229960000892 attapulgite Drugs 0.000 description 1
- 229910001570 bauxite Inorganic materials 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000012876 carrier material Substances 0.000 description 1
- 238000004517 catalytic hydrocracking Methods 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- LRCFXGAMWKDGLA-UHFFFAOYSA-N dioxosilane;hydrate Chemical compound O.O=[Si]=O LRCFXGAMWKDGLA-UHFFFAOYSA-N 0.000 description 1
- WEHWNAOGRSTTBQ-UHFFFAOYSA-N dipropylamine Chemical compound CCCNCCC WEHWNAOGRSTTBQ-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 239000003349 gelling agent Substances 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 239000003701 inert diluent Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000011133 lead Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000012263 liquid product Substances 0.000 description 1
- JCCNYMKQOSZNPW-UHFFFAOYSA-N loratadine Chemical compound C1CN(C(=O)OCC)CCC1=C1C2=NC=CC=C2CCC2=CC(Cl)=CC=C21 JCCNYMKQOSZNPW-UHFFFAOYSA-N 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 1
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 1
- 229910052625 palygorskite Inorganic materials 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 238000000634 powder X-ray diffraction Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- ODLMAHJVESYWTB-UHFFFAOYSA-N propylbenzene Chemical class CCCC1=CC=CC=C1 ODLMAHJVESYWTB-UHFFFAOYSA-N 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 229910052702 rhenium Inorganic materials 0.000 description 1
- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 150000004760 silicates Chemical class 0.000 description 1
- 229960004029 silicic acid Drugs 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000011973 solid acid Substances 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical compound S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 229910052716 thallium Inorganic materials 0.000 description 1
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical compound [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 description 1
- ZCUFMDLYAMJYST-UHFFFAOYSA-N thorium dioxide Chemical compound O=[Th]=O ZCUFMDLYAMJYST-UHFFFAOYSA-N 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- CTDPVEAZJVZJKG-UHFFFAOYSA-K trichloroplatinum Chemical compound Cl[Pt](Cl)Cl CTDPVEAZJVZJKG-UHFFFAOYSA-K 0.000 description 1
- 150000005199 trimethylbenzenes Chemical class 0.000 description 1
- DNYWZCXLKNTFFI-UHFFFAOYSA-N uranium Chemical compound [U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U] DNYWZCXLKNTFFI-UHFFFAOYSA-N 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C15/00—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts
- C07C15/02—Monocyclic hydrocarbons
- C07C15/067—C8H10 hydrocarbons
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
- C07C5/22—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by isomerisation
- C07C5/27—Rearrangement of carbon atoms in the hydrocarbon skeleton
- C07C5/2702—Catalytic processes not covered by C07C5/2732 - C07C5/31; Catalytic processes covered by both C07C5/2732 and C07C5/277 simultaneously
- C07C5/2708—Catalytic processes not covered by C07C5/2732 - C07C5/31; Catalytic processes covered by both C07C5/2732 and C07C5/277 simultaneously with crystalline alumino-silicates, e.g. molecular sieves
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2529/00—Catalysts comprising molecular sieves
- C07C2529/82—Phosphates
- C07C2529/84—Aluminophosphates containing other elements, e.g. metals, boron
- C07C2529/85—Silicoaluminophosphates (SAPO compounds)
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Abstract
A non-equilibrium C8 aromatic-feed mixture is selectively isomerized to obtain an isomerized product enriched in para-xylene by contacting the feed in the presence of hydrogen with a catalyst containing a combination of a platinum group component with an SM-3 acidic crystalline silicaaluminophosphate molecular sieve at C8 aromaticisomerization conditions. The SM-3 molecular sieve is enriched in framework silicon at the surface, resulting in a greater yield of para-xylene compared to prior art processes.
Description
~1'~4045 "CB AROMATICS ISOMERIZATION USING CATALYST CONTAINING
MODIFIED SILICOALUMINOPHOSPHATE MOLECULAR SIEVE"
BACKGROUND
Molecular sieves having a wide variety of compositions and structures have been disclosed in the art as useful in catalysts for hydrocarbon conversion.
The most well known are the crystalline aluminosilicate zeolites formed from corner-sharing A102 and SiOz tetrahedra. The zeolites generally feature pore openings of uniform dimensions, significant ion-exchange capacity and the capability of reversibly desorbing an adsorbed phase which is dispersed throughout the internal voids of the crystal without displacing any atoms which make up the permanent crystal structure.
Zeolites often are characterized by a critical, usually minimum, silica/alumina ratio.
More recently, a class of useful non-zeolitic molecular sieves containing framework tetrahedral units (T02) of aluminum (A102), phosphorus (P02) and at least one additional element EL (ELOZ) has been disclosed. "Non-zeolitic molecular sieves"
include the "ELAPSO" molecular sieves as disclosed in US-A-4793984 and "SAPO"
molecular sieves of US-A-4440871. Generally the above patents teach a wide range of framework metal concentrations, e.g., the mole fraction of silicon in. '871 may be between 0.01 and 0.98 depending on other framework elements with a preferable range of 0.02 to 0.25 mole fraction. US-A-4943424 discloses a silicoaluminophosphate molecular sieve characterized by surface and bulk P205-to-alumina ratios in the surface and bulk of the sieve and silicon content of the surface and its use in dewaxing and hydrocracking.
US-A-4740650 teaches xylene isomerization using a catalyst containing at least one non-zeolitic molecular sieve which preferably is a silicoaluminophosphate.
This '650 patent does not suggest the critical composition gradients which are a feature of the modified molecular sieve used in the present invention.
Catalysts for isomerization of C8 aromatics ordinarily are classified by the manner of processing ethylbenzene associated with the xylene isomers.
Ethylbenzene ~1'~4045 is not easily isomerized to xylenes, but it normally is converted in the isomerization unit because separation from the xylenes by superfractionation or adsorption is very expensive. A widely used approach is to dealkylate ethylbenzene to form principally benzene while isomerizing xylenes to a near-equilibrium mixture. An alternative approach is to react the ethylbenzene to form a xylene mixture via conversion to and reconversion from naphthenes in the presence of a solid acid catalyst with a hydrogenation-dehydrogenation function. The former approach commonly results in higher ethylbenzene conversion, thus lowering the quantity of recycle to the para-xylene recovery unit and concomitant processing costs, but the latter approach enhances xylene yield by forming xylenes from ethylbenzene. A catalyst composite and process which enhance conversion according to the latter approach, i.e., achieve ethylbenzene isomerization to xylenes with high conversion, would effect significant improvements in xylene-production economics.
SUMMARY
A principal object is to provide a novel isomerization process for alkylaromatic hydrocarbons. More specifically, this invention is directed to isomerization of C8-aromatic hydrocarbons using a critically defined molecular-sieve catalyst to obtain improved xylene yields.
This invention is based on the discovery that a catalyst comprising a SAPO
molecular sieve having enriched surface silicon demonstrates improved conversion and selectivity in alkylaromatic, Cg-aromatics, particularly isomerization.
Accordingly, a broad embodiment of the invention is directed toward an alkylaromatics-isomerization process using a silicoaluminophosphate (SAPO) molecular-sieve catalyst having an enriched framework surface-silicon content.
The process comprises isomerization with this catalyst of a feedstock comprising a non-equilibrium mixture of xylenes and ethylbenzene at isomerization conditions to obtain a product having an increased para-xylene content relative to that of the feedstock.
Preferably this SAPO-containing catalyst comprises a platinum-group metal, with ~1'~~04~
platinum being an especially preferred component. The optimal catalyst composite also comprises an inorganic-oxide binder, usually alumina and/or silica.
DETAILED DESCRIPTION
The feedstock to an aromatics isomerization process typically comprises isomerizable alkylaromatic hydrocarbons of the general formula C6H~~°~R", where n is an integer from 1 to 5 and R is CH3, CZHS, C3H,, or C4Hg, in any combination and including all the isomers thereof to obtain more valuable isomers of the alkylaromatic.
Suitable alkylaromatic hydrocarbons include, for example but without so limiting the invention, ortho-xylene, meta-xylene, para-xylene, ethylbenzene, ethyltoluenes, tri-methylbenzenes, di-ethylbenzenes, tri-ethyl-benzenes, methylpropylbenzenes, ethylpropylbenzenes, di-isopropylbenzenes, and mixtures thereof.
Isomerization of a Cg-aromatic mixture containing ethylbenzene and xylenes is a particularly preferred application of the SAPO sieves of the invention.
Generally 1 S such mixture will have an ethylbenzene content in the approximate range of 5 to 50 mass-%, an ortho-xylene content in the approximate range of 0 to 35 mass-%, a meta-xylene content in the approximate range of 20 to 95 mass-% and a para-xylene content in the approximate range of 0 to 15 mass-%. It is preferred that the aforementioned Cg aromatics comprise a non-equilibrium mixture, i.e., at least one C8 aromatic isomer is present in a concentration that differs substantially from the equilibrium concentration at isomerization conditions. Usually the non-equilibrium mixture is prepared by removal of para- and/or ortho-xylene from a fresh C8 aromatic mixture obtained from an aromatics-production process.
The source of the alkylaromatic hydrocarbons feed may be found in appropriate fractions from various refinery petroleum streams, e.g., as individual components or as certain boiling-range fractions obtained by the selective fractionation and distillation of catalytically cracked or reformed hydrocarbons. The isomerizable aromatic hydrocarbons need not be concentrated; this invention allows the isomerization of alkylaromatic-containing streams such as catalytic reformate with or without subsequent aromatics extraction to produce specified xylene isomers and particularly to produce 21~~045 para-xylene. A C$-aromatics feed may contain nonaromatic hydrocarbons, i.e., naphthenes and paraffins, in an amount up to 30 mass-%. Preferably the isomerizable hydrocarbons consist essentially of aromatics, however, to ensure pure products from downstream recovery processes.
S According to the present invention, an alkylaromatic hydrocarbon feed mixture, preferably in admixture with hydrogen, is contacted with a catalyst of the type hereinafter described in an alkylaromatic hydrocarbon isomerization zone.
Contacting may be effected using the catalyst in a fixed-bed system, a moving-bed system, a fluidized-bed system, or in a batch-type operation. In view of the danger of attrition loss of the valuable catalyst and of the simpler operation, it is preferred to use a fixed-bed system. In this system, a hydrogen-rich gas and the feed mixture are preheated by suitable heating means to the desired reaction temperature and then passed into an isomerization zone containing a fixed bed of catalyst. The conversion zone may be one or more separate reactors with suitable means therebetween to ensure that the desired isomerization temperature is maintained at the entrance to each zone.
The reactants may be contacted with the catalyst bed in either upward-, downward-, or radial-flow fashion, and the reactants may be in the liquid phase, a mixed liquid-vapor phase, or a vapor phase when contacted with the catalyst.
The alkylaromatic feed mixture, preferably a non-equilibrium mixture of C8 aromatics, is contacted with the isomerization catalyst at suitable alkylaromatic-isomerization conditions. Such conditions comprise a temperature ranging from 0° to 600°C or more, and preferably is in the range of from a 300° to 500°C. The pressure generally is from 101.3 to 10130 kPa (1 to 100 atmospheres), preferably less than 5065 kPa (50 atmospheres). Sufficient catalyst is contained in the isomerization zone to provide a liquid hourly space velocity (LHSV) with respect to the hydrocarbon feed mixture of from 0.1 to 30 hr'', and preferably 0.5 to 10 hr''. The hydrocarbon feed mixture optimally is reacted in admixture with hydrogen at a hydrogen/hydrocarbon mole ratio of 0.5:1 to about 25:1 or more. Other inert diluents such as nitrogen, argon and light hydrocarbons may be present. .
MODIFIED SILICOALUMINOPHOSPHATE MOLECULAR SIEVE"
BACKGROUND
Molecular sieves having a wide variety of compositions and structures have been disclosed in the art as useful in catalysts for hydrocarbon conversion.
The most well known are the crystalline aluminosilicate zeolites formed from corner-sharing A102 and SiOz tetrahedra. The zeolites generally feature pore openings of uniform dimensions, significant ion-exchange capacity and the capability of reversibly desorbing an adsorbed phase which is dispersed throughout the internal voids of the crystal without displacing any atoms which make up the permanent crystal structure.
Zeolites often are characterized by a critical, usually minimum, silica/alumina ratio.
More recently, a class of useful non-zeolitic molecular sieves containing framework tetrahedral units (T02) of aluminum (A102), phosphorus (P02) and at least one additional element EL (ELOZ) has been disclosed. "Non-zeolitic molecular sieves"
include the "ELAPSO" molecular sieves as disclosed in US-A-4793984 and "SAPO"
molecular sieves of US-A-4440871. Generally the above patents teach a wide range of framework metal concentrations, e.g., the mole fraction of silicon in. '871 may be between 0.01 and 0.98 depending on other framework elements with a preferable range of 0.02 to 0.25 mole fraction. US-A-4943424 discloses a silicoaluminophosphate molecular sieve characterized by surface and bulk P205-to-alumina ratios in the surface and bulk of the sieve and silicon content of the surface and its use in dewaxing and hydrocracking.
US-A-4740650 teaches xylene isomerization using a catalyst containing at least one non-zeolitic molecular sieve which preferably is a silicoaluminophosphate.
This '650 patent does not suggest the critical composition gradients which are a feature of the modified molecular sieve used in the present invention.
Catalysts for isomerization of C8 aromatics ordinarily are classified by the manner of processing ethylbenzene associated with the xylene isomers.
Ethylbenzene ~1'~4045 is not easily isomerized to xylenes, but it normally is converted in the isomerization unit because separation from the xylenes by superfractionation or adsorption is very expensive. A widely used approach is to dealkylate ethylbenzene to form principally benzene while isomerizing xylenes to a near-equilibrium mixture. An alternative approach is to react the ethylbenzene to form a xylene mixture via conversion to and reconversion from naphthenes in the presence of a solid acid catalyst with a hydrogenation-dehydrogenation function. The former approach commonly results in higher ethylbenzene conversion, thus lowering the quantity of recycle to the para-xylene recovery unit and concomitant processing costs, but the latter approach enhances xylene yield by forming xylenes from ethylbenzene. A catalyst composite and process which enhance conversion according to the latter approach, i.e., achieve ethylbenzene isomerization to xylenes with high conversion, would effect significant improvements in xylene-production economics.
SUMMARY
A principal object is to provide a novel isomerization process for alkylaromatic hydrocarbons. More specifically, this invention is directed to isomerization of C8-aromatic hydrocarbons using a critically defined molecular-sieve catalyst to obtain improved xylene yields.
This invention is based on the discovery that a catalyst comprising a SAPO
molecular sieve having enriched surface silicon demonstrates improved conversion and selectivity in alkylaromatic, Cg-aromatics, particularly isomerization.
Accordingly, a broad embodiment of the invention is directed toward an alkylaromatics-isomerization process using a silicoaluminophosphate (SAPO) molecular-sieve catalyst having an enriched framework surface-silicon content.
The process comprises isomerization with this catalyst of a feedstock comprising a non-equilibrium mixture of xylenes and ethylbenzene at isomerization conditions to obtain a product having an increased para-xylene content relative to that of the feedstock.
Preferably this SAPO-containing catalyst comprises a platinum-group metal, with ~1'~~04~
platinum being an especially preferred component. The optimal catalyst composite also comprises an inorganic-oxide binder, usually alumina and/or silica.
DETAILED DESCRIPTION
The feedstock to an aromatics isomerization process typically comprises isomerizable alkylaromatic hydrocarbons of the general formula C6H~~°~R", where n is an integer from 1 to 5 and R is CH3, CZHS, C3H,, or C4Hg, in any combination and including all the isomers thereof to obtain more valuable isomers of the alkylaromatic.
Suitable alkylaromatic hydrocarbons include, for example but without so limiting the invention, ortho-xylene, meta-xylene, para-xylene, ethylbenzene, ethyltoluenes, tri-methylbenzenes, di-ethylbenzenes, tri-ethyl-benzenes, methylpropylbenzenes, ethylpropylbenzenes, di-isopropylbenzenes, and mixtures thereof.
Isomerization of a Cg-aromatic mixture containing ethylbenzene and xylenes is a particularly preferred application of the SAPO sieves of the invention.
Generally 1 S such mixture will have an ethylbenzene content in the approximate range of 5 to 50 mass-%, an ortho-xylene content in the approximate range of 0 to 35 mass-%, a meta-xylene content in the approximate range of 20 to 95 mass-% and a para-xylene content in the approximate range of 0 to 15 mass-%. It is preferred that the aforementioned Cg aromatics comprise a non-equilibrium mixture, i.e., at least one C8 aromatic isomer is present in a concentration that differs substantially from the equilibrium concentration at isomerization conditions. Usually the non-equilibrium mixture is prepared by removal of para- and/or ortho-xylene from a fresh C8 aromatic mixture obtained from an aromatics-production process.
The source of the alkylaromatic hydrocarbons feed may be found in appropriate fractions from various refinery petroleum streams, e.g., as individual components or as certain boiling-range fractions obtained by the selective fractionation and distillation of catalytically cracked or reformed hydrocarbons. The isomerizable aromatic hydrocarbons need not be concentrated; this invention allows the isomerization of alkylaromatic-containing streams such as catalytic reformate with or without subsequent aromatics extraction to produce specified xylene isomers and particularly to produce 21~~045 para-xylene. A C$-aromatics feed may contain nonaromatic hydrocarbons, i.e., naphthenes and paraffins, in an amount up to 30 mass-%. Preferably the isomerizable hydrocarbons consist essentially of aromatics, however, to ensure pure products from downstream recovery processes.
S According to the present invention, an alkylaromatic hydrocarbon feed mixture, preferably in admixture with hydrogen, is contacted with a catalyst of the type hereinafter described in an alkylaromatic hydrocarbon isomerization zone.
Contacting may be effected using the catalyst in a fixed-bed system, a moving-bed system, a fluidized-bed system, or in a batch-type operation. In view of the danger of attrition loss of the valuable catalyst and of the simpler operation, it is preferred to use a fixed-bed system. In this system, a hydrogen-rich gas and the feed mixture are preheated by suitable heating means to the desired reaction temperature and then passed into an isomerization zone containing a fixed bed of catalyst. The conversion zone may be one or more separate reactors with suitable means therebetween to ensure that the desired isomerization temperature is maintained at the entrance to each zone.
The reactants may be contacted with the catalyst bed in either upward-, downward-, or radial-flow fashion, and the reactants may be in the liquid phase, a mixed liquid-vapor phase, or a vapor phase when contacted with the catalyst.
The alkylaromatic feed mixture, preferably a non-equilibrium mixture of C8 aromatics, is contacted with the isomerization catalyst at suitable alkylaromatic-isomerization conditions. Such conditions comprise a temperature ranging from 0° to 600°C or more, and preferably is in the range of from a 300° to 500°C. The pressure generally is from 101.3 to 10130 kPa (1 to 100 atmospheres), preferably less than 5065 kPa (50 atmospheres). Sufficient catalyst is contained in the isomerization zone to provide a liquid hourly space velocity (LHSV) with respect to the hydrocarbon feed mixture of from 0.1 to 30 hr'', and preferably 0.5 to 10 hr''. The hydrocarbon feed mixture optimally is reacted in admixture with hydrogen at a hydrogen/hydrocarbon mole ratio of 0.5:1 to about 25:1 or more. Other inert diluents such as nitrogen, argon and light hydrocarbons may be present. .
~1'~404~
The particular scheme employed to recover an isomerized product from the effluent of the reactors of the isomerization zone is not deemed to be critical.
Typically, the reactor effluent will be condensed and the hydrogen and light-hydrocarbon components removed therefrom by flash separation. The condensed liquid product then is fractionated to remove light and/or heavy byproducts and obtain the isomerized product. In some instances, certain product species such as ortho-xylene may be recovered from the isomerized product by selective fractionation. The product from isomerization of C8 aromatics usually is processed to selectively recover the para-xylene isomer either by crystallization or by selective adsorption or by a combination thereof. Selective adsorption is preferred using crystalline aluminosilicates according to US-A-3201491. Improvements and alternatives within the preferred adsorption recovery process are described in US-A-3626020, US-A- 3696107, US-A-4039599, US-A-4184943, US-A-4381419 and US-A-4402832.
In a separation/isomerization process combination relating to the processing of an ethylbenzene/xylene mixture, a fresh C8-aromatic feed is combined with isomerized product comprising C$ aromatics and naphthenes from the isomerization reaction zone and fed to a para-xylene separation zone; the para-xylene-depleted stream comprising a non-equilibrium mixture of Cg aromatics is fed to the isomerization reaction zone, where the Cg-aromatic isomers are isomerized to near-equilibrium levels to obtain the isomerized product. In this process scheme non-recovered Cg-aromatic isomers preferably are recycled to extinction until they are either converted to para-xylene or lost due to side-reactions. Ortho-xylene separation, preferably by fractionation, also may be effected on the fresh C8 aromatic feed or isomerized product, or both in combination, prior to para-xylene separation.
The type of molecular sieves used in the present invention is within the silicoaluminophosphate molecular sieves described in US-A-4440871. The silicoaluminophosphate molecular sieves are disclosed as microporous crystalline silicoaluminophosphates, having a three-dimensional microporous framework structure of POZ+, A102 and Si02 tetrahedral units, and whose essential empirical chemical composition on an anhydrous basis is:
The particular scheme employed to recover an isomerized product from the effluent of the reactors of the isomerization zone is not deemed to be critical.
Typically, the reactor effluent will be condensed and the hydrogen and light-hydrocarbon components removed therefrom by flash separation. The condensed liquid product then is fractionated to remove light and/or heavy byproducts and obtain the isomerized product. In some instances, certain product species such as ortho-xylene may be recovered from the isomerized product by selective fractionation. The product from isomerization of C8 aromatics usually is processed to selectively recover the para-xylene isomer either by crystallization or by selective adsorption or by a combination thereof. Selective adsorption is preferred using crystalline aluminosilicates according to US-A-3201491. Improvements and alternatives within the preferred adsorption recovery process are described in US-A-3626020, US-A- 3696107, US-A-4039599, US-A-4184943, US-A-4381419 and US-A-4402832.
In a separation/isomerization process combination relating to the processing of an ethylbenzene/xylene mixture, a fresh C8-aromatic feed is combined with isomerized product comprising C$ aromatics and naphthenes from the isomerization reaction zone and fed to a para-xylene separation zone; the para-xylene-depleted stream comprising a non-equilibrium mixture of Cg aromatics is fed to the isomerization reaction zone, where the Cg-aromatic isomers are isomerized to near-equilibrium levels to obtain the isomerized product. In this process scheme non-recovered Cg-aromatic isomers preferably are recycled to extinction until they are either converted to para-xylene or lost due to side-reactions. Ortho-xylene separation, preferably by fractionation, also may be effected on the fresh C8 aromatic feed or isomerized product, or both in combination, prior to para-xylene separation.
The type of molecular sieves used in the present invention is within the silicoaluminophosphate molecular sieves described in US-A-4440871. The silicoaluminophosphate molecular sieves are disclosed as microporous crystalline silicoaluminophosphates, having a three-dimensional microporous framework structure of POZ+, A102 and Si02 tetrahedral units, and whose essential empirical chemical composition on an anhydrous basis is:
~1'~404 mR : (si,tAl~,P~oz wherein "R" represents at least one organic templating agent present in the intracrystalline pore system; "m" represents the moles of "R" present per mole of (SiXAlyP~02 and has a value of from 0.02 to 0.3; "x", "y" and "z" represent, respectively, the mole fractions of silicon, aluminum and phosphorus present in the oxide moiety, said mole fractions being within the compositional area bounded by points A, B, C, D and E on the ternary diagram which is FIG. 1 of US-A-4440871, and represent the following values for "x", "y" and "z":
Mole Fraction Point x ~ z A 0.01 0.47 0.52 B 0.94 0.01 0.05 C 0.98 0.01 0.01 D 0.39 0.60 0.01 E 0.01 0.60 0.39 The silicoaluminophosphates of US-A-4440871 are generally referred to therein as "SAPO" as a class, or as "SAPO-n" wherein "n" is an integer denoting a particular SAPO such as SAPO-11, SAPO-31, SAPO-40 and SAPO-41. The especially preferred species SAPO-11 as referred to herein is a silicoaluminophosphate having a characteristic X-ray powder diffraction pattern which contains at least the d-spacings set forth below:
Mole Fraction Point x ~ z A 0.01 0.47 0.52 B 0.94 0.01 0.05 C 0.98 0.01 0.01 D 0.39 0.60 0.01 E 0.01 0.60 0.39 The silicoaluminophosphates of US-A-4440871 are generally referred to therein as "SAPO" as a class, or as "SAPO-n" wherein "n" is an integer denoting a particular SAPO such as SAPO-11, SAPO-31, SAPO-40 and SAPO-41. The especially preferred species SAPO-11 as referred to herein is a silicoaluminophosphate having a characteristic X-ray powder diffraction pattern which contains at least the d-spacings set forth below:
Relative 20 d Intensity 9.4-9.65 9.41 -9.17 m 20.3-20.6 4.37-4.31 m 21.0-21.3 4.23-4.17 vs 21.1 - 22.35 4.02 - 3.99 m 22.5 - 22.9 (doublet) 3.95 - 3.92 m 23.15 - 23.35 3.84 - 3.81 ms A modified SAPO-11 is specifically used in the present invention and it is generally known as "SM-3." The composition and properties of SM-3 are specified in the teachings of US-A-4943424. SM-3 comprises a Pa05-to-alumina mole ratio at the surface of the silicoaluminophosphate of 0.80 or less, preferably from 0.80 to 0.55;
a P205-to-alumina mole ratio in the bulk of the SAPO of 0.96 or greater, preferably from 0.96 to l; and a silica-to-alumina mole ratio at the surface which is greater than in the bulk of the SAPO. Preferably the SM-3 has a composition in terms of mole ratios of oxides on an anhydrous basis of mR : AI2O3 : nP205 : qSi02 wherein "R" represents at least one organic templating agent present in the intracrystalline pore system, "m" represents the moles of '°R" present and has a value such that there are from 0.02 to 2 moles of "R" per mole of alumina, n has a value of from 0.96 to 1.1 and preferably 0.9fi to 1, and q has a value of from 0.1 to 4 and preferably 0.1 to 1.
The SM-3 sieve preferably is composited with a binder for convenient formation of catalyst particles in a proportion of 5 to 100 mass% SM-3 and 0 to 95 mass-binder, with the SM-3 preferably comprising from 10 to 90 mass% of the composite.
The binder should be porous, adsorptive support having a surface area of 25 to m2/g, uniform in composition and relatively refractory to the conditions utilized in the ~17404~
hydrocarbon conversion process. By the term "uniform in composition," it is meant that the support is unlayered, has no concentration gradients of the species inherent to its composition, and is completely homogeneous in composition. Thus, if the support is a mixture of two or more refractory materials, the relative amounts of these materials will be constant and uniform throughout the entire support., It is intended to include within the scope of the present invention carrier materials which have traditionally been utilized in hydrocarbon conversion catalysts such as: ( 1 ) refractory inorganic oxides such as alumina, titanic, zirconia, chromic, zinc oxide, magnesia, thoria, boric, silica-alumina, silica-magnesia, chromic-alumina, alumina-boric, silica-zirconia, etc.; (2) ceramics, porcelain, bauxite; (3) silica or silica gel, silicon carbide, clays and silicates including those synthetically prepared and naturally occurring, which may or may not be acid treated, for example attapulgite clay, diatomaceous earth, fuller's earth, kaolin, kieselguhr, etc.; (4) crystalline zeolitic aluminosilicates, either naturally occurring or synthetically prepared such as FAU, MEL, MFI, MOR, MTW
(IUPAC Commission on Zeolite Nomenclature), in hydrogen form or in a form which has been exchanged with metal cations, (5) spinets such as MgA1204, FeA1204, ZnA1204, CaA1204, and other like compounds having the formula MO-A1203 where M
is a metal having a valence of 2; and (6) combinations of materials from one or more of these groups.
The preferred refractory inorganic oxide for use in the present invention is alumina. Suitable alumina materials are the crystalline aluminas known as the gamma, eta-, and theta-alumina, with gamma- or eta-alumina giving best results. A
particularly preferred alumina is that which has been characterized in US-A-3852190 and US-A-4012313 as a by-product from a Ziegler higher alcohol synthesis reaction as described in Ziegler's US-A-2892858. For purposes of simplification, such an alumina will be hereinafter referred to as a "Ziegler alumina". Ziegler alumina is presently available from the Vista Chemical Company under the trademark "Catapal" or from Condea Chemie GmbH under the trademark "Pural." This material is an extremely-high-purity pseudoboehmite which, after calcination at a high temperature, has been shown to yield a high purity gamma-alumina.
a P205-to-alumina mole ratio in the bulk of the SAPO of 0.96 or greater, preferably from 0.96 to l; and a silica-to-alumina mole ratio at the surface which is greater than in the bulk of the SAPO. Preferably the SM-3 has a composition in terms of mole ratios of oxides on an anhydrous basis of mR : AI2O3 : nP205 : qSi02 wherein "R" represents at least one organic templating agent present in the intracrystalline pore system, "m" represents the moles of '°R" present and has a value such that there are from 0.02 to 2 moles of "R" per mole of alumina, n has a value of from 0.96 to 1.1 and preferably 0.9fi to 1, and q has a value of from 0.1 to 4 and preferably 0.1 to 1.
The SM-3 sieve preferably is composited with a binder for convenient formation of catalyst particles in a proportion of 5 to 100 mass% SM-3 and 0 to 95 mass-binder, with the SM-3 preferably comprising from 10 to 90 mass% of the composite.
The binder should be porous, adsorptive support having a surface area of 25 to m2/g, uniform in composition and relatively refractory to the conditions utilized in the ~17404~
hydrocarbon conversion process. By the term "uniform in composition," it is meant that the support is unlayered, has no concentration gradients of the species inherent to its composition, and is completely homogeneous in composition. Thus, if the support is a mixture of two or more refractory materials, the relative amounts of these materials will be constant and uniform throughout the entire support., It is intended to include within the scope of the present invention carrier materials which have traditionally been utilized in hydrocarbon conversion catalysts such as: ( 1 ) refractory inorganic oxides such as alumina, titanic, zirconia, chromic, zinc oxide, magnesia, thoria, boric, silica-alumina, silica-magnesia, chromic-alumina, alumina-boric, silica-zirconia, etc.; (2) ceramics, porcelain, bauxite; (3) silica or silica gel, silicon carbide, clays and silicates including those synthetically prepared and naturally occurring, which may or may not be acid treated, for example attapulgite clay, diatomaceous earth, fuller's earth, kaolin, kieselguhr, etc.; (4) crystalline zeolitic aluminosilicates, either naturally occurring or synthetically prepared such as FAU, MEL, MFI, MOR, MTW
(IUPAC Commission on Zeolite Nomenclature), in hydrogen form or in a form which has been exchanged with metal cations, (5) spinets such as MgA1204, FeA1204, ZnA1204, CaA1204, and other like compounds having the formula MO-A1203 where M
is a metal having a valence of 2; and (6) combinations of materials from one or more of these groups.
The preferred refractory inorganic oxide for use in the present invention is alumina. Suitable alumina materials are the crystalline aluminas known as the gamma, eta-, and theta-alumina, with gamma- or eta-alumina giving best results. A
particularly preferred alumina is that which has been characterized in US-A-3852190 and US-A-4012313 as a by-product from a Ziegler higher alcohol synthesis reaction as described in Ziegler's US-A-2892858. For purposes of simplification, such an alumina will be hereinafter referred to as a "Ziegler alumina". Ziegler alumina is presently available from the Vista Chemical Company under the trademark "Catapal" or from Condea Chemie GmbH under the trademark "Pural." This material is an extremely-high-purity pseudoboehmite which, after calcination at a high temperature, has been shown to yield a high purity gamma-alumina.
21'404 An alternative preferred binder is a form of amorphous silica. The preferred amorphous silica is a synthetic, white, amorphous silica (silicon dioxide) powder which is classed as wet-process, hydrated silica. This type of silica is produced by a chemical reaction in a water solution, from which it is precipitated as ultra-fine, spherical particles. It is preferred that the BET surface area of the silica is in the range from 120 to 160 m2/g. A low content of sulfate salts is desired, preferably less than 0.3 wt.%. It is especially preferred that the amorphous silica binder be nonacidic, e.g., that the pH of a 5% water suspension be neutral or basic (pH about 7 or above).
A preferred shape for the catalyst composite is an extrudate. The well-known extrusion method initially involves mixing of the non-zeolitic molecular sieve, either before or after adding metallic components, with the binder and a suitable peptizing agent to form a homogeneous dough or thick paste having the correct moisture content to allow for the formation of extrudates with acceptable integrity to withstand direct calcination. Extrudability is determined from an analysis of the moisture content of the dough, with a moisture content in the range of from 30 to 50 wt.% being preferred.
The dough then is extruded through a die pierced with multiple holes and the spaghetti-shaped extrudate is cut to form particles in accordance with techniques well known in the art. A multitude of different extrudate shapes are possible, including, but not limited to, cylinders, cloverleaf, dumbbell and symmetrical and asymmetrical polylobates. It is also within the scope of this invention that the extrudates may be further shaped to any desired form, such as spheres, by any means known to the art.
A favored alternative shape of the composite is a sphere, continuously manufactured by the well-known oil drop method. Preferably, this method involves dropping the mixture of molecular sieve, alumina sol, and gelling agent into an oil bath maintained at elevated temperatures. The droplets of the mixture remain in the oil bath until they set and form hydrogel spheres. The spheres are then continuously withdrawn from the oil bath and typically subjected to specific aging treatments in oil and an ammoniacal solution to further improve their physical characteristics. The resulting aged and gelled particles are then washed and dried at a relatively low temperature of 50-200°C and subjected to a calcination procedure at a temperature of 450-700°C for ,, a period of 1 to 20 hours. This treatment effects conversion of the hydrogel to the corresponding alumina matrix.
A platinum-group metal, including one or more of platinum, palladium, rhodium, ruthenium, osmium, and iridium, is a preferred component of the present catalyst. The preferred platinum-group metal is platinum. The platinum-group metal component may exist within the final catalyst composite as a compound such as an oxide, sulfide, halide, oxysulfide, etc., or as an elemental metal or in combination with one or more other ingredients of the catalyst composite. It is believed that the best results are obtained when substantially all the platinum-group metal component exists in a reduced state. The platinum-group metal component generally comprises from 0.01 to about 2 mass-% of the final catalyst composite, calculated on an elemental basis.
The platinum-group metal component may be incorporated into the catalyst composite in any suitable manner. One method of preparing the catalyst involves the utilization of a water-soluble, decomposable compound of a platinum-group metal to impregnate the calcined sieve/binder composite. Alternatively, a platinum-group metal compound may be added at the time of compositing the sieve component and binder.
Yet another method of effecting a suitable metal distribution is by compositing the metal component with the binder prior to co-extruding the sieve and binder.
Complexes of platinum-group metals which may be employed according to the above or other known methods include chloroplatinic acid, chloropalladic acid, ammonium chloroplatinate, bromoplatinic acid, platinum trichloride, platinum tetrachloride hydrate, platinum dichlorocarbonyl dichloride, tetramine platinic chloride, dinitrodiaminoplatinum, sodium tetranitroplatinate (II), palladium chloride, palladium nitrate, palladium sulfate, diamminepalladium (II) hydroxide, tetramminepalladium (II) chloride, and the like.
It is within the scope of the present invention that the catalyst composite may contain other metal components known to modify the effect of the platinum-group metal component. Such metal modifiers may include rhenium, tin, germanium, lead, cobalt, nickel, indium, gallium, zinc, uranium, dysprosium, thallium, and mixtures thereof. Catalytically effective amounts of such metal modifiers may be incorporated to 217~04~
into the catalyst by any means known in the art to effect a homogeneous or stratified distribution.
The catalyst composite of the present invention may contain a halogen component. The halogen component may be either fluorine, chlorine, bromine or iodine or mixtures thereof, with chlorine being preferred. The halogen component is generally present in a combined state with the inorganic-oxide support. The optional halogen component is preferably well dispersed throughout the catalyst and may comprise from more than 0.2 to 15 wt.%, calculated on an elemental basis, of the final catalyst. The halogen component may be incorporated in the catalyst composite in any suitable manner, either during the preparation of the inorganic-oxide support or before, while or after other catalytic components are incorporated.
The catalyst composite is dried at a temperature of from 100° to 320°C for a period of from 2 to 24 or more hours and, usually, calcined at a temperature of from 400° to 650°C in an air atmosphere for a period of from 0.1 to 10 hours until the metallic compounds present are converted substantially to the oxide form. If desired, the optional halogen component may be adjusted by including a halogen or halogen-containing compound in the air atmosphere.
The resultant calcined composite optimally is subjected to a substantially water free reduction step to insure a uniform and finely divided dispersion of the optional metallic components. The reduction optionally may be effected in the process equipment of the present invention. Substantially pure and dry hydrogen (i.e., less than 20 vol. ppm H20) preferably is used as the reducing agent in this step. The reducing agent contacts the catalyst at conditions, including a temperature of from 200° to 650°C
and for a period of from 0.5 to 10 hours, effective to reduce substantially all of the Group VIII metal component to the metallic state. In some cases the resulting reduced catalyst composite may also be beneficially subjected to presulfiding by a method known in the art to incorporate in the catalyst composite from 0.05 to 0.5 mass-sulfur calculated on an elemental basis.
A preferred shape for the catalyst composite is an extrudate. The well-known extrusion method initially involves mixing of the non-zeolitic molecular sieve, either before or after adding metallic components, with the binder and a suitable peptizing agent to form a homogeneous dough or thick paste having the correct moisture content to allow for the formation of extrudates with acceptable integrity to withstand direct calcination. Extrudability is determined from an analysis of the moisture content of the dough, with a moisture content in the range of from 30 to 50 wt.% being preferred.
The dough then is extruded through a die pierced with multiple holes and the spaghetti-shaped extrudate is cut to form particles in accordance with techniques well known in the art. A multitude of different extrudate shapes are possible, including, but not limited to, cylinders, cloverleaf, dumbbell and symmetrical and asymmetrical polylobates. It is also within the scope of this invention that the extrudates may be further shaped to any desired form, such as spheres, by any means known to the art.
A favored alternative shape of the composite is a sphere, continuously manufactured by the well-known oil drop method. Preferably, this method involves dropping the mixture of molecular sieve, alumina sol, and gelling agent into an oil bath maintained at elevated temperatures. The droplets of the mixture remain in the oil bath until they set and form hydrogel spheres. The spheres are then continuously withdrawn from the oil bath and typically subjected to specific aging treatments in oil and an ammoniacal solution to further improve their physical characteristics. The resulting aged and gelled particles are then washed and dried at a relatively low temperature of 50-200°C and subjected to a calcination procedure at a temperature of 450-700°C for ,, a period of 1 to 20 hours. This treatment effects conversion of the hydrogel to the corresponding alumina matrix.
A platinum-group metal, including one or more of platinum, palladium, rhodium, ruthenium, osmium, and iridium, is a preferred component of the present catalyst. The preferred platinum-group metal is platinum. The platinum-group metal component may exist within the final catalyst composite as a compound such as an oxide, sulfide, halide, oxysulfide, etc., or as an elemental metal or in combination with one or more other ingredients of the catalyst composite. It is believed that the best results are obtained when substantially all the platinum-group metal component exists in a reduced state. The platinum-group metal component generally comprises from 0.01 to about 2 mass-% of the final catalyst composite, calculated on an elemental basis.
The platinum-group metal component may be incorporated into the catalyst composite in any suitable manner. One method of preparing the catalyst involves the utilization of a water-soluble, decomposable compound of a platinum-group metal to impregnate the calcined sieve/binder composite. Alternatively, a platinum-group metal compound may be added at the time of compositing the sieve component and binder.
Yet another method of effecting a suitable metal distribution is by compositing the metal component with the binder prior to co-extruding the sieve and binder.
Complexes of platinum-group metals which may be employed according to the above or other known methods include chloroplatinic acid, chloropalladic acid, ammonium chloroplatinate, bromoplatinic acid, platinum trichloride, platinum tetrachloride hydrate, platinum dichlorocarbonyl dichloride, tetramine platinic chloride, dinitrodiaminoplatinum, sodium tetranitroplatinate (II), palladium chloride, palladium nitrate, palladium sulfate, diamminepalladium (II) hydroxide, tetramminepalladium (II) chloride, and the like.
It is within the scope of the present invention that the catalyst composite may contain other metal components known to modify the effect of the platinum-group metal component. Such metal modifiers may include rhenium, tin, germanium, lead, cobalt, nickel, indium, gallium, zinc, uranium, dysprosium, thallium, and mixtures thereof. Catalytically effective amounts of such metal modifiers may be incorporated to 217~04~
into the catalyst by any means known in the art to effect a homogeneous or stratified distribution.
The catalyst composite of the present invention may contain a halogen component. The halogen component may be either fluorine, chlorine, bromine or iodine or mixtures thereof, with chlorine being preferred. The halogen component is generally present in a combined state with the inorganic-oxide support. The optional halogen component is preferably well dispersed throughout the catalyst and may comprise from more than 0.2 to 15 wt.%, calculated on an elemental basis, of the final catalyst. The halogen component may be incorporated in the catalyst composite in any suitable manner, either during the preparation of the inorganic-oxide support or before, while or after other catalytic components are incorporated.
The catalyst composite is dried at a temperature of from 100° to 320°C for a period of from 2 to 24 or more hours and, usually, calcined at a temperature of from 400° to 650°C in an air atmosphere for a period of from 0.1 to 10 hours until the metallic compounds present are converted substantially to the oxide form. If desired, the optional halogen component may be adjusted by including a halogen or halogen-containing compound in the air atmosphere.
The resultant calcined composite optimally is subjected to a substantially water free reduction step to insure a uniform and finely divided dispersion of the optional metallic components. The reduction optionally may be effected in the process equipment of the present invention. Substantially pure and dry hydrogen (i.e., less than 20 vol. ppm H20) preferably is used as the reducing agent in this step. The reducing agent contacts the catalyst at conditions, including a temperature of from 200° to 650°C
and for a period of from 0.5 to 10 hours, effective to reduce substantially all of the Group VIII metal component to the metallic state. In some cases the resulting reduced catalyst composite may also be beneficially subjected to presulfiding by a method known in the art to incorporate in the catalyst composite from 0.05 to 0.5 mass-sulfur calculated on an elemental basis.
EXAMPLES
Samples of SM-3 modified silicoaluminophosphate were prepared for testing as isomerization catalysts in the process of the invention. The SM-3 was prepared according to the teachings of US-A-4943424 and had characteristics as disclosed in the '424 patent.
Samples of unmodified SAPO-11 silicoaluminophosphate not of the invention were prepared in accordance with the teachings of US-A-4440871 and as described hereunder. Molar proportions of 50 moles water to 1.8 moles of orthophosphoric acid as 85 mass-% H3P0, were combined, and 1.0 moles of alumina was added to the *
~ solution as Versal 250 with stirring of the mixture: Silica then was added as HiSil 250 in a molar proportion of 0.2 moles. The directing agent was di-n-propylamine, added in a proportion of 1.8 moles. The composition of the reaction mixtures therefore was as follows:
1.8(Pr2NH):0.25iO2:A1~03:U.9P203:SOHZO
SAPO-11 seed amounting to 1.0 mass-% of the oxides was added and the reaction mixture was heated gradually to 195°C and held at that temperature for 12 hours. The solid reaction product was recovered by centrifugation, washed with water and dried in air at 100°C. Certain of the synthesis powders were bound with alurnina as described below and then were calcined at 650° C. in flowing air to remove the synthesis template and set the silica binder of the bound catalyst samples.
The unbound control SAPO-11, not of the invention, was designated as "Control."
Example I
The advantage of the process of the invention was demonstrated in a series of microreactor tests. Unbound catalysts were loaded in the microreactor in a quantity of 250 mg. Mete-xylene was fed to the reactor in a hydrogen atmosphere at varying temperatwes. Conversion of the mete-xylene was measured, as well as the ratio of pare-xylene to ortho-xylene in the product. The test results showed the following for *Trade-mark ~1'~4045 the SM-3 silicoaluminophosphate in comparison to the control SAPO-11 not of the invention:
400°C 500°C
SM-3 Control SM-3 Control Conversion, % 39.14 3.27 47.44 9.2 P-x/o-x, mole-% 1.24 0.73 1.06 1.6 The SM-3 showed a substantial advantage over the control catalyst in meta-xylene conversion at both temperatures. SM-3 also showed control of the para-xylene/ortho-xylene ratio near equilibrium ratios, while ratios of the xylene isomers varied sharply at the low conversion provided by the control catalyst.
Example II
The SM-3 silicoaluminophosphate was composited with alumina and tetramine platinic chloride at alternative platinum levels to aid in formulating the optimum catalyst of the invention. The composites comprised 60 mass-% SM-3 and 40 mass-1 S alumina. Tetramine platinic chloride was incorporated into the composites to effect platinum contents of 0.28 and 0.14 mass-%, respectively, on an elemental basis, and the catalysts were calcined and reduced.
The catalysts were evaluated using a pilot plant flow reactor processing a non-equilibrium C8 aromatic feed having the following composition in mass-%:
ethylbenzene 17%
meta-xylene 58%
ortho-xylene 25%
This feed was contacted with 100 cc of catalyst at a LHSV of 2 hr'', and a hydrogen/hydrocarbon mole ratio of 4. Reactor temperature was adjusted to effect a favorable conversion level. Conversion is expressed as the disappearance per pass of ethylbenzene. C$-aromatic loss is primarily to benzene and toluene, with smaller amounts of light gases being produced. Results were as follows:
Samples of SM-3 modified silicoaluminophosphate were prepared for testing as isomerization catalysts in the process of the invention. The SM-3 was prepared according to the teachings of US-A-4943424 and had characteristics as disclosed in the '424 patent.
Samples of unmodified SAPO-11 silicoaluminophosphate not of the invention were prepared in accordance with the teachings of US-A-4440871 and as described hereunder. Molar proportions of 50 moles water to 1.8 moles of orthophosphoric acid as 85 mass-% H3P0, were combined, and 1.0 moles of alumina was added to the *
~ solution as Versal 250 with stirring of the mixture: Silica then was added as HiSil 250 in a molar proportion of 0.2 moles. The directing agent was di-n-propylamine, added in a proportion of 1.8 moles. The composition of the reaction mixtures therefore was as follows:
1.8(Pr2NH):0.25iO2:A1~03:U.9P203:SOHZO
SAPO-11 seed amounting to 1.0 mass-% of the oxides was added and the reaction mixture was heated gradually to 195°C and held at that temperature for 12 hours. The solid reaction product was recovered by centrifugation, washed with water and dried in air at 100°C. Certain of the synthesis powders were bound with alurnina as described below and then were calcined at 650° C. in flowing air to remove the synthesis template and set the silica binder of the bound catalyst samples.
The unbound control SAPO-11, not of the invention, was designated as "Control."
Example I
The advantage of the process of the invention was demonstrated in a series of microreactor tests. Unbound catalysts were loaded in the microreactor in a quantity of 250 mg. Mete-xylene was fed to the reactor in a hydrogen atmosphere at varying temperatwes. Conversion of the mete-xylene was measured, as well as the ratio of pare-xylene to ortho-xylene in the product. The test results showed the following for *Trade-mark ~1'~4045 the SM-3 silicoaluminophosphate in comparison to the control SAPO-11 not of the invention:
400°C 500°C
SM-3 Control SM-3 Control Conversion, % 39.14 3.27 47.44 9.2 P-x/o-x, mole-% 1.24 0.73 1.06 1.6 The SM-3 showed a substantial advantage over the control catalyst in meta-xylene conversion at both temperatures. SM-3 also showed control of the para-xylene/ortho-xylene ratio near equilibrium ratios, while ratios of the xylene isomers varied sharply at the low conversion provided by the control catalyst.
Example II
The SM-3 silicoaluminophosphate was composited with alumina and tetramine platinic chloride at alternative platinum levels to aid in formulating the optimum catalyst of the invention. The composites comprised 60 mass-% SM-3 and 40 mass-1 S alumina. Tetramine platinic chloride was incorporated into the composites to effect platinum contents of 0.28 and 0.14 mass-%, respectively, on an elemental basis, and the catalysts were calcined and reduced.
The catalysts were evaluated using a pilot plant flow reactor processing a non-equilibrium C8 aromatic feed having the following composition in mass-%:
ethylbenzene 17%
meta-xylene 58%
ortho-xylene 25%
This feed was contacted with 100 cc of catalyst at a LHSV of 2 hr'', and a hydrogen/hydrocarbon mole ratio of 4. Reactor temperature was adjusted to effect a favorable conversion level. Conversion is expressed as the disappearance per pass of ethylbenzene. C$-aromatic loss is primarily to benzene and toluene, with smaller amounts of light gases being produced. Results were as follows:
'~
~1'~404~
Catal~rst mass-% Pt 0.28 0.14 Temperature, °C 386 380 Ethylbenzene conversion, % 28 24.5 C8-aromatics loss, % 2.8 2.8 Example III
Catalyst samples were prepared and tested to illustrate the effect of platinum location on the performance of the catalyst. Catalyst A was prepared as in Example II by coextruding SM-3 silicoaluminophosphate and alumina in a 60/40 mass ratio with tetramine platinic chloride, calcining and reducing to effect a catalyst containing 0.28 mass-% platinum. Catalyst B was prepared by first compositing alumina and tetramine platinic chloride, followed by coextruding with SM-3, calcining and reducing to effect a catalyst having the same overall composition as Catalyst A.
The catalysts were evaluated using a pilot plant flow reactor processing the same non-equilibrium C8-aromatic feed as in Example II. This feed was contacted with 100 cc of catalyst at a LHSV of 2 hr'' and a hydrogen/hydrocarbon mole ratio of 4. Reactor temperature was adjusted to effect a favorable conversion level.
Conversion is expressed as the disappearance per pass of ethylbenzene, and C8-aromatic loss is primarily to benzene and toluene. Results were as follows:
Catalyst: A B
Temperature, °C 386 386 Ethylbenzene conversion, % 28 27.5 C8 aromatics loss, % 2.8 2.7
~1'~404~
Catal~rst mass-% Pt 0.28 0.14 Temperature, °C 386 380 Ethylbenzene conversion, % 28 24.5 C8-aromatics loss, % 2.8 2.8 Example III
Catalyst samples were prepared and tested to illustrate the effect of platinum location on the performance of the catalyst. Catalyst A was prepared as in Example II by coextruding SM-3 silicoaluminophosphate and alumina in a 60/40 mass ratio with tetramine platinic chloride, calcining and reducing to effect a catalyst containing 0.28 mass-% platinum. Catalyst B was prepared by first compositing alumina and tetramine platinic chloride, followed by coextruding with SM-3, calcining and reducing to effect a catalyst having the same overall composition as Catalyst A.
The catalysts were evaluated using a pilot plant flow reactor processing the same non-equilibrium C8-aromatic feed as in Example II. This feed was contacted with 100 cc of catalyst at a LHSV of 2 hr'' and a hydrogen/hydrocarbon mole ratio of 4. Reactor temperature was adjusted to effect a favorable conversion level.
Conversion is expressed as the disappearance per pass of ethylbenzene, and C8-aromatic loss is primarily to benzene and toluene. Results were as follows:
Catalyst: A B
Temperature, °C 386 386 Ethylbenzene conversion, % 28 27.5 C8 aromatics loss, % 2.8 2.7
Claims (7)
1. A process for the isomerization of a non-equilibrium feed mixture of xylenes and ethylbenzene comprising contacting the feed mixture in the presence of hydrogen in an isomerization zone with a catalyst composite comprising an effective amount of an SM-3 crystalline silicoaluminophosphate molecular sieve at C8 isomerization conditions effective to obtain as isomerized product comprising a higher proportion of p-xylene than in the feed mixture, wherein said isomerization conditions are :
a) a temperature range of 0-600°C ;
b) a pressure range of 1-100 atmospheres ;
c) a liquid hourly space velocity of 0.1-30/hr ; and d) a hydrogen to hydrocarbon ratio of 0:5:1 to 25:1.
a) a temperature range of 0-600°C ;
b) a pressure range of 1-100 atmospheres ;
c) a liquid hourly space velocity of 0.1-30/hr ; and d) a hydrogen to hydrocarbon ratio of 0:5:1 to 25:1.
2. The process of Claim 1 wherein the catalytic composite comprises an effective amount of a platinum-group metal component.
3. The process of Claim 1 or 2 wherein the catalyst composite further comprises an inorganic-oxide binder comprising alumina and silica or a mixture thereof.
4. The process of Claim 2 wherein the effective amount of a platinum-group metal component comprises from 0.1 to 2 mass-% platinum on an elemental basis.
5. The process of any one of Claims 1 to 4 wherein the isomerized product comprises greater-than-equilibrium concentration of para-xylene.
6. The process of any one of Claims 1 to 5 wherein the catalyst composite comprises from 0.1 to 2 mass-% on an elemental basis of a platinum component, from 10 to 100 mass-% of an SM-3 crystalline silicoaluminophosphate molecular sieve and an inorganic-oxide binder.
7. The process of any one of Claims 1 to 6 wherein the C8 aromatic isomerization conditions include comprising a temperature of from 300°
to 500°C, a pressure of from 101.3 to 5065 kPa (1 to 50 atm), a LHSV from 0.5 to 10 hr-1 and a hydrogen-to-hydrocarbon mole ratio of from 0.5:1 to 25:1.
to 500°C, a pressure of from 101.3 to 5065 kPa (1 to 50 atm), a LHSV from 0.5 to 10 hr-1 and a hydrogen-to-hydrocarbon mole ratio of from 0.5:1 to 25:1.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US42736295A | 1995-04-24 | 1995-04-24 | |
US427,362 | 1995-04-24 |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2174045A1 CA2174045A1 (en) | 1996-10-25 |
CA2174045C true CA2174045C (en) | 2003-01-28 |
Family
ID=23694545
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002174045A Expired - Fee Related CA2174045C (en) | 1995-04-24 | 1996-04-12 | C8 aromatics isomerization using catalyst containing modified silicoaluminophosphate molecular sieve |
Country Status (21)
Country | Link |
---|---|
US (1) | US5898090A (en) |
EP (1) | EP0739873B1 (en) |
JP (1) | JP2781544B2 (en) |
KR (1) | KR100197926B1 (en) |
CN (1) | CN1054596C (en) |
AT (1) | ATE188463T1 (en) |
AU (1) | AU702788B2 (en) |
CA (1) | CA2174045C (en) |
DE (1) | DE69605967T2 (en) |
DK (1) | DK0739873T3 (en) |
ES (1) | ES2140786T3 (en) |
GR (1) | GR3032969T3 (en) |
MX (1) | MX9601503A (en) |
MY (1) | MY121583A (en) |
NO (1) | NO304936B1 (en) |
PT (1) | PT739873E (en) |
RO (1) | RO117968B1 (en) |
RU (1) | RU2125977C1 (en) |
SG (1) | SG43354A1 (en) |
TW (1) | TW324713B (en) |
ZA (1) | ZA963008B (en) |
Families Citing this family (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1044615C (en) * | 1997-03-26 | 1999-08-11 | 熊斌 | Liquefied hydrocarbons fuel gas as substitute ethyne gas |
US6383967B1 (en) * | 1997-12-08 | 2002-05-07 | Uop Llc | Selective aromatics disproportionation/transalkylation catalyst |
US6222086B1 (en) | 1999-07-02 | 2001-04-24 | Uop Llc | Aromatics isomerization using a dual-catalyst system |
US6512155B1 (en) | 2000-04-25 | 2003-01-28 | Uop Llc | Process for the activation of an alkylaromatic isomerization catalyst by water |
JP4058619B2 (en) * | 2001-10-25 | 2008-03-12 | セイコーエプソン株式会社 | Semiconductor wafer |
US7407907B2 (en) * | 2003-11-07 | 2008-08-05 | Uop Llc | Dual functional catalyst for selective opening of cyclic paraffins and process for using the catalyst |
US20050101819A1 (en) * | 2003-11-07 | 2005-05-12 | Galperin Leonid B. | Dual functional catalyst for selective opening of cyclic paraffins and process for using the catalyst |
US20050101474A1 (en) * | 2003-11-07 | 2005-05-12 | Galperin Leonid B. | Catalyst for selective opening of cyclic naphtha and process for using the catalyst |
US7405177B2 (en) * | 2003-11-07 | 2008-07-29 | Uop Llc | Catalyst for selective opening of cyclic naphtha and process for using the catalyst |
US20060281957A1 (en) * | 2003-11-07 | 2006-12-14 | Galperin Leonid B | Dual functional catalyst for selective opening of cyclic paraffins and process for using the catalyst |
US20050143614A1 (en) * | 2003-12-30 | 2005-06-30 | Leon-Escamilla E. A. | Process and catalyst for C8 alkylaromatic isomerization |
US20050143615A1 (en) * | 2003-12-30 | 2005-06-30 | Bogdan Paula L. | Process and bimetallic catalyst for C8 alkylaromatic isomerization |
CN100512954C (en) * | 2003-12-30 | 2009-07-15 | 环球油品公司 | Process and bimetallic catalyst for c* alkyl aromatic isomerization |
CN1325159C (en) * | 2004-03-22 | 2007-07-11 | 四川大学 | Catalyzer for preparing p-aminophenol by using hydrogenation rearrangement through selection of nitrobenzene |
US20070287871A1 (en) * | 2006-03-20 | 2007-12-13 | Eelko Brevoord | Silicoaluminophosphate isomerization catalyst |
RU2448937C2 (en) * | 2006-03-29 | 2012-04-27 | Торэй Индастриз, Инк. | Method of converting ethylbenzene and method of producing para-xylene |
DK2440328T3 (en) | 2009-06-12 | 2016-11-28 | Albemarle Europe Sprl | SAPO molecular sieve and preparation and uses thereof |
US8058496B2 (en) * | 2010-03-31 | 2011-11-15 | Uop Llc | Process for xylene and ethylbenzene isomerization using UZM-35 |
US8889940B2 (en) * | 2011-11-01 | 2014-11-18 | Uop Llc | Catalyst and process for hydrocarbon conversion |
US9309170B2 (en) * | 2011-11-14 | 2016-04-12 | Uop Llc | Aromatics isomerization using a dual-catalyst system |
EP2993163B1 (en) | 2014-09-05 | 2018-02-21 | Scg Chemicals Co. Ltd. | Process for the separation of ethylbenzene |
WO2018118208A1 (en) | 2016-12-21 | 2018-06-28 | Uop Llc | Composition of matter and structure of zeolite uzm-55 and use in isomerization of aromatic molecules |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4440871A (en) * | 1982-07-26 | 1984-04-03 | Union Carbide Corporation | Crystalline silicoaluminophosphates |
US4793984A (en) * | 1984-04-13 | 1988-12-27 | Union Carbide Corporation | Molecular sieve compositions |
US4740650A (en) * | 1986-06-16 | 1988-04-26 | Union Carbide Corporation | Xylene isomerization |
US4943424A (en) * | 1988-02-12 | 1990-07-24 | Chevron Research Company | Synthesis of a crystalline silicoaluminophosphate |
US5158665A (en) * | 1988-02-12 | 1992-10-27 | Chevron Research And Technology Company | Synthesis of a crystalline silicoaluminophosphate |
US5208005A (en) * | 1988-02-12 | 1993-05-04 | Chevron Research And Technology Company | Synthesis of a crystalline silicoaluminophosphate |
US5087347A (en) * | 1988-02-12 | 1992-02-11 | Chevron Research Company | Silicoaluminophosphate hydrocarbon conversion process using SM-3 |
US5552182A (en) * | 1995-01-31 | 1996-09-03 | Rowland Institute For Science | Inking methods and compositions for production of digitized stereoscopic polarizing images |
-
1996
- 1996-04-12 CA CA002174045A patent/CA2174045C/en not_active Expired - Fee Related
- 1996-04-12 DE DE69605967T patent/DE69605967T2/en not_active Expired - Fee Related
- 1996-04-12 PT PT96302578T patent/PT739873E/en unknown
- 1996-04-12 EP EP96302578A patent/EP0739873B1/en not_active Expired - Lifetime
- 1996-04-12 AT AT96302578T patent/ATE188463T1/en not_active IP Right Cessation
- 1996-04-12 ES ES96302578T patent/ES2140786T3/en not_active Expired - Lifetime
- 1996-04-12 DK DK96302578T patent/DK0739873T3/en active
- 1996-04-16 ZA ZA963008A patent/ZA963008B/en unknown
- 1996-04-22 MX MX9601503A patent/MX9601503A/en not_active IP Right Cessation
- 1996-04-22 MY MYPI96001545A patent/MY121583A/en unknown
- 1996-04-22 AU AU50780/96A patent/AU702788B2/en not_active Ceased
- 1996-04-23 SG SG1996009346A patent/SG43354A1/en unknown
- 1996-04-23 RO RO96-00853A patent/RO117968B1/en unknown
- 1996-04-23 KR KR1019960012353A patent/KR100197926B1/en not_active IP Right Cessation
- 1996-04-23 NO NO961613A patent/NO304936B1/en unknown
- 1996-04-23 JP JP8100810A patent/JP2781544B2/en not_active Expired - Fee Related
- 1996-04-23 RU RU96107973A patent/RU2125977C1/en not_active IP Right Cessation
- 1996-04-23 CN CN96105444A patent/CN1054596C/en not_active Expired - Fee Related
- 1996-06-04 TW TW085106655A patent/TW324713B/en active
-
1997
- 1997-12-17 US US08/992,357 patent/US5898090A/en not_active Expired - Fee Related
-
2000
- 2000-03-16 GR GR20000400669T patent/GR3032969T3/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
RU2125977C1 (en) | 1999-02-10 |
CN1054596C (en) | 2000-07-19 |
EP0739873B1 (en) | 2000-01-05 |
ZA963008B (en) | 1996-11-27 |
NO304936B1 (en) | 1999-03-08 |
CA2174045A1 (en) | 1996-10-25 |
KR960037626A (en) | 1996-11-19 |
CN1139659A (en) | 1997-01-08 |
EP0739873A1 (en) | 1996-10-30 |
RO117968B1 (en) | 2002-11-29 |
MX9601503A (en) | 1997-04-30 |
PT739873E (en) | 2000-06-30 |
DE69605967D1 (en) | 2000-02-10 |
AU5078096A (en) | 1996-11-07 |
ATE188463T1 (en) | 2000-01-15 |
AU702788B2 (en) | 1999-03-04 |
TW324713B (en) | 1998-01-11 |
DE69605967T2 (en) | 2000-10-05 |
ES2140786T3 (en) | 2000-03-01 |
JPH08310977A (en) | 1996-11-26 |
KR100197926B1 (en) | 1999-06-15 |
MY121583A (en) | 2006-02-28 |
SG43354A1 (en) | 1997-10-17 |
JP2781544B2 (en) | 1998-07-30 |
GR3032969T3 (en) | 2000-07-31 |
DK0739873T3 (en) | 2000-05-01 |
US5898090A (en) | 1999-04-27 |
NO961613D0 (en) | 1996-04-23 |
NO961613L (en) | 1996-10-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA2174045C (en) | C8 aromatics isomerization using catalyst containing modified silicoaluminophosphate molecular sieve | |
EP0640389B1 (en) | Magnesium containing non zeolitic molecular sieve and use as isomerization catalyst | |
US7495137B2 (en) | Two-stage aromatics isomerization process | |
US5478787A (en) | Discrete molecular sieve and use | |
EP0234684B1 (en) | Xylene isomerization process | |
EP1896382A2 (en) | Selective aromatics isomerization process | |
EP1699556A2 (en) | Process and catalyst for c8 alkylaromatic isomerization | |
US6576581B1 (en) | Aromatics isomerization using a dual-catalyst system | |
US6388159B1 (en) | Xylene isomerization process using UZM-5 and UZM-6 zeolites | |
US20050143614A1 (en) | Process and catalyst for C8 alkylaromatic isomerization | |
EP0432324A1 (en) | Isomerization of alkylaromatics | |
US20050143615A1 (en) | Process and bimetallic catalyst for C8 alkylaromatic isomerization | |
US4962259A (en) | Catalyst for isomerizing alkylaromatics | |
US5081084A (en) | Catalyst for isomerizing alkylaromatics | |
US8304593B2 (en) | Hydrocarbon conversion using an improved molecular sieve | |
US9309170B2 (en) | Aromatics isomerization using a dual-catalyst system | |
US8431760B2 (en) | Hydrocarbon conversion using an improved molecular sieve | |
US20100152025A1 (en) | Molecular Sieve |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKLA | Lapsed |