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Effect of the Method of Platinum Inclusion into Spherical Promoter of Catalytic Cracking Termofor on its Activity in CO Combustion
Ouczi, L.ct al. (Editors), New Frontiers in Catalysis
Proceedings of the 10th International Congress on Catalysis, 19-24 July, 1992, Budapest, Hungary Q 1993 Elsevicr Science Publishers B.V.All righfs reserved
EFFECT OF THE METHOD OF PLATINUM INCLUSION INTO SPHERICAL PROMOTER OF CATALYTIC CRACKING TERMOFOR ON I'IS ACTIVITY IN CO COMBUSTION M. I. Levinbukj V.B. Melnikov, H. R Shapieva, V. I. Vershinin, V. A. Kuzmin and V.Je. Varshaver Grozny Oil Scientific Research Institute, Br. Dubininih 23, Grozny, Russia
ABSTRACT
Oxidative activity in CO cornbustion of spherical cracking catalyst samples containing Pt introduced separately into zeolite and matrix has baen studied. On the basis of laboratory scale and commercial tests t h e greater effect of Pt inclusion into zeolite component of spherical cracking catalyst is shown. Microspherical promoters of CO combustion in catalytic cracking units added in small amounts into catalyst are used all over the world. In the USSR CO emission in the cracking unit with spherical catalyst is 10 times less than in the unit with microspherical catalyst. However Soviet Thermofor units process great amount of cracking feedstock and CO combustion in them is a real problem. Lower catalyst circulation ratio in Thermofor units requires the use of CO combustion promoter in quantities comparable with spherical catalyst loading into reactor-regenerator block (Table 1). Therefore CO combustion promoter itself is a n active component of petroleum fraction cracking as compared t o microspherical promoter the support of which is inactive in cracking alumina. To simplify the technology of spherical catalyst promoter production Pt compounPs are intruded into the catalyst at the stage of shaping of wet spheres with gelling solutions. Upon separate inclusion of constant Pt compounds quantities into zeolite and catalyst matrix with Corresponding gelling solutions the authors revealed CO different catalytic activity of the contacts in combustion (Table 2 ) in laboratory-scale plant which is a possible result of specific distribution of Pt in the samples.
261 8 Table 1 Comparison of some parameters of catalytic cracking units in the USSR with spherical and microspherical catalyst.
............................................................ catalytic cracking units
.................................... with spherical catalyst
with microspherical catalyst
............................................................ Unit capacities, re1 .% Average emission of carbon oxide in regeneration gases, t/day
69.5
30.5
8.0-14 0 80-120 ............................................................
Content of platinum in CO combustion PROMOTER, wt.% Quantity of CO combustion promoter in mixture with catalyst in reactorregenerator block in cracking units, wt.%
0.0005-0.0015
0.05-0.10
10-25
0.1-0.2
Table 2 Activity of spherical catalysts carbon oxide combustion.
promoted
by
platinum
in
To evaluate Pt distribution over a catalyst granule there were synthesized samples of zeolite zirconium silicate catalysts with separate Pt inclusion into zeolite and zirconium silicate matrix in amount of 0.12 wt%. For investigation there were used well polished mechanical
spalls of two samples which were put into the chamber of raster electron microscope JSM-820 (Japan) with microprobe analyzer ("Link" company Great Britain)/Q/. The X-ray Patterns were preliminary set t o characteristic spectrum lines of aluminium, zirconium and platinum. The areas of high element concentration in scanning range in the photograph will be white and black in those points where the given element is absent. Distribution of zeolitb particles (2-4 p m ) in matrix was determined from X-rays characteristic of zirconium and aluminium because in given samples these elements are concentrated in matrix and zeolite respectively. If silica alumina matrix were used it should be hardly possible to distinguish matrix from zeolite because both of them contain aluminium and silicium. Conglomeration of zeolite particle t h u s determined was studied in X-ray characteristic of platinum. As one can see in figurea 1 . 2 platinum included into the sample with zeolite suspension is mainly concentrated in zeolite particle.
Figure 1. X-ray patterns of zirconium, aluminium and platinum distribution in spall of catalyst sample with Pt introduced into zirconium silicate matrix.
Figure 2. X-ray patterns of zirconium, Platinum distribution in spall of catalyst introduced into zeolite suspension.
aluminium and sample with Pt
The authors relate higher oxidative activity of samples with platinum introduced into zeolite t o formation of AlaPt phase inactive in CO combustion. AlaPt phase was formed upon thermal steam treatment of the catalyst in regenerator according t o the hypothesis /3/. Obviously, its formation is more preferable in amorphous silica alumina matrix than in regular crystalline structure of zeolite. On the basis of the results acquired commercial lots of spherical promoters of CO combustion were produced and tested in Thermofor unit at Salavat Refinery. As can be seen from Table 3 spherical promoters ( a s an additive t o Zeokar-3 catalyst) containing platinum introduced into zeolite are more effective under commercial conditions used in operating cracking units.
Table 3. Changes in parameters of Thermofor cracking unit of Salavat Refinery using Zeokar-3F
............................................................ Mixture, catalyst/ promoter
Residual coke an catalysts, wt5
Average CO emission into atmosphere,t/day
Increase of gaso1 ine yield, wt.5
............................................................
---
Zeokar-3 + Zeokar-3tZeokar-3F2 Zeokar-3+Zeokar-3F4
base -0.25 -0.45
8 -0-14.0 4.0-6.0 2.0-3.5
base 1.1 1.8
1. F.D.Hartzwel1 and A.W. Chaster. Oil and Gas J., v 77, N 16 ( 1 9 7 9 ) 83 2. H.K.Magomadova, M.1. Levinbuk. Zeolite Usage in Catalysis, I V All-Union Conference, Moscow (1989), 204 3. N.A.Zakarina, G.D.Zakumbaeva, Petroleum Chemistry, N 1 ( 1 9 9 0 ) 40 4 . Raster Electron microscopy. Edited by Goldstein and H.Jakovit6. M i r Moscow ( 1 9 7 8 ) 29-466.
Proceedings of the 10th International Congress on Catalysis, 19-24 July, 1992, Budapest, Hungary Q 1993 Elsevicr Science Publishers B.V.All righfs reserved
EFFECT OF THE METHOD OF PLATINUM INCLUSION INTO SPHERICAL PROMOTER OF CATALYTIC CRACKING TERMOFOR ON I'IS ACTIVITY IN CO COMBUSTION M. I. Levinbukj V.B. Melnikov, H. R Shapieva, V. I. Vershinin, V. A. Kuzmin and V.Je. Varshaver Grozny Oil Scientific Research Institute, Br. Dubininih 23, Grozny, Russia
ABSTRACT
Oxidative activity in CO cornbustion of spherical cracking catalyst samples containing Pt introduced separately into zeolite and matrix has baen studied. On the basis of laboratory scale and commercial tests t h e greater effect of Pt inclusion into zeolite component of spherical cracking catalyst is shown. Microspherical promoters of CO combustion in catalytic cracking units added in small amounts into catalyst are used all over the world. In the USSR CO emission in the cracking unit with spherical catalyst is 10 times less than in the unit with microspherical catalyst. However Soviet Thermofor units process great amount of cracking feedstock and CO combustion in them is a real problem. Lower catalyst circulation ratio in Thermofor units requires the use of CO combustion promoter in quantities comparable with spherical catalyst loading into reactor-regenerator block (Table 1). Therefore CO combustion promoter itself is a n active component of petroleum fraction cracking as compared t o microspherical promoter the support of which is inactive in cracking alumina. To simplify the technology of spherical catalyst promoter production Pt compounPs are intruded into the catalyst at the stage of shaping of wet spheres with gelling solutions. Upon separate inclusion of constant Pt compounds quantities into zeolite and catalyst matrix with Corresponding gelling solutions the authors revealed CO different catalytic activity of the contacts in combustion (Table 2 ) in laboratory-scale plant which is a possible result of specific distribution of Pt in the samples.
261 8 Table 1 Comparison of some parameters of catalytic cracking units in the USSR with spherical and microspherical catalyst.
............................................................ catalytic cracking units
.................................... with spherical catalyst
with microspherical catalyst
............................................................ Unit capacities, re1 .% Average emission of carbon oxide in regeneration gases, t/day
69.5
30.5
8.0-14 0 80-120 ............................................................
Content of platinum in CO combustion PROMOTER, wt.% Quantity of CO combustion promoter in mixture with catalyst in reactorregenerator block in cracking units, wt.%
0.0005-0.0015
0.05-0.10
10-25
0.1-0.2
Table 2 Activity of spherical catalysts carbon oxide combustion.
promoted
by
platinum
in
To evaluate Pt distribution over a catalyst granule there were synthesized samples of zeolite zirconium silicate catalysts with separate Pt inclusion into zeolite and zirconium silicate matrix in amount of 0.12 wt%. For investigation there were used well polished mechanical
spalls of two samples which were put into the chamber of raster electron microscope JSM-820 (Japan) with microprobe analyzer ("Link" company Great Britain)/Q/. The X-ray Patterns were preliminary set t o characteristic spectrum lines of aluminium, zirconium and platinum. The areas of high element concentration in scanning range in the photograph will be white and black in those points where the given element is absent. Distribution of zeolitb particles (2-4 p m ) in matrix was determined from X-rays characteristic of zirconium and aluminium because in given samples these elements are concentrated in matrix and zeolite respectively. If silica alumina matrix were used it should be hardly possible to distinguish matrix from zeolite because both of them contain aluminium and silicium. Conglomeration of zeolite particle t h u s determined was studied in X-ray characteristic of platinum. As one can see in figurea 1 . 2 platinum included into the sample with zeolite suspension is mainly concentrated in zeolite particle.
Figure 1. X-ray patterns of zirconium, aluminium and platinum distribution in spall of catalyst sample with Pt introduced into zirconium silicate matrix.
Figure 2. X-ray patterns of zirconium, Platinum distribution in spall of catalyst introduced into zeolite suspension.
aluminium and sample with Pt
The authors relate higher oxidative activity of samples with platinum introduced into zeolite t o formation of AlaPt phase inactive in CO combustion. AlaPt phase was formed upon thermal steam treatment of the catalyst in regenerator according t o the hypothesis /3/. Obviously, its formation is more preferable in amorphous silica alumina matrix than in regular crystalline structure of zeolite. On the basis of the results acquired commercial lots of spherical promoters of CO combustion were produced and tested in Thermofor unit at Salavat Refinery. As can be seen from Table 3 spherical promoters ( a s an additive t o Zeokar-3 catalyst) containing platinum introduced into zeolite are more effective under commercial conditions used in operating cracking units.
Table 3. Changes in parameters of Thermofor cracking unit of Salavat Refinery using Zeokar-3F
............................................................ Mixture, catalyst/ promoter
Residual coke an catalysts, wt5
Average CO emission into atmosphere,t/day
Increase of gaso1 ine yield, wt.5
............................................................
---
Zeokar-3 + Zeokar-3tZeokar-3F2 Zeokar-3+Zeokar-3F4
base -0.25 -0.45
8 -0-14.0 4.0-6.0 2.0-3.5
base 1.1 1.8
1. F.D.Hartzwel1 and A.W. Chaster. Oil and Gas J., v 77, N 16 ( 1 9 7 9 ) 83 2. H.K.Magomadova, M.1. Levinbuk. Zeolite Usage in Catalysis, I V All-Union Conference, Moscow (1989), 204 3. N.A.Zakarina, G.D.Zakumbaeva, Petroleum Chemistry, N 1 ( 1 9 9 0 ) 40 4 . Raster Electron microscopy. Edited by Goldstein and H.Jakovit6. M i r Moscow ( 1 9 7 8 ) 29-466.