U.S. patent application number 12/175835 was filed with the patent office on 2009-01-22 for catalyst and process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock.
This patent application is currently assigned to CHINA PETROLEUM & CHEMICAL CORPORATION. Invention is credited to Minbo HOU, Xueli LI, Zhongneng LIU, Deju WANG, Jianqiang WANG, Zheming WANG.
Application Number | 20090023968 12/175835 |
Document ID | / |
Family ID | 40265389 |
Filed Date | 2009-01-22 |
United States Patent
Application |
20090023968 |
Kind Code |
A1 |
WANG; Deju ; et al. |
January 22, 2009 |
CATALYST AND PROCESS FOR PRODUCING LIGHT AROMATIC HYDROCARBONS AND
LIGHT ALKANES FROM HYDROCARBONACEOUS FEEDSTOCK
Abstract
The present invention provides a catalyst comprising metallic Pt
and/or Pd supported on a binder-free zeolite for producing light
aromatic hydrocarbons and light alkanes from hydrocarbonaceous
feedstock, wherein the amount of metallic Pt and/or Pd is of
0.01-0.8 wt %, preferably 0.01-0.5 wt % on the basis of the total
weight of the catalyst, and the binder-free zeolite is selected
from the group consisting of mordenite, beta zeolite, Y zeolite,
ZSM-5, ZSM-11 and composite or cocrystal zeolite thereof. The
present invention also provides a process for producing light
aromatic hydrocarbons and light alkanes from hydrocarbonaceous
feedstock using said catalyst.
Inventors: |
WANG; Deju; (Shanghai,
CN) ; LIU; Zhongneng; (Shanghai, CN) ; LI;
Xueli; (Shanghai, CN) ; HOU; Minbo; (Shanghai,
CN) ; WANG; Zheming; (Shanghai, CN) ; WANG;
Jianqiang; (Shanghai, CN) |
Correspondence
Address: |
SCULLY SCOTT MURPHY & PRESSER, PC
400 GARDEN CITY PLAZA, SUITE 300
GARDEN CITY
NY
11530
US
|
Assignee: |
CHINA PETROLEUM & CHEMICAL
CORPORATION
Beijing
CN
SHANGHAI RESEARCH INSTITUTE OF PETROCHEMICAL TECHNOLOGY
SINOPEC
Shanghai
CN
|
Family ID: |
40265389 |
Appl. No.: |
12/175835 |
Filed: |
July 18, 2008 |
Current U.S.
Class: |
585/323 ;
502/74 |
Current CPC
Class: |
B01J 29/068 20130101;
B01J 29/74 20130101; B01J 29/22 20130101; B01J 29/44 20130101; B01J
29/80 20130101; B01J 29/126 20130101; B01J 37/0009 20130101; B01J
29/405 20130101; B01J 37/0018 20130101; B01J 29/7415 20130101; B01J
37/10 20130101 |
Class at
Publication: |
585/323 ;
502/74 |
International
Class: |
C07C 5/00 20060101
C07C005/00; B01J 29/18 20060101 B01J029/18; B01J 29/40 20060101
B01J029/40; B01J 29/06 20060101 B01J029/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 18, 2007 |
CN |
200710043940.9 |
Jul 18, 2007 |
CN |
200710043941.3 |
Jul 18, 2007 |
CN |
200710043942.8 |
Claims
1. A catalyst comprising metallic Pt and/or Pd supported on a
binder-free zeolite for producing light aromatic hydrocarbons and
light alkanes from hydrocarbonaceous feedstock, wherein the amount
of metallic Pt and/or Pd is of 0.01-0.8 wt %, preferably 0.01-0.5
wt % on the basis of the total weight of the catalyst, and the
binder-free zeolite is selected from the group consisting of
mordenite, beta zeolite, Y zeolite, ZSM-5, ZSM-11 and composite or
cocrystal zeolite thereof.
2. The catalyst according to claim 1, wherein the binder-free
zeolite is ZSM-5, mordenite, beta zeolite, ZSM-5/USY composite
zeolite, ZSM-5/beta composite zeolite, or ZSM-5/ZSM-11 cocrystal
zeolite.
3. The catalyst according to claim 1, further comprising a promoter
selected from the group consisting of Cu, Zn, Sn, Pb, Fe and
mixture thereof in amount of less than 1 wt %, preferably less than
0.6 wt % on the basis of the total weight of the catalyst.
4. The catalyst according to claim 3, wherein the promoter is
selected from the group consisting of Zn, Sn, Pb and mixture
thereof.
5. The catalyst according to claim 4, wherein the promoter is
Zn.
6. The catalyst according to claim 1, wherein the binder-free
zeolite has a molar ratio SiO.sub.2/Al.sub.2O.sub.3 in range of
10-200, preferably 20-100.
7. The catalyst according to claim 2, further comprising a promoter
selected from the group consisting of Cu, Zn, Sn, Pb, Fe and
mixture thereof in amount of less than 1 wt %, preferably less than
0.6 wt % on the basis of the total weight of the catalyst.
8. The catalyst according to claim 7, wherein the promoter is
Zn.
9. The catalyst according to claim 8, wherein the binder-free
zeolite has a molar ratio SiO.sub.2/Al.sub.2O.sub.3 in range of
10-200, preferably 20-100.
10. A process for producing light aromatic hydrocarbons and light
alkanes from hydrocarbonaceous feedstock, comprising the following
steps: (a) introducing hydrogen and a hydrocarbonaceous feedstock
having boiling point in range of 30-250.degree. C. into at least
one reaction zone; (b) converting the hydrocarbonaceous feedstock
to an effluent enriched in light aromatic hydrocarbons of benzene,
toluene and xylene and light alkanes in the reaction zone in the
presence of the catalyst according to any one of claims 1 to 9,
wherein of the hydrocarbonaceous feedstock the heavy aromatic
hydrocarbons are subjected to hydrodealkylation and/or
transalkylation with light aromatic hydrocarbon, the light aromatic
hydrocarbons are subjected to isomerization and the non-aromatic
hydrocarbons are subjected to hydrocracking reaction; and (c)
recovering the light aromatic hydrocarbons and the light alkanes
respectively by passing the effluent through gas-liquid separation
and distillation sequentially, and the separated heavy fraction is
recycled to the reaction zone for further reaction.
11. The process according to claim 10, wherein in step (a) the
hydrocarbonaceous feedstock is introduced into the reaction zone at
a weight hour space velocity of 0.5-10 hr.sup.-1, preferably 1-4
hr.sup.-1, and the molar ratio of hydrogen to the hydrocarbonaceous
feedstock is of 0.5:1-10:1, preferably 2:1-8:1.
12. The process according to claim 10, wherein in step (b) the
reaction temperature is of 250-600.degree. C., preferably
300-500.degree. C., and the reaction pressure is of 0.5-5.0 MPa,
preferably 2.0-4.0 MPa.
13. The process according to claim 10, wherein the
hydrocarbonaceous feedstock is selected from the group consisting
of reformate, pyrolysis gasoline, naphtha and mixture thereof.
14. The process according to claim 10, wherein in step (c) passing
the effluent through a gas-liquid separator to obtain first
overhead stream comprising hydrogen, methane, ethane and LPG and
first bottom stream comprising aromatic hydrocarbons as well as
residual hydrogen and non-aromatic hydrocarbons, recovering LPG
from the first overhead stream; and passing the first bottom stream
through a distillation column to obtain second overhead stream
comprising residual hydrogen and non-aromatic hydrocarbons and
second bottom stream comprising aromatic hydrocarbons, further
recovering LPG from the second overhead stream, and recovering
aromatic hydrocarbons from the second bottom stream.
15. The process according to claim 11, wherein in step (b) the
reaction temperature is of 250-600.degree. C., preferably
300-500.degree. C., and the reaction pressure is of 0.5-5.0 MPa,
preferably 2.0-4.0 MPa
16. The process according to claim 11, wherein the
hydrocarbonaceous feedstock is selected from the group consisting
of reformate, pyrolysis gasoline, naphtha and mixture thereof.
17. The process according to claim 11, wherein in step (c) passing
the effluent through a gas-liquid separator to obtain first
overhead stream comprising hydrogen, methane, ethane and LPG and
first bottom stream comprising aromatic hydrocarbons as well as
residual hydrogen and non-aromatic hydrocarbons, recovering LPG
from the first overhead stream; and passing the first bottom stream
through a distillation column to obtain second overhead stream
comprising residual hydrogen and non-aromatic hydrocarbons and
second bottom stream comprising aromatic hydrocarbons, further
recovering LPG from the second overhead stream, and recovering
aromatic hydrocarbons from the second bottom stream.
Description
TECHNICAL FIELD
[0001] The present invention relates to a catalyst as well as the
corresponding process for producing light aromatic hydrocarbons and
light alkanes from hydrocarbonaceous feedstock.
BACKGROUND ART
[0002] Regarding the separation of aromatic hydrocarbons
BTX,i.e.benzene, toluene and xylene, from non-aromatic
hydrocarbons, some catalytic conversion processes have been
developed in the prior art. For example, U.S. Pat. No. 3,729,409
disclosed converting non-aromatic hydrocarbons to lower alkanes by
hydrocracking reaction and then separating aromatic hydrocarbons
from non-aromatic hydrocarbons through gas-liquid separation; U.S.
Pat. No. 5,865,986 and U.S. Pat. No. 6,001,241 disclosed a process
for upgrading naphtha fraction, wherein a zeolite-based catalyst is
used in some reactors to improve the production of aromatic
hydrocarbons; and CN1217892C disclosed a similar process, wherein
reformate, pyrolysis gasoline and the like are upgrade to produce
LPG and light aromatic hydrocarbons.
[0003] The acidic catalyst used in these catalytic conversion
processes would deactivate quickly due to coke and/or
carbon-deposition, although this can be alleviated by supporting
the metals with high hydrogenation activity and the hydrogenation
activity of the catalyst also can be adjusted by varying the amount
and/or the distribution of the supported metals, however, too high
hydrogenation activity on the metallic center may result in side
reaction of saturation of aromatic rings. With this regard, U.S.
Pat. No. 5,865,986 proposed to adjust the metallic activity with
sulfur compounds. Furthermore, U.S. Pat. No. 6,001,241 proposed to
use Pb or Bi to control the degree of hydrogenation.
[0004] On the other hand, the zeolite molecular sieve powder used
for said catalysts are generally manufactured into shaped particles
with certain mechanical strengths and shapes, and during this
manufacture some binders e.g. oxides such as Al.sub.2O.sub.3,
SiO.sub.2, TiO.sub.2 and the like as well as clay minerals are
needed usually. This is because the shaped catalysts are widely
used in industries and have to suffer from various stresses during
its use, thus, sufficient mechanical strengths are necessary for
ensuring the whole catalytic process to be conducted smoothly,
otherwise if the shaped catalysts have poor mechanical strengths,
some problems such as the lines being blocked by fine powders, the
liquid being distributed unevenly, the pressure drop being
increased and the like would be introduced, so as to lead to poor
catalytic efficiency, and even a unexpected shut-down in worse
case.
[0005] However, introduction of binders during shaping the zeolite
powders would reduce the concentration of effective components in
the zeolite particles, result in reduced effective surface area,
thus the adsorption value would be reduced. This is because some
binders would enter into part of channels of the zeolite or block
part of pores of the zeolite, thus limiting the diffusion,
resulting in poor adsorption ability and adsorption selectivity as
well as reduced rates of adsorption and desorption, further the
reduced activity and selectivity in the catalytic reactions;
furthermore, undesired side reactions may be initiated in the
presence of binders.
[0006] Regarding the above-mentioned disadvantages in connection
with the introduction of binders during shaping the zeolite
powders, the inventors have tried to develop a process for
producing a binder-free zeolite, c.f. CN1915820A, which is
incorporated herein by reference. The binder-free zeolite means
that the shaped zeolite particles do not comprise inert binders,
thus having high concentration of zeolite and large available
surface area, furthermore, better properties in adsorption
separation and ion exchange as well as better catalytic properties
in some reactions are shown.
[0007] Based on the above-mentioned finding, the inventors further
tried to develop a catalyst using said binder-free zeolite
particles as support. Said catalyst has higher catalytic activity
and stability and can be used for producing light aromatic
hydrocarbons and light alkanes from hydrocarbonaceous
feedstock.
SUMMARY OF THE INVENTION
[0008] The present invention provides a catalyst for producing
light aromatic hydrocarbons and light alkanes from
hydrocarbonaceous feedstock, wherein the binder-free zeolite was
used to support noble metals as catalytic active components, so the
catalyst possesses the advantages such as large acid density,
unobstructed pores, moderate hydrogenation activity and the like,
thus possessing excellent activity and stability.
[0009] Furthermore, the present invention provides a process for
producing light aromatic hydrocarbons and light alkanes from
hydrocarbonaceous feedstock using said catalyst, which process
makes the separation of hydrocarbonaceous feedstock easier and
brings higher additional values to heavy aromatic hydrocarbons and
non-aromatic hydrocarbons.
[0010] Specifically, the present invention provides a catalyst
comprising metallic Pt and/or Pd supported on a binder-free zeolite
for producing light aromatic hydrocarbons and light alkanes from
hydrocarbonaceous feedstock, wherein the amount of metallic Pt
and/or Pd is of 0.01-0.8 wt %, preferably 0.01-0.5 wt % on the
basis of the total weight of the catalyst, and the binder-free
zeolite is selected from the group consisting of mordenite, beta
zeolite, Y zeolite, ZSM-5, ZSM-11 and composite or cocrystal
zeolite thereof.
[0011] According to the catalyst of the present invention, the
binder-free zeolite preferably is selected from the group
consisting of ZSM-5, mordenite, beta zeolite, ZSM-5/USY composite
zeolite, ZSM-5/beta composite zeolite, or ZSM-5/ZSM-11 cocrystal
zeolite.
[0012] According to the catalyst of the present invention, it may
further comprise a promoter selected from the group consisting of
Cu, Zn, Sn, Pb, Fe and mixture thereof, preferably from the group
consisting of Zn, Sn, Pb and mixture thereof, most preferably Zn,
in amount of less than 1 wt %, preferably less than 0.6 wt % on the
basis of the total weight of the catalyst.
[0013] According to the catalyst of the present invention, wherein
the binder-free zeolite has a molar ratio SiO.sub.2/Al.sub.2O.sub.3
in range of 10-200, preferably 20-100, and a pore size of about 4-8
.ANG., preferably 5-7 .ANG. generally.
[0014] According to the catalyst of the present invention, the
acidic center can be adjusted by varying the molar ratio
SiO.sub.2/Al.sub.2O.sub.3 of the binder-free zeolite, and the
hydrogenation activity can be adjusted by varying the supported
amount of Pt and/or Pd as well as the distribution thereof, thus
making the acidic center and metallic center of the catalyst match
with each other.
[0015] Furthermore, when using Pt and Pd in combination as
catalytic active metals, the catalyst of the present invention may
possess better sulfur resistance without compromising the excellent
hydrogenation property, thus it can be adapted to the feedstock
comprising sulfur compounds such as pyrolysis gasoline very well.
This is because when being used in combination rather than being
present separately in the catalyst, some electrical or chemical
effects are occurring between Pt and Pd by complex thereof, so that
providing excellent hydrogenation and sulfur resistance
properties.
[0016] The catalyst according to the present invention can be
prepared as following: firstly synthesizing Na-type binder-free
zeolite, converting the Na-type binder-free zeolite into H-type
binder-free zeolite by ion exchange with ammonium salt solution or
acid solution such as hydrochloric acid and the like followed by
calcination, then supporting Pt and/or Pd as catalytic active
metals thereon by ion exchange or impregnation, finally drying the
obtained catalyst at a temperature of less than 200.degree. C. and
calcining the same at a temperature of 300-600.degree. C.
[0017] During the above-mentioned preparation, the precursor of the
catalytic active metals can be the aqueous solutions of palladium
chloride, palladium nitrate, palladic chloride, palladous chloride,
ammonium palladic chloride, ammonium palladous chloride, platinum
nitrate, platinum chloride, platinic chloride, platinous chloride,
ammonium platonic chloride, ammonium platinous chloride,
tetraammineplatinum chloride and mixture thereof; furthermore, a
promoter selected from the group consisting of Cu, Zn, Sn, Pb, Fe
and mixture thereof can be added in amount of less than 1 wt %,
preferably less than 0.6 wt % on the basis of the total weight of
the catalyst to adjust the hydrogenation activity of the catalytic
active metals.
[0018] Furthermore, the present invention provides a process for
producing light aromatic hydrocarbons and light alkanes from
hydrocarbonaceous feedstock, comprising the following steps:
[0019] (a) introducing hydrogen and a hydrocarbonaceous feedstock
having boiling point in range of 30-250.degree. C. into at least
one reaction zone;
[0020] (b) converting the hydrocarbonaceous feedstock to an
effluent enriched in light aromatic hydrocarbons of benzene,
toluene and xylene and light alkanes in the reaction zone in the
presence of the catalyst according to the present invention,
wherein of the hydrocarbonaceous feedstock the heavy aromatic
hydrocarbons are subjected to hydrodealkylation and/or
transalkylation with light aromatic hydrocarbon, the light aromatic
hydrocarbons are subjected to isomerization and the non-aromatic
hydrocarbons are subjected to hydrocracking reaction; and
[0021] (c) recovering the light aromatic hydrocarbons and the light
alkanes respectively by passing the effluent through gas-liquid
separation and distillation sequentially, and the separated heavy
fraction is recycled to the reaction zone for further reaction.
[0022] In the process for producing light aromatic hydrocarbons and
light alkanes from hydrocarbonaceous feedstock according to the
present invention, wherein:
[0023] in step (a), the hydrocarbonaceous feedstock is introduced
into the reaction zone at a weight hour space velocity of 0.5-10
hr.sup.-1, preferably 1-4 hr.sup.-1, and the molar ratio of
hydrogen to the hydrocarbonaceous feedstock is of 0.5:1-10:1,
preferably 2:1-8:1, wherein the hydrocarbonaceous feedstock is
selected from the group consisting of reformate, pyrolysis
gasoline, naphtha and mixture thereof;
[0024] in step (b), the reaction temperature is of 250-600.degree.
C., preferably 300-500.degree. C., and the reaction pressure is of
0.5-5.0 MPa, preferably 2.0-4.0 MPa; and
[0025] in step (c), passing the effluent through a gas-liquid
separator to obtain first overhead stream comprising hydrogen,
methane, ethane and LPG and first bottom stream comprising aromatic
hydrocarbons as well as residual hydrogen and non-aromatic
hydrocarbons, recovering LPG from the first overhead stream; and
passing the first bottom stream through a distillation column to
obtain second overhead stream comprising residual hydrogen and
non-aromatic hydrocarbons and second bottom stream comprising
aromatic hydrocarbons, further recovering LPG from the second
overhead stream, and recovering aromatic hydrocarbons from the
second bottom stream.
[0026] In the process for producing light aromatic hydrocarbons and
light alkanes from hydrocarbonaceous feedstock according to the
present invention, a target product can be obtained by varying the
feedstock or the composition of the feedstock, e.g. a feedstock
with high concentration of aromatic hydrocarbons such as reformate
and pyrolysis gasoline can be used to improve the yield of aromatic
hydrocarbons, and a feedstock with high concentration of
non-aromatic hydrocarbons such as naphtha can be used to obtain LPG
primarily.
[0027] In the process for producing light aromatic hydrocarbons and
light alkanes from hydrocarbonaceous feedstock according to the
present invention, in the presence of the catalyst according to the
present invention, benzene, toluene and xylene (BTX), which are
important raw organic materials in petrochemical industry, can be
obtained through some simultaneous reactions of hydrocracking
reaction of non-aromatic hydrocarbons as well as hydrodealkylation,
transalkylation and isomerization of aromatic hydrocarbons; at the
same time, light alkanes including LPG are produced as by
products.
[0028] In the process for producing light aromatic hydrocarbons and
light alkanes from hydrocarbonaceous feedstock according to the
present invention, of the reactions in step (b), hydrocracking
reaction is most important because the non-aromatic hydrocarbons in
the hydrocarbonaceous feedstock are hydrocracked into light alkanes
enriched in LPG, thus the solvent extraction and the like are not
necessary for the separation of aromatic hydrocarbons from
non-aromatic hydrocarbons; furthermore, hydrodealkylation,
transalkylation and isomerization upgrade the aromatic hydrocarbons
in the hydrocarbonaceous feedstock, e.g., C.sub.9.sup.+ aromatic
hydrocarbons used as fuel oils can be converted into benzene,
toluene and xylene (BTX) through dealkylation, toluene and xylene
can be produced through transalkylation between benzene and
C.sub.9.sup.+ aromatic hydrocarbons, and C.sub.8 aromatic
hydrocarbons can be subjected to isomerization furthermore; on the
other hand, some olefinic intermediates such as ethylene and
propylene can be produced during hydrocracking and dealkylation,
however, they will be hydrogenated to saturation quickly, so the
catalyst will not deactivate due to the coke resulted from olefins
polymerization and the aromatic hydrocarbons in the product will
not degrade due to transalkylation between olefins and light
aromatic hydrocarbons.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Now the present invention is further described in details by
following non-limiting examples.
EXAMPLE 1
[0030] A mixture of a solution of tetrapropylammonium hydroxide
(TPAOH), tetraethyl orthosilicate (TEOS) and water in molar ratio
of (TPA).sub.2O:5.5TEOS:90H.sub.2O was stirred homogeneously, then
aged and refluxed for 3-day at 80.degree. C. to obtain ZSM-5 seed
crystal orienting agent. Dosing 180 g white carbon black, 10 g
sesbania flour, an aqueous solution of 19.7 g sodium aluminate and
40 g ZSM-5 seed crystal orienting agent, further adding 230 g
silica sol(40 wt %) and required amount of water, then kneading and
drying to obtain a cylindrical precursor. In a reaction vessel, to
which a mixture of 35 g ethylenediamine and 5 g distilled water was
pre-added, 150 g cylindrical precursor as above-prepared was placed
on a porous stainless steel screen therein, and a vapor-solid phase
treatment was carried out at 160.degree. C. for 5-day after sealing
the reaction vessel. The product was washed with distilled water
and dried, then was calcined at 550.degree. C. in air. The calcined
product was demonstrated to be a binder-free ZSM-5 zeolite by XRD
characterization and has a molar ratio SiO.sub.2/Al.sub.2O.sub.3 of
54.6 and a compressive strength of 50 N/mm as determined. Then the
binder-free ZSM-5 zeolite was converted into H-type zeolite through
ion exchange with a solution of ammonium nitrate and calcination.
Supporting 0.15 wt %Pd and 0.15 wt %Pt on the H-type binder-free
ZSM-5 zeolite by impregnation, then calcining at 400.degree. C. for
4-hour to prepare catalyst A.
EXAMPLE 2
[0031] Mixing 100 g white carbon black, 20 g USY zeolite with a
molar ratio SiO.sub.2/Al.sub.2O.sub.3 of 16 and 20 g ZSM-5 seed
crystal orienting agent from example 1, adding aqueous solution of
26 g Al.sub.2(SO.sub.4).sub.3.18H.sub.2O to adjust the Si/Al ratio,
further adding 150 g silica sol(40 wt %), then kneading and drying
to obtain a cylindrical precursor. In a reaction vessel, to which a
mixture of 34 g ethylamine and 5 g distilled water was pre-added,
100 g cylindrical precursor as above-prepared was placed on a
porous stainless steel screen therein, and a vapor-solid phase
treatment was carried out at 180.degree. C. for 5-day after sealing
the reaction vessel. The product was washed with distilled water
and dried, then was calcined at 550.degree. C. in air. The calcined
product was demonstrated to be a binder-free ZSM-5/USY composite
zeolite by XRD characterization, ZSM-5 zeolite and USY zeolite
therein are at amounts of 91 wt % and 9 wt % respectively as
determined through quantitative analysis by XRD, ZSM-5 zeolite
therein has a molar ratio SiO.sub.2/Al.sub.2O.sub.3 of 68.1 as
determined and a determined compressive strength of the calcined
product is of 85 N/mm. And it was shown by SEM that ZSM-5 zeolite
and USY zeolite are cross-growing in the calcined product. Then the
binder-free ZSM-5/USY composite zeolite was converted into H-type
zeolite through ion exchange with a solution of ammonium nitrate
and calcination. Supporting 0.3 wt %Pd on the H-type binder-free
ZSM-5/USY composite zeolite by ion exchange, then calcining at
400.degree. C. for 4-hour to prepare catalyst B.
EXAMPLE 3
[0032] Mixing 180 g white carbon black, 140 g beta zeolite with a
molar ratio SiO.sub.2/Al.sub.2O.sub.3 of 20 and 40 g ZSM-5 seed
crystal orienting agent from example 1, adding an aqueous solution
of 110 g Al.sub.2(SO.sub.4).sub.3.18H.sub.2O to adjust the Si/Al
ratio, further adding 220 g silica sol(40 wt %), then kneading and
drying to obtain a cylindrical precursor. In a reaction vessel, to
which a mixture of 40 g ethylamine and 5 g distilled water was
pre-added, 100 g cylindrical precursor as above-prepared was placed
on a porous stainless steel screen therein, and a vapor-solid phase
treatment was carried out at 150.degree. C. for 7-day after sealing
the reaction vessel. The product was washed with distilled water
and dried, then was calcined at 550.degree. C. in air. The calcined
product was demonstrated to be a binder-free ZSM-5/beta composite
zeolite by XRD characterization, ZSM-5 zeolite and beta zeolite
therein are at amounts of 70.5 wt % and 29.5 wt % respectively as
determined through quantitative analysis by XRD, ZSM-5 zeolite
therein has a molar ratio SiO.sub.2/Al.sub.2O.sub.3 of 26.5 as
determined and a determined compressive strength of the calcined
product is of 87 N/mm. And it was shown by SEM that ZSM-5 zeolite
and beta zeolite are cross-growing in the calcined product. Then
the binder-free ZSM-5/beta composite zeolite was converted into
H-type zeolite through ion exchange with a solution of ammonium
nitrate and calcination. Supporting 0.10 wt %Pd and 0.10 wt %Pt on
the H-type binder-free ZSM-5/beta composite zeolite by ion
exchange, then calcining at 400.degree. C. for 4-hour to prepare
catalyst C.
EXAMPLE 4
[0033] Supporting 0.20 wt %Pt and 0.15 wt %Cu on the H-type
binder-free ZSM-5 zeolite prepared in example 1 by ion exchange,
then calcining at 400.degree. C. for 4-hour to prepare catalyst
D.
EXAMPLE 5
[0034] Mixing 120 g white carbon black, 5 g sesbania flour, 22.4 g
sodium aluminate with an amount of Al.sub.2O.sub.3 of 43 wt % and
200 g beta zeolite with a molar ratio SiO.sub.2/Al.sub.2O.sub.3 of
30, further adding 300 g silica sol (40 wt %), then kneading and
drying to obtain a cylindrical precursor. A mixture of 60 g
cylindrical precursor as above-prepared and 83 g solution of
tetraethylammonium hydroxide (TEAOH)(13 wt %) was charged into a
crystallization vessel to experience a hydrothermal treatment at
145.degree. C. for 4-day therein. The product was washed with
distilled water and dried, then was calcined at 550.degree. C. in
air. The calcined product was demonstrated to be a binder-free beta
zeolite by XRD characterization and has a molar ratio
SiO.sub.2/Al.sub.2O.sub.3 of 40 and a compressive strength of 58
N/mm as determined. Then the binder-free beta zeolite was converted
into H-type zeolite through ion exchange with a solution of
ammonium nitrate and calcination. Supporting 0.15 wt %Pd and 0.15
wt %Pt on the H-type binder-free beta zeolite by ion exchange, then
calcining at 400.degree. C. for 4-hour to prepare catalyst E.
EXAMPLE 6
[0035] Mixing 180 g white carbon black, 12 g sesbania flour, 50 g
SiO.sub.2-containing pseudo-boehmite powder (SiO.sub.2O:26 wt %,
Al.sub.2O.sub.3:44 wt % and H.sub.2O:30 wt %), 21 g sodium
hydroxide, 60 g mordenite with a molar ratio
SiO.sub.2/Al.sub.2O.sub.3 of 20 and 550 g silica sol(40 wt %), then
kneading and drying to obtain a cylindrical precursor. A mixture of
60 g cylindrical precursor as above-prepared and 120 g solution of
sodium hydroxide (2.5 wt %) was charged into a crystallization
vessel to experience a hydrothermal treatment at 160.degree. C. for
3-day therein. The product was washed with distilled water and
dried, then was calcined at 550.degree. C. in air. The calcined
product was demonstrated to be a binder-free mordenite zeolite by
XRD characterization and has a molar ratio
SiO.sub.2/Al.sub.2O.sub.3 of 30 and a compressive strength of 65
N/mm as determined. Then the binder-free mordenite was converted
into H-type zeolite through ion exchange with a solution of
ammonium nitrate and calcination. Supporting 0.15 wt %Pd and
0.15%wtPt on the H-type binder-free mordenite by ion exchange, then
calcining at 400.degree. C. for 4-hour to prepare catalyst F.
EXAMPLE 7
[0036] A mixture of a solution of tetrabutylammonium hydroxide
(TBAOH), tetraethyl orthosilicate (TEOS) and water in molar ratio
of (TBA).sub.2O:6.22TEOS:163H.sub.2O was stirred homogeneously,
then aged and refluxed at 95.degree. C. for 3-day to obtain ZSM-11
seed crystal orienting agent. Dosing 200 g white carbon black, 12.5
g sesbania flour, 36 g SiO.sub.2-containing pseudo-boehmite powder
(SiO.sub.2:26 wt %, Al.sub.2O.sub.3:44 wt % and H.sub.2O:30 wt %)
and 51 g ZSM-11 seed crystal orienting agent, adding 20 g aqueous
solution of sodium hydroxide, further adding 475 g silica sol(40 wt
%), then kneading and drying to obtain a cylindrical precursor. A
mixture of 40 g cylindrical precursor as above-prepared and 80 g
solution of tetrabutylammonium hydroxide (TBAOH)(8 wt %) was
charged into a crystallization vessel to experience a hydrothermal
treatment at 160.degree. C. for 3-day therein. The product was
washed with distilled water and dried, then was calcined at
550.degree. C. in air. The calcined product was demonstrated to be
a binder-free ZSM-11 zeolite by XRD characterization and has a
molar ratio SiO.sub.2/Al.sub.2O.sub.3 of 43 and a compressive
strength of 55 N/mm as determined. Then the binder-free ZSM-11
zeolite was converted into H-type zeolite through ion exchange with
a solution of ammonium nitrate and calcination. Supporting 0.15 wt
%Pd and 0.15 wt %Pt on the H-type binder-free ZSM-11 zeolite by
impregnation, then calcining at 400.degree. C. for 4-hour to
prepare catalyst G.
EXAMPLE 8
[0037] Mixing 200 g white carbon black and 80 g Na-type ZSM-5
zeolite with a molar ratio SiO.sub.2/Al.sub.2O.sub.3 of 60, adding
26 g sodium aluminate with an amount of Al.sub.2O.sub.3 of 43 wt %
to adjust the Si/Al ratio, further adding 45 g ZSM-5 seed crystal
orienting agent from example 1, further adding 410 g silica sol (40
wt %) and 30 g water, then kneading and drying to obtain a
cylindrical precursor. In a reaction vessel, to which a mixture of
34 g ethylamine and 5 g distilled water was pre-added, 100 g
cylindrical precursor as above-prepared was placed on a porous
stainless steel screen therein, and a vapor-solid phase treatment
was carried out at 180.degree. C. for 5-day after sealing the
reaction vessel. The product was washed with distilled water and
dried, then was calcined at 550.degree. C. in air. The calcined
product was demonstrated to be a binder-free ZSM-5 zeolite by XRD
characterization and has a molar ratio SiO.sub.2/Al.sub.2O.sub.3 of
56 and a compressive strength of 11ON/mm as determined. Then the
binder-free ZSM-5 zeolite was converted into H-type zeolite through
ion exchange with a solution of ammonium nitrate and calcination.
Supporting 0.04 wt %Pd and 0.04 wt %Pt on the H-type binder-free
ZSM-5 zeolite by ion exchange, then calcining at 430.degree. C. for
4-hour to prepare catalyst H.
EXAMPLE 9
[0038] Supporting 0.04 wt %Pt and 0.13 wt %Pb on the H-type
binder-free ZSM-5 zeolite prepared in example 8 by ion exchange,
then calcining at 400.degree. C. for 4-hour to prepare catalyst
1.
EXAMPLE 10
[0039] Supporting 0.01 wt %Pt and 0.03 wt %Sn on the H-type
binder-free ZSM-5 zeolite prepared in example 8 by ion exchange,
then calcining at 400.degree. C. for 4-hour to prepare catalyst
J.
[0040] In order to evaluate the properties, testing the
above-prepared catalysts A-J in a fixed bed reactor under following
conditions:
[0041] Composition of the hydrocarbonaceous feedstock ( wt %):
<C.sub.6 non-aromatic hydrocarbons 3.99, C.sub.6-8 non-aromatic
hydrocarbons 3.563, C.sub.6-8 aromatic hydrocarbons 71.662 (wherein
ethylbenzene 5.14 and xylene 9.142), C.sub.9 15.471 (wherein indane
2.466), and C10.sup.+ 5.314 (wherein tetrahydrodicyclopentadiene
4.481); and
[0042] Process conditions: hydrogen pressure 3.0 MPa, H.sub.2/oil
volume ratio 400, inlet temperature 400.degree. C., and WHSV
2.0-4.0 hr.sup.-1.
[0043] The results of reaction are shown in table 1.
TABLE-US-00001 TABLE 1 Test results on catalysts Catalyst A B C D E
F G H I J WHSV/hr.sup.-1 3.7 3.0 3.0 3.0 3.0 2.5 2.0 2.0 2.0 2.0
Distribution <C.sub.6 14.90 14.31 13.25 13.53 13.98 14.40 15.02
15.50 13.78 13.27 of reaction non-aromatic product hydrocarbons (wt
%) C.sub.6-8 aromatic 79.48 78.65 75.86 76.08 78.99 79.21 81.92
82.05 82.4 81.0 hydrocarbons C.sub.6-8 0.18 0.095 0.37 0.23 0.27
0.18 0.056 0.051 0.015 0.03 non-aromatic hydrocarbons C.sub.9 3.50
3.87 4.02 3.45 3.78 3.21 2.95 2.78 2.56 3.56 Ethylbenzene 0.69 1.50
2.80 2.20 3.20 2.9 0.90 0.95 0.80 1.20 Xylene 11.38 11.72 10.58
11.26 12.05 12.10 11.80 11.72 11.50 12.0 Conversion of C.sub.6-8
94.95 97.00 89.62 93.54 92.42 94.95 98.43 98.57 99.6 99.2
non-aromatic hydrocarbons (%) Conversion of C.sub.9 (%) 77.38 75.00
74.02 77.70 75.57 79.25 80.93 82.03 83.45 76.99
COMPARATIVE EXAMPLES 1-2
[0044] Using silica and alumina as binders, shaping raw H-type
ZSM-5 zeolite powder with a molar ratio SiO.sub.2/Al.sub.2O.sub.3
of 60, drying and then calcining at 550.degree. C. for 4-hour to
prepare a shaped H-type ZSM-5 zeolite comprising 28.6 wt % of
silica as binder and a shaped H-type ZSM-5 zeolite comprising 34.4
wt % of alumina as binder respectively. Supporting 0.04 wt %Pt and
0.13 wt %Pb on both of the above-prepared H-type ZSM-5 zeolites by
impregnation, and then calcining at 450.degree. C. for 4-hour to
prepare catalysts R and S.
[0045] In order to evaluate the properties, testing the
above-prepared catalysts R-S in a fixed bed reactor, wherein the
feedstocks and the process conditions being same as that in example
9.
[0046] The results of reaction are shown in table 2.
TABLE-US-00002 TABLE 2 Test results on catalysts Catalyst R S
Distribution <C.sub.6 non-aromatic 11.22 13.83 of reaction
hydrocarbons product C.sub.6-8 aromatic hydrocarbons 74.82 75.02
(wt %) C.sub.6-8 non-aromatic 0.27 0.18 hydrocarbons C.sub.9 8.37
6.89 Ethylbenzene 4.12 3.6 Xylene 9.32 9.18 Conversion of C.sub.6-8
non-aromatic 92.42 94.95 hydrocarbons (%) Conversion of C.sub.9 (%)
45.90 55.46
[0047] As can be seen from the data in tables 1-2, under the same
process conditions, compared with the catalysts based on zeolite
comprising binders in the prior art, the catalyst based on
binder-free zeolite according to the present invention shows much
better activities for hydrodealkylation and cracking reaction,
specifically, the conversion of C.sub.9 is much higher.
EXAMPLE 11
[0048] Supporting 0.04 wt %Pt and 0.13 wt %Sn on the H-type
binder-free ZSM-5 zeolite prepared in example 1 by ion exchange,
then calcining at 450.degree. C. for 4-hour to prepare catalyst
K.
EXAMPLE 12
[0049] Supporting 0.5 wt %Pd on the H-type binder-free ZSM-5
zeolite prepared in example 1 by ion exchange, then calcining at
450.degree. C. for 4-hour to prepare catalyst L.
EXAMPLE 13
[0050] Supporting 0.04 wt %Pd and 0.04 wt %Pt on the H-type
binder-free ZSM-5 zeolite prepared in example 1 by ion exchange,
then calcining at 450.degree. C. for 4-hour to prepare catalyst
M.
[0051] In order to evaluate the properties, testing the
above-prepared catalysts K-M in a fixed bed reactor under following
conditions:
[0052] Composition of the hydrocarbonaceous feedstock ( wt %):
<C.sub.6 non-aromatic hydrocarbons 2.33, C.sub.6-8 non-aromatic
hydrocarbons 2.393, C.sub.6-8 aromatic hydrocarbons 76.578 (wherein
ethylbenzene 6.748 and xylene 8.884), C.sub.9 12.49 (wherein indane
3.425), C.sub.10.sup.+ 6.206 (wherein tetrahydrodicyclopentadiene
3.318), bromine value 14.00 g Br.sub.2/100 g of the feedstock, and
sulfur concentration 105 ppm; and
[0053] Process conditions: hydrogen pressure 3.0 MPa, H.sub.2/oil
volume ratio 500, inlet temperature 350-370.degree. C., and WHSV
2.0-5.0 hr.sup.-1.
[0054] The results of reaction are shown in table 3. The data show
that a better conversion of C.sub.9 can be obtained with the
catalyst according to the present invention, even though the
feedstock comprises sulfur and unsaturated components.
TABLE-US-00003 TABLE 3 Test results on catalysts Catalyst K L M
Inlet temperature .degree. C. 350 370 370 WHSV/hr.sup.-1 4.2 2.1
2.1 Distribution <C.sub.6 non-aromatic 10.14 8.93 9.59 of
reaction hydrocarbons product C.sub.6-8 aromatic hydrocarbons 84.21
81.12 82.78 (wt %) C.sub.6-8 non-aromatic 0 0.12 0 hydrocarbons
C.sub.9 2.78 3.98 2.98 Ethylbenzene 1.88 2.51 1.68 Xylene 9.69 8.96
9.07 Conversion of C.sub.6-8 non-aromatic 100 94.98 100
hydrocarbons (%) Conversion of C.sub.9 (%) 77.74 68.13 76.14
EXAMPLE 14
[0055] Supporting 0.05 wt %Pt and 0.08 wt %Zn on the H-type
binder-free ZSM-5 zeolite prepared in example 8 by ion exchange,
then calcining at 400.degree. C. for 4-hour to prepare catalyst
N.
EXAMPLE 15
[0056] A mixture of 40 g cylindrical precursor prepared in example
7 and 80 g solution comprising 5 wt % of tetrabutylammonium
hydroxide (TBAOH) and 3 wt % of tetrapropylammonium
hydroxide(TPAOH) was charged into a crystallization vessel to
experience a hydrothermal treatment at 170.degree. C. for 3-day
therein. The product was washed with distilled water and dried,
then was calcined at 550.degree. C. in air. The calcined product
was demonstrated to be a binder-free ZSM-5/ZSM-11 cocrystal zeolite
by XRD characterization and has a molar ratio
SiO.sub.2/Al.sub.2O.sub.3 of 42.9 and a compressive strength of 62
N/mm as determined. Then the binder-free ZSM-5/ZSM-11 cocrystal
zeolite was converted into H-type zeolite through ion exchange with
a solution of ammonium nitrate and calcination. Supporting 0.05 wt
%Pt and 0.08 wt %Zn on the H-type binder-free ZSM-5/ZSM-11
cocrystal zeolite by impregnation, then calcining at 400.degree. C.
for 4-hour to prepare catalyst O.
[0057] In order to evaluate the properties, testing the
above-prepared catalysts N-O in a fixed bed reactor by running for
1000-hour continuously under following conditions:
[0058] Composition of the hydrocarbonaceous feedstock (wt %):
<C.sub.6 non-aromatic hydrocarbons 0.144, C.sub.6-8 non-aromatic
hydrocarbons 2.985, C.sub.6-8 aromatic hydrocarbons 52.098 (wherein
ethylbenzene 8.145 and xylene 9.892), C.sub.9 30.069 (wherein
indane 8.084), and C.sub.10.sup.+ 14.704 (wherein
tetrahydrodicyclopentadiene 3.408); and
[0059] Process conditions: hydrogen pressure 3.0 MPa, H.sub.2/oil
volume ratio 500, inlet temperature 380.degree. C., and WHSV 2.1
hr.sup.-1.
[0060] The results of reaction after running for 1000-hour are
shown in table 4.
TABLE-US-00004 TABLE 4 Test results on catalysts Catalyst N O
Distribution of <C.sub.6 non-aromatic hydrocarbons 18.56 20.43
reaction C.sub.6-8 aromatic hydrocarbons 71.30 72.54 product
C.sub.6-8 non-aromatic hydrocarbons 0.26 0.10 (wt %) C.sub.9 4.17
2.73 Ethylbenzene 0.42 0.36 Xylene 17.17 10.02 Conversion of
C.sub.6-8 non-aromatic hydrocarbons 91.29 96.65 (%) Conversion of
C.sub.9 (%) 86.13 90.92
[0061] As can be seen from the data in table 4, as to the catalyst
according to the present invention, when Zn being used as the
promoter, a higher conversion of C.sub.9 can be obtained, and when
ZSM-5/ZSM-11 cocrystal zeolite being used, the conversion of
C.sub.9 can be improved furthermore.
EXAMPLE 16
[0062] Supporting 0.35 wt %Pd and 0.60 wt %Zn on the H-type
binder-free ZSM-5 zeolite prepared in example 8 by ion exchange,
then calcining at 400.degree. C. for 4-hour to prepare catalyst
P.
[0063] In order to evaluate the properties, testing catalyst P in a
fixed bed reactor under following conditions:
[0064] Composition of the hydrocarbonaceous feedstock (wt %):
C.sub.6-8 aromatic hydrocarbons 11.552 (wherein ethylbenzene 2.367
and xylene 9.185), C.sub.9 66.203 (wherein indane 17.154), and
C.sub.10.sup.+ 22.245 (wherein tetrahydrodicyclopentadiene 15.155);
and
[0065] Process conditions: hydrogen pressure 3.0 MPa, H.sub.2/oil
volume ratio 800, inlet temperature 380.degree. C., and WHSV 2.0
hr.sup.-1.
[0066] The results of reaction are shown in table 5.
EXAMPLE 17
[0067] Supporting 0.04 wt %Pt, 0.12 wt %Pd and 0.20 wt %Zn on the
H-type binder-free ZSM-5 zeolite prepared in example 8 by ion
exchange, then calcining at 400.degree. C. for 4-hour to prepare
catalyst Q.
[0068] In order to evaluate the properties, testing catalyst Q in a
fixed bed reactor under following conditions:
[0069] Composition of the hydrocarbonaceous feedstock (wt %):
C.sub.6-8 aromatic hydrocarbons 11.704 (wherein ethylbenzene 2.121
and xylene 9.031), C.sub.9 62.627 (wherein indane 16.546), and
C.sub.10.sup.+ 25.669 (wherein tetrahydrodicyclopentadiene 16.702);
and
[0070] Process conditions: hydrogen pressure 3.0 MPa, H.sub.2/oil
volume ratio 800, inlet temperature 380.degree. C., and WHSV 2.0
hr.sup.-1.
[0071] The results of reaction are shown in table 5.
TABLE-US-00005 TABLE 5 Test results on catalysts Catalyst P Q
distribution <C.sub.6 non-aromatic 33.938 38.404 of reaction
hydrocarbons product C.sub.6-8 aromatic hydrocarbons 56.875 54.904
(wt %) C.sub.6-8 non-aromatic 0 0 hydrocarbons C.sub.9 3.977 4.318
C.sub.10.sup.+ 5.21 2.374 Ethylbenzene 0.675 0.205 Xylene 14.029
16.306 Indane 0.058 0 Tetrahydrodicyclopentadiene 0.257 0.206
Conversion of C.sub.9 (%) 93.99 93.10
EXAMPLE 18
[0072] In order to evaluate the properties, testing catalyst N
prepared in example 14 in a fixed bed reactor by running for
1500-hour continuously, wherein the feedstock and the process
conditions being same as that in example 17.
[0073] The results of reaction at different time points during
running for 1500-hour are shown in table 6.
TABLE-US-00006 TABLE 6 Test results on catalysts Time of running/hr
384 826 1450 distribution <C.sub.6 non-aromatic 26.012 25.859
30.23 of reaction hydrocarbons product C.sub.6-8 aromatic
hydrocarbons 58.495 57.196 57.006 (wt %) C.sub.6-8 non-aromatic 0 0
0 hydrocarbons C.sub.9 7.249 7.575 6.594 C.sub.10.sup.+ 8.244 9.370
6.170 Ethylbenzene 0.228 0.164 0.143 Xylene 16.657 17.061 17.554
Indane 0.182 0.183 0.075 Tetrahydro- 4.293 5.077 2.917
dicyclopentadiene Conversion of C.sub.9 (%) 88.42 87.90 89.47
[0074] As can be seen from the data in tables 5-6, the catalyst
according to the present invention can achieve better conversion
and stability, even though the feedstock comprises heavy aromatic
hydrocarbons at higher amounts.
* * * * *