U.S. patent application number 12/321769 was filed with the patent office on 2010-07-29 for method for recovering reforming catalyst, catalyst and adsorbent.
This patent application is currently assigned to CPC CORPORATION. Invention is credited to Hung-Tzu Chiu, Cheng-Tsung Hong, Wen-Cheng Kang, Cheng-Chieh Shih, Shu-Li Wang.
Application Number | 20100190631 12/321769 |
Document ID | / |
Family ID | 42354632 |
Filed Date | 2010-07-29 |
United States Patent
Application |
20100190631 |
Kind Code |
A1 |
Kang; Wen-Cheng ; et
al. |
July 29, 2010 |
METHOD FOR RECOVERING REFORMING CATALYST, CATALYST AND
ADSORBENT
Abstract
A method for recovering reforming catalyst comprises obtaining
spent reforming catalysts; immersing the spent reforming catalysts
with different degrees of aging into a light solution to obtain
immersed catalysts and allowing the light solution to enter pores
in the spent reforming catalysts to lower a pseudo-skeletal density
of each spent reforming catalyst to obtain immersed catalysts;
immersing the immersed catalysts into a heavy solution that has a
density greater than pseudo-skeletal density of the immersed
catalysts and replacing the light solution in the pores in the
immersed catalysts by the heavy solution to increase density of the
immersed catalysts; and awaiting the immersed catalysts to settle
in the heavy solution to obtain settled catalysts, wherein
different settling velocities due to aging creates layers of
settled catalysts. Therefore, the reforming catalysts with
different degrees of aging are easily classified into different
layers, which can be reused for cost saving.
Inventors: |
Kang; Wen-Cheng; (Chiayi
City, TW) ; Chiu; Hung-Tzu; (Chiayi City, TW)
; Wang; Shu-Li; (Chiayi City, TW) ; Shih;
Cheng-Chieh; (Chiayi City, TW) ; Hong;
Cheng-Tsung; (Chiayi City, TW) |
Correspondence
Address: |
COOPER & DUNHAM, LLP
30 Rockefeller Plaza, 20th Floor
NEW YORK
NY
10112
US
|
Assignee: |
CPC CORPORATION
|
Family ID: |
42354632 |
Appl. No.: |
12/321769 |
Filed: |
January 26, 2009 |
Current U.S.
Class: |
502/31 ;
502/22 |
Current CPC
Class: |
B01J 38/54 20130101;
B01J 20/103 20130101; B01J 38/56 20130101; B03D 3/00 20130101; B01J
20/3408 20130101; B01J 20/20 20130101; B01J 20/3433 20130101; B01J
20/3475 20130101; B01J 20/18 20130101; B01J 20/3416 20130101; B01J
38/12 20130101; B01J 20/12 20130101; B01J 20/08 20130101 |
Class at
Publication: |
502/31 ;
502/22 |
International
Class: |
B01J 38/56 20060101
B01J038/56; B01J 38/48 20060101 B01J038/48 |
Claims
1. A method for recovering reforming catalyst comprising: obtaining
spent reforming catalysts; immersing the spent reforming catalysts
with different degrees of aging into a light solution to obtain
immersed catalysts; immersing the immersed catalysts into a heavy
solution having a density greater than the light solution and
replacing the light solution in pores in the immersed catalysts
with the heavy solution to increase a pseudo-skeletal density of
the immersed catalysts, so that the light solution is removed from
the pores of the immersed catalysts; and awaiting the immersed
catalysts to settle in the heavy solution to obtain settled
catalysts having allowing the immersed catalysts to have different
settling velocities to obtain settled catalysts, so that the
reforming catalysts with different degrees of aging are layered and
classified into distinct layers and less aged reforming catalyst is
settled directly upon severely aged reforming catalyst.
2. The method for recovering reforming catalyst as claimed in claim
1, wherein the step of obtaining spent reforming catalysts includes
burning coke deposits from surfaces of the spent reforming
catalysts.
3. The method for recovering reforming catalyst as claimed in claim
2, wherein the light solution has a density lower than 2.5
g/cm.sup.3 and the density of the heavy solution is greater than
1.5 g/cm.sup.3.
4. The method for recovering reforming catalyst as claimed in claim
2, wherein the light solution has a density lower than 1.5
g/cm.sup.3 and the density of the heavy solution is greater than
1.5 g/cm.sup.3.
5. The method for recovering reforming catalyst as claimed in claim
2, wherein the light solution is selected from the group consisting
of naphtha, gasoline, kerosene, diesel oil, hydrocarbons and a
mixture thereof; and hydrocarbons are selected from the group
consisting of paraffin, olefin, aromatic hydrocarbons and a mixture
thereof; the heavy solution is halogenated hydrocarbon that is
selected from the group consisting of tetrachloroethane,
tetrachloroethylene, tetrabromoethane, diiodomethane and a mixture
thereof.
6. The method for recovering reforming catalyst as claimed in claim
2, wherein the light solution has a volume equal to a total pore
volume of the spent reforming catalysts.
7. The method for recovering reforming catalyst as claimed in claim
2, wherein the density of the heavy solution is greater than the
pseudo-skeletal density of the immersed catalysts.
8. The method for recovering reforming catalyst as claimed in claim
1, further comprising collecting desired settled catalysts after
the settled catalysts are obtained; and recycling the heavy
solution after collecting desired settled catalysts, wherein the
heavy solution contains the light solution from previous steps.
9. The method for recovering reforming catalyst as claimed in claim
8, wherein collecting desired settled catalysts comprises
separating a desired layer or desired layers of settled catalysts
from the heavy solution to obtain collected reforming catalysts;
washing the collected reforming catalysts using a solvent; drying
the collected reforming catalysts; and calcining the collected
reforming catalysts for reuse.
10. The method for recovering reforming catalyst as claimed in
claim 8, wherein collecting desired settled catalysts comprises
separating overall settled catalysts from the heavy solution;
washing the settled catalysts using a solvent; drying the settled
catalysts; collecting a desired layer or desired layers of settled
catalysts to obtain collected reforming catalysts; and calcining
the collected reforming catalysts for reuse.
11. A method for recovering catalyst comprising: obtaining spent
catalysts; immersing the spent catalysts with different degrees of
aging into a light solution to obtain immersed catalysts; immersing
the immersed catalysts into a heavy solution having a density
greater than the light solution and replacing the light solution in
pores in the immersed catalysts with the heavy solution to increase
a pseudo-skeletal density of the immersed catalysts, so that the
light solution is removed from the pores of the immersed catalysts;
and awaiting the immersed catalysts to settle in the heavy solution
to obtain settled catalysts having allowing the immersed catalysts
to have different settling velocities to obtain settled catalysts,
so that the catalysts with different degrees of aging are layered
and classified into distinct layers and less aged reforming
catalyst is settled directly upon severely aged reforming
catalyst.
12. The method for recovering catalyst as claimed in claim 11,
wherein the light solution has a density lower than 2.5 g/cm.sup.3
and the density of the heavy solution is greater than 1.5
g/cm.sup.3.
13. The method for recovering catalyst as claimed in claim 11,
wherein the light solution has a density lower than 1.5 g/cm.sup.3
and the density of the heavy solution is greater than 1.5
g/cm.sup.3.
14. The method for recovering catalyst as claimed in claim 11,
wherein the light solution is selected from the group consisting of
naphtha, gasoline, kerosene, diesel oil, hydrocarbons and a mixture
thereof; and hydrocarbons are selected from the group consisting of
paraffin, olefin, aromatic hydrocarbons and a mixture thereof; the
heavy solution is halogenated hydrocarbon that is selected from the
group consisting of tetrachloroethane, tetrachloroethylene,
tetrabromoethane, diiodomethane and a mixture thereof.
15. The method for recovering catalyst as claimed in claim 11,
wherein the light solution has a volume equal to a total pore
volume of the spent catalysts; and the density of the heavy
solution is greater than the pseudo-skeletal density of the
immersed catalysts.
16. A method for recovering adsorbent comprising: obtaining spent
adsorbents; immersing the spent adsorbents with different degrees
of aging into a light solution to obtain immersed adsorbents;
immersing the immersed adsorbents into a heavy solution having a
density greater than the light solution and replacing the light
solution in pores in the immersed adsorbents with the heavy
solution to increase a pseudo-skeletal density of the immersed
adsorbents so that the light solution is removed from the pores of
the immersed adsorbents; and awaiting the immersed adsorbents to
settle in the heavy solution to obtain settled adsorbents having
allowing the immersed adsorbents to have different settling
velocities to obtain settled adsorbents, so that the adsorbents
with different degrees of aging are layered and classified into
distinct layers and less aged adsorbent is settled directly upon
severely aged adsorbent.
17. The method for recovering adsorbent as claimed in claim 16,
wherein the light solution has a density lower than 2.5 g/cm.sup.3
and the density of the heavy solution is greater than 1.5
g/cm.sup.3.
18. The method for recovering adsorbent as claimed in claim 16,
wherein the light solution has a density lower than 1.5 g/cm.sup.3
and the density of the heavy solution is greater than 1.5
g/cm.sup.3.
19. The method for recovering adsorbent as claimed in claim 16,
wherein the light solution is selected from the group consisting of
naphtha, gasoline, kerosene, diesel oil, hydrocarbons and a mixture
thereof; and hydrocarbons are selected from the group consisting of
paraffin, olefin, aromatic hydrocarbons and a mixture thereof; the
heavy solution is halogenated hydrocarbon that is selected from the
group consisting of tetrachloroethane, tetrachloroethylene,
tetrabromoethane, diiodomethane and a mixture thereof
20. The method for recovering adsorbent as claimed in claim 16,
wherein the light solution has a volume equal to a total pore
volume of the spent adsorbents; and the density of the heavy
solution is greater than the pseudo-skeletal density of the
immersed adsorbents.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to a method for recovering
reforming catalyst and more particularly to a method for
classifying used catalysts with different degrees of aging, so
reforming catalysts with a low degree of aging are collected easily
to be recovered and reused.
[0003] 2. Description of the Related Art
[0004] Catalytic reforming procedure is a main procedure in
secondary processing of feed oil and is used to produce ingredients
for gasoline, aromatic hydrocarbons and hydrogen cheaply in
petroleum refineries. Catalytic reforming procedure categories
include three kinds of reforming processes depending on processes
for reforming catalysts, including a semi-regeneration reforming
process, a continuous catalytic reforming process and a cyclic
catalytic reforming process. In related industry, above processes
are used in a proportion of 6:3:1. Now most new units adopt
continuous catalytic reforming process.
[0005] The continuous catalytic reforming process comprises
platinum (Pt)/tin (Sn) bimetallic catalysts having metallic
properties and acidity. Furthermore, the continuous catalytic
reforming process can be performed under an extremely low pressure
(about 50 psig), which is useful for an aromatization reaction of
oil and a conversion from gasoline with low octane value (such as
straight-run gasoline, pyrolysis gasoline or the like) into
gasoline with high octane value (such as motor gasoline, blending
oils for aviation gasoline or the like) or petrified ingredients
for refining benzene, toluene, xylene or the like.
[0006] Catalytic reforming procedure is performed under high
temperature (490.about.540.degree. C.). After the catalytic
reforming procedure, an activity of reforming catalysts is
decreased due to carbon deposits and an increased agglomeration of
Pt/Sn. In the continuous catalytic reforming process, the reforming
catalysts can be activated by a carbon burning step, oxidation
step, rejuvenation step, reduction step and chloriding step to
reform and activate the used catalysts and maintain original
activation of the used catalysts. However, total surface area of
the used catalysts will be gradually decreased as the catalysts are
used multiple times, so an operational life of the catalysts will
be reduced.
[0007] With reference to FIG. 1, when a total surface area of
reforming catalysts is decreased due to multiple use, a chloride
content and a degree of metal dispersion in the reforming catalysts
also decreases, which lowers the activation of reforming catalysts.
For maintaining throughput of feed oil and quality of product,
reaction temperature and added amount of dichloroethane should be
increased, otherwise throughput of the feed oil should be lowered
to maintaining product quality. Furthermore, phase form of aluminum
oxide (Al.sub.2O.sub.3) support also affects the total surface
area. Generally, a surface area of .gamma.-Al.sub.2O.sub.3 is much
larger than that of .alpha.-Al.sub.2O.sub.3, so the reaction
temperature should be controlled to prevent .gamma.-Al.sub.2O.sub.3
from converting to .alpha.-Al.sub.2O.sub.3.
[0008] Traditionally, the amount of the total surface area of the
reforming catalysts is one of indexes for changing fresh catalysts.
However, when a total output value of catalytic reformers decreases
because properties of the catalysts are less preferential, a lost
output value is more expensive than cost of the fresh catalysts. In
other words, the catalysts are replaced by fresh catalysts at an
economic point when costs of lost output outweigh replacement
costs.
[0009] Under theoretical conditions, catalysts in a system have a
same degree of aging to allow the catalysts to have the same
activity and characteristics. But units have troubles sometimes,
some catalysts may be more severely aging due to unusual operation
conditions such as hot spot in certain area of catalyst cycle
system. Under extraordinary conditions, catalysts are severely
loss, so a large amount of fresh catalysts should be supplied.
Under these unusual conditions, catalysts have different degrees of
aging. If all catalysts are substituted, less aged catalysts are
wasted. Economic benefits of the catalytic reformers will be
affected if the catalysts are not substituted correctly.
[0010] Characteristics of reforming catalysts change greatly when
the reforming catalysts are converted and deactivated from the
.gamma.-form Al.sub.2O.sub.3 support to .alpha.-form
Al.sub.2O.sub.3 support, such as particle sizes of the reforming
catalysts are decreased or a density of reforming catalysts is
increased. Therefore, the reforming catalysts can be classified
using screen or according to the density, as shown in U.S. Pat. No.
4,720,473. However, the particle sizes or the densities between
reforming catalysts with different degrees aged do not present
significant differences, so the reforming catalysts cannot be
easily and effectively classified.
[0011] Currently, two methods for separating spent fluidized
catalytic cracking catalyst include float/sink density separation
(Beyerlein, R. A. et al., ACS Symposium Series 452, 109, 1990) and
magnetic separation.
[0012] The more aged cracking catalyst, the more density of it. The
float/sink density separation is usually used in laboratories and
separates catalysts with different degrees of aging by adding used
catalysts in a solution and adjusting density of the solution
according to density of aged catalysts. Cracking catalyst consists
of a certain amount of zeolite and a dimension of each molecule of
the solution is chosen to be larger than a pore of zeolite, so
molecules of the solution cannot enter into pores of the zeolite
allowing the cracking catalysts to float on the solution.
Therefore, the float/sink density separation is suitable for spent
cracking catalyst. However, because reforming catalyst has large
pores and most liquid solution is easily filled in the pores of the
reforming catalyst and a solution with a density greater than the
density of .gamma.-form Al.sub.2O.sub.3 (3.97 g/cm.sup.3) is not
easy obtained, especially without negative effect after
separation.
[0013] U.S. Pat. No. 4,406,773 and U.S. Pat. No. 5,147,527
disclosed a separation of spent cracking catalyst by using magnetic
field to recover spent cracking catalyst with low vanadium (V)
content and low nickel (Ni) content. This method has been put into
practice. However, less metal deposits on the reforming catalyst
during reforming process and the reforming catalysts with different
degrees of aging have the same content of metal. Therefore, this
method cannot be used for separating reforming catalysts.
[0014] To overcome the shortcomings, the present invention provides
a method for recovering reforming catalyst to mitigate or obviate
the aforementioned.
SUMMARY OF THE INVENTION
[0015] The primary objective of the present invention is to provide
a method for classifying used catalysts with different degrees of
aging, so less aged reforming catalysts are collected easily to be
recovered and reused.
[0016] To achieve the objective, a method for recovering reforming
catalysts in accordance with the present invention comprises
obtaining spent reforming catalysts; immersing the spent reforming
catalysts with different degrees of aging into a light solution to
obtain immersed catalysts and allowing the light solution to enter
pores in the spent reforming catalysts to lower a pseudo-skeletal
density of each spent reforming catalyst to obtain immersed
catalysts; immersing the immersed catalysts into a heavy solution
that has a density greater than the pseudo-skeletal density of the
immersed catalysts and replacing the light solution in the pores in
the immersed catalysts by the heavy solution to increase
pseudo-skeletal density of the immersed catalysts; and awaiting the
immersed catalysts to settle in the heavy solution to obtain
settled catalysts being layered due to different settling
velocities.
[0017] Therefore, the reforming catalysts with different degrees of
aging are easily classified into different layers, which can be
reused for saving cost.
[0018] Other objectives, advantages and novel features of the
invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a chart of catalyst cycle numbers in an F
catalytic reformer of the CPC Corporation, Taiwan; and
[0020] FIGS. 2A to 2D show a series of cross sectional side view of
a method for recovering reforming catalyst in accordance with the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] As used herein, "a pseudo-skeletal density" indicates a
ratio of weight of solid and solution in pores to volume of solid
and solution in pores. The volume of solid is defined as a sum of
the volume of the solid material and any closed pores within the
solid. These pores cannot be penetrated with any fluid. (Principles
of catalyst development by James T. Richardson 1989, p. 141)
[0022] A method for recovering reforming catalyst in accordance
with the present invention comprises obtaining spent reforming
catalysts, immersing the spent reforming catalysts into a light
solution to obtain immersed catalysts, immersing the immersed
catalysts into a heavy solution, awaiting the immersed catalysts to
settle in the heavy solution to obtain settled catalysts,
collecting desired settled catalysts and recycling the heavy
solution.
[0023] Obtaining spent reforming catalysts may comprise burning
coke deposits from surfaces of the spent reforming catalysts with
an oxygen containing gas.
[0024] Immersing the spent reforming catalysts into a light
solution to obtain immersed catalysts comprises immersing the spent
reforming catalysts with different degrees of aging into a light
solution and allowing the light solution to enter pores in the
spent reforming catalysts for lowering a pseudo-skeletal density of
each spent reforming catalyst to obtain immersed catalysts.
[0025] The light solution is an organic solution and has a density
lower than 2.5 g/cm.sup.3 and is preferably lower than 1.5
g/cm.sup.3. The light solution includes, without limitation,
naphtha (about 0.66.about.0.82 g/cm.sup.3), gasoline, kerosene
(about 0.78 g/cm.sup.3), diesel oil (about 0.77.about.0.86
g/cm.sup.3), hydrocarbons (such as paraffin, olefin, aromatic
hydrocarbons or the like) or a mixture thereof. The light solution
may have a volume equal to a total pore volume of the spent
reforming catalysts.
[0026] Immersing the immersed catalysts into a heavy solution
comprises immersing the immersed catalysts into a heavy solution
that has a density greater than the density of the light solution
and replacing the light solution in the pores in the immersed
catalysts with the heavy solution to increase a pseudo-skeletal
density of the immersed catalysts.
[0027] The density of the heavy solution is greater than the
pseudo-skeletal density of the immersed catalysts and may be
greater than 1.5 g/cm.sup.3. A preferred heavy solution is
halogenated hydrocarbon. Most preferably, the heavy solution
includes, without limitation, tetrachloroethane (about 1.589
g/cm.sup.3), tetrachloroethylene (about 1.6 g/cm.sup.3),
tetrabromoethane (about 2.967 g/cm.sup.3), diiodomethane (about
3.32 g/cm.sup.3) or a mixture thereof.
[0028] Although the ranges of the densities of the light solution
and the heavy solution overlap, a person ordinarily skilled in the
art is able to provide the heavy solution having a greater density
than the light solution.
[0029] Awaiting the immersed catalysts to settle in the heavy
solution according to different settling velocities to obtain
settled catalysts, so the reforming catalysts are classified with
different degrees of aging into different layers. Because severely
aged reforming catalyst has a greater pseudo-skeletal density than
the pseudo-skeletal density of the less aged reforming catalyst and
has pores with decreased volume, the severely aged reforming
catalyst adsorbs less light solution than the less aged reforming
catalyst, the light solution in the pores of the severely aged
reforming catalysts is replaced quickly by the heavy solution so
the settling velocity of the severely aged reforming catalysts is
faster than that of the less aged reforming catalysts.
[0030] Collecting desired settled catalysts may comprise first
separating a desired layer or desired layers of settled catalysts
from the heavy solution to obtain collected reforming catalysts,
washing the collected reforming catalysts using a solvent, drying
the collected reforming catalysts and calcining the collected
reforming catalysts for reuse. Otherwise, collecting desired
reforming catalysts may comprise separating overall settled
catalysts from the heavy solution, washing the settled catalysts
using a solvent, drying the settled catalysts, collecting a desired
layer or desired layers of settled catalysts to obtain collected
reforming catalysts and calcining the collected reforming catalysts
for reuse. More preferred, collecting desired settled catalysts
comprises collecting less aged reforming catalysts (in an upper
layer). The solvent may be n-hexane.
[0031] Recycling the heavy solution comprises reusing the heavy
solution with the light solution for further processing. After many
times of recycling, recycled heavy solution has decreased density.
Distillation can be used to easily separate the light solution from
the heavy solution because boiling points of the light solution and
of the heavy solution are greatly distinguished.
[0032] The reforming catalysts may be replaced by normal catalysts,
absorbents or the like. The absorbent has pores and may be silica
gel, active carbon, aluminum oxide (Al.sub.2O.sub.3), molecular
sieves (such as zeolite molecular sieves, carbon molecular sieves
or the like), natural clay or other absorbent that is known by a
person ordinarily skilled in the art.
EXAMPLES
[0033] The present invention will become clearer from the following
description and accompanying drawings.
[0034] With reference to FIGS. 2a and 2c, spent reforming catalysts
(10) are added into a container (20) and immersed in a light
solution (30) in the container (20) to obtain immersed catalysts
(10a). The volume of the light solution (30) is equal to a total
pore volume of the spent reforming catalysts, therefore, no light
solution remains in the container (20). The light solution (30) is
diesel oil.
[0035] With reference to FIG. 2b, a heavy solution (50) that has a
density greater than the pseudo-skeletal density of each immersed
catalyst (10a) is filled into a funnel-shaped container (40). The
heavy solution (50) is a mixture of tetrachloroethane and
tetrabromoethane.
[0036] With reference to FIG. 2c, the immersed catalysts (10a) are
poured into the funnel-shaped container (40). Severely aged
catalysts (10b) settle to a bottom of the funnel-shaped container
(40).
[0037] With reference to FIG. 2d, then less aged catalysts (10b)
settle upon the severely aged catalysts (10b) since settling
velocities of the immersed catalysts depend on the degrees of aging
of the spent reforming catalysts.
[0038] A mixed solution (50a) including the light solution and the
heavy solution is drained out of the funnel-shaped container (40).
All reforming catalysts (10a, 10b) are washed using n-Hexane and
are dried. Then, the reforming catalysts (10a, 10b) are separated
to a plurality of sections and one or more of the sections are
collected. The collected reforming catalysts are burned at high
temperature (about higher than 450.degree. C.) to remove solvent
residue, solution residue or the like. Finally, desired reforming
catalysts can be obtained.
[0039] In following examples, settled catalysts are classified into
six sections, wherein the first (1st) section of catalysts include
the catalysts first settled at a bottom of a funnel-shaped
container and are severely aged catalysts while the sixth (6th)
section of catalysts are the catalyst last to settle in the
funnel-shaped container and are less aged catalysts. The examples
here are only for exemplifying the present invention, a person
ordinarily skilled in the art may classify the settled catalysts
without limitation and may classify the settled catalysts into less
than six sections or more than six sections.
[0040] Reforming catalysts used in the following examples are
obtained from F catalytic reformer and S catalytic reformer of the
CPC Corporation, Taiwan. The reforming catalysts in the F catalytic
reformer or S catalytic reformer are all used for six years. The F
catalytic reformer was operating poorly, so the reforming catalysts
in the F catalytic reformer were severely damaged and a certain
amount of fresh catalysts were supplied into the F catalytic
reformer. The S catalytic reformer was in smooth operation, so the
reforming catalysts in the S catalytic reformer were slightly
damaged and fewer amounts of fresh catalysts were supplied into the
S catalytic reformer.
[0041] Characteristics of fresh catalysts, the reforming catalysts
in the F catalytic reformer and in the S catalytic reformer are
shown in Table. 1.
TABLE-US-00001 TABLE 1 Characteristics of catalysts catalysts in F
catalysts catalytic in S catalytic characteristics of catalyst
fresh catalysts reformer reformer average particle size 1.7359
1.6499 1.6746 (mm) largest particle size (mm) 2.05 1.83 1.95
smallest particle size 1.58 1.42 1.44 (mm) specific surface area
210.2 133.3 133.7 (m.sup.2/g)* pore volume (m.sup.3/g).sup.# 0.75
0.76 0.76 *BET Surface Area .sup.#85 .ANG.~1500 .ANG. Pore
Volume
Example 1
[0042] 12 g of reforming catalysts from F catalytic reformer, which
had been burned to remove coke deposits and were charged in a
container to obtain immersed catalysts. The reforming catalysts
were immersed in 9 g of n-hexadecane. A mixture of
tetrachloroethane and tetrabromoethane (2.56 g/cm.sup.3) were
filled in a funnel-shaped container. The immersed catalysts were
poured into the funnel-shaped container and immersed in the
mixture. Then, most severely aged reforming catalysts firstly
settled to the bottom of the funnel-shaped container and other
immersed catalysts sequentially settled according to degrees of
aging. After all immersed catalysts settled in the funnel-shaped
container to obtain settled catalysts, all solution including the
heavy solution and the light solution were drained out of the
funnel-shaped container. The settled catalysts were washed by
n-hexane, classified into six sections and taken out from the
funnel-shaped container. The six sections of the settled catalyst
were calcined and were analyzed as shown in Table 2.
TABLE-US-00002 TABLE 2 Characteristics of the settled catalysts
after calcination in example 1 Characteristics of catalyst 1st 2nd
3rd 4th 5th 6th percentage of weight (%) 9.67 14.60 11.15 13.95
19.12 31.51 average particle size (mm) 1.5487 1.6024 1.6213 1.6330
1.6449 1.7186 largest particle size (mm) 1.65 1.76 1.80 1.80 1.82
1.85 smallest particle size (mm) 1.34 1.37 1.42 1.42 1.41 1.57
specific surface area (m.sup.2/g) 118.5 129.1 128.3 131.1 136.3
146.7 pore volume (m.sup.3/g) 0.70 0.74 0.75 0.76 0.79 0.80
[0043] These specific surface areas (136.3 m.sup.2/g/146.7
m.sup.2/g) of the settled catalysts in the fifth section and in the
sixth section (totally about 50.6 wt %) are larger than that (133.3
m.sup.2/g) of the reforming catalysts in F catalytic reformer.
Particularly, there are 31.5 wt % of the settled catalysts in the
sixth section and specific surface area is 146.7 m.sup.2/g.
According to the curve in FIG. 1, 500 cycle numbers indicates that
the reforming catalysts are used for 6 years and 150 cycle numbers
indicates that the reforming catalysts are used for less than 2
years. Therefore, 50.6 wt % of the settled catalysts in the fifth
section and the sixth section were recovered from about 500 cycle
numbers to about 170 cycle numbers, i.e. activity of the settled
catalysts in the fifth section and the sixth section were
recovered.
Example 2
[0044] The method of Example 1 was repeated with 12 g of reforming
catalysts from F catalytic reformer which had not been burned so
comprised coke deposits absorbed on the surface of the reforming
catalysts. The six sections of the settled catalyst were calcined
and were analyzed as shown in Table 3.
TABLE-US-00003 TABLE 3 Characteristics of the settled catalysts
after calcination in Example 2 Characteristics of catalyst 1st 2nd
3rd 4th 5th 6th percentage of weight (%) 7.20 9.20 10.40 13.40 16.8
43.10 average particle size (mm) 1.4791 1.5880 1.5942 1.6125 1.6586
1.6983 largest particle size (mm) 1.68 1.72 1.77 1.78 1.83 1.87
smallest particle size (mm) 1.21 1.46 1.41 1.40 1.43 1.51 specific
surface area (m.sup.2/g) 100.2 125.0 129.5 128.8 127.5 145.3 pore
volume (m.sup.3/g) 0.60 0.74 0.75 0.76 0.73 0.80
[0045] There are 43.1 wt % of the settled catalysts in the sixth
section and specific surface area of the settled catalysts is 145.3
m.sup.2/g. According to the curve in FIG. 1, the settled catalysts
in the sixth section were recovered from about 500 cycle numbers to
less than 150 cycle numbers and the activity of the settled
catalysts in the sixth section were recovered.
[0046] Therefore, regarding examples 1 and 2, almost half of the
reforming catalysts in the F catalytic reformer can be recovered
and reused no matter whether coke deposits were removed or not.
Example 3
[0047] The method of Example 1 was further applied to 12 g of
reforming catalysts obtained from S catalytic reformer. The six
sections of the settled catalyst were calcined and analyzed as
shown in Table 4.
TABLE-US-00004 TABLE 4 Characteristics of the settled catalysts
after calcination in Example 3 characteristics of catalyst 1st 2nd
3rd 4th 5th 6th percentage of weight (%) 8.48 10.57 12.56 9.85
14.91 43.63 average particle size (mm) 1.6025 1.6348 1.6390 1.6418
1.6627 1.6910 largest particle size (mm) 1.78 1.77 1.77 1.80 1.83
1.93 smallest particle size (mm) 1.35 1.45 1.52 1.44 1.49 1.55
specific surface area (m.sup.2/g) 132.7 132.3 135.3 133.9 134.6
139.4 pore volume (m.sup.3/g) 0.72 0.75 0.77 0.77 0.77 0.79
[0048] The specific surface area (139.4 m.sup.2/g) of the settled
catalysts in the sixth section (totally about 43.63 wt %) is larger
than that (133.7 m.sup.2/g) of the reforming catalysts in S
catalytic reformer. Therefore, the settled catalysts in the S
catalytic reformer were recovered using the present invention, but
recovering efficiency in S catalytic reformer is less than that in
F catalytic reformer. Because the S catalytic reformer was in
smooth operation and fewer reforming catalysts were damaged and
lost, there are a fewer differences between the settled catalysts
in six sections.
Example 4
[0049] The method of Example 2, was applied to 12 g of unburned
reforming catalysts obtained from S catalytic reformer. The six
sections of the settled catalyst were calcined and were analyzed as
shown in Table 5.
TABLE-US-00005 TABLE 5 Characteristics of the settled catalysts
after calcination in Example 4 characteristics of catalyst 1st 2nd
3rd 4th 5th 6th percentage of weight (%) 7.39 9.63 13.06 10.04
10.92 48.95 average particle size (mm) 1.5994 1.6338 1.6507 1.6535
1.6749 1.6831 largest particle size (mm) 1.80 1.79 1.83 1.84 1.83
1.84 smallest particle size (mm) 1.43 1.42 1.41 1.43 1.56 1.50
specific surface area (m.sup.2/g) 130.6 134.1 130.7 136.2 133.7
136.3 pore volume (m.sup.3/g) 0.75 0.77 0.76 0.79 0.78 0.80
[0050] There are 58.23 wt % of the settled catalysts in the fifth
section and the sixth section. Particularly, the specific surface
area of the settled catalysts in the sixth section is 136.3
m.sup.2/g while the specific surface area of the reforming
catalysts is 133.7 m.sup.2/g. Therefore, the settled catalysts in
example 4 were recovered, but recovering efficiency in example 4 is
less than that in example 3. It is proved that after the reforming
catalysts were burned to remove the coke deposits, the settled
catalysts can be separated more efficiently.
[0051] According to the above examples, the method of the present
invention can be used for classifying the reforming catalysts.
Furthermore, if the reforming catalysts have no coke deposits
absorbed on surface of the reforming catalysts, the reforming
catalysts can be separated efficiently. The method of the present
invention is easy to recovery the less aged reforming catalysts and
lower catalyst costs of catalytic reformer.
[0052] Even though numerous characteristics and advantages of the
present invention have been set forth in the foregoing description,
together with details of the structure and function of the
invention, the disclosure is illustrative only. Changes may be made
in detail, especially in matters of shape, size and arrangement of
parts within the principles of the invention to the full extent
indicated by the broad general meaning of the terms in which the
appended claims are expressed.
* * * * *