U.S. patent application number 16/210088 was filed with the patent office on 2019-04-11 for noble metal zeolite catalyst for second-stage hydrocracking to make middle distillate.
The applicant listed for this patent is Chevron U.S.A. Inc.. Invention is credited to Richard Joseph Coser, Jifei Jia, Theodorus Ludovicus Michael Maesen, Andrew Rainis, Thomas Michael Rea, Yihua Zhang.
Application Number | 20190105640 16/210088 |
Document ID | / |
Family ID | 56740501 |
Filed Date | 2019-04-11 |
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United States Patent
Application |
20190105640 |
Kind Code |
A1 |
Jia; Jifei ; et al. |
April 11, 2019 |
NOBLE METAL ZEOLITE CATALYST FOR SECOND-STAGE HYDROCRACKING TO MAKE
MIDDLE DISTILLATE
Abstract
A second-stage hydrocracking catalyst is provided, comprising:
a) a zeolite beta having an OD acidity of 20 to 400 .mu.mol/g and
an average domain size from 800 to 1500 nm2; b) a zeolite USY
having an ASDI between 0.05 and 0.12; c) a catalyst support; and d)
0.1 to 10 wt % noble metal; wherein the second-stage hydrocracking
catalyst provides a hydrogen consumption less than 350 SCFB across
a range of synthetic conversions up to 37 wt % when used to
hydrocrack hydrocarbonaceous feeds having an initial boiling point
greater than 380.degree. F. (193.degree. C.). A second-stage
hydrocracking process using the second-stage hydrocracking process
is provided. A method to make the second-stage hydrocracking
catalyst is also provided.
Inventors: |
Jia; Jifei; (Hercules,
CA) ; Rainis; Andrew; (Walnut Creek, UA) ;
Maesen; Theodorus Ludovicus Michael; (Moraga, CA) ;
Coser; Richard Joseph; (Fairfield, CA) ; Zhang;
Yihua; (Albany, CA) ; Rea; Thomas Michael;
(Vacaville, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chevron U.S.A. Inc. |
San Ramon |
CA |
US |
|
|
Family ID: |
56740501 |
Appl. No.: |
16/210088 |
Filed: |
December 5, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14823839 |
Aug 11, 2015 |
10183286 |
|
|
16210088 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 37/0207 20130101;
B01J 23/88 20130101; B01J 29/80 20130101; C10G 47/18 20130101; B01J
29/7007 20130101; B01J 37/0018 20130101; B01J 37/0201 20130101;
B01J 2229/20 20130101; B01J 37/08 20130101; B01J 2229/42 20130101;
B01J 29/084 20130101; B01J 35/0026 20130101; B01J 29/7415 20130101;
B01J 35/002 20130101; B01J 23/888 20130101; B01J 37/0236 20130101;
B01J 29/126 20130101; B01J 37/0009 20130101; B01J 35/0006 20130101;
B01J 37/04 20130101; B01J 2229/186 20130101 |
International
Class: |
B01J 29/80 20060101
B01J029/80; B01J 35/00 20060101 B01J035/00; B01J 37/02 20060101
B01J037/02; B01J 37/00 20060101 B01J037/00; C10G 47/18 20060101
C10G047/18; B01J 37/08 20060101 B01J037/08; B01J 37/04 20060101
B01J037/04; B01J 23/88 20060101 B01J023/88; B01J 23/888 20060101
B01J023/888; B01J 29/08 20060101 B01J029/08; B01J 29/70 20060101
B01J029/70 |
Claims
1. A second-stage hydrocracking process, comprising: hydrocracking
a hydrocarbonaceous feed having an initial boiling point greater
than 380.degree. F. (193.degree. C.) in a second-stage
hydrocracking reactor using a second-stage hydrocracking catalyst,
wherein greater than 70 wt % of an effluent from the second-stage
hydrocracking reactor has a hydrocracked boiling point greater than
380.degree. F. (193.degree. C.) and wherein the second-stage
hydrocracking catalyst provides a hydrogen consumption less than
350 SCFB across a range of synthetic conversions up to 37 wt %;
wherein the second-stage hydrocracking catalyst comprises: a. a
zeolite beta having an OD acidity of 20 to 400 .mu.mol/g and an
average domain size from 800 to 1500 nm.sup.2; b. a zeolite USY
having an ASDI between 0.05 and 0.12; c. a catalyst support; and d.
0.1 to 10 wt % noble metal.
2. The process of claim 1, wherein a wt % of the zeolite beta is
greater than the wt % of the zeolite USY in the second-stage
hydrocracking catalyst.
3. The process of claim 1, wherein the zeolite beta has the OD
acidity from 30 to 100 .mu.mol/g.
4. The process of claim 1, wherein the zeolite beta has the average
domain size from 900 to 1250 nm.sup.2.
5. The process of claim 1, wherein the zeolite USY has a total
Bronsted acid sites determined by FTIR after H/D exchange of 0.080
to 0.200 mmol/g.
6. The process of claim 1, wherein the second-stage hydrocracking
catalyst has the hydrogen consumption between 250 and 350 SCFB over
the range of synthetic conversion <625.degree. F. (329.degree.
C.) from 23 to 37 wt %.
7. The process of claim 1, wherein the second-stage hydrocracking
catalyst has a compacted bulk density from 420 to 620 g/l.
8. The process of claim 1, wherein the second-stage hydrocracking
catalyst has a LOT (1000.degree. F[538.degree. C.]) less than 12 wt
%.
9. The process of claim 1, wherein the noble metal comprises
platinum, platinum, or mixture thereof.
Description
[0001] This application is related to two co-filed applications
titled "MIDDLE DISTILLATE HYDROCRACKING CATALYST CONTAINING ZEOLITE
BETA WITH LOW OD ACIDITY AND LARGE DOMAIN SIZE" and "MIDDLE
DISTILLATE HYDROCRACKING CATALYST CONTAINING ZEOLITE USY, AND
ZEOLITE BETA WITH LOW ACIDITY AND LARGE DOMAIN SIZE", herein
incorporated in their entireties.
TECHNICAL FIELD
[0002] This application is directed to a second-stage hydrocracking
catalyst, a process for second-stage hydrocracking of a
hydrocarbonaceous feed, and a method for making a second-stage
hydrocracking catalyst.
BACKGROUND
[0003] Improved second-stage hydrocracking catalysts and processes
for using them and making them are needed. Earlier second-stage
hydrocracking catalysts have not provided the desired improved
levels of activity to make high quality middle distillates. Earlier
second-stage hydrocracking catalysts have provided good yields of
middle distillate and heavy naphtha, but at lower activity that
what is optimal.
SUMMARY
[0004] This application provides a second-stage hydrocracking
catalyst, comprising: a zeolite beta having an OD acidity of 20 to
400 .mu.mol/g and an average domain size from 800 to 1500 nm2; b. a
zeolite USY having an ASDI between 0.05 and 0.12; c. a catalyst
support; and d. 0.1 to 10 wt % noble metal; wherein the
second-stage hydrocracking catalyst provides a hydrogen consumption
less than 350 SCFB across a range of synthetic conversions up to 37
wt % when used to hydrocrack hydrocarbonaceous feeds having an
initial boiling point greater than 380.degree. F. (193.degree.
C.).
[0005] This application also provides a second-stage hydrocracking
process, comprising: hydrocracking a hydrocarbonaceous feed having
an initial boiling point greater than 380.degree. F. (193.degree.
C.) in a second-stage hydrocracking reactor using a second-stage
hydrocracking catalyst, wherein greater than 70 wt % of an effluent
from the second-stage hydrocracking reactor has a hydrocracked
boiling point greater than 380.degree. F. (193.degree. C.) and
wherein the second-stage hydrocracking catalyst provides a hydrogen
consumption less than 350 SCFB across a range of synthetic
conversions up to 37 wt %; wherein the second-stage hydrocracking
catalyst comprises: [0006] a. a zeolite beta having an OD acidity
of 20 to 400 .mu.mol/g and an average domain size from 800 to 1500
nm2; [0007] b. a zeolite USY having an ASDI between 0.05 and 0.12;
[0008] c. a catalyst support; and [0009] d. 0.1 to 10 wt % noble
metal.
[0010] This application also provides a method for making a
second-stage hydrocracking catalyst, comprising: [0011] a. mixing
together a zeolite beta having an OD acidity of 20 to 400 .mu.mol/g
and an average domain size from 800 to 1500 nm.sup.2, a zeolite USY
having an ASDI between 0.05 and 0.12, a catalyst support, and
enough liquid to form an extrudable paste; [0012] b. extruding the
extrudable paste to form an extrudate base; [0013] c. impregnating
the extrudate base with a metal impregnation solution containing at
least one noble metal to make a metal-loaded extrudate; and [0014]
d. post-treating the metal-loaded extrudate by subjecting the
metal-loaded extrudate to drying and calcination; wherein the
second-stage hydrocracking catalyst provides a hydrogen consumption
less than 350 SCFB across a range of synthetic conversions up to 37
wt % when used to hydrocrack hydrocarbonaceous feeds having an
initial boiling point greater than 380.degree. F. (193.degree.
C.).
[0015] The present invention may suitably comprise, consist of, or
consist essentially of, the elements in the claims, as described
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a chart of the domain measurements made on two
samples of zeolite beta.
[0017] FIG. 2 is a chart of the average domain sizes of two samples
of zeolite beta.
[0018] FIG. 3 is a chart showing the normalized hydrocracking
temperatures vs. time on stream for two different second-stage
hydrocracking catalysts.
[0019] FIG. 4 is a chart showing hydrogen consumption vs. synthetic
conversion less than 625.degree. F. (329.degree. C.) for two
different second-stage hydrocracking catalysts.
[0020] FIG. 5 is a diagram of an embodiment of a two-stage
hydroprocessing unit having a second-stage hydrocracking reactor
designed for optimizing yields of middle distillates.
[0021] FIG. 6 is a diagram of the pilot plant used for the
evaluation of the second-stage hydrocracking catalysts in this
disclosure.
GLOSSARY
[0022] "Hydrocracking" refers to a process in which hydrogenation
and dehydrogenation accompanies the cracking/fragmentation of
hydrocarbons, e.g., converting heavier hydrocarbons into lighter
hydrocarbons, or converting aromatics and/or
cycloparaffins(naphthenes) into non-cyclic branched paraffins.
[0023] "Second-stage hydrocracking" refers to a process for
hydrocracking a hydrocarbonaceous feed produced in a first-stage
hydroprocessing reactor. The second-stage hydrocracking is done in
a second-stage hydrocracking reactor that is fluidly connected to
the first-stage hydroprocessing reactor.
[0024] "TBP" refers to the boiling point of a hydrocarbonaceous
feed or product, as determined by ASTM D2887-13.
[0025] "Cut point" refers to the temperature on a True Boiling
Point (TBP) curve at which a predetermined degree of separation is
reached.
[0026] "Hydrocarbonaceous" means a compound or substance that
contains hydrogen and carbon atoms, and which can include
heteroatoms such as oxygen, sulfur, or nitrogen.
[0027] "Hydrocracked boiling point" refers to the boiling point of
a hydrocarbonaceous product produced in a hydrocracking
reactor.
[0028] "Middle Distillates" include products having cut points from
380.degree. F. to 625.degree. F. Middle distillates can include jet
(380-566.degree. F.) and diesel (566-625.degree. F.).
[0029] "Finished catalyst" refers to the second-stage hydrocracking
catalyst composition comprising all of its components and after all
of the processing and any post-processing steps used to manufacture
it.
[0030] "LHSV" means liquid hourly space velocity.
[0031] "WHSV" means weight hourly space velocity.
[0032] "SCFB" refers to a unit of standard cubic foot of gas (e.g.,
nitrogen, hydrogen, air, etc) per barrel of hydrocarbonaceous
feed.
[0033] "SiO.sub.2/Al.sub.2O.sub.3 mole ratio (SAR) is determined by
inductively coupled plasma (ICP) elemental analysis. A SAR of
infinity means there is no aluminum in the zeolite, i.e., the mole
ratio of silica to alumina is infinity. In that case, the zeolite
is comprised of essentially all silica.
[0034] "Zeolite beta" refers to zeolites having a 3-dimensional
crystal structure with straight 12-membered ring channels with
crossed 12-membered ring channels and having a framework density of
about 15.3 T/1000 .ANG..sup.3. Zeolite beta has a BEA framework as
described in Ch. Baerlocher and L. B. McCusker, Database of Zeolite
Structures: http://www.iza-structure.org/databases/
[0035] "Zeolite USY" refers to ultra-stabilized Y zeolite. Y
zeolites are synthetic faujasite (FAU) zeolites having a SAR of 3
or higher. Y zeolite can be ultra-stabilized by one or more of
hydrothermal stabilization, dealumination, and isomorphous
substitution. Zeolite USY can be any FAU-type zeolite with a higher
framework silicon content than a starting (as-synthesized) Na--Y
zeolite precursor.
[0036] "Catalyst support" refers to a material, usually a solid
with high surface area, to which a catalyst is affixed.
[0037] "Periodic Table" refers to the version of the IUPAC Periodic
Table of the Elements dated Jun. 22, 2007, and the numbering scheme
for the Periodic Table Groups is as described in Chemical And
Engineering News, 63(5), 27 (1985).
[0038] "OD acidity" refers to the amount of bridged hydroxyl groups
exchanged with deuterated benzene at 80.degree. C. by Fourier
transform infrared spectroscopy (FTIR). OD acidity is a measure of
the BrOnsted acid sites density in a catalyst. The extinction
coefficient of OD signals was determined by analysis on a standard
zeolite beta sample calibrated with .sup.1H magic-angle spinning
nuclear magnetic resonance (MAS NMR) spectroscopy. A correlation
between the OD and OH extinction coefficients was obtained as
following:
.epsilon..sub.(-OD)=0.62*.epsilon..sub.(-OH).
[0039] "Domain Size" is the calculated area, in nm.sup.2, of the
structural units observed and measured in zeolite beta catalysts.
Domains are described by Paul A. Wright et. al., "Direct
Observation of Growth Defects in Zeolite Beta", JACS
Communications, published on web Dec. 22, 2004. The method used to
measure the domain sizes of zeolite beta is further described
herein.
[0040] "Acid site distribution index (ASDI)" is an indicator of the
hyperactive site concentration of a zeolite. ASDI is determined by
the following equation: ASDI=(HF'+LF')/(HF+LF). In some
embodiments, the lower the ASDI the more likely the zeolite will
have a greater selectivity towards the production of heavier middle
distillate products.
[0041] "Amorphous silica aluminate (ASA)" refers to a synthetic
material having some of the alumina present in tetrahedral
coordination as shown by nuclear magnetic resonance imaging. ASA
can be used as a catalyst or catalyst support. Amorphous silica
alumina contains sites which are termed Bronsted acid (or protic)
sites, with an ionizable hydrogen atom, and Lewis acid (aprotic),
electron accepting sites and these different types of acidic site
can be distinguished by the ways in which, say, pyridine
attaches.
[0042] "Pseudo-boehmite alumina refers to an aluminum compound with
the chemical composition AlO(OH). Pseudo-boehmite alumina consists
of finely crystalline boehmite with a higher water content than
boehmite.
[0043] "API gravity" refers to the gravity of a petroleum feedstock
or product relative to water, as determined by ASTM D4052-11.
[0044] "Polycyclic index (PCI)" refers to a measure of the content
of compounds having several aromatic rings. PCI is useful in
evaluating feedstocks for hydroprocessing. PCI is measured using
UV-spectroscopy and is calculated as follows:
[0045] PCI={[Absorbance @385 nm-(0.378.times.Absorbance@435
nm)]/115.times.c}.times.1000; where c is the original concentration
of the sample in solvent in g/cm.sup.3.
[0046] "Noble metal" refers to a metal that is resistant to
corrosion and oxidation in moist air (unlike most base metals).
Examples of noble metals are ruthenium, rhodium, palladium, silver,
osmium, iridium, platinum, and gold.
[0047] "Particle density" refers to the density of a catalyst
including its pore volume in g/l, and can be measured by mercury
porosimetry. The determination of particle density is based on the
fact that mercury does not wet the surface of most materials, and
therefore, will not enter the pores of a solid catalyst unless
forced to under pressure. The particle density can be measured
either volumetrically or gravimetrically by fully immersing the
catalyst sample in mercury. In the gravimetric method, the equation
for particle density(D) is: D=(C.times.p)/(A+B-C), where C is the
catalyst sample weight, A is the weight of the test cell filled
with mercury, B is the weight of the test cell with both the
catalyst sample and mercury, and p is the density of mercury. In
the volumetric method, the equation for particle density (D) is:
D=C/.DELTA.V, where .DELTA.V is the difference in volume
measurement in the test cell with and without the catalyst
sample.
[0048] "Catalyst Activation Temperature (C.A.T.)" in the context of
this disclosure refers to the temperature needed to reach a 30 wt %
conversion target less than 625.degree. F. (329.degree. C.).
DETAILED DESCRIPTION
[0049] The distribution of the acid sites of a zeolite generally
determines the catalytic activity and selectivity towards
particular refining products. The ASDI provides a measurement of
the super acid site concentration of a zeolite. During the
commercial operation of a hydrocracking unit, the concentrations of
the acid sites can increase, leading to increased hydrocracking of
the hydrocarbonaceous feedstock. The increased hydrocracking can
cause increased production of lesser value products such as light
naphtha and C.sub.1-C.sub.4 gas.
[0050] Without being bound by theory, it is believed that the
unique combination of zeolite beta with a defined OD acidity and a
defined average domain size, combined with a zeolite USY with a
defined acid site distribution index (ASDI), supported on a
catalyst support and impregnated with one or more noble metals
provides a much-improved second-stage hydrocracking catalyst. The
unique combination of these components in a second-sage
hydrocracking catalyst gives improved hydrogen consumption,
generally less than 350 SCFB across a range of synthetic conversion
<625.degree. F. (329.degree. C.) from 23 to 37 wt % while
providing excellent selectivity for producing a hydrocracked
effluent having a TBP of 380-625.degree. F. The second-stage
hydrocracking catalyst can also provide improved activity, such as
from 1 to 30.degree. F. at 30% conversion compared to other
second-stage hydrocracking catalysts that do not have the unique
combination of components disclosed herein.
[0051] Second-Stage Hydrocracking Catalyst Composition--Zeolite
Beta:
[0052] The zeolite beta has an OD acidity of 20 to 400 .mu.mol/g
and an average domain size from 800 to 1500 nm.sup.2. In one
embodiment, the OD acidity is from 30 to 100 .mu.mol/g.
[0053] In one embodiment the zeolite beta is synthetically
manufactured using organic templates. Examples of three different
zeolite beta are described in Table 1.
TABLE-US-00001 TABLE 1 SiO.sub.2/Al.sub.2O.sub.3 Molar OD Acidity,
Zeolite Betas Ratio (SAR) .mu.mol/g H-BEA-35 35 304 H-BEA-150
(ZE0090) 150 36 CP811C-300 (ZE0106) 300 Not measured
[0054] The total OD acidity was determined by H/D exchange of
acidic hydroxyl groups by FTIR spectroscopy. The method to
determine the total OD acidity was adapted from the method
described in the publication by Emiel J. M. Hensen et. al., J.
Phys. Chem., C2010, 114, 8363-8374. Prior to FTIR measurement, the
sample was heated for one hour at 400-450.degree. C. under vacuum
<1.times.10.sup.-5 Torr. Then the sample was dosed with
C.sub.6D.sub.6 to equilibrium at 80.degree. C. Before and after
C.sub.6D.sub.6 dosing, spectra were collected for OH and OD
stretching regions. Bronsted acid sites density (OD acidity) was
determined by using the integrated area of peak 2660 cm.sup.-1 for
zeolite beta.
[0055] The average domain size was determined by a combination of
transmission electron (TEM) and digital image analysis, as
follows:
[0056] I. Zeolite Beta Sample Preparation:
[0057] The zeolite beta sample was prepared by embedding a small
amount of the zeolite beta in an epoxy and microtoming. The
description of suitable procedures can be found in many standard
microscopy text books.
[0058] Step 1. A small representative portion of the zeolite beta
powder was embedded in epoxy. The epoxy was allowed to cure.
[0059] Step 2. The epoxy containing a representative portion of the
zeolite beta powder was microtomed to 80-90 nm thick. The microtome
sections were collected on a 400 mesh 3 mm copper grid, available
from microscopy supply vendors.
[0060] Step 3. A sufficient layer of electrically-conducting carbon
was vacuum evaporated onto the microtomed sections to prevent the
zeolite beta sample from charging under the electron beam in the
TEM.
[0061] II. TEM Imaging:
[0062] Step 1. The prepared zeolite beta sample, described above,
was surveyed at low magnifications, e.g., 250,000-1,000,000.times.
to select a crystal in which the zeolite beta channels can be
viewed.
[0063] Step 2. The selected zeolite beta crystals were tilted onto
their zone axis, focused to near Scherzer defocus, and an image was
recorded .gtoreq.2,000,000.times..
[0064] III. Image Analysis to Obtain Average Domain Size
(nm.sup.2):
[0065] Step 1. The recorded TEM digital images described previously
were analyzed using commercially available image analysis software
packages.
[0066] Step 2. The individual domains were isolated, and the domain
sizes were measured in nm.sup.2. The domains where the projection
was not clearly down the channel view were not included in the
measurements.
[0067] Step 3. A statistically relevant number of domains were
measured. The raw data was stored in a computer spreadsheet
program.
[0068] Step 4. Descriptive statistics, and frequencies were
determined--The arithmetic mean (d.sub.av), or average domain size,
and the standard deviation (s) were calculated using the following
equations:
The average domain size, d.sub.av=(a n.sub.id.sub.i)/(a
n.sub.i)
The standard deviation, s=(a(d.sub.i-d.sub.av).sup.2/(a
n.sub.i)).sup.1/2
[0069] In one embodiment the average domain size is from 900 to
1250 nm.sup.2, such as from 1000 to 1150 nm.sup.2.
[0070] Second-Stage Hydrocracking Catalyst Composition--Zeolite
USY:
[0071] The zeolite USY has an acid site distribution index (ASDI)
between 0.05 and 0.12. In one embodiment, the zeolite USY has an
ASDI that favors the production of heavy middle distillates.
[0072] ASDI is determined by H/D exchange of acidic hydroxyl groups
by FTIR spectroscopy, as described previously. Bronsted acid sites
density was determined by using the integrated area of peak 2676
cm.sup.-1 as the first high frequency OD (HF), 2653 cm.sup.-1 as
the 2.sup.nd high frequency OD (HF'), 2632 cm.sup.-1 and 2620
cm.sup.-1 as the first low frequency OD (LF) and 2600 cm.sup.-1 as
the 2.sup.nd low frequency OD (LF'). The acid site distribution
index factor was determined by the following equation:
ASDI=(HF'+LF')/(HF+LF); which reflects the hyperactive acid sites
content in the zeolite sample. In one embodiment the zeolite USY
has a total Bronsted acid sites determined by FTIR after H/D
exchange of 0.080 to 0.200 mmol/g.
[0073] In one embodiment, the wt % of the zeolite beta is greater
than the wt % of the zeolite USY in the hydrocracking catalyst. For
example, the wt % of the zeolite beta can be from 0.45 to 9.95 wt %
greater than the wt % of the zeolite USY. In one embodiment, the wt
% of the zeolite beta is from 1 to 5 wt % higher than the wt % of
the zeolite USY. In one embodiment, the hydrocracking catalyst has
a weight ratio of the zeolite USY to the zeolite beta that is less
than 0.90, such as from 0.01 to 0.80, or from 0.02 to 0.48.
[0074] Second Stage Hydrocracking Catalyst Composition--Catalyst
Support:
[0075] The hydrocracking catalyst comprises a catalyst support. The
catalyst support can be inert or can participate in the catalytic
reactions performed by the hydrocracking catalyst. Typical catalyst
supports include various kinds of carbon, alumina, and silica. In
one embodiment, the catalyst support comprises an amorphous silica
aluminate. In one embodiment, the catalyst support comprises an
amorphous silica aluminate and a second support material.
[0076] In one embodiment, the amorphous silica aluminate (ASA) has
greater thermal stability than high purity aluminas. Examples of
suitable amorphous silica aluminates are SIRAL.RTM. ASAs, described
below:
TABLE-US-00002 TABLE 2 Typical Properties SIRAL 1 SIRAL 5 SIRAL 10
SIRAL 20 SIRAL 30 SIRAL 40 Al.sub.2O.sub.3 + SiO.sub.2 % 75 75 75
75 75 75 Loss on Ignition (LOI) % 25 25 25 25 25 25
Al.sub.2O.sub.3:SiO.sub.2 % 99:1 95:5 90:10 80:20 70:30 60:40 C %
0.2 0.2 0.2 0.2 0.2 0.2 Fe.sub.2O.sub.3 % 0.02 0.02 0.02 0.02 0.02
0.02 Na.sub.2O % 0.005 0.005 0.005 0.005 0.005 0.005 Loose bulk
density [g/l] 600-800 450-650 400-600 300-500 250-450 250-450
Particle size (d.sub.50) [.mu.m] 50 50 50 50 50 50 Surface area
(BET)* [m.sup.2/g] 280 370 400 420 470 500 Pore volume* [ml/g] 0.50
0.70 0.75 0.75 0.80 0.90 *After activation at 550.degree. C. for 3
hours. SIRAL .RTM. is a registered trademark of SASOL.
[0077] Examples of the second support material, when used, can
include kieselguhr, alumina, silica, and silica-alumina. Other
examples of the second support material include alumina-boria,
silica-alumina-magnesia, silica-alumina-titania and materials
obtained by adding zeolites and other complex oxides thereto. In
one embodiment, the second support material is porous, and
comprises a natural clay or a synthetic oxide. The second support
material can be selected to provide adequate mechanical strength
and chemical stability at the reaction conditions under which the
hydrocracking catalyst is employed.
[0078] In one embodiment, the second support material comprises a
pseudo-boehmite alumina. Examples of pseudo-boehmite alumina are
CATAPAL.RTM. high purity aluminas. CATAPAL.RTM. is a registered
trademark of SASOL. Typical properties of the CATAPAL high purity
aluminas are summarized below:
TABLE-US-00003 TABLE 3 Typical CATAPAL CATAPAL CATAPAL CATAPAL
Properties B C1 D 200 Al.sub.2O.sub.3, wt % 72 72 76 80 Na.sub.2O,
wt % 0.002 0.002 0.002 0.002 Loose Bulk 670-750 670-750 700-800
500-700 Density, g/l Packed Bulk 800-1100 800-1100 800-1100 700-800
Density, g/l Average 60 60 40 40 Particle size (d.sub.50), .mu.m
Surface Area* 250 230 220 100 (BET), m.sup.2/g Pore Volume*, 0.50
0.50 0.55 0.70 ml/g Crystal 4.5 5.5 7.0 40 size, nm *Surface area
and pore volume were determined after activation at 550.degree. C.
for 3 hours.
[0079] In one embodiment, the second alumina has a second alumina
BET surface area that is high enough such that the second-stage
hydrocracking catalyst has a BET surface area from 450 to 650
m.sup.2/g. For example, the second alumina can have a second
alumina BET surface area greater than 150 m.sup.2/g, such as from
155 to 350 m.sup.2/g, from 200 to 300 m.sup.2/g, or from 220 to 280
m.sup.2/g.
[0080] In one embodiment, the second alumina has an alumina
compacted bulk density greater than 700 g/l, such as from 800 to
1100 g/l.
[0081] Second-Stage Hydrocracking Catalyst Composition--Noble
Metal:
[0082] The second-stage hydrocracking catalyst additionally
comprises at least one noble metal. The total amount of a noble
metal in the second-stage hydrocracking catalyst is from 0.1 wt. %
to 10 wt. % based on the bulk dry weight of the finished
hydrocracking catalyst. In one embodiment, the noble metal is
selected from the group of platinum, palladium, and mixtures
thereof.
[0083] In different embodiments, the second-stage hydrocracking
catalyst can have one or more of the following physical
properties:
[0084] a. a compacted bulk density from 420 to 620 g/l,
[0085] b. a LOI (1000.degree. F.[538.degree. C.]) less than 12 wt
%, or from 0.5 to less than 10 wt %,
[0086] c. a total PtPd H2 adsorption from 70 wt % to 98 wt %,
and
[0087] d. a particle density from 800 to 1200 g/l.
[0088] In one embodiment, the second-stage hydrocracking catalyst
is in the form of extruded pellets (extrudates) that have an
extruded pellet diameter of 10 mm or less, such as from 1.0 to 5.0
mm. In one embodiment, the extruded pellet has a length-to-diameter
ratio of 10 to 1. Examples of other types and sizes of pellets used
for the second-stage hydrocracking catalysts are 1 to 10 mm
diameter spheres; 1 to 10 mm diameter cylinders with a
length-to-diameter ratio of 4 to 1; 1 to 10 mm asymmetric shapes
(including quadrolobes), and up to 10 mm diameter hollow cylinders
or rings.
[0089] The .degree. F. or .degree. C. more activity for a given
catalyst is a commercially significant value since the overall
kinetics of a hydrocracking process involves deactivation of the
catalyst with time which requires the constant incremental increase
in the operating temperature of the process as a function of time
to maintain constant conversion of the hydrocarbon feedstock. The
process equipment necessarily has temperature constraints such that
when the process reaches a designated temperature the process must
be shut down, i.e., terminated, and the catalyst changed. Since
these shutdowns are quite costly, a catalyst which provides the
desired conversion at a lower temperature (as indicated by .degree.
F. or .degree. C. more activity) has a longer life in the
hydrocracking process since it requires a longer time to achieve
the shutdown temperature. For example, the typical temperature
increment for a commercial hydrocracking process can be on the
order of 0.05 to 0.1.degree. F. per day of operation and a catalyst
which has 10.degree. F. more activity can provide from 100 to 200
additional days of plant operation before catalyst changeover.
[0090] Hydrogen consumption is the amount of hydrogen consumed in
the hydroprocessing reaction process. Hydrogen consumption is a key
value driver for refineries. Reduction in hydrogen consumption will
add values to refineries significantly.
[0091] Hydrogen consumption is measured with H NMR and calculated
as follows:
Hydrogen consumption=Hydrogen in the product gas stream+Sum of
hydrogen in the products-Hydrogen in the feed.
[0092] Second-Stage Hydrocracking Process
[0093] The second-stage hydrocracking catalysts described above can
be used to hydrocrack hydrocarbonaceous feeds having an initial
boiling point greater than 380.degree. F. (193.degree. C.).
[0094] In one embodiment, the hydrocarbonaceous feed comprises a
first-stage hydrocracking reactor effluent. In another embodiment,
the hydrocarbonaceous feed is a blend of an effluent from a
first-stage hydrocracker and a raw feed, such as diesel. In one
embodiment, the raw feed that is blended with the effluent from the
first-stage hydrocracker is the feedstock to the first-stage
hydrocracker. Examples of these types of raw feeds include
visbroken gas oils, heavy coker gas oils, gas oils derived from
residue hydrocracking or residue desulfurization, other thermally
cracked oils, de-asphalted oils, Fischer-Tropsch derived
feedstocks, cycle oils from a fluid catalytic cracking (FCC) unit,
heavy coal-derived distillates, coal gasification byproduct tars,
heavy shale-derived oils, organic waste oils such as those from
pulp or paper mills or from waste biomass pyrolysis units.
[0095] In one embodiment, the hydrocarbonaceous feed has a PCI less
than 5000, such as from zero to less than 1000.
[0096] Table 4 lists some typical bulk properties for a
hydrocarbonaceous feed that can be used.
TABLE-US-00004 TABLE 4 Property API Gravity 13.5-30.0 N, ppm 0-500
S, wt % 0-0.5 Polycyclic Index (PCI) 0-8000 TBP Range, .degree. F.
(.degree. C.) 381-1200.degree. F. (194-649.degree. C.)
[0097] Table 5 lists some typical hydrocracking process conditions
that can be used.
TABLE-US-00005 TABLE 5 Property Liquid Hourly Space 0.1-5 Velocity
(LHSV), hr.sup.-1 H.sub.2 partial pressure, psig (kPa) 400-3,500
(2758-24,132) H.sub.2 Consumption Rate, SCF/B 50-20,000 H.sub.2
Recirculation Rate, SCF/B 50-9,000 Operating Temperature
200-450.degree. C. (392-842.degree. F.) Conversion (wt %)
20-100
[0098] Depending on the feedstock, target product slate and amount
of available hydrogen, the second-stage hydrocracking catalyst
described herein can be used alone or in combination with other
conventional hydrocracking catalysts.
[0099] In one embodiment, the second-stage hydrocracking catalyst
is deployed in one or more fixed beds in a second-stage
hydrocracking unit, with or without recycle (once-through).
Optionally, the second-stage hydrocracking unit may employ multiple
second-stage units operated in parallel.
[0100] In one embodiment, the second-stage hydrocracking catalyst
is deployed in one or more beds or units in a two-stage
hydrocracking unit, with and without intermediate stage separation,
and with or without recycle. Two-stage hydrocracking units can be
operated using a full conversion configuration (meaning all of the
hydrotreating and hydrocracking is accomplished within the
hydrocracking loop via recycle). This embodiment may employ one or
more distillation units within the hydrocracking loop for the
purpose of stripping off product prior to the second stage
hydrocracking step or prior to recycle of the distillation bottoms
back to the first and/or second stage.
[0101] Two stage hydrocracking units can also be operated in a
partial conversion configuration (meaning one or more distillation
units are positioned within a hydrocracking loop for the purpose of
stripping of one or more streams that are passed on for further
hydroprocessing). Operation of the second-stage hydrocracking unit
or reactor in this manner allows a refinery to hydroprocess highly
disadvantaged feedstocks by allowing undesirable feed components
such as the polynuclear aromatics, nitrogen and sulfur species
(which can deactivate hydrocracking catalysts) to pass out of the
hydrocracking loop for processing by equipment better suited for
processing these components, e.g., an FCC unit.
[0102] In one embodiment, the second-stage hydrocracking catalyst
is used in the second stage of a partial conversion, two-stage
hydrocracking configuration which is well suited for making at
least one middle distillate and a heavy vacuum gas fluidized
catalytic cracking feedstock (HVGO FCC), by:
[0103] (a) hydrocracking a hydrocarbonaceous feedstock to produce a
first stage hydrocracked effluent;
[0104] (b) distilling the hydrocracked feedstock by atmospheric
distillation to form at least one middle distillate fraction and an
atmospheric bottoms fraction;
[0105] (c) further distilling the atmospheric bottoms fraction by
vacuum distillation to form a side-cut vacuum gas oil fraction and
a heavy vacuum gas oil FCC feedstock;
[0106] (d) second-stage hydrocracking the side-cut vacuum gas oil
fraction to form a second stage hydrocracked effluent; and
[0107] (e) combining the second stage hydrocracked effluent with
the first stage hydrocracked effluent.
[0108] The refinery configuration illustrated above has several
advantages over conventional two-stage hydrocracking schemes.
First, in this configuration, the catalyst and operating conditions
of the first stage are selected to yield a HVGO FCC stream having
only the minimum feed qualities necessary to produce FCC products
which meet the established commercial specifications. This is in
contrast to a conventional two-stage hydrocracking scheme where the
first stage hydrocracking unit is operated at a severity necessary
to maximize distillate yield which, in turn, requires the unit to
be operated at more severe conditions (which requires more hydrogen
and reduces the life of the catalyst).
[0109] Second, in this optional configuration, the side-cut vacuum
gas oil (VGO) sent to the second stage hydrocracker unit is cleaner
and easier to hydrocrack than a conventional second-stage
hydrocracker feed. Therefore, higher quality middle distillate
products can be achieved using a smaller volume of second-stage
hydrocracking catalyst which, in turn, allows for the construction
of a smaller hydrocracker reactor and consumption of less hydrogen.
The second-stage hydrocracking unit configuration reduces
construction cost, lowers catalyst fill cost and operating
cost.
[0110] Second-Stage Hydrocracking Catalyst Preparation
[0111] The second-stage hydrocracking catalyst can be prepared by:
[0112] a. mixing together a zeolite beta having an OD acidity of 20
to 400 .mu.mol/g and an average domain size from 800 to 1500
nm.sup.2, a zeolite USY having an ASDI between 0.05 and 0.12, a
catalyst support, and enough liquid to form an extrudable paste;
[0113] b. extruding the extrudable paste to form an extrudate base;
[0114] c. impregnating the extrudate base with a metal impregnation
solution containing at least one noble metal to make a metal-loaded
extrudate; and [0115] d. post-treating the metal-loaded extrudate
by subjecting the metal-loaded extrudate to drying and
calcination.
[0116] The liquid used in step a) can be water or a mild acid. In
one embodiment the liquid used in step a) is a diluted HNO.sub.3
acid aqueous solution with from 0.5 to 5 wt % HNO.sub.3.
[0117] Prior to impregnation, the extrudate base can be dried at a
temperature between 90.degree. C. (194.degree. F.) and 150.degree.
C. (302.degree. F.) for 30 minutes to 3 hours. The dried extrudate
base can then be calcined at one or more temperatures between
350.degree. C. (662.degree. F.) and 700.degree. C. (1292.degree.
F.).
[0118] In one embodiment, the metal impregnation solution is made
by dissolving metal precursors in a solvent. Suitable solvents
include water, C.sub.1-C.sub.3 alcohols, ethers, and amines. In one
embodiment, the solvent is deionized water. In one embodiment, the
impregnation solution is adjusted to a basic pH, such as a basic pH
greater than 8. In one embodiment, the metal impregnation solution
has a basic pH from 9.1 to 9.5. The concentration of the
impregnation solution can be determined by the pore volume of the
support and by the selected metal loading. In one embodiment, the
extrudate base is exposed to the impregnation solution for 0.1 to
24 hours. If the second-stage hydrocracking catalyst comprises two
or more metals, these metals can be impregnated sequentially or
simultaneously.
[0119] In one embodiment the metal-loaded extrudate is dried at one
or more temperatures in the range of 38.degree. C. (100.degree. F.)
to 177.degree. C. (350.degree. F.) for 0.1 to 10 hours. The dried
metal-loaded extrudate can be further calcined at one or more
temperatures from 316.degree. C. (600.degree. F.) to 649.degree. C.
(1200.degree. F.), with purging excess dry air, for 0.1 to 10
hours.
[0120] Products Made by Second-Stage Hydrocracking
[0121] The second-stage hydrocracking catalyst can produce
optimized yields of products boiling above 380.degree. F.
(193.degree. C.). In one embodiment, the second-stage hydrocracking
process using the second-stage hydrocracking catalyst produces
greater than 70 wt % of an effluent from the second-stage
hydrocracking reactor having a hydrocracked boiling point greater
than 380.degree. F. (193.degree. C.). In one embodiment, the
second-stage hydrocracking catalyst provides desired selectivity
for naphtha, jet fuel, and diesel. In one embodiment the
second-stage hydrocracking process using the second-stage
hydrocracking catalyst and processes described herein can produce
an effluent that comprises less than 10 wt % boiling below
380.degree. F. In one embodiment, the second-stage hydrocracking
processes described herein produce an effluent from the
second-stage hydrocracking reactor that comprises from 85 to 97 wt
%, or from 90 to 95 wt %, products having a TBP boiling point from
380.degree. F. (193.degree. C.) to 700.degree. F. (371.degree.
C.).
EXAMPLES
Example 1
Domain Size Analysis of Two Different Beta Zeolites
[0122] Domain size determinations were made on two samples of
commercial zeolite betas. One sample was H-BEA-150 zeolite beta
(ZE0090). The other sample was a comparison zeolite beta from
Zeolyst International (CP811C-300, ZE0106) that had a higher SAR
than H-BEA-150. The raw data and statistical analysis of the data
for the domain size analysis is summarized below, in Table 6.
TABLE-US-00006 TABLE 6 H-BEA-150 Comparison Domain Size Analysis
(ZE0090) (ZE0106) Average Domain Size (Mean), nm.sup.2 1089.9 663.6
Standard Error 119.2 67.8 Median 907.2 530.2 Standard Deviation
715.5 454.8 Sample Variance 511881.8 206846.9 Kurtosis 1.2 7.8
Skewness 1.1 2.6 Range 2972.4 2358.0 Minimum 207.7 205.8 Maximum
3180.1 2563.8 Sum 39236.8 29862.5 Total Count 36.0 45.0 Count of
Small Domains, 8 20 200 to 600 nm.sup.2 Count of Large Domains, 11
1 1200 to 2000 nm.sup.2 Count of Extra Large Domains, 9 2 1500 to
3200 nm.sup.2
[0123] The data from these domain size analyses were also charted
and are shown in FIGS. 1 and 2. FIG. 1 shows the differences in the
frequency of the domain sizes between the two zeolite betas. FIG. 2
shows that the domain sizes for the H-BEA-150 were larger and more
broadly distributed than those shown for the comparison zeolite
beta. The standard deviation for the domain sizes for the H-BEA-150
was greater than 700 nm.sup.2, while the standard deviation for the
domain sizes for the comparison zeolite beta was less than 500
nm.sup.2. Also, the H-BEA-150 zeolite beta had more large domains
that had a domain size from 1200 to 2000 nm.sup.2 than small
domains that had a domain size from 200 to 600 nm.sup.2; which is
notably different that the distribution of the domain sizes in the
comparison zeolite beta. The H-BEA-150 had a similar distribution
(9 vs. 8) of extra-large domains with a domain size from 1500 to
3200 nm.sup.2 to small domains with a domain size from 200 to 600
nm.sup.2. In this context, similar distribution means that the
ratio of the count of domains in the two different domain size
ranges is from 0.8:1 to 1.2:1.
Example 1
Preparation of Exemplary Catalyst Sample
[0124] An exemplary catalyst sample was prepared by combining, on a
dry basis, 894.0 g SIRAL 40, 258.0 g CATAPAL B alumina, 13.2 g
zeolite USY (A), and 34.8 zeolite beta (H-BEA-150); and mixing them
well.
[0125] The properties of the ZEOLITE USY (A) are summarized in
Table 7.
TABLE-US-00007 TABLE 7 SiO.sub.2/Al.sub.2O.sub.3 60 Mole Ratio
Nominal Hydrogen Cation Form Na.sub.2O, Wt % 0.03 Unit Cell 24.24
Size, .ANG. Surface 720 Area, m.sup.2/g
[0126] The ZEOLITE USY (A) had an acid site distribution index
(ASDI) of 0.086. Additional properties of the ZEOLITE USY (A) are
summarized in Table 8.
TABLE-US-00008 TABLE 8 Bronsted acid sites determined by FTIR after
H/D exchange (mmol/g) HF(OD) 0.076 HF'(OD) 0.005 LF(OD) 0.034
LF'(OD) 0.003 Total OD 0.118 Acidity ASDI 0.086
[0127] To this mixture described above, a diluted HNO.sub.3 acid
aqueous solution (3 wt %) was added to form an extrudable paste
with 58 wt % volatiles. The extrudable paste was extruded into an
asymmetric quadrolobe shape and dried at 266.degree. F.
(130.degree. C.) for 1 hour. The dried extrudates were calcined at
1100.degree. F. (593.degree. C.) for 1 hour with purging excess dry
air and cooled down to 300.degree. F. (149.degree. C.).
[0128] Pt and Pd were pore volume impregnated onto the dried
extruded catalyst base described above by immersing the dried
extruded catalyst base into a PtPd metal solution having a pH from
9.2-9.4. The PtPd metal solution was made by mixing 6.552 g
Pt(NH.sub.3).sub.4(NO.sub.3).sub.2, 3.593 g
Pd(NH.sub.3).sub.4(NO.sub.3).sub.2, ammonia water, and deionized
water. 100 g (dry basis) of the dried extruded catalyst base was
immersed in the PtPd metal solution at room temperature for twelve
hours. The metal impregnated extruded catalyst was dried at
302.degree. F. (150.degree. C.) for 1 hour. The dried catalyst was
then calcined at 815.degree. F. (435.degree. C.) for 1 hour with
purging excess dry air, and cooled down to 300.degree. F.
(149.degree. C.). The composition and physical properties of this
finished Catalyst Sample are shown in Table 9.
Example 2
Comparative Catalyst Sample
[0129] A comparative Catalyst Sample was made by preparing the
catalyst base and impregnating the base with Pt and Pd, similar to
the steps used to prepare the Exemplary Catalyst Sample described
in Example 1.
[0130] The catalyst compositions and physical properties of the
catalyst sample from Example land the comparative catalyst sample
described here are shown in Table 9.
TABLE-US-00009 TABLE 9 Catalyst Compositions and Physical
Properties Comparative Exemplary Catalyst Sample Catalyst Sample
Base Description 16.0 wt % 21.5 wt % CATAPAL B, 80 CATAPAL B, wt %
SIRAL 40, 74.5 wt % SIRAL 4.0 wt % zeolite 40, 2.9 wt % H- USY (A)
BEA-150 zeolite beta, 1.1 wt % zeolite USY (A) Surface Area (BET),
m.sup.2/g 369 369 N.sub.2 Micropore Volume, cm.sup.3/g 0.591 0.713
Compacted Bulk Density, g/l 591 519 Particle Density, g/l 1091.0
944.5 LOI (1000.degree. F.), wt % 18.44 1.34 Total PtPd H.sub.2
Adsorption, wt % 88.9 92.6 Al.sub.2O.sub.3, wt % 63.84 66.03
SiO.sub.2, wt % 35.75 33.56 PtO, wt % 0.23 0.23 PdO, wt % 0.18 0.18
Surface area (BET) was measured by ASTM D3663-03(Reapproved 2008).
N2 micropore volume was measured by ASTM D4365-13. Compacted bulk
density was measured by ASTM D4512-03(2013).epsilon.1. Particle
density was measured by mercury porosimetry. Loss on ignition [LOI
(1000.degree. F.)] was measured by ASTM D7348-13. PtPd H2
adsorption was measured by ASTM D3908-03(Reapproved 2008).
Example 3
Hydrocracking Second-Stage Feeds
[0131] The example catalysts described above were used to process a
hydrocracking second-stage feed produced in first-stage
ISOCRACKING.RTM. hydrocracking unit. The properties of this
hydrocracking second-stage feed are described in Table 10.
TABLE-US-00010 TABLE 10 API Gravity 36.2 N, ppm 0.5 S, wt % <5
H, wt % by NMR 13.92 Polycyclic Index (PCI) 35 22 .times. 22 Mass
Spec, vol % Paraffins 41.5 Naphthenes 51.3 Aromatics 7.2 Sulfur 0.0
TBP Range, .degree. F. (.degree. C.) 0.5 437 5 492 10 524 30 610 50
669 70 720 90 800 95 838 99.5 926
[0132] ISOCRACKING.RTM. is a registered trademark of Chevron
Intellectual Property LLC. ISOCRACKING processes are described in
A. G. Bridge and U. K. Mukherjee, "Isocracking-Hydrocracking for
Superior Fuels and Lube Production," Handbook of Petroleum Refining
Processes, 3.sup.rd ed., R. A. Meyers ed., Chapter 7.1,
McGraw-Hill, 2003.
Example 4
Comparison of Second-Stage Hydrocracking
[0133] Hydrocracking tests were performed using the feed described
in Example 3 in the pilot plant that is shown in FIG. 6. The
hydrocracking process conditions during the tests included a total
pressure of 1900 psig, a LHSV of 1.92, and 6,000 SCFB gas rate. The
hydrocracking target was set at 30 wt % synthetic conversion less
than 625.degree. F. (329.degree. C.). A chart showing the
normalized hydrocracking temperatures over time on stream for two
hydrocracking tests done with the exemplary catalyst sample
described in Example 1 and the comparative catalyst sample
described in Example 2 is shown in FIG. 3. The product yields at
30.0 wt % synthetic conversion less than 625.degree. F.
(329.degree. C.), and the hydrogen consumption, are summarized
below in Table 11.
TABLE-US-00011 TABLE 11 Catalyst Comparative Catalyst Exemplary
Catalyst Sample Sample No Loss Yields, wt % C4- 1.0 0.8
C.sub.5-380.degree. F. 10.5 8.3 380-566.degree. F. 28.4 29.2
566-625.degree. F. 15.0 16.7 625.degree. F.+ 46.1 46.0 Mass
Closure, Wt % 99.19 99.59 Hydrogen Consumption, 365 297 SCFB
[0134] FIG. 3 shows that the exemplary catalyst sample was
20.degree. F. more active than the comparative catalyst sample over
the total time on stream.
[0135] At the conditions tested, with 30.0 wt % synthetic
conversion less than 625.degree. F. (329.degree. C.), the exemplary
catalyst sample made 0.2 wt % less C4-, 2.2 wt % less
C.sub.5-380.degree. F. naphtha, 0.8 wt % more 380-566.degree. F.
jet, and 1.7 wt % more 566-625.degree. F. diesel.
[0136] Most of the jet, diesel and unconverted oil (UCO) properties
were similar for the runs using the two different catalyst samples.
The cloud points, however, were lowered when using the exemplary
catalyst sample. Cloud points can be measured by ASTM D2500-11 or
ASTM D5771-15. The cloud point for the jet made using the exemplary
catalyst sample was -47.degree. C., while the cloud point for the
jet made using the comparative catalyst sample was -41.degree. C.
The cloud point for the diesel made using the exemplary catalyst
sample was -16.degree. C., while the cloud point for the diesel
made using the comparative catalyst sample was only -7.degree.
C.
Example 5
Effect of Conversion on Hydrogen Consumption during
Hydrocracking
[0137] Additional hydrocracking tests were performed using the feed
described in Example 3 in the pilot plant that is shown in FIG. 4.
The hydrocracking process conditions were adjusted by adjusting the
reactor temperatures during the tests to achieve a range of
synthetic conversion less than 625.degree. F. (329.degree. C.) from
about 23 to 37 wt %. As in the previous tests, the hydrocracking
conditions included a total pressure of 1900 psig, a LHSV of 1.92,
and 6,000 SCFB gas rate. A chart showing the hydrogen consumption
vs. synthetic conversion less than 625.degree. F. (329.degree. C.)
for these hydrocracking tests done with the exemplary catalyst
sample from Example 1 and the comparative catalyst sample from
Example 2 is shown in FIG. 4. The hydrogen consumption in the tests
using the exemplary catalyst sample were lower across the range of
synthetic conversions tested, and the higher the synthetic
conversion the greater the difference in the hydrogen consumption
between the two different hydrocracking catalysts.
Example 6
UV Absorptivity for Stripper Bottom Products
[0138] Hydrocarbon product samples from the hydrocracking runs
described in Example 4, made using the comparative catalyst sample
and exemplary catalyst sample, were taken periodically during the
runs. The hydrocarbon product samples were stripped by nitrogen at
elevated temperatures as shown in FIG. 6 and the stripper bottoms
were analyzed for UV absorbance by a method adapted from ASTM
D2008-91. UV absorbance was measured using a HP 8453
spectrophotometer interfaced to an HP Chem-station. The details of
the process conditions, time on stream, and UV absorbance of the
stripper bottoms are shown in Table 12.
TABLE-US-00012 TABLE 12 UV Absorptivity for Stripper Bottoms
Products Catalyst Sample Comparative Exemplary Comparative
Exemplary Comparative Exemplary Exemplary Exemplary Time on Stream,
Hours 808 1048 1288 1600 1552 1312 1672 1792 C.A.T., .degree. F.
(.degree. C.) 596 (1105) 580 (1076) 596 (1105) 580 (1076) 603
(1117) 580 (1076) 589 (1092) 589 (1092) LHSV 1.17 1.13 1.15 1.14
1.15 1.13 1.14 1.14 Total Pressure, PSIG 1307 1305 1311 1318 1310
1300 1316 1311 H.sub.2 Rate, SCFB 6325 6517 6442 6509 6412 6531
6508 6500 Conv. <625 F., wt. % 30.24 30.00 25.62 25.01 29.68
28.41 36.70 36.81 UV Absorbance, nm nm Comparative Exemplary
Comparative Exemplary Comparative Exemplary Exemplary Exemplary 226
0.03040 0.02886 0.03261 0.03077 0.04028 0.03026 0.03873 0.03937 255
0.00507 0.00393 0.00522 0.00404 0.00739 0.00403 0.00593 0.00600 305
0.02840 0.02689 0.02794 0.02618 0.02995 0.02657 0.02885 0.02902 340
0.00535 0.00460 0.00533 0.00452 0.00647 0.00460 0.00557 0.00561 348
0.00643 0.00577 0.00640 0.00563 0.00774 0.00574 0.00684 0.00691 385
0.00061 0.00048 0.00064 0.00048 0.00092 0.00048 0.00071 0.00071 435
0.00011 0.00011 0.00012 0.00012 0.00014 0.00011 0.00012 0.00012 450
0.00009 0.00006 0.00009 0.00007 0.00010 0.00006 0.00009 0.00008 495
0 0 0 0 0 0 0 0
[0139] The stripper bottoms made using the exemplary catalyst
sample had lower UV absorption, which indicated that the exemplary
catalyst sample was better at saturating aromatics than the
comparative catalyst sample. It is theorized that the increased
aromatics saturation was due to the better cracking activity of the
exemplary catalyst sample, such that the C.A.T. was significantly
lowered. The lower hydrocracking temperature favored aromatics
saturation.
[0140] The transitional term "comprising", which is synonymous with
"including," "containing," or "characterized by," is inclusive or
open-ended and does not exclude additional, unrecited elements or
method steps. The transitional phrase "consisting of" excludes any
element, step, or ingredient not specified in the claim. The
transitional phrase "consisting essentially of" limits the scope of
a claim to the specified materials or steps "and those that do not
materially affect the basic and novel characteristic(s)" of the
claimed invention.
[0141] For the purposes of this specification and appended claims,
unless otherwise indicated, all numbers expressing quantities,
percentages or proportions, and other numerical values used in the
specification and claims, are to be understood as being modified in
all instances by the term "about." Furthermore, all ranges
disclosed herein are inclusive of the endpoints and are
independently combinable. Whenever a numerical range with a lower
limit and an upper limit are disclosed, any number falling within
the range is also specifically disclosed. Unless otherwise
specified, all percentages are in weight percent.
[0142] Any term, abbreviation or shorthand not defined is
understood to have the ordinary meaning used by a person skilled in
the art at the time the application is filed. The singular forms
"a," "an," and "the," include plural references unless expressly
and unequivocally limited to one instance.
[0143] All of the publications, patents and patent applications
cited in this application are herein incorporated by reference in
their entirety to the same extent as if the disclosure of each
individual publication, patent application or patent was
specifically and individually indicated to be incorporated by
reference in its entirety.
[0144] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to make and use the invention. Many
modifications of the exemplary embodiments of the invention
disclosed above will readily occur to those skilled in the art.
Accordingly, the invention is to be construed as including all
structure and methods that fall within the scope of the appended
claims. Unless otherwise specified, the recitation of a genus of
elements, materials or other components, from which an individual
component or mixture of components can be selected, is intended to
include all possible sub-generic combinations of the listed
components and mixtures thereof.
[0145] The invention illustratively disclosed herein suitably may
be practiced in the absence of any element which is not
specifically disclosed herein.
* * * * *
References