U.S. patent application number 13/851176 was filed with the patent office on 2013-10-03 for coprocessing of biofeeds with bulk mixed metal catalysts.
This patent application is currently assigned to ExxonMobil Research and Engineering Company. The applicant listed for this patent is EXXONMOBIL RESEARCH AND ENGINEERING COMPANY. Invention is credited to Bradley R. Fingland, Patrick Loring Hanks, Sabato Miseo, Stuart Leon Soled.
Application Number | 20130261362 13/851176 |
Document ID | / |
Family ID | 49235893 |
Filed Date | 2013-10-03 |
United States Patent
Application |
20130261362 |
Kind Code |
A1 |
Fingland; Bradley R. ; et
al. |
October 3, 2013 |
COPROCESSING OF BIOFEEDS WITH BULK MIXED METAL CATALYSTS
Abstract
This invention relates to methods for deoxygenation utilizing
bulk metal catalysts feedstocks derived in part or whole from
biological sources and alternatively, further hydrotreatment
processing of such deoxygenated feedstocks. Feedstocks containing
bio-derived feed components, and preferably additionally mineral
oil feed components, are deoxygenated in a first stage or zone
using a bulk metal catalyst. In additional embodiments, the
deoxygenated feedstock effluent from the deoxygenation stage is
further subjected to a hydrodesulfurization stage or zone.
Inventors: |
Fingland; Bradley R.;
(Annandale, NJ) ; Hanks; Patrick Loring; (Fairfax,
VA) ; Soled; Stuart Leon; (Pittstown, NJ) ;
Miseo; Sabato; (Pittstown, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EXXONMOBIL RESEARCH AND ENGINEERING COMPANY |
Annandale |
NJ |
US |
|
|
Assignee: |
ExxonMobil Research and Engineering
Company
Annandale
NJ
|
Family ID: |
49235893 |
Appl. No.: |
13/851176 |
Filed: |
March 27, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61617984 |
Mar 30, 2012 |
|
|
|
Current U.S.
Class: |
585/324 ;
585/639 |
Current CPC
Class: |
C10G 2300/202 20130101;
C10G 3/46 20130101; B01J 37/20 20130101; C10G 3/47 20130101; C10G
65/04 20130101; B01J 2523/00 20130101; B01J 23/883 20130101; C10G
45/04 20130101; B01J 23/888 20130101; B01J 23/882 20130101; B01J
35/1019 20130101; B01J 35/1014 20130101; Y02P 30/20 20151101; B01J
23/8885 20130101; B01J 23/002 20130101; B01J 2523/00 20130101; B01J
2523/68 20130101; B01J 2523/69 20130101; B01J 2523/847
20130101 |
Class at
Publication: |
585/324 ;
585/639 |
International
Class: |
C10G 3/00 20060101
C10G003/00 |
Claims
1. A method for hydroprocessing a biocomponent feedstock,
comprising: exposing a biocomponent feedstock comprising at least a
bio-derived fraction to a bulk mixed metal catalyst in the presence
of hydrogen under effective deoxygenation conditions, the bulk
mixed metal catalyst comprising at least one Group VI metal and at
least one Group VIII metal; and forming a deoxygenated effluent
wherein at least 75% of the oxygen has been removed from the
biocomponent feedstock compounds.
2. The method of claim 1, wherein the biocomponent feedstock
further comprises a mineral oil fraction.
3. The method of claim 2, wherein the at least one Group VI metal
is selected from Mo and W and at least one Group VIII metal is
selected from Co and Ni.
4. The method of claim 3, wherein the total amount of the Group VI
metals and Group VIII metals comprise at least 80 wt % of the bulk
mixed metal catalyst.
5. The method of claim 4, wherein the bulk mixed metal catalyst
contains less than 15 wt % carrier or support material.
6. The method of claim 3, wherein the bulk mixed metal catalyst is
further combined with a binder.
7. The method of claim 6, wherein the binder is selected from
silica, silica-alumina, alumina, titania, zirconia, and mixtures
thereof.
8. The method of claim 7, wherein the amount of binder is from
about 5 wt % to about 95 wt % binder based on the total weight of
the bulk mixed metal catalyst and the binder.
9. The method of claim 3, wherein the bulk mixed metal catalyst is
further comprised of at least one organic compound.
10. The method of claim 9, wherein the bulk mixed metal catalyst is
further sulfided prior to exposing the biocomponent feedstock to
the bulk mixed metal catalyst, and the at least one organic is
present on the bulk mixed metal catalyst at the time the catalyst
is exposed to the sulfiding conditions.
11. The method of claim 10, wherein the at least one organic
compound is a condensation/decomposition reaction product derived
from an amine, a carboxylic acid, or combinations thereof.
12. The method of claim 11, wherein the amine, carboxylic acid, or
combination thereof is subjected to a reaction temperature of from
about 195.degree. C. to about 250.degree. C. (about 383.degree. F.
to about 482.degree. F.) to form the condensation/decomposition
reaction product.
13. The method of claim 12, wherein the at least one Group VI metal
is Mo and at least one Group VIII metal is Co.
14. The method of claim 3, wherein the bulk mixed metal catalyst is
comprised of at least two Group VI metals, such Group VI metals
being Mo and W, and at least one Group VIII metal selected from Co
and Ni.
15. The method of claim 14, wherein the bulk mixed metal catalyst
is further sulfided prior to exposing the biocomponent feedstock to
the bulk mixed metal catalyst.
16. The method of claim 14, wherein the bulk mixed metal catalyst
is comprised of Mo, W, and Ni.
17. The method of claim 16, wherein the bulk mixed metal catalyst
is comprised of at least 90 wt % Mo, W, and Ni, and this portion of
the bulk mixed metal catalyst has the formula:
(Ni).sub.b(Mo).sub.c(W).sub.dO.sub.z wherein the molar ratio of
b:(c+d) is 0.5:1 to 3:1; the molar ratio of c:d is preferably
>0.01:1; the molar ratio of Mo and W is 2:3 to 3:2; and
z=[2b+6(c+d)]/2.
18. The method of claim 3, wherein the effective deoxygenation
conditions include a hydrogen partial pressure of from about 200
psig (1.4 MPag) to about 2000 psig (13.8 MPag), a reaction
temperature of from about 400.degree. F. to about 750.degree. F.
(204.degree. C. to 399.degree. C.), a liquid hourly space velocity
of from about 0.1 hr.sup.-1 to about 10 hr.sup.-1, and a hydrogen
treat gas rate from about 500 scf/B (84 Nm.sup.3/m.sup.3) to about
10,000 scf/B (1685 Nm.sup.3/m.sup.3).
19. The method of claim 18, wherein the effective deoxygenation
conditions include a reaction temperature of from about 400.degree.
F. to about 500.degree. F. (204.degree. C. to 260.degree. C.).
20. The method of claim 18, wherein the effective deoxygenation
conditions include a reaction temperature of from about 400.degree.
F. to about 490.degree. F. (204.degree. C. to 254.degree. C.).
21. The method of claim 2, further comprising: exposing at least a
portion of the deoxygenated effluent to a hydrodesulfurization
catalyst under effective hydrodesulfurization conditions to produce
a deoxygenated/desulfurized effluent having a sulfur content of
about 100 wppm or less.
22. The method of claim 21, wherein the effective
hydrodesulfurization conditions include, a total pressure from
about 200 psig (1.4 MPa) to about 3000 psig (20.7 MPa), a
temperature of from about 450.degree. F. (232.degree. C.) to about
750.degree. F. (399.degree. C.), a liquid hourly space velocity of
about 0.3 to about 5.0 hr.sup.-1, a treat gas containing at least
about 80% hydrogen, and a hydrogen treat gas rate of about 500
scf/bbl (84 m.sup.3/m.sup.3) to about 10000 scf/bbl (1685
m.sup.3/m.sup.3).
23. The method of claim 22, wherein hydrodesulfurization catalyst
is comprised of at least one Group VIB metal and at least one Group
VIII metal deposited upon a support, wherein the support is
comprised of a material selected from silica, silica-alumina,
alumina, and titania.
24. The method of claim 23, wherein the bulk mixed metal catalyst
and the hydrodesulfurization catalyst are located in a common
reactor.
25. The method of claim 23, wherein the bulk mixed metal catalyst
and the hydrodesulfurization catalyst are each located in separate
reactors and the effective hydrodesulfurization conditions include
a temperature of from about 650.degree. F. (343.degree. C.) to
about 750.degree. F. (399.degree. C.).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 61/617,984 filed Mar. 30, 2012, which is
herein incorporated by reference in its entirety. This application
contains disclosures and claims to an invention that has an
effective filing date on or after Mar. 16, 2013.
FIELD
[0002] This invention relates to methods for deoxygenation and
alternatively hydrotreatment of feeds derived in part or whole from
renewable biological sources utilizing bulk metal catalysts to
deoxygenate the biocomponent feeds.
BACKGROUND
[0003] Regulations related to renewable fuels provide an example of
how product requirements can change over time. During the next
decade, the United States, Canada, and the European Union have
increased and/or are likely to increase the required amount of
product from renewable sources that is contained in transportation
fuels. Based on such regulatory requirements, fuels from vegetable,
animal, or algae sources such as "biodiesel" will become
increasingly important as a refinery product. As a result, methods
are needed that will allow existing refinery equipment to produce
suitable transportation fuels that incorporate increasing amounts
of renewable components.
[0004] Unfortunately, the differences in chemical composition
between renewable carbon sources and mineral sources poses some
difficulties for refinery processing. For example, typical
biologically-derived sources for fuels have oxygen contents of 1 wt
% or more, possibly as much as 10 wt % or more. Conventional
hydroprocessing methods can remove oxygen from a feedstock, but the
by-products from deoxygenation can lead to catalyst poisoning
and/or contaminant build-up in a reaction system.
[0005] U.S. Patent Application Publication 2010/0163458 describes a
method for converting effluents of renewable origin into fuel. The
method includes the use of a supported catalyst containing
MoS.sub.2 and a dopant, such as phosphorus, carbon, or silicon. The
method is described as favoring removal of oxygen by
hydrodeoxygenation as opposed decarbonylation or
decarboxylation.
[0006] U.S. Patent Application Publication 2011/0166396 describes a
hydrodeoxygenation catalyst and a method for using such a catalyst.
The catalyst is a supported catalyst containing Mo, with a support
that includes a bimodal pore distribution. Additionally, at least 2
volume percent of the pores in the support are greater than 50 nm
in diameter. The Mo catalyst with the specified pore distribution
is used to perform hydrodeoxygenation on feeds containing up to 35
vol. % of renewable organic material.
SUMMARY OF EMBODIMENTS OF THE INVENTION
[0007] In one embodiment of the present invention herein is a
method for hydroprocessing a biocomponent feedstock,
comprising:
[0008] exposing a biocomponent feedstock comprising at least a
bio-derived fraction to a bulk mixed metal catalyst in the presence
of hydrogen under effective deoxygenation conditions, the bulk
mixed metal catalyst comprising at least one Group VI metal and at
least one Group VIII metal; and
[0009] forming a deoxygenated effluent wherein at least 75% of the
oxygen has been removed from the biocomponent feedstock compounds.
In a preferred embodiment, the biocomponent feedstock further
comprises a mineral oil fraction.
[0010] In another embodiment, the at least one Group VI metal is
selected from Mo and W and at least one Group VIII metal is
selected from Co and Ni. While in yet another embodiment, the total
amount of the Group VI metals and Group VIII metals comprise at
least 80 wt % of the bulk mixed metal catalyst.
[0011] In another embodiment herein, the bulk mixed metal catalyst
is further comprised of at least one organic compound. The at least
one organic compound may be a condensation/decomposition reaction
product derived from an amine, a carboxylic acid, or combinations
thereof. More preferably, the amine, carboxylic acid, or
combination thereof is subjected to a reaction temperature of from
about 195.degree. C. to about 250.degree. C. (about 383.degree. F.
to about 482.degree. F.) to form the condensation/decomposition
reaction product.
[0012] In yet another embodiment herein, the bulk mixed metal
catalyst is comprised of at least two Group VI metals, such Group
VI metals being Mo and W, and at least one Group VIII metal
selected from Co and Ni. Here, in a more preferred embodiment, the
bulk mixed metal catalyst is comprised of Mo, W, and Ni.
[0013] In embodiments herein, the effective deoxygenation
conditions can include a hydrogen partial pressure of from about
200 psig (1.4 MPag) to about 2000 psig (13.8 MPag), a reaction
temperature of from about 400.degree. F. to about 750.degree. F.
(204.degree. C. to 399.degree. C.), a liquid hourly space velocity
of from about 0.1 hr.sup.-1 to about 10 hr.sup.-1, and a hydrogen
treat gas rate from about 500 scf/B (84 Nm.sup.3/m.sup.3) to about
10,000 scf/B (1685 Nm.sup.3/m.sup.3). In other embodiments, the
effective deoxygenation conditions can include a reaction
temperature of from about 400.degree. F. to about 500.degree. F.
(204.degree. C. to 260.degree. C.).
[0014] In yet other embodiments herein, the method may further
comprise:
[0015] exposing at least a portion of the deoxygenated effluent to
a hydrodesulfurization catalyst under effective
hydrodesulfurization conditions to produce a
deoxygenated/desulfurized effluent having a sulfur content of about
100 wppm or less. In these embodiments herein, the effective
hydrodesulfurization conditions can include, a total pressure from
about 200 psig (1.4 MPa) to about 3000 psig (20.7 MPa), a
temperature of from about 450.degree. F. (232.degree. C.) to about
750.degree. F. (399.degree. C.), a liquid hourly space velocity of
about 0.3 to about 5.0 hr.sup.-1, a treat gas containing at least
about 80% hydrogen, and a hydrogen treat gas rate of about 500
scf/bbl (84 m.sup.3/m.sup.3) to about 10000 scf/bbl (1685
m.sup.3/m.sup.3).
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 schematically shows a reaction system suitable for
performing a process according to an embodiment of the
invention.
[0017] FIG. 2 depicts a reaction system suitable for performing a
process according to an embodiment of the invention.
[0018] FIGS. 3 through 5 show analysis plots from comparative
experiments performed according to an embodiment of the invention
as associated testing is further described in the Examples
herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] In various aspects, methods are provided for processing of
bio-feedstocks or biocomponent feedstocks using utilizing bulk
metal catalysts in order to remove oxygen (deoxygenate) from the
bio- or biocomponent feedstocks. By the term "bio-feedstock" used
herein it is meant a material that is essentially 100% biologically
derived materials. The term "biocomponent feedstock" (or
alternatively "bio-containing feedstock") used herein it is meant a
material that contains at least in part some biologically derived
materials; this term may encompass a stream containing 100%
biologically derived materials. Preferably, the term "biocomponent
feedstock" contains at least in part some biologically derived
materials as well at least in part some mineral oils. In contrast,
the term a "mineral feedstock" (or "mineral oil") as used herein
means a hydrocarbon material that is derived from sources termed in
the industry as "non-renewable" sources, such as feedstocks
containing or derived from crude oils, oil shales, oil sands, tar
sands, natural gases and the like.
[0020] The deoxygenation step or "zone" as described herein may be
used independently of the requirement of any further processing
step, or it may be used as part of a stacked catalyst bed
arrangement. The deoxygenation zone or the stacked beds can include
one or more at least partial catalyst beds of a bulk metal (or
"bulk mixed metal") catalyst as further described here in. One or
more subsequent beds can include a hydrotreating catalyst, such as,
but not limited to, a supported CoMo or NiMo hydrotreating
catalyst.
[0021] One way to adapt existing reactors to meet changing
requirements can be to co-process multiple feeds within a reactor.
However, co-processing of multiple feeds in a hydroprocessing
reactor can pose a variety of challenges. For example, feedstocks
based on biological sources, such as feeds containing vegetable,
animal, or algae oils or fats, can contain a substantial amount of
oxygen. The oxygen contents of the biological source feedstocks can
lead to production of undesirable amounts of CO and/or CO.sub.2.
The resulting CO and/or CO.sub.2 generated from hydroprocessing of
the biological source feedstock can cause poisoning of the
hydroprocessing catalyst. The product gases generated from such
hydroprocessing may also have an increased ability to corrode
hydroprocessing equipment. Still another concern is that removal of
oxygen from a biocomponent feed is an exothermic reaction,
potentially leading to difficulties in maintaining temperature
control in a reactor. Additionally, removal of oxygen from a
biocomponent feed typically requires a hydrogen source. Many
refineries already have limitations on available hydrogen, and
having yet another process that consumes hydrogen further limits
the choices available to such a refinery.
[0022] It has been discovered herein that other problems that exist
in deoxygenating and refining biocomponent feedstocks is that the
activity of some hydrotreating catalysts may be sensitive to
changes in reaction/processing conditions. In detail, the activity
of some of the hydrotreating catalysts used in the art may be very
sensitive to even minor changes in the reaction temperatures of the
process when it relates to the deoxygenation reaction of the
bio-components of the feedstocks. It has also been discovered
herein that other problems that exist in deoxygenating and refining
biocomponent feedstocks is that some hydrotreating catalysts in the
art may consume a significant amount of hydrogen.
[0023] It has been discovered that one option for addressing at
least some of the above problems is to use a bulk metal catalyst
that includes at least one Group VI metal and at least one Group
VIII metal in a deoxygenation zone for processing a bio-containing
feed, i.e., a feed including both mineral-derived feedstock and
biocomponent-derived feedstock. In some aspects, a feed including a
mixture of mineral-derived feedstock and biocomponent-derived
feedstock can be exposed to the bulk metal catalyst under low
pressure conditions, such as a hydrogen partial pressure of 400
psig (2.75 MPag) or less.
[0024] By the term "bulk metal catalyst" (or equivalent term "bulk
mixed metal catalyst") as used herein, it is meant that the
catalyst is comprised of at least 80 wt % active metals. By the
term "active metals" it is meant at least one Group VI metal
(corresponding to Group 6 of the modern IUPAC periodic table) and
at least one Group VIII metal (corresponding to Groups 8-10 of the
modern IUPAC periodic table). Preferably, the bulk metal catalyst
comprises at least 90 wt %, more preferably at least 95 wt %,
active metals. These bulk metal catalysts, and their preferred
embodiments for use in the presently disclosed processes, are
detailed further herein.
[0025] The bulk metal catalyst can be incorporated into a single or
standalone deoxygenation reaction stage or zone, or conversely as
part of a reaction system as part of multi-bed and/or multi-stage
process for processing of a biocomponent feedstock. In the system,
one or more initial beds or stages include a bulk metal catalyst.
In the deoxygenation stage, a biocomponent feed is initially
exposed to a bulk metal catalyst under effective conditions for at
least a portion of the oxygen from the feed. The feed with reduced
oxygen content can then optionally further be exposed to a
conventional hydrotreatment catalyst under effective hydrotreatment
conditions for removal of sulfur and nitrogen, as well as any
remaining oxygen.
[0026] Treating a feed containing a biocomponent portion with a
bulk metal catalyst prior to hydrotreatment of the feed can provide
a variety of advantages. One potential advantage is reduction of
the exotherm across the catalyst bed for the hydrotreating
catalyst. Deoxygenation reactions are strongly exothermic, so
combining deoxygenation of a biocomponent feed with a conventional
hydrodesulfurization process on a sulfur-containing mineral feed
could lead to an excessive temperature increase across a catalyst
bed. Because the bulk metal catalysts herein are selective for
performing deoxygenation relative to desulfurization, the
temperature increase across the catalyst bed for the bulk metal
catalyst will typically be more manageable. Another potential
advantage is an improved overall catalyst activity for the
combination of the bulk metal catalyst and the hydrotreating
catalyst, relative to using a similar size bed of only
hydrotreating catalyst. Deoxygenation reactions typically produce
both water and carbon oxides as residual products. The combination
of water and carbon oxides can lead to deactivation of some types
of hydrotreating catalysts. In some reaction system configurations,
one or more initial beds of a bulk metal catalyst can be used to
perform deoxygenation prior to exposing a feedstock to a
hydrotreating catalyst. The water and carbon oxide contaminants
generated during deoxygenation can be separated out prior to
exposing the deoxygenated feed to an alternative subsequent
hydrotreating catalyst, thus reducing or avoiding any deactivation
of the hydrotreating catalyst.
Feedstocks
[0027] In the discussion below, a biocomponent feed or feedstock
refers to a hydrocarbon feedstock derived at least in part from a
biological raw material component, such as vegetable fats/oils or
animal fats/oils, fish oils, pyrolysis oils, and algae lipids/oils,
as well as components of such materials, and in some embodiments
can specifically include one or more types of lipid compounds.
Lipid compounds are typically biological compounds that are
insoluble in water, but soluble in nonpolar (or fat) solvents.
Non-limiting examples of such solvents include alcohols, ethers,
chloroform, alkyl acetates, benzene, and combinations thereof.
[0028] Major classes of lipids include, but are not necessarily
limited to, fatty acids, glycerol-derived lipids (including fats,
oils and phospholipids), sphingosine-derived lipids (including
ceramides, cerebrosides, gangliosides, and sphingomyelins),
steroids and their derivatives, terpenes and their derivatives,
fat-soluble vitamins, certain aromatic compounds, and long-chain
alcohols and waxes.
[0029] In living organisms, lipids generally serve as the basis for
cell membranes and as a form of fuel storage. Lipids can also be
found conjugated with proteins or to carbohydrates, such as in the
form of lipoproteins and lipopolysaccharides.
[0030] Examples of vegetable oils that can be used in accordance
with this invention include, but are not limited to rapeseed
(canola) oil, soybean oil, coconut oil, sunflower oil, palm oil,
palm kernel oil, peanut oil, linseed oil, tall oil, corn oil,
castor oil, jatropha oil, jojoba oil, olive oil, flaxseed oil,
camelina oil, safflower oil, babassu oil, tallow oil and rice bran
oil.
[0031] Vegetable oils as referred to herein can also include
processed vegetable oil material. Non-limiting examples of
processed vegetable oil material include fatty acids and fatty acid
alkyl esters. Alkyl esters typically include C.sub.1-C.sub.5 alkyl
esters. One or more of methyl, ethyl, and propyl esters are
preferred.
[0032] Examples of animal fats that can be used in accordance with
the invention include, but are not limited to, beef fat (tallow),
hog fat (lard), turkey fat, fish fat/oil, and chicken fat. The
animal fats can be obtained from any suitable source including
restaurants and meat production facilities.
[0033] Animal fats as referred to herein also include processed
animal fat material. Non-limiting examples of processed animal fat
material include fatty acids and fatty acid alkyl esters. Alkyl
esters typically include C.sub.1-C.sub.5 alkyl esters. One or more
of methyl, ethyl, and propyl esters are preferred.
[0034] Algae oils or lipids can typically be contained in algae in
the form of membrane components, storage products, and/or
metabolites. Certain algal strains, particularly microalgae such as
diatoms and cyanobacteria, can contain proportionally high levels
of lipids. Algal sources for the algae oils can contain varying
amounts, e.g., from 2 wt % to 40 wt % of lipids, based on total
weight of the biomass itself.
[0035] Algal sources for algae oils can include, but are not
limited to, unicellular and multicellular algae. Examples of such
algae can include a rhodophyte, chlorophyte, heterokontophyte,
tribophyte, glaucophyte, chlorarachniophyte, euglenoid, haptophyte,
cryptomonad, dinoflagellum, phytoplankton, and the like, and
combinations thereof. In one embodiment, algae can be of the
classes Chlorophyceae and/or Haptophyta. Specific species can
include, but are not limited to, Neochloris oleoabundans,
Scenedesmus dimorphus, Euglena gracilis, Phaeodactylumn
tricornutum, Pleurochrysis carterae, Prymnesium parvum, Tetrasenis
chui, and Chlamydomonas reinhardtii. Additional or alternate algal
sources can include one or more microalgae of the Achnanthes,
Amphiprora, Amphora, Ankistrodesmus, Asteromonas, Boekelovia,
Borodinella, Botryococcus, Bracteococcus, Chaetoceros, Carteria,
Chlamydomonas, Chlorococcum, Chlorogonium, Chlorella, Chroomonas,
Chrysosphaera, Cricosphaera, Crypthecodinium, Cryptomonas,
Cyclotella, Dunaliella, Ellipsoidon, Emiliania, Eremosphaera,
Ernodesmius, Euglena, Franceia, Fragilaria, Gloeothamnion,
Haematococcus, Halocafeteria, Hymenonmonas, Isochrysis,
Lepocinclis, Micractinium, Monoraphidium, Nannochloris,
Nannochloropsis, Navicula, Neochloris, Nephrochloris, Nephrosehnis,
Nitzschia, Ochromonas, Oedogonium, Oocystis, Ostreococcus, Pavlova,
Parachlorella, Pascheria, Phaeodactyilum, Phagus, Platymonas,
Pleurochrysis, Pleurococcus, Prototheca, Pseudochlorella,
Pyramimonas, Pyrobotrys, Scenedesmus, Skeletonema, Spyrogvra,
Stichococcus, Tetraselmis, Thalassiosira, Viridiella, and Volvox
species, and/or one or more cyanobacteria of the Agmenellum,
Anabaena, Anabaenopsis, Anacystis, Aphanizomenon, Arthrospira,
Asterocapsa, Borzia, Calothrix, Chamaesiphon, Chlorogloeopsis,
Chroococcidiopsis, Chroococcus, Crinalium, Cyanobacterium,
Cyanobium, Cyanocystis, Cyanospira, Cyanothece, Cylindrospermopsis,
Cylindrospermum, Dactylococcopsis, Dermocarpella, Fischerella,
Fremyella, Geitleria, Geitlerinema, Gloeobacter, Gloeocapsa,
Gloeothece, Halospirulina, Iyengariella, Leptolyngbya, Limnothrix,
Lyngbya, Microcoleus, Microcystis, Mvxosarcina, Nodularia, Nostoc,
Nostochopsis, Oscillatoria, Phormidium, Planktothrix, Pleurocapsa,
Prochlorococcus, Prochloron, Prochlorothrix, Pseudanabaena,
Rivularia, Schizothrix, Scytonema, Spirulina, Stanieria, Starria,
Stigonema, Symploca, Synechococcus, Synechocystis, Tolypothrix,
Trichodesmiunm, Tychonema, and Xenococcus species.
[0036] Other biocomponent feeds usable in the present invention can
include any of those which comprise primarily triglycerides and
free fatty acids (FFAs). The triglycerides and FFAs typically
contain aliphatic hydrocarbon chains in their structure having from
8 to 36 carbons, preferably from 10 to 26 carbons, for example from
14 to 22 carbons. Types of triglycerides can be determined
according to their fatty acid constituents. The fatty acid
constituents can be readily determined using Gas Chromatography
(GC) analysis. This analysis involves extracting the fat or oil,
saponifying (hydrolyzing) the fat or oil, preparing an alkyl (e.g.,
methyl) ester of the saponified fat or oil, and determining the
type of (methyl) ester using GC analysis. In one embodiment, a
majority (i.e., greater than 50%) of the triglyceride present in
the lipid material can be comprised of C.sub.10 to C.sub.26 fatty
acid constituents, based on total triglyceride present in the lipid
material. Further, a triglyceride is a molecule having a structure
identical to the reaction product of glycerol and three fatty
acids. Thus, although a triglyceride is described herein as being
comprised of fatty acids, it should be understood that the fatty
acid component does not necessarily contain a carboxylic acid
hydrogen. If triglycerides are present, a majority of triglycerides
present in the biocomponent feed can preferably be comprised of
C.sub.12 to C.sub.18 fatty acid constituents, based on total
triglyceride content. Other types of feed that are derived from
biological raw material components can include fatty acid esters,
such as fatty acid alkyl esters (e.g., FAME and/or FAEE).
[0037] Typically, the feed can include at least 0.1 wt % of feed
based on a biocomponent source, or at least 0.5 wt %, or at least 1
wt %, or at least 3 wt %, or at least 10 wt %, or at least 15 wt %.
Additionally or alternately, the feed can include 35 wt % or less
of a feed based on a biocomponent source, or 25 wt % or less, or 15
wt % or less. Optionally, the feedstock can include at least about
1% by weight of glycerides, lipids, fatty acids, fatty acid esters
(such as fatty acid alkyl esters), or a combination thereof. The
glycerides can include monoglycerides, diglycerides, or
triglycerides. For example, the feedstock can include at least
about 5 wt %, or at least about 10 wt %, or at least 20 wt % of
glycerides, lipids, fatty acids, fatty acid esters, fatty acid
alkyl esters, or a combination thereof. If the feedstock contains
glycerides, lipids, or fatty acid compounds, the feedstock can
include about 35 wt % or less, or about 25 wt % or less, or about
15 wt % or less, or about 10 wt % or less of glycerides, lipids,
fatty acids, fatty acid esters, fatty acid alkyl esters, or a
combination thereof. For example, the feedstock can include
glycerides and/or fatty acid esters. Preferably, the feedstock can
include triglycerides, fatty acid methyl esters, or a combination
thereof.
[0038] In an embodiment, the biocomponent portion of the feedstock
(such as the glycerides and/or fatty acid esters) can be a
non-hydrotreated portion. A non-hydrotreated feed can typically
have an olefin content and an oxygen content similar to the content
of the corresponding raw biocomponent material. Examples of
suitable biocomponent feeds can include food grade vegetable oils,
and biocomponent feeds that are refined, bleached, and/or
deodorized.
[0039] Biocomponent based diesel boiling range feedstreams can have
a wide range of nitrogen and/or sulfur contents. For example, a
biocomponent based feedstream based on a vegetable oil source can
contain up to about 300 wppm nitrogen. In contrast, a biomass based
feedstream containing whole or ruptured algae can sometimes include
a higher nitrogen content. Depending on the type of algae, the
nitrogen content of an algae based feedstream can be at least about
2 wt %, for example at least about 3 wt %, at least about 5 wt %,
or at least about 10 wt %, and algae with still higher nitrogen
contents are known. The sulfur content of a biocomponent feed can
also vary. In some embodiments, the sulfur content can be about 500
wppm or less, for example about 100 wppm or less, about 50 wppm or
less, or about 10 wppm or less.
[0040] Aside from nitrogen and sulfur, oxygen can be another
heteroatom component in biocomponent based feeds. A biocomponent
diesel boiling range feedstream based on a vegetable oil, prior to
hydrotreatment, can include up to about 10 wt % oxygen, for example
up to about 12 wt % or up to about 14 wt %. Additionally or
alternately, such a biocomponent diesel boiling range feedstream
can include at least about 1 wt % oxygen, for example at least
about 2 wt %, at least about 3 wt %, at least about 4 wt %, at
least about 5 wt %, at least about 6 wt %, or at least about 8 wt
%. Further additionally or alternately, a biocomponent feedstream,
prior to hydrotreatment, can include an olefin content of at least
about 3 wt %, for example at least about 5 wt % or at least about
10 wt %.
[0041] A mineral feedstock refers to a conventional (e.g.,
non-biocomponent) feedstock, typically derived from crude oil and
that has optionally been subjected to one or more separation and/or
other refining processes. In one preferred embodiment, the mineral
feedstock can be a petroleum feedstock boiling in the diesel range
or above. Examples of suitable feedstocks can include, but are not
limited to, virgin distillates, hydrotreated virgin distillates,
kerosene, diesel boiling range feeds (such as hydrotreated diesel
boiling range feeds), light cycle oils, atmospheric gasoils, and
the like, and combinations thereof.
[0042] Mineral feedstocks for blending with a biocomponent
feedstock can have a nitrogen content from about 50 wppm to about
2000 wppm nitrogen, for example from about 50 wppm to about 1500
wppm or from about 75 to about 1000 wppm. In some embodiments, the
mineral feedstock can have a sulfur content from about 100 wppm to
about 10,000 wppm sulfur, for example from about 200 wppm to about
5,000 wppm or from about 350 wppm to about 2,500 wppm. Additionally
or alternately, the combined (biocomponent plus mineral) feedstock
can have a sulfur content of at least about 5 wppm, for example at
least about 10 wppm, at least about 25 wppm, at least about 100
wppm, at least about 500 wppm, or at least about 1000 wppm. Further
additionally or alternately, the combined feedstock can have a
sulfur content of about 2000 wppm or less, for example about 1000
wppm or less, about 500 wppm or less, about 100 wppm or less, or
about 50 wppm or less.
[0043] The content of sulfur, nitrogen, oxygen, and olefins in a
feedstock created by blending two or more feedstocks can typically
be determined using a weighted average based on the blended feeds.
For example, a mineral feed and a bio-component feed can be blended
in a ratio of 80 wt % mineral feed and 20 wt % biocomponent feed.
If the mineral feed has a sulfur content of about 1000 wppm, and
the biocomponent feed has a sulfur content of about 10 wppm, the
resulting blended feed could be expected to have a sulfur content
of about 802 wppm.
[0044] Diesel boiling range feedstreams suitable for use in the
present invention tend to boil within the range of about
215.degree. F. (about 102.degree. C.) to about 800.degree. F.
(about 427.degree. C.). Preferably, the diesel boiling range
feedstream has an initial boiling point of at least about
215.degree. F. (about 102.degree. C.), for example at least about
250.degree. F. (about 121.degree. C.), at least about 275.degree.
F. (about 135.degree. C.), at least about 300.degree. F. (about
149.degree. C.), at least about 325.degree. F. (about 163.degree.
C.), at least about 350.degree. F. (about 177.degree. C.), at least
about 400.degree. F. (about 204.degree. C.), or at least about
451.degree. F. (about 233.degree. C.). Preferably, the diesel
boiling range feedstream has a final boiling point of about
800.degree. F. (about 427.degree. C.) or less, or about 775.degree.
F. (about 413.degree. C.) or less, or about 750.degree. F. (about
399.degree. C.) or less. In some embodiments, the diesel boiling
range feedstream can have a boiling range from about 451.degree. F.
(about 233.degree. C.) to about 800.degree. C. (about 427.degree.
C.). Additionally or alternately, the feedstock can be
characterized by the boiling point required to boil a specified
percentage of the feed. For example, the temperature required to
boil at least 5 wt % of a feed is referred to as a "T5" boiling
point. A suitable mineral (petroleum) feedstock can have a T5
boiling point of at least about 230.degree. F. (about 110.degree.
C.), for example at least about 250.degree. F. (about 121.degree.
C.) or at least about 275.degree. F. (about 135.degree. C.).
Further additionally or alternately, the mineral (petroleum)
feedstock can have a T95 boiling point of about 775.degree. F.
(about 418.degree. C.) or less, for example about 750.degree. F.
(about 399.degree. C.) or less or about 725.degree. F. (about
385.degree. C.) or less. In another embodiment, the diesel boiling
range feedstream can also include kerosene range compounds to
provide a feedstream with a boiling range from about 250.degree. F.
(about 121.degree. C.) to about 800.degree. F. (about 427.degree.
C.).
Reactions for Oxygen Removal
[0045] Oxygen removal during hydroprocessing of a feedstock
typically occurs via one of three reaction pathways. One potential
reaction pathway is hydrodeoxygenation. In a hydrodeoxygenation
reaction, oxygen is removed from feed molecule as water. The carbon
chain for the feed molecule remains intact after a typical
hydrodeoxygenation reaction. Water is a contaminant that can
potentially contribute to deactivation of some conventional
hydrotreating catalysts, such as NiMo or CoMo type catalysts.
However, by itself water does not lead to corrosion within a
reaction system. Additionally, removing oxygen as water maintains
the chain length of a feed molecule. Maintaining the chain length
of molecules intended for use as a fuel or fuel blending product is
usually beneficial, as it means that a greater percentage of the
carbon from the feed is incorporated into the final fuel
product.
[0046] Hydrodecarboxylation removes oxygen by forming CO.sub.2 from
biofeeds. This CO.sub.2 forms carbonic acid when combined with
water. Carbonic acid corrosion may require metallurgical upgrades
to carbon steel in downstream equipment, particularly fin fans,
heat exchangers, and other locations that liquid water will be
present prior to a an amine scrubbing system or other system for
removing CO.sub.2.
[0047] Hydrodecarbonylation removes oxygen by forming CO from
biofeeds. CO is a known inhibitor for hydrodesulfurization. For
example, 1000 ppm CO can deactivate a conventional CoMo catalyst by
10%. CO is also not removed in appreciable quantities by
conventional amine scrubbing systems. As such, CO can build up
through gas recycle and can be cascaded to downstream
hydrotreatment, dewaxing, and/or hydrofinishing stages. As a
result, removing oxygen from a biocomponent feed as CO may require
the use of pressure swing adsorbers (including rapid cycle pressure
swing adsorbers) or other gas cleaning equipment in order to remove
CO from a reaction system.
[0048] Depending on the conditions present in a reactor, the
relative amounts of CO and CO.sub.2 in a reactor can be modified by
the water gas shift reaction. The water gas shift reaction is an
equilibrium reaction that can convert CO.sub.2 and H.sub.2 into CO
and H.sub.2O. Due to the water gas shift reaction, the amount of
decarbonylation and decarboxylation may not be clear, due to
conversion from one form of carbon oxide to another.
Hydrodeoxygenation can be distinguished at least in part from
decarbonylation and decarboxylation by characterizing the odd
versus even numbered carbons in a deoxygenated product.
[0049] Because feeds derived from biological sources typically have
carbon chains with even numbers of carbon molecules,
hydrodeoxygenation can be distinguished from decarbonylation and
decarboxylation based on the carbon chain length of the resulting
molecules. Hydrodeoxygenation typically leads to production of
molecules with an even number of carbon atoms while decarbonylation
and decarboxylation lead to molecules with an odd number of carbon
atoms.
Deoxygenation Stage Catalysts
[0050] A catalyst suitable for oxygen removal during processing of
a biocomponent feedstock in the deoxygenation stage (i.e., zone)
herein is a bulk metal (or equivalent term "bulk mixed metal")
catalyst. As used herein, the term "bulk", when describing a mixed
metal catalyst composition, indicates that the catalyst composition
is self-supporting in that it does not require a carrier or
support. It is well understood that bulk catalysts may have some
minor amount of carrier or support material in their compositions
(e.g., about 15 wt % or less, about 10 wt % or less, about 5 wt %
or less, or substantially no carrier or support, based on the total
weight of the catalyst composition); for instance, bulk
hydroprocessing catalysts may contain an amount of a binder, e.g.,
to improve the physical and/or thermal properties of the catalyst.
In contrast, heterogeneous or supported catalyst systems typically
comprise a carrier or support onto which one or more catalytically
active materials are deposited, often using an impregnation or
coating technique.
[0051] Nevertheless, heterogeneous catalyst systems without a
carrier or support (or with a minor amount of carrier or support)
are generally referred to as bulk catalysts and are frequently
formed by co-precipitation techniques. In the bulk metal catalysts
(or equivalent term "bulk mixed metal catalysts") as used herein,
it is meant that the catalyst is comprised of at least 80 wt %
active metals. By the term "active metals" it is meant at least one
Group VI metal (corresponding to Group 6 of the modern IUPAC
periodic table) and at least one Group VIII metal (corresponding to
Groups 8-10 of the modern IUPAC periodic table). In alternative
embodiments, the bulk metal catalysts herein may contain at least
two Group VI metals and at least one Group VIII metal. Preferably,
the bulk metal catalyst comprises at least 90 wt %, more preferably
at least 95 wt %, active metals. The remainder of these bulk metal
catalysts may be comprised of a suitable carrier or support, or in
some embodiments, may contain additional organic compounds.
[0052] Preferably, the at least one Group VI metal is selected from
Mo and W. Preferably, the at least one Group VIII metal is selected
from Co and Ni. Preferred metal combinations for the bulk metal
catalysts utilized herein in the deoxygenation stage are CoMo,
NiMo, and NiMoW. Two preferred bulk metal catalysts for the
deoxygenation stage are further described herein as well as
exemplified by embodiments utilized in the Examples section
herein.
[0053] Catalyst 1--Group VI/Group VIII/Organic Bulk Metal
Catalyst
[0054] In a preferred embodiment herein a bulk metal catalyst
comprising at least one Group VI metal, at least one Group VIII
metal, and at least one organic compound. It is desired that the
organic compound is present on the catalyst at least at the
beginning of the catalyst sulfiding step, but may be converted or
destroyed during the sulfiding of the catalyst. In embodiments, the
Group VI metal is selected from Mo and W. The Group VI metal is
preferably Mo. In embodiments, the Group VIII metal is selected
from Co and Ni. The Group VIII metal is preferably Co.
[0055] In preferred embodiments, the Group VI/Group VIII/organic
bulk metal catalyst is comprised of at least 80 wt % Group VI/Group
VIII oxides prior to sulfiding. In more preferred embodiments the
Group VI/Group VIII/organic bulk metal catalyst is comprised of at
least 90 wt % Group VI/Group VIII oxides prior to sulfiding. In
alternate embodiments, the Group VI/Group VIII/organic bulk metal
catalyst may contain from about 1 wt % to less than about 15 wt %
of a support or binder material.
[0056] This aspect of the present invention relates to a bulk metal
catalyst composition comprising at least one Group VI metal, at
least one Group VIII metal, and a condensation reaction product
formed from (i) a first organic compound containing at least one
first functional group, and/or (ii) a second organic compound
separate from said first organic compound and containing at least
one second functional group, wherein said first functional group
and said second functional group are capable of undergoing a
condensation reaction and/or a (decomposition) reaction causing an
additional unsaturation to form an associated product. Though the
description above and herein often refers specifically to the
condensation reaction product being an amide, it should be
understood that any in situ condensation reaction product formed
can be substituted for the amide described herein. For example, if
the first functional group is a hydroxyl group and the second
functional group is a carboxylic acid or an acid chloride or an
organic ester capable of undergoing transesterification with the
hydroxyl group, then the in situ condensation reaction product
formed would be an ester.
[0057] The reaction product can be obtained by heating the
composition (though specifically the condensation reactants, or the
amine-containing compound and/or the carboxylic acid-containing
compound) to a temperature preferably in the range of from about
195.degree. C. to about 250.degree. C. (about 383.degree. F. to
about 482.degree. F.) for a time sufficient for the first and/or
second organic compounds to form a condensation product, such as an
amide, and/or an additional (decomposition) unsaturation in situ.
It is desired that this reaction product is comprised of organic
compounds and that these reaction products are present on the Group
VI/Group VIII/organic bulk metal catalyst at the time that the
catalyst is sulfided.
[0058] The Group VI/Group VIII/organic bulk metal catalyst may
optionally further comprise at least one Group V one metal
(corresponding to Group 5 of the modern IUPAC periodic table).
[0059] Generally, the atomic ratio of the Group VI metal(s) to the
Group VIII metal(s) can be from about 2:1 to about 1:3, for example
from about 5:4 to about 1:2, from about 5:4 to about 2:3, from
about 5:4 to about 3:4, from about 10:9 to about 1:2, from about
10:9 to about 2:3, from about 10:9 to about 3:4, from about 20:19
to about 2:3, or from about 20:19 to about 3:4. When the
composition further comprises at least one metal from Group 5, that
at least one metal can be V and/or Nb.
[0060] Non-limiting examples of suitable mixed metal oxide
compositions can include, but are not limited to, nickel-tungsten
oxides, cobalt-tungsten oxides, nickel-molybdenum oxides,
cobalt-molybdenum oxides, nickel-molybdenum-tungsten oxides,
cobalt-molybdenum-tungsten oxides, cobalt-nickel-tungsten oxides,
cobalt-nickel-molybdenum oxides, cobalt-nickel-tungsten-molybdenum
oxides, nickel-tungsten-niobium oxides, nickel-tungsten-vanadium
oxides, cobalt-tungsten-vanadium oxides, cobalt-tungsten-niobium
oxides, nickel-molybdenum-niobium oxides,
nickel-molybdenum-vanadium oxides,
nickel-molybdenum-tungsten-niobium oxides,
nickel-molybdenum-tungsten-vanadium oxides, and the like, and
combinations thereof.
[0061] Suitable mixed metal oxide compositions can advantageously
exhibit a specific surface area (as measured via the nitrogen BET
method using a Quantachrome Autosorb.TM. apparatus) of at least
about 20 m.sup.2/g, for example at least about 30 m.sup.2/g, at
least about 40 m.sup.2/g, at least about 50 m.sup.2/g, at least
about 60 m.sup.2/g, at least about 70 m.sup.2/g, or at least about
80 m.sup.2/g. Additionally or alternately, the mixed metal oxide
compositions can exhibit a specific surface area of not more than
about 500 m.sup.2/g, for example not more than about 400 m.sup.2/g,
not more than about 300 m.sup.2/g, not more than about 250
m.sup.2/g, not more than about 200 m.sup.2/g, not more than about
175 m.sup.2/g, not more than about 150 m.sup.2/g, not more than
about 125 m.sup.2/g, or not more than about 100 m.sup.2/g.
[0062] In an embodiment of any of the compositions and/or processes
described herein, the first organic compound can comprise at least
10 carbon atoms, for example can comprise from 10 to 20 carbon
atoms or can comprise a primary monoamine having from 10 to 30
carbon atoms. Additionally or alternately, the second organic
compound can comprise at least 10 carbon atoms, for example can
comprise from 10 to 20 carbon atoms or can comprise only one
carboxylic acid group and can have from 10 to 30 carbon atoms.
[0063] Representative examples of organic compounds containing
amine groups can include, but are not limited to, primary and/or
secondary, linear, branched, and/or cyclic amines, such as
triacontanylamine, octacosanylamine, hexacosanylamine,
tetracosanylamine, docosanylamine, erucylamine, eicosanylamine,
octadecylamine, oleylamine, linoleylamine, hexadecylamine,
sapienylamine, palmitoleylamine, tetradecylamine, myristoleylamine,
dodecylamine, decylamine, nonylamine, cyclooctylamine, octylamine,
cycloheptylamine, heptylamine, cyclohexylamine, n-hexylamine,
isopentylamine, n-pentylamine, t-butylamine, n-butylamine,
isopropylamine, n-propylamine, adamantanamine,
adamantanemethylamine, pyrrolidine, piperidine, piperazine,
imidazole, pyrazole, pyrrole, pyrrolidine, pyrroline, indazole,
indole, carbazole, norbornylamine, aniline, pyridylamine,
benzylamine, aminotoluene, alanine, arginine, aspartic acid,
glutamic acid, glutamine, glycine, histidine, isoleucine, leucine,
lysine, phenylalanine, serine, threonine, valine,
1-amino-2-propanol, 2-amino-1-propanol, diaminoeicosane,
diaminooctadecane, diaminohexadecane, diaminotetradecane,
diaminododecane, diaminodecane, 1,2-diaminocyclohexane,
1,3-diaminocyclohexane, 1,4-diaminocyclohexane, ethylenediamine,
ethanolamine, p-phenylenediamine, o-phenylenediamine,
m-phenylenediamine, 1,2-propylenediamine, 1,3-propylenediamine,
1,4-diaminobutane, 1,3-diamino-2-propanol, and the like, and
combinations thereof. In an embodiment, the molar ratio of the
Group VI metal(s) in the composition to the first organic compound
during treatment can be from about 1:1 to about 20:1.
[0064] The amine functional group from the first organic compound
can include primary or secondary amines, as mentioned above, but
generally does not include tertiary or quaternary amines, as
tertiary and quaternary amines tend not to be able to form amides.
Furthermore, the first organic compound can contain other
functional groups besides amines, whether or not they are capable
of participating in forming an amide or other condensation reaction
product with one or more of the functional groups from second
organic compound.
[0065] Additionally or alternately, the amine portion of the first
organic compound can be a part of a larger functional group in that
compound, so long as the amine portion (notably the amine nitrogen
and the constituents attached thereto) retains the capability of
participating in forming an amide or other condensation reaction
product with one or more of the functional groups from second
organic compound.
[0066] Representative examples of organic compounds containing
carboxylic acids can include, but are not limited to, primary
and/or secondary, linear, branched, and/or cyclic amines, such as
triacontanoic acid, octacosanoic acid, hexacosanoic acid,
tetracosanoic acid, docosanoic acid, erucic acid, docosahexanoic
acid, eicosanoic acid, eicosapentanoic acid, arachidonic acid,
octadecanoic acid, oleic acid, elaidic acid, stearidonic acid,
linoleic acid, alpha-linolenic acid, hexadecanoic acid, sapienic
acid, to palmitoleic acid, tetradecanoic acid, myristoleic acid,
dodecanoic acid, decanoic acid, nonanoic acid, cyclooctanoic acid,
octanoic acid, cycloheptanoic acid, heptanoic acid, cyclohexanoic
acid, hexanoic acid, adamantanecarboxylic acid, norbornaneacetic
acid, benzoic acid, salicylic acid, acetylsalicylic acid, citric
acid, maleic acid, malonic acid, glutaric acid, lactic acid, oxalic
acid, tartaric acid, cinnamic acid, vanillic acid, succinic acid,
adipic acid, phthalic acid, isophthalic acid, terephthalic acid,
ethylenediaminetetracarboxylic acids (such as EDTA), fumaric acid,
alanine, arginine, aspartic acid, glutamic acid, glutamine,
glycine, histidine, isoleucine, leucine, lysine, phenylalanine,
serine, threonine, valine, 1,2-cyclohexanedicarboxylic acid,
1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,
and the like, and combinations thereof. In an embodiment, the molar
ratio of the Group VI metal(s) in the composition to the second
organic compound during treatment can be from about 3:1 to about
20:1.
[0067] In certain embodiments, the organic compound(s)/additive(s)
and/or the reaction product(s) are not located/incorporated within
the crystal lattice of the mixed metal oxide precursor composition,
e.g., instead being located on the surface and/or within the pore
volume of the precursor composition and/or being associated with
(bound to) one or more metals or oxides of metals in a manner that
does not significantly affect the crystalline lattice of the mixed
metal oxide precursor composition, as observed through XRD and/or
other crystallographic spectra. It is noted that, in these certain
embodiments, a sulfided version of the mixed metal oxide precursor
composition can still have its sulfided form affected by the
organic compound(s)/additive(s) and/or the reaction product(s),
even though the oxide lattice is not significantly affected.
[0068] While there is not a strict limit on the ratio between the
first organic compound and the second organic compound when
utilized together, because the goal of the addition of the first
and second organic compounds is to attain a condensation reaction
product, it may be desirable to have a ratio of the reactive
functional groups within the first and second organic compounds,
respectively, from about 1:4 to about 4:1, for example from about
1:3 to about 3:1 or from about 1:2 to about 2:1.
[0069] In additional embodiments, although not required, the Group
VI/Group VIII/organic bulk metal catalyst may be combined with a
binder for use in the biocomponent feed deoxygenation processes
described herein. Also, although not required, it is preferred that
the binder be added to the Group VI/Group VIII/organic bulk metal
catalyst after performing the reaction step described herein (i.e.,
the thermal heating step to form the condensation and/or
decomposition products from the organic catalyst components).
[0070] In one embodiment, the heating temperature of the reaction
step can be at least about 120.degree. C., for example at least
about 150.degree. C., at least about 165.degree. C., at least about
175.degree. C., at least about 185.degree. C., at least about
195.degree. C., at least about 200.degree. C., at least about
210.degree. C., at least about 220.degree. C., at least about
230.degree. C., at least about 240.degree. C., or at least about
250.degree. C. Additionally or alternately, the heating temperature
can be not greater than about 400.degree. C., for example not
greater than about 375.degree. C., not greater than about
350.degree. C., not greater than about 325.degree. C., not greater
than about 300.degree. C., not greater than about 275.degree. C.,
not greater than about 250.degree. C., not greater than about
240.degree. C., not greater than about 230.degree. C., not greater
than about 220.degree. C., not greater than about 210.degree. C.,
or not greater than about 200.degree. C.
[0071] In one embodiment, the heating can be conducted in a low- or
non-oxidizing atmosphere (and conveniently in an inert atmosphere,
such as nitrogen). In an alternate embodiment, the heating can be
conducted in a moderately- or highly-oxidizing environment. In
another alternate embodiment, the heating can include a multi-step
process in which one or more heating steps can be conducted in the
low- or non-oxidizing atmosphere, in which one or more heating
steps can be conducted in the moderately- or highly-oxidizing
environment, or both. The period of time for the heating in the
environment can be from about 5 minutes to about 168 hours, for
example from about 10 minutes to about 96 hours, from about 10
minutes to about 48 hours, or from about 10 minutes to about 24
hours.
[0072] In an embodiment, the organically treated catalyst precursor
composition and/or the catalyst precursor composition containing
the reaction product can contain from about 4 wt % to about 20 wt
%, for example from about 5 wt % to about 15 wt %, carbon resulting
from the first and/or second organic compounds and/or from the
condensation product, as applicable, based on the total weight of
the relevant composition.
[0073] A sulfided catalyst composition can then be produced by
sulfiding the Group VI/Group VIII/organic bulk metal catalyst.
Sulfiding is generally carried out by contacting the catalyst
precursor composition containing the reaction product with a
sulfur-containing compound (e.g., elemental sulfur, hydrogen
sulfide, polysulfides, or the like, or a combination thereof, which
may originate from a fossil/mineral oil stream, from a
biocomponent-based oil stream, from a combination thereof, or from
a sulfur-containing stream separate from the aforementioned oil
stream(s)) at a temperature and for a time sufficient to
substantially sulfide the composition and/or sufficient to render
the sulfided composition active as a deoxygenation catalyst. For
instance, the sulfidation can be carried out at a temperature from
about 300.degree. C. to about 400.degree. C., e.g., from about
310.degree. C. to about 350.degree. C., for a period of time from
about 30 minutes to about 96 hours, e.g., from about 1 hour to
about 48 hours or from about 4 hours to about 24 hours. The
sulfiding can generally be conducted before or after combining the
metal (oxide) containing composition with a binder, if desired, and
before or after forming the composition into a shaped catalyst. The
sulfiding can additionally or alternately be conducted in situ in a
hydroprocessing reactor. Obviously, to the extent that a reaction
product of the first and second organic compounds contains an in
situ amide and/or additional unsaturations, it would generally be
desirable for the sulfidation (and/or any catalyst treatment after
the organic treatment) to significantly maintain the in situ amide
and/or additional unsaturations of said reaction product.
[0074] The sulfided Group VI/Group VIII/organic bulk metal catalyst
composition preferably exhibits a layered structure comprising a
plurality of stacked YS.sub.2 layers, where Y is the Group VI
metal(s), such that the average number of stacks (typically for
bulk organically treated catalysts) can be from about 1.5 to about
3.5, for example from about 1.5 to about 3.0, from about 2.0 to
about 3.3, from about 2.0 to about 3.0, or from about 2.1 to about
2.8. For instance, the treatment of the metal (oxide) containing
precursor composition according to the invention can afford a
decrease in the average number of stacks of the treated precursor
of at least about 0.8, for example at least about 1.0, at least
about 1.2, at least about 1.3, at least about 1.4, or at least
about 1.5, as compared to an untreated metal (oxide) containing
precursor composition. As such, the number of stacks can be
considerably less than that obtained with an equivalent sulfided
mixed metal (oxide) containing precursor composition produced
without the first and second organic compound treatment and
optionally but preferably less than that obtained to with an
equivalent sulfided mixed metal (oxide) containing precursor
composition produced by treatment with either the first organic
compound or the second organic compound (but not both). The
reduction in the average number of stacks can be evidenced, e.g.,
via X-ray diffraction spectra of relevant sulfided compositions, in
which the (002) peak appears significantly broader (as determined
by the same width at the half-height of the peak) than the
corresponding peak in the spectrum of the sulfided mixed metal
(oxide) containing precursor composition produced without the
organic treatment (and/or, in certain cases, with only a single
organic compound treatment) according to the present invention.
Additionally or alternately to X-ray diffraction, transmission
electron microscopy (TEM) can be used to obtain micrographs of
relevant sulfided compositions, including multiple microcrystals,
within which micrograph images the multiple microcrystals can be
visually analyzed for the number of stacks in each, which can then
be averaged over the micrograph visual field to obtain an average
number of stacks that can evidence a reduction in average number of
stacks compared to a sulfided mixed metal (oxide) containing
precursor composition produced without the organic treatment
(and/or, in certain cases, with only a single organic compound
treatment) according to the present invention.
[0075] As noted, the sulfided Group VI/Group VIII/organic bulk
metal catalyst composition described above can be used in the
processes herein as a deoxygenation catalyst, either alone or in
combination with a binder. When a binder is utilized with the Group
VI/Group VII/organic bulk metal catalysts, it is preferred that the
amount of binder is less than 50 wt % based on the weight of the
total bound Group VI/Group VIII/organic bulk metal catalyst. More
preferably, the amount of binder utilized is less than 20 wt %,
more preferably less than 10 wt %, based on the weight of the total
bound Group VI/Group VIII/organic bulk metal catalyst.
[0076] However, the use is not so limited. In embodiments, the
bound Group VI/Group VIII/organic bulk metal catalyst (i.e.,
catalyst+binder) may comprise from about 5 wt % to about 95 wt %
binder based on the total weight of the bound catalyst. In other
embodiments, the bound Group VI/Group VIII/organic bulk metal
catalyst (i.e., catalyst+binder) may comprise from about 10 wt % to
about 90 wt % binder, from about 15 wt % to about 80 wt % binder,
or from about 15 wt % to about 75 wt % binder based on the total
weight of the bound catalyst. Non-limiting examples of suitable
binder to materials can include, but are not limited to, silica,
silica-alumina (e.g., conventional silica-alumina, silica-coated
alumina, alumina-coated silica, or the like, or a combination
thereof), alumina (e.g., boehmite, pseudo-boehmite, gibbsite, or
the like, or a combination thereof), titania, zirconia, cationic
clays or anionic clays (e.g., saponite, bentonite, kaoline,
sepiolite, hydrotalcite, or the like, or a combination thereof),
and mixtures thereof. In some preferred embodiments, the binder can
include silica, silica-alumina, alumina, titania, zirconia, and
mixtures thereof. These binders may be applied as such or after
peptization. It may also be possible to apply precursors of these
binders that, during precursor synthesis, can be converted into any
of the above-described binders. Suitable precursors can include,
e.g., alkali metal aluminates (alumina binder), water glass (silica
binder), a mixture of alkali metal aluminates and water glass
(silica-alumina binder), a mixture of sources of a di-, tri-,
and/or tetravalent metal, such as a mixture of water-soluble salts
of magnesium, aluminum, and/or silicon (cationic clay and/or
anionic clay), chlorohydrol, aluminum sulfate, or mixtures
thereof.
[0077] Generally, the binder material to be used can have lower
catalytic activity than the remainder of the catalyst composition,
or can have substantially no catalytic activity at all (less than
about 5%, based on the catalytic activity of the Group VI/Group
VIII/organic bulk metal catalyst composition being about 100%).
Consequently, by using a binder material, the activity of the
catalyst composition may be reduced. Therefore, the amount of
binder material to be used, at least in bulk catalysts, can
generally depend on the desired activity of the final catalyst
composition. Therefore, to take advantage of the resulting unusual
high activity of bulk catalyst deoxygenation catalysts described
herein, binder amounts, when added, can most preferably be from
about 0.5 wt % to about 20 wt % of the total bound Group VI/Group
VIII/organic bulk metal catalyst.
[0078] Additional embodiments and details of Group VI/Group
VIII/organic bulk metal catalysts that may be utilized in the
processes described herein may be found in U.S. patent application
Ser. No. 13/150,662 and Ser. No. 13/150,720, both of which are
incorporated herein by reference. An embodiment of a Group VI/Group
VIII/organic bulk metal catalyst as described in this section as
utilized in embodiments of the present deoxygenation processes is
also exemplified as Catalyst 1 of the Example section herein.
[0079] Catalyst 2--NiMoW Bulk Metal Catalyst
[0080] In a preferred embodiment herein a NiMoW bulk metal catalyst
is utilized in the deoxygenation stage to remove oxygen
particularly present the bio-derived feed portion of the
biocomponent feedstream. In preferred embodiments, the NiMoW bulk
metal catalyst is comprised of at least 80 wt % nickel (Ni),
molybdenum (Mo), and tungsten (W) oxides. In more preferred
embodiments the NiMoW bulk metal catalyst is comprised of at least
90 wt % nickel (Ni), molybdenum (Mo), and tungsten (W) oxides. More
preferably, the NiMoW bulk metal catalyst essentially consists of
nickel (Ni), molybdenum (Mo), and tungsten (W) oxides.
[0081] This bulk mixed metal oxide composition is preferably
sulfided prior to use as a catalyst, and the NiMoW portion of the
catalyst is preferably of the formula:
(Ni).sub.b(Mo).sub.c(W).sub.dO.sub.z
[0082] wherein the molar ratio of b:(c+d) is 0.5:1 to 3:1,
preferably 0.75:1 to 1.5:1, more preferably 0.75:1 to 1.25:1. The
molar ratio of c:d is preferably >0.01:1, more preferably
>0.1:1, still more preferably 1:10 to 10:1, still more
preferably 1:3 to 3:1, most preferably substantially equimolar
amounts of Mo and W (e.g., 2:3 to 3:2); and z=[2b+6(c+d)]/2.
[0083] The essentially amorphous material has a unique X-ray
diffraction pattern showing crystalline peaks at d=2.53 Angstroms
and d=1.70 Angstroms.
[0084] Although not required to practice the present processes, the
NiMoW bulk metal deoxygenation catalysts described herein may also
include a binder in similar amounts (i.e., binder content as a % of
total bound NiMoW bulk metal catalyst) as described above for the
Group VI/Group VIII/organic bulk metal catalysts. Additionally
alternatively, the NiMoW bulk metal deoxygenation catalysts
described herein may be sulfide in a similar manner(s) as described
above for the Group VI/Group VIII/organic bulk metal catalysts.
[0085] Additional embodiments and details of NiMoW bulk metal
catalysts that may be utilized in the processes described herein
may be found in U.S. patent application Ser. No. 08/900,389, which
is incorporated herein by reference. An embodiment of a NiMoW bulk
metal catalyst as described in this section as utilized in
embodiments of the present deoxygenation processes is also
exemplified as Catalyst 2 of the Example section herein.
Deoxygenation Stage Conditions
[0086] Typical effective conditions for the deoxygenation
processing f a biocomponent feedstock in the presence of a bulk
metal catalyst to remove oxygen can include conditions effective
for hydrodeoxygenation, decarbonylation, and/or decarboxylation. In
some embodiments, the effective conditions can be selected to
increase the selectivity for removing oxygen via hydrodeoxygenation
rather than via decarbonylation or decarboxylation. A variety of
conditions may be suitable as effective conditions. The pressure
during processing of a feedstock for oxygen removal can correspond
to a hydrogen partial pressure of about 400 psig (2.8 MPag) or
less. At pressures of 400 psig or less, the bulk metal catalyst
will perform little or no sulfur removal on a feed. Lower hydrogen
partial pressures are also beneficial for reducing or minimizing
the amount of olefin saturation, including the amount of saturation
from propylene to propane that occurs during deoxygenation.
However, the bulk metal catalysts are effective for oxygen removal
at such hydrogen partial pressures. Depending on the nature of the
feed, still lower pressures may be suitable for deoxygenation, such
as a total pressure of about 300 psig (2.1 MPag) with a hydrogen
partial pressure of about 200 psig (1.4 MPag) or less.
[0087] Alternatively, higher partial pressures of hydrogen can also
be used, such as a hydrogen partial pressure of between about 200
psig (1.4 MPag) to about 2000 psig (13.8 MPag), such as from about
from about 1500 psig (10.3 MPag) to about 2000 psig (13.8 MPag), or
from about 300 psig (2.1 MPag) to about 600 psig (4.1 MPag). Higher
hydrogen partial pressures can be effective for maintaining a given
deoxygenation activity while increasing the throughput of a
reactor. However, higher hydrogen partial pressures may reduce the
selectivity of the catalyst for performing deoxygenation versus
olefin saturation.
[0088] The effective conditions for oxygen removal utilizing the
catalysts and processes herein can include a temperature, a
hydrogen treat gas rate, and a liquid hourly space velocity (LHSV).
Suitable effective temperatures can be from about 400.degree. F. to
about 750.degree. F. (204.degree. C. to 399.degree. C.). As will be
noted in the Example herein, the bulk metal deoxygenation catalysts
possess superior and unexpected activities over the reference
particularly when utilized at deoxygenation stage temperatures of
about 500.degree. F. (260.degree. C.) or lower. Some more preferred
operating ranges for the deoxygenation stage (or zone) herein are
from about 400.degree. F. to about 500.degree. F. (204.degree. C.
to 260.degree. C.), 400.degree. F. to about 495.degree. F.
(204.degree. C. to 257.degree. C.), from about 400.degree. F. to
about 490.degree. F. (204.degree. C. to 254.degree. C.), from about
400.degree. F. to about 475.degree. F. (204.degree. C. to
246.degree. C.), or from about 400.degree. F. to about 450.degree.
F. (204.degree. C. to 232.degree. C.).
[0089] In the deoxygenation zone, the LHSV is preferably from about
0.1 hr.sup.-1 to about 10 hr.sup.-1, such as from about 0.2
hr.sup.-1 to about 5.0 hr.sup.-1. The hydrogen treat gas rate can
be any convenient value that provides sufficient hydrogen for
deoxygenation of a feedstock. Typical values can range from about
500 scf/B (84 Nm.sup.3/m.sup.3) to about 10,000 scf/B (1685
Nm.sup.3/m.sup.3). One option for selecting a treat gas rate can be
to select a rate based on the expected stoichiometric amount of
hydrogen for complete deoxygenation of the feedstock. For example,
many types of biocomponent feeds have a stoichiometric hydrogen
need for deoxygenation of between 200 scf/B (34 Nm.sup.3/m.sup.3)
to about 1500 scf/B (253 Nm.sup.3/m.sup.3), depending on the
mechanism for oxygen removal. The hydrogen treat gas rate can be
selected based on a multiple of the stoichiometric hydrogen need,
such as at least about 1 times the hydrogen need, or at least about
1.5 times the hydrogen need, or at least about 2 times the hydrogen
need.
[0090] The effective conditions for deoxygenation can be suitable
for reducing the oxygen content of the feed to less than about 1.0
wt %, such as less than about 0.5 wt % or less than about 0.2 wt %.
Although the stoichiometric hydrogen need is calculated based on
complete deoxygenation, reducing the oxygen content to
substantially zero is typically not required to allow further
processing of the deoxygenated feed in conventional equipment.
Alternatively, in some aspects the effective conditions can be
selected to perform at least a partial deoxygenation of the
feedstock. A partial deoxygenation corresponds to conditions
suitable for reducing the oxygen content of the feed by at least
about 40%, such as by at least about 50% or at least about 75%. In
preferred embodiments of the present invention, at least 75 wt %,
more preferably at least 85 wt %, and even more preferably at least
95 wt % of the oxygen is removed from the biocomponent feed.
Optional Hydrodesulfurization Stage Catalysts and Conditions
[0091] After at least partial deoxygenation, the mixture of mineral
and biocomponent feed can alternatively be additionally
hydrodesulfurized in one or more reaction stages. A reaction stage
can correspond to one or more catalyst beds. Optionally, the bulk
metal deoxygenation catalyst and the separate hydrodesulfurization
catalyst can be included in a single stage, such as in a single
reactor.
[0092] Reaction conditions in a hydrodesulfurization stage can be
effective conditions suitable for reducing the sulfur content of
the feedstream. The reaction conditions can include an LHSV of 0.3
to 5.0 hr.sup.-1, a total pressure from about 200 psig (1.4 MPa) to
about 3000 psig (20.7 MPa), a treat gas containing at least about
80% hydrogen (remainder inert gas) with a hydrogen treat gas rate
of about 500 scf/bbl (84 m.sup.3/m.sup.3) to about 10000 scf/bbl
(1685 m.sup.3/m.sup.3), and a temperature of from about 400.degree.
F. (204.degree. C.) to about 800.degree. F. (427.degree. C.).
Preferably, the reaction conditions include an LHSV of from about
0.5 to about 1.5 hr.sup.-1, a total pressure from about 1400 psig
(9.7 MPa) to about 2000 psig (13.8 MPa), and a temperature of from
about 450.degree. F. (232.degree. C.) to about 750.degree. F.
(399.degree. C.). If the hydrodesulfurization stage and associated
hydrodesulfurization catalyst(s) are located in a separate reactor
from the deoxygenation stage, temperatures from about 650.degree.
F. (343.degree. C.) to about 750.degree. F. (399.degree. C.) may be
preferred.
[0093] Optionally, the hydrodesulfurization stage(s) can be
operated at a pressure below about 700 psig (4.8 MPa), or below
about 800 psig (5.5 MPa). For example, the pressure in a stage in
the hydrotreatment reactor can be at least about 300 psig (2.1
MPa), or at least about 350 psig (2.4 MPa), or at least about 400
psig (2.8 MPa), or at least about 450 psig (3.1 MPa). The pressure
in a stage in the hydrodesulfurization reactor can be about 700
psig (4.8 MPa) or less, or about 650 psig (4.5 MPa) or less, or
about 600 psig (4.1 MPa) or less. Optionally, the
hydrodesulfurization reactor can also include one or more other
types of stages or beds, such as hydrocracking or hydrofinishing
beds.
[0094] The catalyst in a hydrodesulfurization stage can be a
conventional hydrodesulfurization catalyst, such as a catalyst
composed of a Group VIB metal and/or a Group VIII metal deposited
upon a support. Suitable metals include cobalt, nickel, molybdenum,
tungsten, or combinations thereof. Preferred combinations of metals
include nickel and molybdenum or nickel, cobalt, and molybdenum.
Suitable supports include silica, silica-alumina, alumina, and
titania. The amount of Group VI metal supported on the catalyst
support can vary depending on the catalyst. Suitable total amounts
of metals range from about 1 wt % to about 35 wt % relative to the
total weight of the catalyst.
[0095] The hydrodesulfurization conditions should be selected to
reduce the sulfur, and optionally, additionally the nitrogen
content of the feed to a desired level. One option is to
hydrodesulfurize the feed under conditions effective to reduce the
sulfur to less than about 100 wppm, or less than about 50 wppm, or
less than about 15 wppm, or less than about 10 wppm. The amount of
sulfur remaining can be dependent on the desired standard for the
country of use. The amount of nitrogen can similarly be reduced to
about 15 wppm or less, or about 10 wppm or less, or about 1 wppm or
less.
Examples of Processing Configurations
[0096] FIG. 1 schematically shows an example of a processing
configuration suitable for use according to the invention. In FIG.
1, a reactor 110 is shown that includes two catalyst beds. A first
catalyst bed 122 corresponds to a hydrodeoxygenation zone (or
"stage") containing a bulk metal deoxygenation catalyst as
described herein. Please note that the term "hydrodeoxygenation" as
utilized herein simply means that the deoxygenation
process/reactions take place in the presence of a hydrogen or
hydrogen-containing gas stream. While not required, the reactor 110
in FIG. 1 illustrates an optional embodiment wherein a second
catalyst bed 142 corresponding to a hydrodesulfurization zone (or
stage) wherein a hydrodesulfurization catalyst as described herein
is further included in the same reactor 110. A biocomponent feed
105, preferably containing a combination of bio-derived components
and mineral oil components, can be introduced into the reactor 110
along with a hydrogen-containing stream 101. The mixture can be
deoxygenated, and optionally further desulfurized, under effective
conditions, including a pressure of 400 psig (2.8 MPag). The
configuration in FIG. 1 shows only one bed of each type of
catalyst, but additional beds of one or both catalysts can also be
used. The resulting reactor effluent 151 can be used in any
convenient manner, such as by adding the effluent to the diesel
pool or subjecting the effluent to further processing. As an
alternative, a configuration similar to FIG. 1 can be constructed
by placing first catalyst bed 122, containing the bulk metal
deoxygenation catalyst, and second catalyst bed 142, containing the
hydrodesulfurization catalyst, in separate reactors and cascading
the effluent the first catalyst bed 122 located in a first into a
second reactor containing second catalyst bed 142.
[0097] FIG. 2 schematically shows an example of another processing
to configuration. In FIG. 2, catalyst beds (or zones) 222 and 224
are located in a first reactor 220. Catalyst beds 222 and 224 in
FIG. 2 correspond to beds of one or more bulk metal deoxygenation
catalysts, as described in embodiments herein. Optionally, a single
catalyst bed could be used in reactor 220, or more than two
catalyst beds could be used. A biocomponent feed 205 such as
described for FIG. 1 is contacted with the bulk metal deoxygenation
catalyst in a first reactor 220 in the presence of a
hydrogen-containing stream 201. The first reactor effluent 228 from
reactor 220 containing the deoxygenation stage(s) can then be
passed through a separation stage 230. The separation stage 230 can
include one or more separators. The separation stage can include,
for example, a hot gas-liquid separator to remove at least a
majority of the water and carbon oxides present in the effluent.
The remaining liquid phase effluent from the separation stage 230
can then be passed into the second reactor 240 under
hydrodesulfurization conditions to reduce the amount of sulfur in
the feed. The feed is hydrodesulfurized in the presence of the
catalyst in beds 242 and 244 and in the presence of a
hydrogen-containing stream 241. The resulting deoxygenated and
desulfurized second reactor effluent 251 can be used in any
convenient manner, such as by adding the effluent to the diesel
pool or subjecting the effluent to further processing. Optionally,
a single catalyst bed could be used in the second reactor 240, or
more than two catalyst beds could be used. Optionally, one of the
catalyst beds in the second reactor 240 can correspond to a
hydrocracking or hydrofinishing catalyst.
Example of Deoxygenating Biocomponent Feed with a Single Metal
Catalyst
[0098] A series of catalysts and conditions were tested in parallel
in a multiple catalyst testing apparatus. The test rig included a
plurality of reaction vessels contained in an apparatus with an
isothermal reaction zone. Each reaction vessel was loaded with
either 1.0 cc or 1.5 cc of catalyst. The catalysts were sulfided by
exposing the catalysts to a feed spiked with dimethyl disulfide
(DMDS) to achieve 2.6 wt % total sulfur and held at a temperature
of at least 450.degree. F. for an extended period of time. Spiking
with DMDS increased the sulfur concentration from 1.37 wt % to 2.6
wt % in the sulfiding feed. The sulfiding feed had a T10 boiling
point of 427.degree. F. and a final boiling point of 777.degree. F.
The flow rate of the spiked feed in each reactor during sulfidation
was 1.5 cc per hour.
[0099] The data presented herein includes comparative experiments
for four (4) catalysts corresponding as follows.
[0100] Catalyst 1 (part of invention) was an embodiment of the
GroupVI/GroupVIII/organic bulk metal deoxygenation catalysts as
described herein. This was a bulk mixed metal catalyst comprising
Ni and W which was formulated by adding on organic additive to the
active metal slurry, and further drying at a temperature low enough
to maintain a portion of the organic carbon compounds on the
catalyst and then sulfiding the catalyst containing Ni oxide, W
oxide and the residual organic carbon compounds.
[0101] Catalyst 2 (part of invention) was an embodiment of the
Ni/Mo/W bulk metal deoxygenation catalysts as described herein.
This was a bulk mixed metal catalyst comprising Ni, Mo and W.
[0102] Catalyst 3 (reference catalyst) was a commercially available
supported NiMo hydroprocessing catalyst.
[0103] Catalyst 4 (reference catalyst) was a commercially available
alumina supported CoMo hydroprocessing catalyst.
[0104] After sulfidation, the sulfided catalysts were used to treat
a feed composed of 30 wt % soybean oil and 70 wt % dodecane. The
soybean oil had an oxygen content of 11.0 wt %. The catalysts were
then subjected to a series of ten (10) different operating
conditions and the resulting products from each of the catalyst
samples was periodically sampled and measured. Table 1 shows the
ten (10) separate reaction conditions under which the catalysts
were studied.
TABLE-US-00001 TABLE 1 Reaction Conditions Temperature Pressure
Feed Bio Content Liquid Feed Rate Condition (.degree. F.) (psig)
(wt % bio) (cc hr.sup.-1) 1 500 400 30 1.5 2 575 400 30 1.5 3 650
400 30 1.5 4 550 400 50 1.5 5 550 1800 50 1.5 6 475 1800 50 1.5 7
600 1800 50 1.5 8 600 1800 30 2.6 9 550 1800 30 2.6 10 575 400 30
1.5
[0105] Using the parallel experimental apparatus, each of the four
catalysts were tested at each of the ten conditions in Table 1. In
addition to the above, at conditions 1-4 the feed included a
spiking agent to produce a sulfur level of 500 wppm. The amount of
spiking agent was increased to produce a sulfur level of 1 wt % for
conditions 5-10. In the following figures, each of the conditions
is indicated in the horizontal axis direction by the numbers 1-10
inserted into each graph. Each change in condition is also shown by
a dotted dividing line.
[0106] As an initial characteristic, the amount of deoxygenation
that occurred for each catalyst at each condition was determined.
One method for determining the deoxygenation would be to do a total
mass balance of all oxygen-containing species in the feed and the
products. However, this was not practical to perform on a daily
basis, so instead the amount of conversion of molecules from above
322.degree. C. to below 322.degree. C. was measured. For the
soybean oil feed used in the experiments, molecules boiling above
322.degree. C. correspond to molecules having greater than 18
carbon atoms, while any deoxygenated products will have 18 carbon
atoms or less.
[0107] FIG. 3 shows the amount of triglyceride conversion relative
to 322.degree. C. for the four (4) catalysts tested over the
various ten (10) test conditions.
[0108] It can be seen in FIG. 3 that under at reaction temperatures
above about 500.degree. F., all four (4) of the catalysts tested
performed fairly similarly for triglyceride conversion. However,
when the reaction temperatures were dropped below about 500.degree.
F., a very significant difference in conversion activity was
witnessed between the two (2) bulk mixed metal catalysts of the
invention (Catalysts 1 and 2) and the two (2) reference catalysts
(Catalysts 3 and 4). At temperatures below about 500.degree. F.,
the triglyceride conversion levels of Catalysts 1 and 2 remained
fairly constant and maintained a triglyceride conversion rate of
about 95 to 100%. In contrast, the activity of reference Catalysts
3 and 4 dropped of precipitously to a conversion rate of about 30
to 60%. The comparative results at Condition 6 in the testing are
summarized as follows in Table 2.
TABLE-US-00002 TABLE 2 Triglyceride Conversions at Test Condition 6
Triglyceride Conversion (range based on 322.degree. C.+ Catalyst
conversion) Catalyst 1 95-100% (of invention) Catalyst 2 95-100%
(of invention) Catalyst 3 30-60% (reference) Catalyst 4 30-60%
(reference)
[0109] As can be seen from this Example, Catalysts 1 and 2 show
excellent conversion/activity stability over the wide range of
operating temperatures. This leads to the ability to control
related reaction temperatures over a wider range without
experiencing significant loss in catalytic activity. Additionally,
Catalysts 1 and 2 allow the hydrodeoxygenation processes to be run
under lower temperatures which results in significant reductions in
overall commercial unit operating energy costs.
[0110] FIG. 4 shows the amount of hydrogen consumption per barrel
of the bio-feed component for the four (4) catalysts tested over
the various ten (10) test conditions. A second benefit of Catalysts
1 and 2 of the invention can be shown here. Due to the higher
stability in the conversion activity of the Catalysts 1 and 2, the
hydrogen consumption level for Catalysts 1 and 2 are more stable
over the various operating conditions than hydrogen consumption
levels for references Catalysts 3 and 4. This again leads to more
stability in operating the processes over a greater range of
processing conditions. This can assist with stabilizing associated
refinery processes from which the necessary hydrogen is drawn
resulting in more stable inter-unit refinery operations.
[0111] A third, significantly economic benefit of the present
invention is illustrated in FIG. 5. FIG. 5 shows the estimated
amount of hydrogen consumption per barrel of the bio-feed component
at 100% deoxygenation for the four (4) catalysts tested over the
various ten (10) test conditions. As there are several reaction
routes through which the various catalysts can deoxygenate the
bio-component of the feed, the amount of hydrogen required on a
"unit basis" of deoxygenated feed will differ.
[0112] The calculations for the hydrogen usage per barrel of 100%
deoxygenated biofeed are based on an analysis of the product
streams from each of the catalyst/test conditions. As can be seen
in FIG. 5, the bulk metal deoxygenation catalysts of the invention
(Catalyst 1 and 2) have a lower hydrogen consumption per unit
bio-feed at constant conversion (i.e., 100% deoxygenation) in
almost all tested cases. Therefore, under most general
hydrodeoxygenation conditions, Catalysts 1 and 2 have the added
benefit of consuming less hydrogen at constant deoxygenation
levels.
Additional Embodiments
[0113] Additionally or alternately, the present invention can be
described according to one or more of the following
embodiments.
Embodiment 1
[0114] A method for hydroprocessing a biocomponent feedstock,
comprising:
[0115] exposing a biocomponent feedstock comprising at least a
bio-derived fraction to a bulk mixed metal catalyst in the presence
of hydrogen under effective deoxygenation conditions, the bulk
mixed metal catalyst comprising at least one Group VI metal and at
least one Group VIII metal; and
[0116] forming a deoxygenated effluent wherein at least 75% of the
oxygen has been removed from the biocomponent feedstock
compounds.
Embodiment 2
[0117] The method according to embodiment 1, wherein the
biocomponent feedstock further comprises a mineral oil
fraction.
Embodiment 3
[0118] The method according to any prior embodiment, wherein the at
least one Group VI metal is selected from Mo and W and at least one
Group VIII metal is selected from Co and Ni.
Embodiment 4
[0119] The method according to any prior embodiment, wherein the
total amount of the Group VI metals and Group VIII metals comprise
at least 80 wt % of the bulk mixed metal catalyst.
Embodiment 5
[0120] The method according to any prior embodiment, wherein the
bulk mixed metal catalyst contains less than 15 wt % carrier or
support material.
Embodiment 6
[0121] The method according to any prior embodiment, wherein the
bulk mixed metal catalyst is further combined with a binder.
Embodiment 7
[0122] The method according to embodiment 6, wherein the binder is
selected from silica, silica-alumina, alumina, titania, zirconia,
and mixtures thereof.
Embodiment 8
[0123] The method according to any one of embodiments 6-7, wherein
the amount of binder is from about 5 wt % to about 95 wt % binder
based on the total weight of the bulk mixed metal catalyst and the
binder.
Embodiment 9
[0124] The method according to any prior embodiment, wherein the
bulk mixed metal catalyst is further comprised of at least one
organic compound.
Embodiment 10
[0125] The method according to embodiment 9, wherein the bulk mixed
metal catalyst is further sulfided prior to exposing the
biocomponent feedstock to the bulk mixed metal catalyst, and the at
least one organic is present on the bulk mixed metal catalyst at
the time the catalyst is exposed to the sulfiding conditions.
Embodiment 11
[0126] The method according to any one of embodiments 9-10, wherein
the at least one organic compound is a condensation/decomposition
reaction product derived from an amine, a carboxylic acid, or
combinations thereof.
Embodiment 12
[0127] The method according claim 11, wherein the amine, carboxylic
acid, or combination thereof is subjected to a reaction temperature
of from about 195.degree. C. to about 250.degree. C. (about
383.degree. F. to about 482.degree. F.) to form the
condensation/decomposition reaction product.
Embodiment 13
[0128] The method according to any prior embodiment, wherein the at
least one Group VI metal is Mo and at least one Group VIII metal is
Co.
Embodiment 14
[0129] The method according to any one of embodiments 1-8, wherein
the bulk mixed metal catalyst is comprised of at least two Group VI
metals, such Group VI metals being Mo and W, and at least one Group
VIII metal selected from Co and Ni.
Embodiment 15
[0130] The method according to any prior embodiment, wherein the
bulk mixed metal catalyst is further sulfided prior to exposing the
biocomponent feedstock to the bulk mixed metal catalyst.
Embodiment 16
[0131] The method according to any one of embodiments 1-8 and
14-15, wherein the bulk mixed metal catalyst is comprised of Mo, W,
and Ni.
Embodiment 17
[0132] The method according to any one of embodiments 1-8 and
14-16, wherein the bulk mixed metal catalyst is comprised of at
least 90 wt % Mo, W, and Ni, and this portion of the bulk mixed
metal catalyst has the formula:
(Ni).sub.b(Mo).sub.c(W).sub.dO.sub.z
[0133] wherein the molar ratio of b:(c+d) is 0.5:1 to 3:1; the
molar ratio of c:d is preferably >0.01:1; the molar ratio of Mo
and W is 2:3 to 3:2; and z=[2b+6(c+d)]/2.
Embodiment 18
[0134] The method according to any prior embodiment, wherein the
effective deoxygenation conditions include a hydrogen partial
pressure of from about 200 psig (1.4 MPag) to about 2000 psig (13.8
MPag), a reaction temperature of from about 400.degree. F. to about
750.degree. F. (204.degree. C. to 399.degree. C.), a liquid hourly
space velocity of from about 0.1 hr.sup.-1 to about 10 hr.sup.-1,
and a hydrogen treat gas rate from about 500 scf/B (84
Nm.sup.3/m.sup.3) to about 10,000 scf/B (1685
Nm.sup.3/m.sup.3).
Embodiment 19
[0135] The method according to embodiment 18, wherein the effective
deoxygenation conditions include a reaction temperature of from
about 400.degree. F. to about 500.degree. F. (204.degree. C. to
260.degree. C.).
Embodiment 20
[0136] The method according to embodiment 18, wherein the effective
deoxygenation conditions include a reaction temperature of from
about 400.degree. F. to about 490.degree. F. (204.degree. C. to
254.degree. C.).
Embodiment 21
[0137] The method according to any prior embodiment, further
comprising:
[0138] exposing at least a portion of the deoxygenated effluent to
a hydrodesulfurization catalyst under effective
hydrodesulfurization conditions to produce a
deoxygenated/desulfurized effluent having a sulfur content of about
100 wppm or less.
Embodiment 22
[0139] The method according to embodiment 21, wherein the effective
hydrodesulfurization conditions include, a total pressure from
about 200 psig (1.4 MPa) to about 3000 psig (20.7 MPa), a
temperature of from about 450.degree. F. (232.degree. C.) to about
750.degree. F. (399.degree. C.), a liquid hourly space velocity of
about 0.3 to about 5.0 hr.sup.-1, a treat gas containing at least
about 80% hydrogen, and a hydrogen treat gas rate of about 500
scf/bbl (84 m.sup.3/m.sup.3) to about 10000 scf/bbl (1685
m.sup.3/m.sup.3).
Embodiment 23
[0140] The method according to any one of embodiments 21-22,
wherein hydrodesulfurization catalyst is comprised of at least one
Group VIB metal and at least one Group VIII metal deposited upon a
support, wherein the support is comprised of a material selected
from silica, silica-alumina, alumina, and titania.
Embodiment 24
[0141] The method according to any one of embodiments 21-23,
wherein the bulk mixed metal catalyst and the hydrodesulfurization
catalyst are located in a common reactor.
Embodiment 25
[0142] The method according to any one of embodiments 21-23,
wherein the bulk mixed metal catalyst and the hydrodesulfurization
catalyst are each located in separate reactors and the effective
hydrodesulfurization conditions include a temperature of from about
650.degree. F. (343.degree. C.) to about 750.degree. F.
(399.degree. C.).
* * * * *