Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
2 1. Field of the Invention
3 This invention relates ~o a start-up process
4 for hydrorefining heavy hydrocarbonaceous oils,
2. Descri~ion of_he Prior Art
6 Hydrorefining is a well known process for
7 upgrading a variety of hydrs~carbon Eractions. The term
8 "hydrorefining" is used herein to designate a catalytic
g treatment in the presence of hydrogen, of a hydro-
10 carbonaceous oil, to upgrade the oil by eliminating or
11 reducing the concentration of contaminants in the oil
12 such as sulfur compounds, nitrogenous compounds, metal
3 contaminants and/or partial saturation of the oll.
14 U.S. Patents 3,953,321 and 4,098,721 disclose
15 a hydrodesulfurization process for heavy hydrocarbon-
16 aceous oils such as gas oils in which a conventional
17 hydrodesulfurization catalyst is sulfided and heat
18 treated at a temperature of 750 to 850F prior to
19 initiating the hydrodesulfurization. The catalyst is
20 sulfided by contact with a lighter boiling range oil
21 (column 3, lines 59-68) or is heat treated in the
22 presence of the lighter oil~ free from sulfur (column 4,
23 lines 14-19).
24 U.S. Patent 2,954,339 discloses use of a
25 spent cobalt-molybdenum-alumina catalyst for hydrode-
26 sulfurization of a hydrocarbonaceous oil which may be
27 a gas oil. Prior to contact with the gas oil, the
28 catalyst is used to hydrotreat naphtha.
29 Il.S. Patent 3,423 t 307 discloses a start-up
30 method for a hydrodesulfurization process for heavy
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1 residual feeds which contain asphaltic materials. The
2 catalyst is initially contacted with an asphaltic-free
3 feed.
4 U.S. Patent 3,528,910 discloses a hydrotreat-
ing process for hydrocarbonaceous oils. A catalyst,
6 such as a supported nickel-molybdenum catalyst, is
7 sulfided in the presence of hydrogen with a distillate
8 containing disulfide sulfur prior to the hydrotreating
g reaction.
U,S. Patent 4,149,965 discloses a start-up
11 process for hydrorefining of naphtha. The catalyst is
12 partially deactivated by treatment with a substantially
13 non-metal containing hydrocarbon oil in the presence
1~ f hydrogen prior to contacting the catalys~ with the
naphtha feed.
16 U.S. Patent 3,368,965 discloses a slurry
17 hydrogenation process in which a catalyst, such as
18 cobalt molybdate on alumina, is pretreated by wetting
19 the catalyst with a clean (i.e. non-aromatic) hydro-
carbonaceous oil such as a lubricating oil fraction
21 to form a slurry which is then introduced into the
22 hydrocarbonaceous oil to be hydrogenated.
23 It has now been ~ound that by pretreating a
24 sulfided hydrorefining catalyst with a light hydrocar-
bonaceous oil in the presence of hydrogen prior to
26 hydrorefining the heavy hydrocarbonaceous oil feed, the
27 initial activity of the catalyst can be incr2ased.
28 All boiling points to which reference is made
29 herein are atmospheric boiling points unless otherwise
specified.
l The Periodic Table referred to herein is
2 in accordance with Handbook of Chemistr~ and Physics,
3 published by the Chemical Rubber Company, Cleveland,
4 Ohio, 45th Edition, 1954.
5 SUMMARY OF T~IE INVENTION
6 In accordance wi~h the invention there is
7 provided, in a hydrorèfining process which comprises
8 contacting a heavy hydrocarbonaceous oil having a
g boiling point ranging from about 650F to about 1050F
with hydrogen in the presence of a. sulfided hydro-
11 refining catalyst comprising a hydrogenation component
12 sel~cted from the group consisting of Group VIB metal
13 components and Group VIII non-noble metal components
14 and an alumina-containing support, at hydrorefining
conditions, the improvement which comprises initially
16 contacting said sulfided catalyst with a hydrocarbon-
17 aceous oil lighter than said heavy oil feed~ in the
18 presence of hydrogen, at a temperature ran~ing from
19 about 500 ~o about 725F, for at least 2 days, and
subsequently contacting said catalyst with said heavy
21 oil at said hydrorefining conditions.
22 BRIEF DESCRIPTION OF THE DRAWING
23 The igu~e shows graphs of catalyst activi~y
24 versus days on oil.
DETAILED DESCRIPTION OF THE INVENTION
26 The start-up method of the present invention is
27 suited for use at the beginning of a process for hydro-
28 refining heavy hydrocarbonaceous oil feeds utilizing a
29 hydrorefining catalyst that has already been sulfided
in a conventional manner. The sulfided hydrorefining
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1 catalyst is contacted with a hydrocarbonaceous oil
2 lighter than the hydrocarbonaceous oil feed which is to
3 be hydrorefined, at conditions shown in Table I.
4 TABLE I
LIGHT OIL TREATMENT CONDITIONS
~ Conditions Broad Range Preferred Ran~e
7 Temperature, F 500-750 600-700
8 Pressure, psig 500-3500 800-3000
g Liquid hourly space
10 velocity, V/HR/V 0.05-5.0 0.1-300
11 ~Iydrogen Rate, SCF/B 300-20,000 600-12,000
12 Hydrogen Partial
13 Pressure, psig 500-3500 650-2500
14 Suitable hydrorefining catalysts for use in
the process comprise a hydrogenation componen~ and an
16 alumina-containing support. The hydrogenation component
17 is selected from the group consisting of Group VIB metal
18 component and a non-noble Group VIII metal components
19 and mixtures thereof, such as cobalt, molybdenum,
nickel, tungsten and mixtures thereof. The alumina-
21 ~ontaining support may comprise a minor amount of
~22 another inorganic oxide such as siIica, magnesia, boria,
23 zirconia, strontia, hafnia, phosphorous oxide and
2~ mixtures thereofO Preferably, the support is an alumina-
containing support which additionally comprises minor
26 amounts of silica, such as for example from 1 to 6
27 percent silica, based on the weight of the support.
28 Such catalysts are described, for example, in U.S.
29 Patents 3,770,618 and 3,509,044 and 4,113,656~ The
preferred catalyst comprises molybdenum and cobalt or
31 nickel on an alumina support containing from 1 to 6
.
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5 --
1 percent silica, based on the support. The hydrogenation
2 component of the catalyst may initiaily be present as
3 elemental metal, metal oxide, metal sulfide and mixtures
4 thereof of the stated metals. When the initial hydro-
5 genation component is not in the sulfided state, then
6 the catalyst, e.g. the nickel oxide-containing catalyst,
7 is sulfided in a conventional manner well-known in the
8 art prior to the contacting step of the present inven-
g tion with the light hydrocarbon oil~ Suitable lighter
hydrocarbon oils for initial contact with the already
11 sulfided catalyst include hydrocarbonaceous oils having
12 an at~ospheric pressure boiling point not greater than
13 about 700F, preferably a boiling point ranging from
14 about Cs to not greater than about 700F. The contact-
ing with the lighter oil is conducted for at least 2
16 days. After the catalyst has been contacted with a
17 light oil, for the required time, in the presence of
18 hydrogen and at the above given conditions, the catalyst
19 i5 contacted with a heavy oil feed to be hydrorefined at
hydrorefining conditions. The contact of the light oil
21 ~ay be discontinued prior to contacting immediately
22 with the heavy oil or the heavy oil may be gradually
23 contacted with the catalyst while there is still some
24 light oil present. When the heavy oil is contacted with
the catalyst while the light oil is still present, the
26 contact with the light oil is continued, preferably for
27 at least a time sufficient for the sulfur concentration
28 in the hydrorefined oil product~ under the given operat-
29 ing conditions to be approximately constant (that is, a
period at least sufficient to obtain a line-out of
31 product sulfur concentration). Eventually, the Elow of
32 light oil to contact the catalyst is discontinued~ It
should also be noted that a hydrogen-containing gas is
34 being introduced into the hydrorefining zone during the
light oil pretreatment of the catalyst as well as during
36 the hydrorefining reaction stage. The contacting of
`` 1~0~6~36
1 the heavy oil feed with the catalyst is performed
2 im~ediately after the contacting of the catalyst with
3 a light oil without any intervening treatment steps
4 such as heat treating steps. Sui~able heavy oil feeds
to be hydrore~ined include oils which are substantially
6 asphaltene-free and which boil in the range of about
7 6S0F to about 1050F at atmospheric pressure, such as
8 gas oils. The hydrocarbonaceous oîls may be derived
g from any source such as tar sand oils, shale oil,
liquids derived from coal liquefaction processes and
11 mixtures thereof. The oils to be hydrorefined comprise
12 at least 0.25 weight percent sulfur and may comprise up
13 to 8 weight percent sulfur and may additionally comprise
14 up to 4 weight percent nitrogen usually present as
organic sulfur compounds and organic nitrogen compounds.
16 Suitable operating conditions in the hydro-
17 refining zone are summarized in Table II.
18 TABLE II
19 HYDROREFINING OPERATING CONDITIONS
20 Conditions ~ Preferred Ranqe
21 Temperature, F 600-900 650-850
22 Pressure, psig 600-3500 800 3200
23 Liquid hourly space 0.0S-5.0 0.1-2.5
24 velocity~ V/V/HR
25 Hydrogen rate, SCF/BBL 300-20,000 600-12,000
26 Hydrogen partial 500-3000 800-2500
27 pressure, psig
28 The catalyst may be disposed in the hydro-
29 refining reaction zone as a fixed bed, moving b~d,
30 dispersed phase, fluidized bed, ebullating bed or a
31 slurry. The process of the present invention is par-
32 ticularly suited for use in fixed bed processes~
:
1 Contact of the heavy oil feed in the presence of hydro-
2 gen and the catalyst at hydrorefining conditions pro-
3 duces a hydrorefined heavy oil having a decreased
4 content of sulfur and nitrogen contaminants~
PREFERRED EMBODIMENT
6 The following example is presented to illus-
7 trate the invention.
8 EXAMPLE
9 Comparative hydrorefining runs were made
utilizing the start-up procedure of the present inven-
11 tion and conventional start-up procedures. The catalyst
12 used in all the runs was the same catalyst, that is,
13 a conventional nickel-molybdenum-alumina catalyst
14 containing about 3 percent nickel r calculated as nickel
oxide, and about 15 percent molybd~num, calculated as
16 molybdenum oxide~ The catalyst was sulfided in the
17 conventional manner by contact with a blend of 10 volume
18 percent hydrogen sulfide and hydrogen. The feed used
19 in the hydrorefining runs was the same heavy hydrocar-
bonaceous oil feed having a boiling point ranging from
21 about 650 to about 1050F, a sulfur content of 2.3
22 wei~ht percent and a nitrogen content of 0.1 weight
23 percent. The feed was substantially free of asphaltenes
24 In runs A and B, which simulate a conventional
start-up procedure, the heavy oil was introduced into
26 the reaction zone immediately after the catalyst had
27 been sulfided. In runs C and D, which are runs in
28 accordance with the start-up procedure of the present
29 inven~ion, the sulfided catalyst was contacted with a
light hydrocarbonaceous oil having a boiling point
31 ranging from Cs to 700F in the presence of hydrogen
, .,
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1 for about 30 to about 40 days at the conditions given in
2 Table III prior to introducing the heavy oil to be
3 hydrorefined into the hydrorefining zone.
4 The light oil treatment conditions used in
Runs C and D are summarized in Table III~
6 TABLE III
7 LIGHT OIL TRERTMENT CONDITIONS
8 Conditions ~ Run CRun D
g Temperature, F 629-662630
10 Hydrogen pressure, psig 1200 1200
11 Liquid hourly space
12 velocity, V/HR/V 0.3-1~0 0~5
13 Hydrogen Rate, SCF/B 3000 3000
14 The hydrorefining conditions and ~esults of
these runs are summarized in Table IV.
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l The hydrodesulfurization and hydrodenitrogena-
2 tion activities of the catalyst in runs A, B, C and D,
3 that is, without light oil treatment and with light oil
4 treatment, versus days on oil is shown in the four
graphs in the accompanying figure.
6 As can be seen from Table IV, runs C and D
7 showed increased catalyst activity. The increased
8 activity can be used to decrease the catalyst require-
9 ment or to decrease the start o the run temperature7
As can be seen from the figure, the hydro-
ll denitrogenation and hydrodesulfurization rate cons~a,nts
12 of the catalyst in runs C and D (runs in accordance with
13 the present invention) were lined out and the catalyst
14 maintained a higher level of activity than the catalyst
of runs A and B, which had not been treated in accord-
16 ance with the present invention.
:
