Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ ~ 64 3 ~3 6 ~A~F BlF~N-l
F I ELD OF THE I MVENT I ON
The present invention relates to a process for
hydrotreating carbonaceous material utilizing empirical
hydrates of cer-tain alkali metal sulfur compounds.
BACKGROI~D OF THE INVENTION
Many processes are known for treating petroleum
oils and the li~e with alkali metal compounds or sulfides.
For example, U.S. Patent No. 3,252,774 discloses
a process for cracking liquid hydrocarbons to produce
hydrogen-containing gases by contacting the feedstock
with a melt of an alkali metal compound (e.g., the sulfides),
at temperatures between about 800 and 1800F in the
presence of steam.
U.S. Patent No. 3,617,529 discloses removing
elemental sulfur from petroleum oil by contacting the oil
at ambient temperature with an aqueous solution containing
sodium hydrosulfide alone or in combination with sodium
hydroxide and ammonium hydroxide. The aqueous solution
and oil are separated, and the aqueous solution is treated
to ree the sulfur from the polysulfides that are formed
during the contacting step.
U.S. Patent Nos. 3,787,315 and 3,788,978 disclose
processes for desulfurizing petroleum oil. The oil is
contacted with an alkali metal or alloy in the presence
of hydrogen to form a sulfide, thereby desulfurizing the
oil. The sulfide is separated from the oil by treating
with hydrogen sulfide, and the separated monosulfide is
treated with a sodium polysulfide to form a polysulfide
of lower sulfur content, which is then electrolyzed to
produce sodium.
U.S. Patent No. 3,816,298 discloses a two-stage
process for upgrading (partially desulfurizing, hydrogenat-
ing, and hydrocracking) heavy hydrocarbons (e.g., vacuum
residuum) into liquid hydrocarbon products and a hydrogen-
containing gas. In the first stage, the hydrocarbon feed
is contacted with a gas containing hydrogen and carbon
-2- ~ 643(~
oxide in the presence of any of numerous catalysts,
including alkali metal sulfides and hydrosulfides. The
pressure must be above 150 psig and the average tempera-
ture between about 700 and 1,100F. An example shows
feeding steam (as well as hydrogen and carbon oxides) to
the first stage with K2 C03 catalyst, at 3~0 psig and
910F. A by-product, solid carbonaceous material, is
deposited on the catalyst and a por-tion of the catalyst
is sent to the second reaction stage where it is contacted
with steam, at a pressure a~ove 150 psig and an average
temperature above 1,200F.
U.S. Patent No. 4,003,823 discloses another
process for upgrading heavy hydrocarbons, by con~acting
them with alkali metal hydroxides, at hydrogen pressures
of from about 500 to 5,000 psig a~d temperatures of from
about 500 to 2,000F. Hydrogen sulfide may be added to
the products withdrawn from the reaction zone to convert
alkali metal sulfides formed in the reactor to hydro-
sulfides, as the first s-tep in regenera-ting ~he alkali
metal hydroxides.
U.S. Patent No. 4,018,572 discloses a process
for desulfurizing fossil fuels by contacting -the material
with aqueous solutions or melts of alkali metal poly-
sulfides to form salts with higher sulfur content, which
are decomposed to regenerate the polysulfides of reduced
sulfur content.
Finally, U.S. Patent No. ~,119,528 discloses
another process for treating heavy carbonaceous feedstoc~s,
using potassium sulfide and hydrogen pressures of from
about 500 to 5,000 psig and temperatures of from 500 to
2,000F. The products are desulurized, lower-boiling
oils and potassium hydrosulfide, which may be converted
back to potassium sul~ide. The potassium sulfide may be
charged to the reactor as such or made in situ by reacting
various potassium compounds with sulfur compounds, such
as hydrogen sulfide. The potassium sulfide may also be
made by reducing potassium compounds, such as the hydro-
sulfide or the polysulfides, with reducing agents, such
as hydrogen. The sul~ide may also be made by the high
~ 3 ~3~6
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temperature s-teaming of potassium hydrosulfide. Preferably,
a mixture of po-tassium and sodium sulfides i6 used because
the sodium sulfide acts as a "getter" for -the hydrogen sul-
ide produced during reaction that would otherwise reac-t
with the potassiurn sul:Eide to for~ "inactive" po-tassium
hydrosulfide.
The following U.S. pa-tents also disclose processes
for treating petroleurn oils and the like with alkali metal
compounds or sulfides: 1,300,816; 1,423,005; 1,729,943;
1,938,672; 1,974,724; 2,145,657; 2,gS0,245; 3,112,257;
3,185,641, 3,36~,875; 3,354,081; 3,382,1~, 3,348,119;
3,553,279; 3,565,792; 3,663,431; 3,745,109 and 4,007,109.
SUMMARY OF I'HE INVENTION
A problem with prior ar-t processes, including
those referred to above, is that severe processing condi-
tions, e.g., high temperature and/or pressure, are required
-to produce useful products in high yields. The present in-
ven-tion is directed to a solution of the foregoing problem.
I have now surprisingly found that by use in a
hydrotreating process of an empirical hydrate reagent, here-
ina~ter more fully disclosed, the yield of useful products,
with only relatively mild processing conditions, is much
higher than for any other known hydrotreating process, in-
cluding those re~erred to above. For example, the reaction
temperature with my process need not be greater than about
410C and the pressure need not be above atmospheric. Also,
because conversion efficiency and yield of useful products
are surprisingly high wi-th my process and require less cost-
ly processing conditions, reduction of consumer costs can be
expected.
More specifically and in accordance with the in-
vention I provide a process for hydrogenating, hydrocracX-
ing, denitrogenating and demetallizing carbonaceous material
to produce principally normally liquid hydrocarbon products
3 ~ ~
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of increased hydrogen content as compared to the carbona-
ceous material, characterized by subjecting -the carbonaceous
material in a reac-tion vessel to steam and a reagent com-
prising an empirical hydrate oE a sulfur-containing compound
comprising al~ali metal hydrosulfides, alkali metal monosul-
fides, or alkali metal polysulfides and recovering -the said
hydrocarbon products, there ~eing essentially no liquid
water present during such contac-ting.
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None of the above-mentioned U.S. patents dis-
closes or suggests the use of empirical hydrates of
alkali metal hydrosulides, sulfides, or polysulfides -to
hydrotreat (e.g., hydrogen~te a~d hydrocrack) carbonaceous
material in accordance with the process of our invention.
As used herein, the term "carbonaceous material"
includes oils, shale, tar sands, and the like, but not
coal. Thus, the term "carbonaceous material" embraces
crude oils, atmos~heric resicls (cracked and uncracked),
and vacuum resids (vis- and non-vis-broken~, and non-
petroleum oils. "Hydrotreating" includes hydrogenating
and hydrocracking. The term "empirical hydrates" is used
because the reagents of this invention appear to be
hydrates in -that they contain bound or associated wa-ter
that is freed at discrete temperatures as the reagents
are heated.
The use of steam in my process is essential
because it maintains the reagents in their empirically
hydrated (high-activi-ty) forms.
The novel process provides many benefits.
Aside from the benefits already mentioned, denitrogenation
and demetallizing occur concomitantly with the hydrotreat-
ing. Additionally, depending on process conditions and
on which reagents are used, desulfurization may also take
place; see my U.S. Patent No. 4,160,721, which discloses a
desulfurization process.)
Also, the efficiency and degree of hydrotreating
achievable are very high. For example, in a preferred
embodiment wherein hydrogen sulfide is co-fed to a reaction
zone in which a resid having an initial boiling point of
over 343C is treated in one pass, essentially all of the
resultin~ products boil at temperatures below 343C.
This illustrates the high degree of cracking at relatively
mild condi-tions achievable with the present invention.
Other advantages of the present process will be
apparent from the following description.
DETAILED D_SCRIPTION OF THE INVENTION
Broadly, the process comprises contacting -the
carbonaceous material with the reagent. The carbonaceous
. . . . . . .
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.5_
material will usually be employed in the liquid phase,
but preliminary research indicates that vapor phase
contact may also be used. Steam is passed through the
reaction mixture to maintain the reagent ln its ernpiri-
cally hydrated ~highly reactive) form. ~For carbonaceous
materials high in naphthenic acids, -the steam flow is
kept to a minimum because water tends to decompose these
materials. In such cases, hydrogen may be advantageously
co-fed.) Free li~uid water causes the reagen-t to decompose
and thus the reaction condi-tions should be chosen to
prevent the presence of a significant amount of liquid
water. Preferably, conditions are chosen so that there
is essentially no free liquid water in the reaction zone.
The reaction mixture is heated to vaporize
treated product, and the steam and product are withdrawn
from the reaction zone, cooled, and separated. If desired,
the product may be -taken off as a series of distillation
cuts and the heavier (higher boiling temperature~ cuts
recycled for further treatment. The steam and vaporized
product need not be withdrawn continuously or at all;
however, without periodic withdrawal, the pressure will
rise and cause the steam to condense. This in turn will
decompose the reagent and halt reaction. Accordingly, it
is preferred that there be at least periodic vapor removal,
and continuous removal is most preferred.
Treatment may be carried out in almost any type
of equipment. For example, a tank reactor could be used.
A staged, column reactor, allowing product cuts to be
taken off overhead and as sidestreams, could also be
used. The process may be run in continuous or batch
fashion and with one or more reaction stages. A tank
reactor would usually be operated batch-wise; a staged
column lends itself to continuous operation.
In a preferred embodiment, hydrogen sulfide is
also fed to the reaction zone to contact the reaction
mixture. This regenerates a portion of the reagent and
results in higher productivity. As explained below,
hydrogen sulfide is produced during trea~nent and is
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withdrawn with the s-team and vaporized product. Accord-
ingly, it is most advantageous if the hydrogen sulfide
withdrawn is recycled to the reaction zone.
The reaction temperatures are comparatively
low, generally between approximately 40 and 410C. For
certain materials (e.g., vacuum resids), essentially no
reaction occurs until the temperature is relatively high
~e.g., 370C~. The pressures need no-t be above atmos~
pheric, but engineering design consi~erations may dictate
that higher pressures be used, for example, to reduce the
diameter ~and cost) of a column-type reactor. Whatever
conditions are employed, they should not result in conden-
sation of a significant amount of the steam, and preferably
essentially none of the steam condenses.
The reagents used herein are the empirical
hydrates of the hydrosulfides, monosulfides, and polysul-
fides of the Group IA elements of the Periodic Table
other than hydrogen. The francium and cesium compounds
are not generally used. Thus, the sodium, potassium,
lithium, and rubidium compounds will more often be used.
The potassium, rubidium, and sodium compounds are preferred,
and the potassium are most preferred. (However, in some
cases, e.g., with Heavy Canadian Crude Oil, the sodium
reagents have been superior to the potassium.) A reagent
comprising empirical hydrates of three hydrosulfides
equivalent to 14% rubidium hydroxide, 29% potassium
hydroxide, and the rest sodium hydrosulfide (based on the
total of the two hydroxides and one hydrosulfide) has
been found to be the most effective.
During reaction, at low temperatures the reagent
is actually a mixture of the empirical hydrates of the
hydrosulfide and sulfides (mono and poly) of each alkali
metal employed, and during reaction there is in-terconver~
sion of these sulfur-containing forms. (As the reaction
-temperature rises, some of these forms disappear because
their decomposition temperatures have been exceeded.)
Accordingly, the reagent may be charged initially to the
reaction zone as the hydrosulfide empirical hydrate or as
one or more of the sulfide hydrates or as a mixture of
3 8 ~)
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the hydrosulfide and sulfide empirical hydrates. The
empirical hydrate reagents may also be made in situ, but
preferably they are charged in their empirical hydrate
form. (Each of the alkali metal hydrosulfides and mono-
and polysulfldes may have more than one empirical hydrate
and unless otherwise noted, the -term "empirical hydrate"
is meant to include all the hydra-tes.)
More specifically, taking the potassium series
as an example, there are six svlfides of potassium, K2S,
K2S2, K2S3, K2S4, K2S5, and K2S6, and one hydrosulfide,
KHS. The molecule containing the greatest number of
sulfur atoms may be thought of as being "saturated" with
respect to sulfur (i.e., K2S6), and those containing less
as being relatively unsaturated with respect to sulfur.
Considering now potassium monosulfide ~K2S),
for example, it crystallizes as an empirical pentahydrate.
Under reaction conditions, at 162C, the empirical penta-
hydrate decomposes to an empirical dihydrate, with the
vigorous and observable liberation of three moles of
water per mole of K2S. At 265 - 270C, further decomposi-
tion occurs to a lower empirical hydrate, with liberation
of water. Some water of empirical hydration probably
remains up to or near the melting point of 448C. ~he
liberation of water at discrete temperatures is clear
evidence of the presence of bound or associated water
analogous to water of hydration.
The present process denitrogenates and demet-
allizes as it hydrogenates and hydrocracks. The nitrogen
leaves the system as ammonia vapor. The me-tals removed
include vanadium, nickel, cobalt, and cadmium, and remain
in the reagent left in the reaction zone. Additionally,
if H2S is co-fed or if the less sulfur saturated reagents
are used, the process also desulfurizes.
Increasing the overall sulfur to alkali metal
ratio in the reaction zone (including the sulfur in the
carbonaceous material) tends to decrease the severity of
cracking -that occurs and to decrease the desulfurization.
Lower sulfur to alkali metal ratios tend to increase the
cracking severity and increase the desulfurization. If
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hydrogen sulfide is corfed, the timiny of its addi-tion
also affects the cracking severity. Commencement of
addition before removal of all the liquid water (at about
110 - 135C) decreases the severi-tyi commencement of
addition after removal increases the severi-ty.
For the potassium reagents, overall ratios o~
0.5/1 ~equivalent -to 100% ~2S) to 2.5/1 (equivalent to
100% K2S5) may be employed. However, for most carbona-
ceous materials, a more useful range is 0.55/1 to 1.5/1,
and the preferred range is 0.75/1 to 1/1. The limits of
the preferred range may be thought of as corresponding to
K2S1.5 (0.75/1) and K2S2 (1/1). The preferred range for
the sodium series is 0.55/1 to 1/1. Lower ratios may be
re~uired when processing materials that are difficult to
crack, e.g., vacuum resids. If the sulfur to alkali
me-tal ratio of the combined reagent and carbonaceous
material is too low, elemental sulfur may be added; if
too high, additional unsaturated reagent may be added.
The amount of reagent employed must be suffi-
cient to provide adequate contact with the feedstock and
the desired rate of reaction. The maximum amount of
feedstock that can be processed with a given amolmt of
catalyst is not known, but as much as 500 grams of a
vacuum resid have been treated with 9.5 grams of KHS (as
the empirical hydrate).
The reagents may be made in several ways. The
manufacture of the preferred po-tassium reagents will be
exemplified. First, sulfur in a 15% excess may be added
to potassium in a liquid ammonia medium. This yields
potassium sulfide hydrate ~empirical hydrate). A portion
of the hydrate is then reacted with additional sulfur to
yield the pentasulfide empirical hydrate. The two hydrates
are combined and used.
A second method is to dissolve potassium hydroxide
in water and add just enough of a low-boiling alcohol
(e.g., ethanol, propanol-13 to cause two layers to form.
For example, 1 gram-mole of KOH is dissolved in 2 gram-
moles of water. Sufficient alcohol (e.g., ethanol or
higher) is added to form two layers (the to-tal volumP
3 ~ 6
g
will be 160 milliliters or less), and then elemental
sulfur is added to bring the S/K ratio to the desired
value.
This second method yields almost exclusively
empirical hydrates of sulfides and not of -the hydrosulfide.
The little hydrosulfide that is produced remains in the
alcohol layer, and the water layer contains only sulfides.
The wa-ter layer sulfides have been used successfully in
hydrotreating runs. This evidences the viability of the
sulfide reagents.
The third (and preferred method) involves
dissolving potassium hydroxide in an alcohol in which the
KOH is soluble and then contacting the solution with
hydrogen sulfide. The alcohols will usually be primary
alcohols, methanol and e-thanol being preferred because
KOH is more soluble in these than in higher alcohols.
The resulting mixture contains potassium hydrosulfide
empirical hydrates. (This procedure may also be used to
prepare the rubidium reagents. The sodium hydrosulfide
reagents are not prepared this way; instead, commercially
available flakes of NaHS empirical hydrate may be charged
directly to the reaction zone.)
The manufacture of potassium hydrosulfide
empirical hydrate reagent according to the preferred
procedure is illustrated as follows. Two l-liter gradu-
ated cylinders are each filled with slightly less than
600 milliliters of ethanol, and 3 gram-moles of potassium
hydroxide are dissolved in each. A hydrogen sulfide
source is connected to the first cylinder so as to intro-
duce H2S near the bottom of the KOH-ethanol solution.
The vapor overhead from the first cylinder is piped to a
second cylinder and enters near the bottom of the solution
therein.
The following overall reaction occurs:
H2S + KOH = KHS ~ H2O
This reaction is so rapid that if the H2S flow is too
low, the solution in each cylinder will be drawn up its
respective vapor feed tube. ~as flow to the first cylinder
is halted as soon as H2S freely passes to the second
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cylind~r, any precipi-tate in the first cylinder has been
dissolved, and the temperature of the first cylinder has
dropped below 22C. At that point, -the first cylinder
contains high-quality reagent (potassium hydrosulfide
empirical dihydrate (KHS.2H2O) in ethanol) and should be
removed from the system and stoppered.
A typical batch procedure for treating carbona-
ceous material in accordance with this invention using
the the preferred po-tassium reagent made by the preferred
method is as follows (petroleum oil is the carbonaceous
material). The oil is charged to the reaction vessel and
nitrogen (or another iner-t gas) is continuously sparged
into the oil to agitate it as the oil is heated. (Mechani-
cal means such as a magnetic stirrer may be used instead
of gas agitation.) If elemental sulfur is required to
raise the sulfur to alkali metal ratio, it may be added
to oil at this point. The reagent mixture (potassium
hydrosulfide empirical dihydrate in ethanol) is then
added. (Alternatively, the extra sulfur may be added to
the reagent mixture rather than to the oil.) The tempera-
ture is raised to approximately 130C, and steam sparging
is commenced. The steam flow need not be more than
enough to cause hub~les to be visible on the surface of
the oil. If the steam is providing sufficient agitation,
the nitrogen sparging may be halted.
The overhead vapor is continuously withdrawn
and variously contains the alcohol and water from the
reagent mixture, steam, hydrogen sulfide from the reaction,
and both vaporized and uncondensible hydrocarbon products
from the treatment (assuming that the reaction initiation
temperature has been reached). The overhead stream is
cooled with cooling water and the resulting condensate is
sent to a liquid-liquid separator. The uncondensed vapor
may be fed to a cold trap (e.g., at -60F) to recover
additional hydrocarbon products.
As the bulk temperature of the oil in the
reactor rises, varivus overhead products are recovered in
the overhead system. The nitrogen sparged into the oil
starts to strip the alcohol and water associated with -the
J ~ ~38~
reagent almost as soon as the reagent is added (at about
40C). By 90C, the first drops of a separate hydrocarbon
layer are visible in the liquid-liquid separator. Before
that, however, the light hydrocarbons produced (e.g.,
three-, four-, five-, and six-carbon atom compounds) have
already come overhead, and at least a portion of them
have dissolved in the alcohol in the separator.
By 135C, distillation of the alcohol and water
from the reagent mixture has been substantially completed.
The water-alcohol layer in the separator preferably is
withdrawn and recycled to the steam ~enerator that provides
the sparging steam. This ultimately returns the lighter
hydrocarbons to the reaction vessel and tends to suppress
further formation of them. Alternatively, the water and
alcohol could be separated and only the water recycl~d to
the steam generator. This would prevent "bumping" in -the
reaction vessel, caused by the revapori~ation of the
recycled alcohol.
The temperature of the oil may be raised con-
tinuously or held at one or more temperatures (after
steam flow is commenced at about 130). Maintaining a
low temperature for an extended period of time favors
production of lighter products, but also results in more
steam stripping of the heavier feedstock from the reaction
zone.
Table I/ below, indicates the cumulative ~uanti-
ties of products that were recovered in the liquid-liquid
separator when processing a light crude oil having 11.75%
(by weight~ hydrogen using a potassium empirical hydrate
having an S/K ratio = 1/1, the oil having been held at
each indicated temperature above 140C for fifteen minutes.
1 3 ~ 6
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Table I
Bulk OilCumulative Products Recovered
TemperatureAs A Percent ge of Oil Feed
,_
Up to 140Capprox. 24% ~by weight)
180C approx. 38% (by weight)
220C __
270C approx. 59% (by weight)
320C __
340C approx. 96% (by weight~
The residue in the reaction vessel was less than 2% (by
weight) of the oil feedstock. During this run, approxi-
mately 4.7 grams of product were recovered in a -60F
cold trap.
It has been found that excep-ting those oils
high in naphthenic acids, no matter which light petrole1lm
oil is processed in a batch system without addition of
hydrogen sulfide, the hydrogen, nitrogen, and sulfur
contents of various product cuts are within certain
ranges. Table II, below, indicates these expected values.
lThe "Below 140C Cut" is that hydrocarbon material
recovered while the bulk oil temperature is below 140C.
The "140 - 170C Cut" is the material recovered when the
bulk oil temperature is from 140 ~o 170~C, and so forth.
Table II
Product Cut Amount Of Element In Product Cut
~Oil Bulk Temp.) Hydro~en Nitro~_ Sulfur
Below 140C 13.8-14.1% less than less than
0.05% 0-05%
140 - 170C 13.4-13.6% less than 0.07%
0.05%
170 - 270C 13% 0.1% 0.36-
0.48%
270 - 340C 12.4-13.0% one-half two-thirds
initial initial
~ :1 B4386
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Many variations in the processing sequence are
possible. One or more of the product cuts may be recycled
to the reactor for further cracking. For example, it is
possible to recycle all of the products cuts recovered at
bulk temperatures over 140C and produce essentially only
a 140C net product.
AnQther ~ariation is regenerating the empirical
hydxate reagent. This involves recovering the hydrogen
sulfide in the vapor stream withdrawn from the reactor
and treating the potassium compounds left in the reactor.
To recover the H2S in the vapor stream, the overhead from
the reactor is passed through a coolin~ water cooler, as
before, and the uncondensed material is then passed
through an alcohol wash to remove the lighter hydrocarbons
because they hinder recovery of the hydrogen sulfide in
the next step. (The alcohol wash solution may be recycled
to the steam generator.) The remaining ~as stream contain-
ing H2S is then fed to an alkali metal hydroxide-in-alcohol
solution, which removes the hydrogen sulfide in the gas
stream in forming regenerated empirical hydrate of the
alkali metal hydrosulfide or sulfide in much the same
manner as the preferred method for making fresh reagent.
Desirably, a multi-stage H2S scrubber is used, and the
vapor effluent from the last stage contains essentially
no hydrogen sulfide.
To recover the potassium in the reactor (if
potassium reagents axe used) and regenerate the reagent,
the solids in the reactor, comprising polysulfides and
metal compounds formed during reaction, are withdrawn
therefrom and approximately 3 moles of water per mole of
potassium are added to form an aqueous solution. Option-
ally, a volume of alcohol is added in an amount less than
or equal to the volume of the aqueous solution. The
alcohol stabilizes the reagent precursors during subsequent
processing. The mixture is then cool~d to less than
22~C, causing some alkali metal hydroxide to form, and
hydrogen sulfide, which can be recycled ~2S from an
operating reactor, is bubbled through the mixture with
~ ~ 6~38S
~14-
cooling to maintain the temperature below 22C. This
causes sulur to precipitate out, and the liquid is
separated from the solids. The liquid is then heated to
drive off most of the water and alcohol (if any were
employed) and leave an empirical potassium hydrate melt.
In the case of the potassium reagents, heating
to a temperature of 105-110C under a water atmosphere
will leave an empirical hydrate melt containing approxi-
mately 35% (by weight) bound water. ~he melt is then
dissolved in just enough low-boiling alcohol (preferably
methanol or ethanol) to form a saturated solution. (More
dilute solutions may be used but require additional
energy to vapori~e the surplus alcohol.) In the case of
the potassium reagents, at ambient temperature, approxi-
mately 150 milliliters of methanol or somewhat more of
ethanol are required to dissolve 1 gram-mole of KHS.
Hydrogen sulfide is bubbled through the solu~ion at a
tempexature over 60C, resulting in a solution of empirical
hydrate reagent in alcohol. The solution is then ready
for use in the hydrotreating reactor; however, desirably
the solution is first used to wash the hydrocarbon products.
This clarifies the distillates, removes free sulfur
therein, and tends to improve the effectiveness of the
reagent.
In a preferred embodiment, hydrogen sulfide is
fed to the reactor. The ~2 S, apparently, tends to suppress
decomposition or deactivation of the reagent, and, as
noted above, depending on when its flow is commenced, the
cracking severity tends to increase or decrease. The
minimum and maximum amounts of hydrogen sulfide that can
be used beneficially are not presently known.
The following examples are provided for illus-
trative purposes only and are not intended to limit the
scope of the invention.
~ 36~38~
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Exame~
One hundred si~ty-four and one-half grams of a
Texas crude oil, 2 grams of elemental sulfur, and 40
milliliter~ of a me~hanol solution containing 15.2 grams
of KHS and 7.6 grams of water (the water bound in an
empirical dihydrate) were placed in a flask, and the
contents were agi~ated by nitrogen introduced below the
surface of the liquid, near the bottom of the flask. The
flask was heated by a heating mantel and a s~eam generator
sparged steam into the li~uid in the flask. Steam flow
was started when the bulk liquid temperature was about
120C.
The overhead vapors were fed to a cooling water
condenser and the condensate was collected in a flask.
During operation, the methanol-water condensate from the
water-cooled condenser was periodically returned to the
steam generator. The hydrocarbon condensates at different
oil bulk temperatures (cuts) were periodically removed
and analyzed. The uncondensed vapor was passed through a
solution of 0.5 moles of XOH in 100 milliliters of methanol
(removing essentially all the H2S), through a water
scrubber (removing methanol), and then through an isopro-
panol-dry ice bath (removing some lighter hydrocarbons).
Analyses of the crude oil and of the product cuts are
shown below.
Analysis
MaterialAmount Hydro~en Nitro~en Sulfur
Crude Oil 164 . 5g 12.11%0.14% 1.51%
Below 140C Cut 29.4g13.87% <0.05% 0.05%
140-170C Cut 16.6g 13.6%<0.05% 0.07%
170-275C Cut 25.7g 13.1% 0.07% 0.8%
275~340C Cut45.0g 12.3% 0.1% 1.1%
There was no carbonaceous residue in the reaction flask,
and the condensate from the cold trap totalled 22 milli-
liters.
The data indicate that the process hydrogenates,
denitrogena-te~, and desulfuxizes. All product cuts
contain (in weight fractions) more bound hydrogen, less
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bound nitrogen, and less bound sulfur than does the crude
oil. ~he distillate from the cold trap was not analyzed
but obviously has a greater fraction of bound hydrogen
than does t~e crude oil.)
Exam~le II
Two hundred grams of an Alaskan crude oil were
treated using the procedure of Example I except that
steam flow was commenced at 135C and a cold trap was not
us~d. Analyses of the crude oil and the products are
shown below (there was essentially no oil residue in the
flask).
Analysis
-
Material Amount Hydro~en Nitrogen Sulfur
Crude oil 200g 12.04 0.23% 1.5%
Non-cond~nsibles 74g
Below 140C Cut 38.4g 13.99% <0.05% <0.05%
140-180C Cut 20.1g 13.77% <0.05% 0.07%
180-343C Cut 59.lg 12.8% 0.1% 0.9%
Example III
one hundred seventy-five grams of Trinidad
crude oil were treated with 30 milliliters of a methanol
reagent solution containing 11.4 grams of K~S and 5.7
grams of water ~bound in the empirical hydrate). Because
of its high naphthenic acid content, this oil is susceptible
to degradation by water. Thus, a minimal amount of steam
was used ~the steam generator was kept at 99C, at s~a
level) and gaseous hydrogen was also sparged. Analyses
o the crude oil and products are shown below.
I ~ 6~3~
-17-
:
An lysis
Material __ Amount ~ydro~en Nitrogen Sulfur
Crude Oil 175g 11.83% 0.32% 1.43%
Below 180C Cut~ 13.01% O.05% 0.24%
Hydrocarbons in) 33% vol. of 12.89% 0.06% 0.55%
alcohol-water3 crude oil
condensate
1~0-240C Cut 21% v~l.12.39% 0.06% 0.58%
of crude oil
Residue ln 20% vol.11.87~ 0.31% 1.~3%
flask of crude oil
Because of the apparatus configuration, the hydrogen
could not be introduced close enough to the bottom of the
reaction flask to contact the bottommost material; hence,
the 20% xesidue.
Example IV
O~e hundred fifty grams of a light Arab crude
oil, 2 grams of elemental sulfur, and 40 milliliters of a
methanol solution containing 15.6 grams of KHS and 7.8 grams
of water (bound in the empirical hydrate) were charged
into a reaction flask, and the run proceeded as in Example I,
except that steam flow was commenced at 130C. Analyses
of the crude oil and recovered products are shown below.
AnalYsis
.
Material Hydrogen Nitrogen Sulfur
. ~
Crude Oil 12.25%0.1% 1.8%
Below 140C Cut 13.8% <0.05% 0.09%
: 140-170C Cut 13.5%<0.05% 0.12%
170-27~C Cut 13.1%0.07% 2.3%
270-330C Cut 12.8%0.11% 0.8%
. Exam~le V
: A straight-run vacuum resid (produced with an
initial boiling point under vacuum of 593~C) and a methanol
solution of KHS (0.47 grams KHS/milliliter solution) were
charged to a reaction flask. Heating was commenced and
the reactor contents were agitated with nitrogen from
ambient temperature to 170C, at which point the nitrogen
-18- i 3 ~386
flow was halted and steam flow was commenced. The run
was halted when the bulk resid temperature reached 400~C,
at which time the residue remaining in the flask was 51%
of that initially charged. Analyses of the resid feedstock
and of the two distillates are shown below.
_ Anal~sis
Material _Hydro~en Nitrogen Sulfur
Resid lO.Sl% 0.52~ 3.83%
Below 110C Cut12.02% 0.22% 2.61%
110-400C Cut11.41% 0.21~ 2.96%
Example VI
The straight-run vacuum resid of Example V was
again treated with KHS reagent, this time using hydrogen
to agitate the system from ambient temperature to 240C .
Steam flow commenced at 170C. The run was halted at
425~C, at which time the coked material left in the
reactor amounted to 9% of the resid initially charged.
Analyses of the resid, of the two distillates collected,
and of the residue in the flask are shown below.
Analysis _
Material~Iydro~en Nitrogen Sulfur
Resid 10.51% 0.52% 3.83%
Below 360C Cut12.17~ 0.13% 2.41%
360-425~C Cut 12.29% 0.11% 1~95%
Resldue in flask6.67% 0.23% 2.46%
and condenser
washings
Chromatographic analysis of the uncondensed gas stream
indicated that it contained 30.52% hydrocarbons, broken
down as follows.
Compound(s)_Pexcent_of Gas Stream H~drocarbon
Methane 59%
Ethane + Ethylene21%
Propane + Propylene 6%
Butane~ 6~
Pentanes 2%
The rest of the gas stream (69.48%) 1~ believed to have
been air in the gas chromatography tube. The condensed
4 3,~ 6
--19--
distillates were very light, no heavier than ~2 heating
oil or diesel fuel. Additionally, the absence of any
precipitate in the effluent gas scrubber, containing an
alcoholic solution of KOH, indicated that little or no
carbon dioxide was produced in the reactor.
Example VII
One hundred fifty milliliters of a different
vacuum resid and 22 millilit~rs of a methanol solution
containing an empirical hydrate of KHS (O.477 gram of KHS
per milliliter of solution) were charged to a reaction
vessel and heated. Nitrogen agitation was used from
ambient temperature to 190C, at which time the nitrogen
was stopped and the flow of steam (superheated to 140C)
was commenced. A single distillate ~as collected and
kept at 100C to drive off the water. Those hydrocarbons
that did not distill off with the water are denominated
the "100 - 425C Cut," and those that did distill off as
the "Below 100C Cut." Analyses of the resid, of the two
hydrocarbon products~ and of the residue in the flask are
shown below:
_ Analysis
_Material Amount Hydrogen Nitro~ Sulfur
Resid 150 ml 10.85% 0.44% 2.91%
Below 100C Cut27 ml 12.92% 0.07% 1.03%
100 - 425C Cut110 ml 12.08% 0.25% 2.26%
Residue in flask 20 g 3.02% 1.25% 4.47%
Example VIII
Example VII was repeated~ the only change being
the use of hydrogen instead of ni-~rogen, from ambient
temperature to the final temperature of 425C. At the
end of the run, the same amount of residue (20 grams)
remained in the flask. Analyses of the resid and of the
single distillate are shown below.
~ ~ 6~3~6
-20-
Analysis
Materlal_ H~dro~en Nitro~en Sulfur
Resid 10.85% 0.44% 2.91%
Distillate 12.19% 0.17% 1.95%
Exa~
One hundred sixty milliliters of the ~acuum
resid of Examples VI~ and VIII and 25 grams o~ dry,
co~nercially available NaHS flakes (technical grade) were
charged to a reaction flask. This material is inherently
in the empirical hydrate form. Methanol was added to the
steam generator. Hydrogen agitation was used throughout,
with steam flow commencing at 220C. Analyses of the
resid and of the single distillate are shown below.
Ana~ysis
Hydro2en Nitro~en Sulfur
Resid 10.85% 0.44% 2.91%
Distillate 12.07% 0.18% ~.53%
Example X
A cracked resid and an alcoholic solution of
the empirical hydrate of K~IS (O.47 grams of KHS per
milliliter of solution) were charged to a reaction flask.
~itrogen agitation was used from ambient-temperature to
190C, at which point nitrogen flow was halted and steam
flow was commenced. At the end of the run, 13.3% of the
resid remained (in uncoked form) in the flask. The
single distillate was held at 100C to vaporize the
condensed water. Hydrocarbons vaporized with the water
were recovered and dried and are denominated the "Below
100C Cut." Analyses of the resid and of the two products
are shown below.
Analysis
Material H~ro~e_ Nltrogen Sulfur
~ ._
Resid 10.45%0.53% 3.33%
Below 100C Cut 12.55%<0.05% 1.91%
Over 100C Cut 11.84%0.2% 2.57%
. . _
-21-
_xam~le XI
Example X was repeated except that hydrogen,
and not nitrogen, was used from ambient temperature to
the final temperature of ~50C, wi-th minimal amounts of
steam. Analyses of the resid and of the three distillates
are shown below.
_ Anal,ysls
MaterialAmount Hydro~en Nitrogen Sulfur
Resld - 10.45% 0.53% 3.33%
Cut l20% of total 12.66% 0.08% 2.12%
distillate
Cut 230% of total 11.9B% 0.15% 2.34%
distillate
Cut 3S0% of total 11.6% 0.25% 2.2%
distillate
Example XII
Example XI was repeated except that commercial:Ly
available NaHS flakes (technical grade) were charged
directly to the reactor and methanol was added to the
steam generator, in~tead of using the alkanolic solution
of K~S. The NaHS flakes are inherently in the empirical
hydrate form. Analyses of the resid and of the two dis-
tillates are shown below.
Analy__s __
Material H~ Nitrogen Sulfur
Resid 10.45% 0.53% 3.33%
Cut l 12.3~% 0.07% 1.99%
Cut 2 11.79% 0.18% 2.1~%
Example XIII
One hundred twenty-five milliliters of a cracked,
desulfuri2ed resid, 1.8 grams of elemental sulfur, and 25
milliliters of an ethanol solution of the empirical
hydrate of KHS (O.24 grams of KHS per milliliter of
solution) were placed in a flat-bottom flask, which
rested on a hot plate and contained a magnetic stir bar.
The vessel contents were stirred rapidly and heated to
-22-
120~ to drive off the ethanol and water from the reagent
solu ion, and heat~ng continued. Steam flow was commenced
at 130C and continlled to the final temperature of 325C.
Analyses of th~ resid, o~ the two distillates, and of the
residue in the flask ar~ shown below.
, Analysis
_ Matèrial Amount~Iydroqen Nltrogen Sulfur
Resid 125 g 9.08% 0.45% 1.81%
Low-temp. Cut 57 ml 11.84% 0.06% 0.70%
High--temp. Cut - 9.77% 0.35% 1.91%
Resldue in flask - 8.75% 0.43% 1.91%
Example XIV
In this run, hydrogen sulfide was co-fed to a
two-stage reactor to treat a vacuum resid. Fifty milli-
liters of a methanol solution of potassium hydrosulide
empirical dihydrate (0.38 grams KHS/ml solution~ were
placed in the first reaction stage, a vertical, cylindrical
vessel with a total volume of approximately 1 liter and
equipped with a heating mantel. Twenty-five milliliters
of reagent solution were placed in the second reaction
stage, a round flas~, equipped with a heating mantel.
H2S gas fed to the first stage was introduced under the
surface of the liquid therein and near the bottom of the
vessel by a sparge tube. Similarly, vapor overhead from
the first stage was fed to the second stage under the
surface of the liquid therein by a sparge tube. Vapor
from the second stage was cooled and partially condensed
in a water-cooled unit.
At the start of the run, several hundred grams
of the vacuum resid were heated (so that the resid would
flow) and placed in an addition vessel directly above the
first-stage reactor. Some of the resid was permitted to
enter tha-t reactor, and both reactors were heated. At
the same time, the flow of steam, nitrogen, an~ hydrogen
sulfide into the first-stage reactor was commenced. The
H2S flow could not be measured, but it was estimated to
be 3 gram-moles/hour. As the temperature rose in the
~ 7 ~
~23-
first stage, the methanol and water of empirical hydration
added with the reagent distilled and entered the secp~d
stage, which was at 110C to prevent condensation of
water therein.
Reaction in the first stage commenced at approxi-
mately 370nC. Over the course of the run, the temperature
in the first stage rose from 370 to 390C and that in the
second stage from 110 to 270C. A total of 286 grams of
resid were added to the first stage durin~ the run, and
less than lD grams remained in the first stage a* the
end. Analyses of the vacuum resid, product retained in
the second reac-tion stage, and product collected from the
water-cooled unit are given below.
_ An_l~sis
Materlal Amount Hydrogen Nitro~en Sulfur
Vacuum Resid 286 g 10.04~ 0.64% 2.02%
Second-stage 57.1 g 11.22% 0.42% 1.48%
Product
Final Product186.5 g 12.99% 0.50% 1.19%
The final product had an initial boiling point of 23C,
and a peak dis-tillation temperature of 118C. Uncon-
densed product vapor was estimated to approximately
35 grams. The second-stage and final products were 17.4
and 50.4 degrees API at 60F, respectively, compared to
6.0 for the vacuum resid. Metals content are given below
(figures are in parts per million; "N/DI' indicates none
detectable).
Analvs i s
.
Material Na V K Fe Ni
Vacuum Re~id 2.6 102 2.3 24 62
- Second-stage 0.35 N/D 2 9 N/D N/D
Product
Final Product 1.6 N/D 46 0.93 N/D
Example X
Shale oil was treated in the first-stage reactor
of Example XIV using a methanol solution o~ the empirical
~ :~ 6 ~
-24~
hydrate of KHS, steam, and nitrogen, but no H2S. Analyses
of the shale oil, products, and residue in the reactor
are given below.
Analysis__
MaterialAmount Hy~ Nitro~en Sulfur
Shale Oil 200 g 9.90% 1.45% 6.23%
Below 280C Cut 22 g 10.33% 1.16% 6.85%
280 - 300C Cu~35 ~ 10.59% 0.95% 6.80%
Residue 100 g 8.33% 1.47% 5.76%
By difference, uncondensed volatiles total approximately
43 grams. Metals content axe given below (unless otherwise
noted, figures in parts per million; "N/D" indicates none
detectable).
_ Analysis
~aterialNa V K Fe Ni Ca
Shale Oil ll 124 64 106 86 1223
Below 280C Cut 1.2 5 5 N/D 20
280 - 300C Cut0.61 l9 4.6 N/D N/D
Re~idue 21 56 2.89% 34 565
Exam~
A heavy crude oil of 10.5 degrees ~PI at 60F
was treated with reagent, steam, and hydrogen sulfide
using the apparatus and procedure of Example XIV, except
that th~ second-stage reactor was not used and 100 milli-
liters of reagent solution were employed. A single
product wa~ obtained at 370 - 390C. Analyses of the
crude oil and product are given below. At the end oE the
run less than 2 p0rcent of the crude oil remained in the
reactor.
_ _ Analysis
MaterlalHydrogen Nitrogen Sulfur
Crude Oil10,80% 0.40% 4.42%
Product11.69% 0.13% 3.15%
The product was 24.3 degrees API at 60F and had an
initial boiling point of 110C and an end point (97%
~ ~ 64t~
-25
recovery) of 360C. Metals content are given below
(figures in parts per million; "N/D" indicates none
. detectable).
: Anal sis
. _ X~
Material Na V K Fe Ni
. . _
Crude Oil 5 203 3 6 99
Product o. 06 N/D N/D 0.66 N/D
Many variations and modifications will be
apparent to one skilled in the art and the claims are
intended to cover all variations and modifications that
fall within the true spirit and scope of this invention.
