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2,413,312
Patented Dec. 31, 19.46
UNITED STATES PATENT OFFICE
2.413.312
CATALYTIC FINISHING 0F GASOLINES
Robert M. Cole, Oakland, Calif” assignor to Shell
Development Company, San Francisco, __Calif.,
a corporation of Delaware
No Drawing.
Application January ‘26, 1945,
Serial No. 574,755
5 Claims. (Cl. 196-28)
1
This invention relates to the treatment of
thermally cracked gasolines, catalytically cracked
gasolines, thermally reformed gasolines, and sim
ilar materials of the gasoline boiling range con
taining substantial amounts of ole?ns and other
unsaturated bodies and other impurities such as
sulfur compounds, nitrogen compounds, etc., to
2
contain appreciable amounts of sulfur compounds,
nitrogen compounds, and other impurities. They
have poor color stability, poor gum stability and
poor lead susceptibility. Consequently these
stocks generallywrequire some sort of ?nishing
treatment to make them acceptable for use'in
gasoline of present-day quality. The conven
effect a substantial desulfurization and to remove
or render innocuous various gum-forming bodies.‘
tional method of re?ning these materials is the
an improved process for the treatment of various
saturated blending materials for premium grade
conventional sulfuric acid treatment followed by
More particularly the invention relates to the 10 a Doctor treatment and rerunning. This method
treatment of such materials by the combined
has the recognized disadvantages of incomplete
action of hydrogen and catalysts under such con
sulfur removal, high acid consumption, poor
ditions and in such a manner as to afford the V yields, and an appreciable depreciation of anti
desired ?nishing or re?ning treatment with a
knock properties. In view of these disadvan
minimum loss of material, minimum consumption 15 tages considerable attention has been given to
of hydrogen and with substantially no deprecia
the catalytic ?nishing of such materials by cata
tion of the anti-knock characteristics of the orig
lytic hydrogenation. Certain such processes have '
inal material.
been proposed. However, the proposed processes ‘_
In my copending application Serial No. 569,234,
have certain disadvantages and furthermore are
?led December 21, 1944, of which this applica 20 too costly to make their use economical except
tion is a continuation-in-part, I have described
in the special case of preparation of substantially
sulfur-bearing gasoline stocks including various
cracked and reformed stocks with hydrogen for
aviation gasoline.
.
The present process provides a means for ef
the primary purpose of effecting desulfurization 25 fecting excellent desulfurization and re?ning
thereof without loss of anti-knock properties.
while a?'ording a. product of excellent anti-knock
The process of said copending application is re
characteristics. These desirable results are fur
stricted to the treatment of such stocks as con
thermore obtained with a minimum consumption
tain more than 0.10% sulfur and is restricted to
of hydrogen and with improved catalyst life.
the use of particular catalysts. The process of v30 Consequently the process of the invention is ap
the present invention is an improved process
plicable and particularly advantageous for the
directed speci?caliy to the treatment of unsatu
catalytic ?nishing of motor gasolines of substan
rated gasoline fractions such in particular as
tially full boiling range and similar ‘non-premium
cracked and reformed gasolines in a different and
products.
particular manner to achieve the above men 35 . The process of the invention in its broader
tioned objects. The material treated may or may
more general aspect comprises treating the gaso
not contain more than 0.10% sulfur. Also, other
line in the presence of an excess of hydrogen
catalysts than those speci?ed in the above men
_ and a sulf-active hydrogenation catalyst at a
tioned copending application may be used. When
temperature between about 400° F. and 825° F.
treating such cracked stocks containing more 40 under conditions adjusted to give only a partial
than 0.10% sulfur with the particular catalysts
speci?ed in said copending application according
to the process of the present invention, however,
the process depends in part upon the principles
disclosed in said copending application.
Gasolines produced by thermal cracking, gaso
lines produced by catalytic cracking, and gasolines
produced by thermal reforming of various gaso
line stocks usually have the following character
istics: They contain appreciable quantities of
desulfurization and to hydrogenate only a minor
part of the ole?ns, separating- the partially de
sulfurized material into a lower boiling fraction
and a higher boiling fraction, treating the'higher
boiling fraction in the presence of an excess of
hydrogen and a sulf-active hydrogenation-dehy
drogenation catalyst at a temperature between
about 850° F. and 1000° F. under conditions ad
justed to effect substantial desulfurization and
substantial saturation of ole?ns, and blending
ole?ns and other unsaturated bodies and con
the ‘product of the latter treatment with the lower
sequently have a high bromine number and high
boiling fraction to produce an ole?n-containing
acid heat. They contain appreciable quantities
desulfurized‘?nished gasoline having an octane
of aromatics and naphthenes. They have rela
number at least as high as that of the original
tively good anti-knock characteristics. They 55 starting material. In a more speci?c embodi
-
'
2,413,812
I
ment of the process at least the major portion
of the hydrogen required for the ?rst, or low
temperature, treating step is obtained from the
second, or high temperature, treating step. In
a further more particular embodiment the con
4
300-400° F. fraction of the product is 0.10% or
slightly below 0.10%. The ?rst index is prefer
ably used when a catalyst other than a sul?de of
a metal of the iron group is used in the second,
or high temperature, treatment and the second
index is preferably used when the catalyst in the
second, or high temperature, treatment is a sul
ditions in the ?rst, or low temperature, treating
step and the cut point in the separation are
?de of a metal of the iron group.
adjusted such that the higher boiling fraction
The partially desulfurized material from the
of the product 01' the ?rst step contains in the
order of 0.10% sulfur and catalysts of a particular 10 above-described low temperature treatment is
separated into a lower boiling ole?nie fraction
type are employed in the second, or high tem
and a higher boiling ole?nic fraction. The sep.
perature, treating step. '
aration may be effected at any convenient point
The process is generally applicable for the cat
according to. the character of the material, but
alytic ?nishing of various sulfur and ole?n-con
the split between the fraction is preferably made
taining distillates such as motor gasolines ob
between 200° F. and 300“ F. When employing a
tained from thermalcracking, thermal reform
sul?de of a'metal of the iron group as the catalyst
ing, catalytic cracking and similar high temper
ature treatments, and is designed to re?ne or ?n-v _ in the second, or high temperature, treatment the
split is preferably made such that the higher
ish such materials to the extent of e?ecting a
substantial desulfurization and rendering them 20 bo’ling fraction contains about 0.10% sulfur.
Otherwise the split is preferably made at the
acceptable with respect to such properties as lead
higher end of the range consistent with a satis
susceptibility, gum-forming tendency and color.
factory sulfur content of the lower boiling frac
The treatment,- however, is not designed to give a
tions.
substantially saturated product having a low acid
The higher boiling fraction is then treated with
heat and is not recommended for the production
an excess of hydrogen and a sulf-active hydro
or premium grade aviation gasoline. On the oth
genat’on-dehydrogenation catalyst at a tempera_
er hand, the treatment is designed to produce
turein the range of 850° F. and 1000" F. A large
stable acceptable products having large amounts
excess of hydrogen such as from 5 to 30 moles per
of ole?ns, such as desired for motor gasoline.
mole of hydrocarbon is recommended. The pres
The material treated may be a full range gaso
sure is usually between about 500 and 1100 p. s. i.
line or it may be a gasoline blending stock boiling
The catalyst used in this step may be any one of
essentially in the gasoline boiling range.
the known suit-active hydrogenation-dehydro
The material to be treated is ?rst mixed with a
genation catalysts. However, in order to a?ord
large excess of hydrogen and subjected to a very
a substantially continuous operation a sul?de cat
mild desuli'urization-hydrogenation treatment in
alyst is preferred. Particularly suitable catalysts
the presence of a sulf-active hydrogenation cat
comprise a sul?de of a metal of the iron group,
alyst. In general the amount of ‘hydrogen em
if desired in combination with a sul?de of a
ployed is between about 5 and 30 moles per mole
metal of group VI of the periodic system of the
of the hydrocarbon feed. The pressure is usu
elements. Examples of such catalysts are nickel
ally between about 200 and 1000 p. s. 1. Any of 40
sul?de, iron sul?de and cobalt sul?de, alone and
the many known sulf-active hydrogenation cat
in combination with sul?des of molybdenum or
alysts may be employed in this step. Examples
tungsten. These catalysts may be used substan
of such suitable catalysts are the oxides and sul
tially continuously in the present process for hun
?des of V, Cr, Mn, Fe, Co, Ni, Mo, W. The tem
dreds of hours without regeneration. Further
perature in this step is maintained between about
more, they are particularly e?lcient in e?ecting
400° F. and 825° F. Within this temperature
reactions leading to the production of increased
range the lower temperatures consistent with the
amounts of aromatic hydrocarbons in the prod
activity of the catalyst and the other treating
uct. When using these preferred catalysts the
conditions are preferred. Thus, in general, with
?rst,‘ or low temperature, treatment and/or the
a catalyst of average activitya temperature in
fractionation are adjusted so that the feed to
the neighborhood of 500-600° F. is generally pre
the second, or high temperature, treatment con
ferred. Under these conditions the material tends' . tains not more than about 0.10% sulfur.
to become completely hydrogenated to a satu
The high temperature treatment is carried out
rated non-aromatic product of-low octane num- ,
.ber. This is prevented, however, by e?ecting the
treatment ~at such a rate that only a super?cial
hydrogenation is e?ected. This super?cial hy
relatively slowly, liquid hourly space velocities in
the'order of 0.5 to 3 being typical. Under these
conditions the ole?ns are substantially hydro
genated, further desulfurization is e?ected, and
considerable dehydrogenation of hydroaromatic
drogenation under these relatively drastic condi
tions effects a substantially complete removal of
naphthenes takes place.
gum and color-forming bodies and e?ects a par 60 In the second, or high temperature treatment
tial removal of sulfur compounds and nitrogen
appreciable amounts of hydrogen are produced by
compounds, but hydrogenates only a small
the dehydrogenation of naphthenic constituents.
amount of_ the ole?ns present and does not at
tack the aromatic hydrocarbons at all. The ex- ' This hydrogen provides a considerable portion of
tent of this treatment is adjusted, preferably by 65 the hydrogen required for the treatment andin
some cases may supply hydrogen also for the ?rst,
controlling the throughput rate and/or the tem
or low temperature, treatment. The hydrogen
perature to one of the following criteria or in
gas recycled to the treatments to maintain the
dexes of treatment, depending upon the sulfur
desired excess hydrogen may be treated by con
content of the feed stock, the cut point in the
following separation, and the type of catalyst
used in the second, or high temperature, treating
step. (1) The conditions are adjusted such that
the sulfur content of the IOU-300° F. fraction of
-the product is about 0.10%. (2) The conditions
are adjusted such that the sulfur content of the 75
ventional methods to remove the hydrogen sul
?de formed in the process. An advantageous
cycle is, for example, to pass the hydrogen gas
separated from the product of the second, or high
temperature, treatment to the ?rst. or low tem
perature, treatment; treat the hydrogen gas sep
2,418,812
arated from the‘ low temperature treatment to
remove hydrogen sul?de; and to cycle the hy- I:
drogen from the hydrogen sul?de removal step
to the second, or high temperature, treatment.
. 6
_
_
oi’ the feed under the higher temperature condi
tions as in step 2, (5) treating the lower boiling
material alone as in step 1 and treating the higher
boiling material alone as in step 2.
When operating in this manner, it is advanta
I claim as my invention:
1
geous to add any fresh hydrogen required to the
1. Process for the catalytic ?nishing of sulfur
second, or high temperature, cycle.
containing ole?nic gasolines which comprises
The product of the high temperature treatment
treating
the gasoline in the presence of an excess
is reblended with the lower boiling fraction. The
hydrogen and a sulf-active hydrogenation cat
blend, ‘or the separate fractions, may be caustic 10 of
alyst at a temperature between about 400° F. and
washed to remove traces of hydrogen sul?de.
825°
F. under conditions chosen to e?‘ect only a
The blended product normally meets all of the
partial desuliurization and to hydrogenate only
usual requirement regarding gum stability, color,
a minor part of the ole?ns, separating said par
etc. It has an octane number (A. S. T. M.) at
tially
desulfurized material into a lower boiling
least as good as that of the original feed and 15
ole?nic fraction and a higher boiling ole?nic ‘
usually considerably better. Also the lead sus
ceptibility is greatly improved. The hydrogen
fraction, treating said higher boiling fraction in
the presence of an excess of hydrogen and a
consumption-is generally very small since only a
suit-active
hydrogenation-dehydrogenation cat
portion of the ole?ns 'are saturated. The yield
oiproduct, based on the feed, is in the order of 20 alyst at a temperature between about 850° F. and
1000° F. under conditions chosen to effect sub
96-99%.
stantial further desulfurization and substantial
It will be noted that in the above-described _ saturation
oi.’ ole?ns, and blending the product
process the higher boiling portion of the feed is
of said second treatment with said lower boiling
treated twice under different conditions. The
fraction‘ to produce a re?ned ole?nlc gasoline
?rst treatment of this material is e?ected at a low 25 having an octane number at least as high as the
temperature in the presence of the lower boiling
original‘starting material.
/
portion of the feed and the second is e?ected at a
2.
Process
according
to
claim
1
in which a
higher temperature in the absence of the lower
sul?de
01'
a
metal
of
the
iron
group
is employed
boiling portion of the feed. This particular man
as a catalyst in the second or higher temperature
ner of operation is found to give results which 30 treatment.
are much superior to various alternative one and
3. Process according to claim 1 in which a com
two step processes such, for example, as the fol
bination nickel sul?de-tungsten sul?de catalyst
lowing: (1) treating all of the material under the
is employed in the second or higher temperature
low temperature conditions as in step one, (2)
treatment.
treating all of the material under the high tem 35
4. Process according to claim 1 in which the
perature conditions as in step 2, (3) treating all
split between the lower and the higher boiling
of the material under the low temperature condi
fractions is made between 200° F. and 300° F.
tions as in step 1 followed by treating all the ma
5. Process according to claim 1 in which the
terial under the high temperature conditions as
severity in the ?rst or lower temperature treat- '
in step 2, (4) treating the higher boiling portion 40 mentis
adjusted so that the sulfur content of the ,
of the feed under the low temperature conditions _
higher
boiling
fraction is about 0.10%.
as in step 1 and treating the lower boiling portion
‘
ROBERT M. COLE.
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