close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3091595

код для вставки
rice
Uted States atent
3,091,585
Patented May 28, 1963
2
1
Another object of this invention is to provide a process
for removing odoriferous materials from petroleum frac
tions by treatment with an aqueous alkali metal hydroxide
3,091,585
METHOD OF PREPARING PETROLEUM FRAC
TIONS OF IMPROVED ODOR USING ?-LAC
solution and a {i-lactone.
These and further objects of the invention will become
TONES
George W. Ayers, Chicago, and William A; Krewer,
Arlington Heights, IlL, assignors to The Pure Oil Com
pany, Chicago, IlL, a corporation of Ohio
No Drawing. Filed May 3, 1961, Ser. No. 120,456
20 Claims. (Cl. 208—199)
apparent as the speci?cation herein proceeds.
This invention is directed to the use of the combina
tion of a ?-lactone and caustic solution in removing
odoriferous substances from certain petroleum fractions.
10 The B-lactones which are used have the reactive nucleus
This invention relates to the preparation of petroleum
fractions of improved odor and, more particularly, to the
use of ?-lactones in improving the odor of distillate fur
0-— :0
with the free valences preferably satis?ed by hydrogen
The presence of appreciable quantities of mercaptans 15 or hydrocarbon radicals such as alkyl, cycloalkyl, aryl
nace oils.
'
in distillate furnace oils, or components thereof, obtained
from many crude oils, is undesirable due to their very
objectionable odors. The odors of such petroleum frac
tions must be improved before they are suitable for
or alkaryl radicals. More speci?cally, it is preferred
that the hydrocarbon radicals contain 1 to 10 carbon
atoms. Non-limting examples of compounds coming
within the scope of the foregoing formula and de?nition
marketing. The odors are improved either by removing 20
the mercaptans from the oils or by converting them into
?-Propiolactone
substances having lower odor-imparting characteristics.
?-Butyrolactone ( ?-methyl-?-propiolactone)
One of the well-known processes for converting these ob~
B-Methyl-B-butyrolactone (B-p-dimethyl-?-propiolactone)
jectional substances to less obnoxious compounds is
“doctor treatment.” In this sweetening process, the 25 ?-Ethyl-?-butyrolactone
?-Phenyl-B-propiolactone
odorous petroleum fraction is treated withan aqueous
solution of an alkali metal hydroxide containing sodium
_ The ?-lactone reacts especially with tertiary mercap
plumbite and elementary sulfur. The mercaptans are
tans, such as aromatic mercaptans of the thiophenol type,
converted into disul?des, which have much lower odor
in the presence of the alkali solution. The mercaptans
30
are:
imparting properties, and the doctor-treated petroleum
.
are converted into water-soluble substances, thus lower
ing the sulfur content of the petroleum fraction. The re
fraction exhibits a great improvement in odor. The
amount of elementary sulfur used in doctor treatment is
rigidly controlled so that barely enough sulfur is present
to obtain precipitation, or “break,” of lead sul?de from
the petroleum fraction and conversion of mercaptans into
disul?des. The settling of the dark-colored material
from the petroleum fractions leaves a clear “sweetened”
action proceeds as represented by the following equation:
our-on,
|
A}
+ ormsn + mon --,
o-- =0
?-Propiolactone Phenylmer- Sodium
captan (thio- hydroxide
phenol)
product of good odor. The principal disadvantages of
0
the doctor treatment are that the sulfur content of the
%
CuHs-S-OHrCHz-O
+ H2O
product oil is essentially the same as that of the untreated 40
oil, and that extreme care must be exercised not to use
O-Nd
excess sulfur or the product oil will be corrosive to metals
Sodium phenylmercaptopropionate Water
such as copper and hence unsuitable for marketing. In
The B-lactones show a negligible reactivity with the mer
addition, in the case of certain very odorous petroleum
captans unless a caustic solution is present. The ?-lac
fractions, extreme difficulty is experienced in obtaining 45 tone and caustic may be added to the petroleum fraction
the “break” even when an undesirable excess of sulfur is
present, and a long time interval may be required.
In accordance with the present invention, it has been
found that the odor of furnace oils is improved by
treatment with a ?-lactone and an alkali metal hydroxide.
It has been found that in treating odoriferous furnace oils
with an aqueous alkali metal hydroxide solution and a
,B-lactone, a portion of the obnoxious sulfur compounds
which imparts odors to the oils is removed and there is
a decrease in the total sulfur content of the treated oils.
It has also been found that a preliminary treatment of
exceedingly odoriferous petroleum fractions with a p
lactone and an aqueous alkali metal hydroxide solution
signi?cantly reduces the time required for the doctor
“break,” as well as the sulfur requirement, during a sub
sequent doctor treatment. As an alternative method of
application, the B-lactone may be added to the doctor so
lution. Other methods of application will become ap—
parent from a further description of this invention.
Accordingly, it is a primary object of this invention to
provide a process of preparing a petroleum fraction of
improved odor.
Another object of this invention is to provide a process
for sweetening furnace oils.
Another object of this invention is to provide a re
duction in the time and elementary sulfur requirements
for doctor-treating petroleum fractions.
simultaneously or separately. It is preferred that the t3
lactone not be added to the caustic solution prior to the
caustic solution being added to the petroleum fraction
50 since the lactone will also react with it to give, with #
propiolactone for example, sodium hydracrylate. This
reaction is less rapid than the reaction with the mercap
tans. If the [i-propiolactone is added to the caustic so
lution for any appreciable length of time prior to its use
55 in treating the sour petroleum fraction, appreciable
amounts of the ?-lactone will be lost in the reaction with
the caustic solution.
The amount of the ,B-lactone used per amount of ‘pe
troleum fraction will depend uponv the amount of the
60 reactive odoriferous mercaptans present in the petroleum
fraction to be treated.
At least a st'oichiometric amount
of the p-lactone to react with the active mercaptans
present in the petroleum fraction should be used. An ex
cess over the stoichiornetric amount is recommended.
65
A temperature of about 150° to 230° F. is preferred
during the treatment of the oil with the B-lactone and
aqueous caustic solution. Other temperatures may
be used, but temperatures lower than about 150° F. will
require longer contact periods than are considered prac
70 tical. A contact time of about one to ten minutes is
effective at temperatures of about 150° to 230° F. The
method of contacting may be mechanical or by turbulent
so G91,
85
4
3
?ow. The process of this invention may be conducted
batchwise as well as continuously.
At least a stoichiometric amount of the caustic soda
is added preferably as a 1 to 25% aqueous solution, al
move any remaining alkali. The treated oil had a greatly
improved odor and was marketable.
though other concentrations may be used. Although
sodium hydroxide is preferred because of its cheapness,
other alkali metal hydroxides, such as potassium hy
One hundred grams of untreated furnace oil (boiling
range similar to that of the furnace oil used in Example
1), containing 0.93% total sulfur and 0.046% mercaptan
sulfur, and of very poor odor quality, was treated with
10 grams of 20% sodium hydroxide solution and 3.6
grams of ?-propiolactone at 230° F. for ?ve minutes with
mechanical stirring. After the mixture had cooled to
room temperature, the oil phase was separated and water~
washed to neutrality. The odor of the oil was signi?
cantly improved, but the oil was not doctor-sweet. The
droxide or lithium hydroxide, or any combination of these
three alkali metal hydroxides, may be used. The caustic
solution may be used repeatedly, (1) with periodic addi
tions of fresh caustic, until the accumulation of salts
necessitates discarding the solution, or (2) with continu
Example 111
ous or periodic additions of fresh caustic (or caustic
solution) with continuous or periodic withdrawals of
equivalent volumes of the used caustic solution.
15 oil was then treated with an excess of doctor solution,
and 0.014 gram of sulfur, an amount just sufficient to
If the B-lact-one is added during the doctor treatment
instead of being used in a preliminary treatment with an
obtain a break of the doctor sludge.
The break was com—
plete within about two minutes. The odor of the doctor
sweet treated oil was very satisfactory and the product
one mole of B-lactone should be used per mole of mer
captan present in the oil to be treated. This is preferred 20 was suitable for marketing.
Another 100-gram sample of the furnace oil was agi
to prevent rapid fouling of the doctor solution with alkali
tated with a large excess of doctor solution while 3.6
metal salts which are not removed by the usual methods
grams of B-propiolactone were added slowly. After
of regeneration of the doctor solution.
about three minutes, sulfur was added in small increments
The petroleum fractions that can be treated successfully
in accordance with this invention include those that con 25 until a break was obtained. Sixteen-thousandths of one
aqueousalkali metal hydroxid solution, not more than
tain tertiary mercaptans, particularly aromatic mercap
gram of sulfur was added to obtain a break in about two
minutes. The product separated was doctor-sweet, of
tans of thiophenolic type and other mercaptans not of
greatly improved odor, and marketable.
the primary or secondary types, as an appreciable part
A third 100-gram sample of the furnace oil was treated
of their mercaptan content. Virgin and cracked petro
leum fractions boiling in the range of approximately 300° 30 with an excess of doctor solution and with elementary
sulfur after a preliminary treatment with 20 grams of
F. to 700° F. are especially susceptible to treatment in
20% sodium hydroxide solution for one hour at 230° F.
accordance with this invention. The present invention is
In the doctor treatment, 0.025 gram of sulfur was required
also specially applicable to those petroleum fractions
to obtain a break which was not complete until after
with which di?iculty is experienced in obtaining breakout
35 about two hours. The odor of the doctor-sweet product
of doctor sludge during doctor treating.
was satisfactory and it was marketable.
In order to demonstrate the invention, the following
examples are presented:
Example IV
Example I
One hundred grams of very sour, poor-odor-quality,
untreated V.M. & P. naphtha (236—289° F. boiling
A 100-gram sample of a poor-odor-quality furnace-oil 40 range), containing alkyl mercaptans mainly of primary
stock (352—550° F. boiling range), obtained from a mix
and/or secondary types, was treated with 3.6 grams of
ture of western sour crude oils and containing 0.05%
B-propiolactone and 10 grams of 20% sodium hydroxide
mercaptan sulfur and 0.53% total sulfur, was treated
solution under the conditions described in Example I.
with 10 grams of 20% sodium hydroxide solution and
45 The odor of the product was unpleasant, rendering it
3.6 grams of ?-propiolactone at 230° F. for one hour
with mechanical stirring. After this treatment, the mix
ture was cooled to room temperature and the oil and
aqueous phases were separated. Following this, the oil
unmarketable as a naphtha.
Another portion of the un
treated V.M. & P. naphtha was subjected to similar treat
ment except that ?-propiolactone Was added slowly over
a 45-minute period. The odor quality of the naphtha was
was water~washed until the washings were no longer basic.
not improved by this treatment.
The washed product was found to show a great improve 50
This example demonstrates that the process of this in
ment in odor quality and was very suitable for marketing.
vention is not e?ective in improving the odor of certain
Another portion of the furnace oil was treated in a
petroleum fractions. The sour V.M. & P. naphtha, which
like manner except that the contacting was done at room
contained mercaptans mainly of primary and secondary
temperature. The odor of the product was inferior to
types, was not noticeably improved in odor when it was
that of the product of the ?rst treatment, but was suit 55 treated in accordance with this invention.
able for marketing.
The embodiments of the invention‘ in which an exclu
Another 100 grams of poor-odor-quality furnace-oil
sive property or privilege is claimed are de?ned as
stock was treated under similar conditions except the
follows:
B-propiolactone was omitted. This treatment had little
1. A method of preparing a petroleum fraction of im
60
or no effect on the odor quality of the furnace-oil stock.
A similar treatment'of 100 grams of the furnace-oil
stock was conducted except the sodium hydroxide was
proved odor, which comprises treating a mercaptan-con
tai-ning petroleum fraction with a reagent consisting essen
tially of a ?-lactone and an aqueous solution containing
omitted. This treatment was without effect on the odor
an alkali metal hydroxide.
quality and the product remained unmarketable.
2. A method in accordance with claim 1 wherein said
65
Example 11
?-lactone has the reactive nucleus:
A 100-gram sample of cycle stock (442-625 ° F. boil
ing range), having a very obnoxious odor and containing
0.007% mercaptan sulfur and 1.01% total sulfur, was 70 with the free valences satis?ed by the same or different
treated with two grams of 20% sodium hydroxide solu
substituent radicals selected from the group consisting of
tion and 0.7 gram of ?-propiolactone at 230° F. for 15
hydrogen and hydrocarbon radicals containing 1 to 10
minutes with mechanical stirring. The oil and aqueous
carbon atoms.
phases were then'separated after the mixture had cooled
3. A method in accordance with claim 2 wherein said
to room temperature. The oil was water-washed to re 7 ,8~lactone is ?-propiolactone.
<'>_<';=0
3,091,585
6
5
improved odor, which comprises treating a mercaptan
containing petroleum fraction containing tertiary mer
4. A method in accordance with claim 1 wherein said
alkali metal hydroxide is present in said aqueous solu
tion in an amount included in the range of about 1 to
captans as an appreciable proportion of its mercaptan
content with a reagent consisting essentially of a ,B-lactone
25% by weight.
having the reactive nucleus:
5. A method in accordance with claim 1 wherein the
treatment is conducted at a temperature of at least
_t_é_
l I
150° F.
6. A method in accordance with claim 1 wherein said
petroleum fraction boils within the range of approxi
O—O=O
with the free valances satis?ed by the same or di?erent
mately 300° F. to 700° F. and contains tertiary mer 10 sulbstituent radicals selected from the group consisting of
captans as an appreciable proportion of its mercaptan
hydrogen [and hydrocarbon radicals containing 1 to 10
content.
carbon atoms, in the presence of an aqueous solution
7. A method in accordance with claim 6 wherein said
containing from about 1 to 25% by weight of an alkali
tertiary mercapta-ns are aromatic mercaptans of the thio
metal hydroxide, said n-lactone and alkali metal hydrox
15 ide being used in amount at least equivalent to the ter
phenol type.
8. In a method of preparing a doctor-sweet petroleum
tiary mercaptan content of said petroleum fraction, for
fraction of improved odor wherein a mercaptan-contain
a period of time su?icient to produce a petroleum frac
ing petroleum ‘fraction is treated with doctor solution and
tion of improved odor.
18. In a method of preparing a doctor-sweet petroleum
narily treating said petroleum fraction with a reagent con 20 fraction of improved odor wherein a mercaptamcontain
sisting essentially of a B-lactone and an aqueous solution
ing petroleum fraction containing tertiary mercaptans as
containing an‘ alkali metal hydroxide.
an appreciable proportion of its mercaptan content is
9. A method in accordance with claim 8 wherein said
treated with doctor solution and elementary sulfur, the
?-lactone has the reactive nucleus:
improvement comprising preliminary treating said petro
25
leum fraction with a reagent consisting essentially of a
elementary sulfur, the improvement comprising prelimi
,B-lactone having the reactive nucleus:
with the free valences satis?ed by the same or di?erent
substituent radicals selected from the group consisting of 30
with the free valances satis?ed by the same or diiierent
hydrogen and hydrocarbon radicals containing 1 to 10
substituent radicals selected from the group consisting of
carbon atoms.
hydrogen and hydrocarbon radicals containing 1 to 10
10. A method in‘ accordance with claim 9 wherein said
?-lactone is ?-propiolactone.
carbon atoms, in the presence of an aqueous solution
11. A method in accordance with claim 8 wherein said 35 containing from about 1 to 25% by weight of an alkali
metal hydroxide, said IS-lactone and alkali metal hydrox
alkali metal hydroxide is present in said aqueous solution
ide being used in amounts at least equivalent to the ter
tiary mercaptan content of said petroleum fraction, for
a period of time su?icient to produce a petroleum frac
12. A method in accordance with claim 8 wherein said
preliminary treatment is conducted at a temperature of at 40 tion of improved odor.
19. In a method of preparing a doctor~sweet petroleum
least 150° F.
fraction‘ of improved odor wherein a mercaptan-contain
13. A method in‘ accordance with claim 8 wherein said
ing petroleum fraction containing tertiary mercaptans as
petroleum fraction boils within the range of approxi
an appreciable proportion of its mercaptan content is
mately 300° F. to 700° F. and contains tertiary mer
captans as an appreciable proportion of its mercaptan 45 treated with a doctor solution and elementary sulfur, the
improvement comprising adding to said doctor solution
content.
a ?-lactone having the reactive nucleus:
14. A method in accordance with claim 13 wherein
said tertiary menoaptans are aromatic mercaptans of the
in an amount included in the range of about 1 to 25%
by weight.
thiophenol type.
15. In a method of preparing a doctor-sweet petroleum 50
fraction of improved odor wherein a mercaptan-contain
with the free valances satis?ed by the same or diiferent
ing petroleum fraction is treated with a doctor solution
substituent radicals selected from the group consisting of
and elementary sulfur, the improvement comprising add
hydrogen and hydrocarbon radicals containing 1 to 10
ing to said doctor solution a reagent consisting essentially 55 carbon atoms, said ,B-lactone being used in an amount
of a B-lactone.
such that the mole ratio of B-lactone to mercaptan's is
16. A method in accordance with claim 15 wherein
not ‘greater than 1:1.
said B-lactone has the reactive nucleus:
.20. A method in accordance with claim 16 wherein
said B-lactone is ?-propiolactone.
60
with the free valences satis?ed by the same or di?erent
substituent radicals selected from the group consisting of
References Cited in the ?le of this patent
UNITED STATES PATENTS
2,316,759
hydrogen and hydrocarbon radicals containing 1 to 10 65 2,831,905
2,946,744
carbon atoms.
17. A method of preparing a petroleum traction of
2,952,627
Bond _______________ __ Apr. 20, 1943
Nelson ______________ .._ Apr. 22, 1958
Ayers et a1. __________ __ July 26, 1960
Rippie
-----------
sept- 13, 1960
Документ
Категория
Без категории
Просмотров
0
Размер файла
500 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа