close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2115781

код для вставки
Patented May 3, 1938
2,115,781
UNITED STATES PATENT OFFICE- ~
PROCESS FOR THE TREATMENT OF STORED
CRACKED GASOLINE
.
Jacque C. Morrell, Chicago, Ill., assignor to Uni
versal Oil Products Company, Chicago, 111., a
corporation of Delaware
No
>
Application November 12, 1984,
Serial No. 752,707
'1 Claim.
a
(01. ‘196-43) '
This invention relates more particularly to the
cracked and the conditions of cracking'in the case
treatment of unstable gasolines whose ‘properties 'of cracked gasolines._ The presence of relatively
have deteriorated on storage due to oxidation, small quantities of nitrogen, sulfur and oxygen
polymerization and other reactions among their‘ derivatives of hydrocarbons may also in?uence
constituents, the present application being a con
the rate of deterioration. In re?nery practice it 5
tinuation in part of my earlier applicationSerial may be most economical to produce and store con-'
No. 406,514 ?led Nov. 11, 1929.
siderable quantities of motor fuel during the
It has been observed that when motor fuels or seasons when consumption of gasoline is low, so
gasolines are stored, particularly cracked gaso
that it frequently happens that stocks are stored
10 lines, and especially under the in?uence-of light
for abnormally longperiods. In such cases con- 10
and oxygen, chemical changes occur which a?ect siderable deterioration may ensue, particularly if
color, increase the gum formation, and reduce the storage tanks are not full and there is con
the anti-knock properties. The chemistry of siderable “breathing" in the vapor space above the
these changes is somewhat obscure, although in - oil. The present process comprises a method of - .
15 practically all cases oxidation promotes these de
treatment for restoring as far as possible the 15
preciatin'g effects which occur upon storage. valuable properties of motor fuels which have been .
Cracked gasolines contain a relatively high per
centage of unsaturated hydrocarbons, and it is
_ believed that the changes whichoccur in the
20 properties of the motor fuel during storage are re
25
lated to chemical changes in these unsaturated
hydrocarbons, especially in the more highly ‘un
saturated groups, for example, the diole?ns.
The formation of color in gasoline is undesirable
because changes in color are‘usually accompanied
by the formation of gum and tar-like substances
which affect not only the sales value of the motor
fuel, but also its performance in the operation‘of
the motor, particularly in clogging up the gasoline
feed lines, the moving parts of the carburetor and
causing the sticking of valves in the motor. The
development of more intense coloration is very
undesirable from a sales standpoint as a small
~ change in intensity makes a great di?erence in
lost on storage.
,
.
In one speci?c embodiment the present inven
tion comprises the treatment of materially de
teriorated motor fuels with selected inorganic 20
salts having a reducing action. The saltsmay be
used either as solids or in solution.
>
'
'
A large amount of experimental and analytical 7
work has shown the approximate course of the re
actions which lead ultimately to the loss in color 25 ‘
and anti-knock value and the increase'in gums
commonly observed in anti-knock 'motor fuels
which ‘have'been stored for considerable periods
of time. It is .quite well established that the
-'primary reaction which instigates the later‘ 30
changes consists in the addition of oxygen to
ole?ns containing conjugated double bonds" to
form organic peroxides. At ?rst the formation of
these compounds is relatively-slow but as they
accumulate and their total percentage exceeds 35
The anti-knock property of a gasoline is among some de?nite value, the rate of formation is con
‘its most important and valuable characteristics -. siderably accelerated-so that the process becomes
whichehave a tendency to depreciate under aver
autocatalytic and not only hastens the formation
age storage conditions in re?neries. Knocking of further quantities of peroxides but exerts, a
40
in a motor is evidenced by a pinging metallic pronounced polymerizing e?ect upon ole?ns and 40
35 the appearance of gasoline in glass pump bowls.
' sound which is accompanied by a reduction in the
‘other polymerizable compounds. In addition,
there may be a morede?nite oxidizing action lead
per gallon of the fuel. The use of agents or kinds ing to the‘ production of relatively stable dom-v
e?iciency of the motor and in the mileage obtained
of motor fuel which prevent knocking adds to the
45 e?iciency of the motor and the motor fuell
pounds comprising aldehydes, alcohols, and acids
in varying amounts. It has further been shown
The rate at ‘which different hydrocarbon motor that the gums themselves which deposit from
fuels deteriorate on storage in' respect to their gasolines either on storage ‘or during their car
valuable properties varies markedly with the buretion and distribution in engine manifolds con
chemical characteristics of the fuel which depend '. tam-considerable quantities of peroxides. The
in‘ turn upon the nature of the on distilled or presence of these peroxides in a motor fuel tends
o
45
,
,
50
2,115,781
2
to accelerate combustion and increase the knock
ing propensities of the fuel.
The restoration of properties, involving the sub
of these alternative methods of operation have
their advantages in individual cases and may be
. employed as desired.
The present process may also be employed in
stantiallyvcomplete elimination of peroxides, the ‘conjunction
with any other treatments which
partial reduction of aldehydes, alcohols and acids
and the depolymerization of ‘high boiling polymers
may be accomplished according to the present in
vention by treatment with solutions (generally
aqueous) of various inorganic metal salts in which
10 the metal exhibits its lower valence. In some
cases the salts may be used in the solid form.
This point will be discussed further in later para
graphs. Such salts are usually known as the
“ous” salts and the different salts included in
15 this category have the general property of ab
sorbing oiwgen or other elements and assuming a
may be considered necessary or of advantage in
bringing aged stocks back as nearly as possible
to their original values. Analytical data indicate
that the principal action‘ of reducing agents of
the present character ‘on stored distillates is to 10
“deoxidize” the same, to eliminate peroxides and
to some extent the compounds in which the oxy
gen is in more stable combination such as the
aldehydes, alcohols and acids already mentioned.
It is seldom possible to depolymerize to any great 15
extent and in case gummy or resinous materials
have "been formed in relatively large amounts,
higher valence.
‘
Vv
_
following the treatments will be
As examples of metals having reducing salts redistillation
necessary, in which step the materials boiling
which are well known and as a rule easily avail- ,
above the desired endpoint of the ?nished gaso 20
20 able may be mentioned iron, tin, chromium, line remain as a heavy re?ux in the fractionator.
nickel, cobalt, cerium, copper, manganese, mer
cury and thallium. As a general rule, the use of
salts of the commoner acids, such as the halogen
It is a feature of the present invention that
its greatest value lies in its application to un
stable gasoline stocks which, have suffered more
- acids and sulfuric acid will be preferable since
or less serious deterioration in their properties. 25
these
can
be
used
with
varying
degrees
of
e?i
26
Laboratory tests have indicated that extensive
ciency without having recourse to rarer and pos-' changes seldom occur when the peroxide content
sibly more expensive compounds. The solubility of a gasoline is about 0.5 or less, measured as
of these reducing salts in water varies considerably mgs. of available oxygen per liter of sample. Be
.and in the case of any one salt there will be an yond this point extensive changes occur which 30
30 optimum concentration in water, a de?nite tem
follow the previously indicated mechanism.
perature andagde?nite volume of solution cor
When large amounts of peroxides have been
responding to ‘most effective treatment. It is formed with the accompanying gums, aldehydes,
not intended to infer that salts which may be et cetera, it has been found that further depreci
used alternatively have identical treating effects, ation of gasolines cannot be prevented by the $5
fact being more or less obvious to chemists. use of ordinary inhibitors since these are inef
35. thisOther
groups of reducing salts which may be fective in the presence of the relatively large
used within the concepts of the present invention amounts of reactive oxygen. Since the amount'
include certain *arsenites, antimonites and- phos
of inhibitor which may be used is limited by such
phites, usually of the alkali metals since these considerations as the cost of the material, the 40
have sufficient solubility in water at ordinary q residue formed on evaporation, possible color
temperatures to make possible the use of treat
effects, et cetera, the present process oifers a
ing solutions of good e?lciency. It is within the de?nite
supplementary treatment which renders
scope of the invention also to use ferrocyanides stocks otherwise not susceptible to inhibition
'in case their solubility in water is great enough. ,. capable of proper response.
45
The operations of treatment for} restoring
The following examples are given to indicate
properties of deteriorated gasolines by the pres
the general character of treating effects obtain
' ent process are relatively simple and when solu
able in thepractical application of the present
tions of salts are used may be conducted in the process and while they are illustrative they are
same general types of-equipment as are ordinarily selected from a considerable number and they
employed in treating oils with liquid reagents . are not given with the intent of limiting the scope
such as sulfuric acid, caustic soda and sweetening of the invention to the speci?c instances pre
and washing solutions. For example, a solution
- of a reducing salt may be agitated with a deterio
sented:
‘
rated gasoline in the ordinary type of batch agi
A deteriorated cracked gasoline vwas treated 55'
lation from the bottom of the agitator back into vby agitation at ordinary temperatures . with 7
the top'by means of outside force pumps. The _ granular ferrous chloride used in an amount of
55 tator usingmechanical stirring devices or circu
solutions may also be used in continuous treate about 1% of the weight of the gasoline._ ‘The '
‘ing plants consisting of a series of- connected signi?cantproperties of the gasoline before and
units each comprising a mixer followed by a after this treatment are given in the-following
settling tank from the bottom of which spent
or partly spent aqueous reagents are drawn and
the treated liquids are discharged from the top.
treat
__
* PNMY- '
mam;
mt
In other words, the process is not limited to the
use of any particular type of mechanical equip
table:
V
ment.
-
-
'
I
‘
Y
>
Puoxidenumbersni?. ....... -.‘__..._
As an alternative mode of procedure it may ‘ ' Color; Saybolt ............... -.
sometimes be convenient and practical to effect
the desired reducing treatments using ?nely d1
70 vided solid salts. In such cases the solid may be
agitated with the gasoline to be treated either at
ordinary or elevated temperatures. (using re?ux
a
Before treat
5.4 . :
Light yellow
Octanenumbu' .................... -._.
1.0
26
_
an
Example II
70
The same gasoline as in Example I was treated '
ing or increased pressures ‘ to prevent loss of . with solid cuprous chloride. In this case-itwas
light constituents), or the gasoline may be ?ltered‘
‘75. through granular beds of ‘reducing salts. Each
found that after agitation for about'24 hours at,
ordinary. temperatures that the peroxide number 176
‘a
2,115,":
was substantially zero while the color and anti-
suits of this treatment are again tabulated be
knock value had been restored the same as in
low:
Example I.
4
>
‘
~
Example III
Properties
A Mid-Continent cracked gasoline which had
been stored for a considerable time was found
Peroxide number ........... -.
8g‘§{,'esggg°gg;;;;_ _____________ 6:
in the following table:
>
'
-
Beiore treat-
mpemes
ment
20 Peroxide nunlber_____ __- _______ -_..---__
Color, Sayb01t__‘-__.-___-_
-_
6. 3
-_
Octane number _________ _, .......... __
Example 'IV
25
B81256elKem
'
to have deteriorated considerably in respect to
gum content, anti-knock value and color. It
10 had a peroxide number of 6.3. This deteriorated
gasoline was treated at ordinary temperatures
with about 10% by volumejof a saturated solu
tion of ferrous sulfate.‘ The signi?cant prop
erties before and after treatment are again given
15
‘
'
v
.
Alter treat
ment
l. 1
Yellow
20
45
61
as
0.00
Yam};
6’;
The ‘features and advantages of the present 10
process are obvious from a consideration of the
preceding speci?cation and numerical data pre-p
sented, although neither section should be con
strued ‘as imposing undue limitations upon the
16
invention's generally broad scope.
I claim as my invention:
A process for restoring deteriorated cracked
gasoline containing organic peroxides developed
therein as a characteristic of the' deterioration
and tending to form gums and to reduce the anti
knock value characteristic of the gasoline before
its said deterioration, said process comprising
treating said deteriorated cracked gasoline with
In this case the same deteriorated gasoline‘ used a'ferrous salt having a reducing action on said
in Example III was treated with about 5% by' ‘peroxides, and separating any unconsumed quan
tity of said salt and the reaction products from
volume of a saturated solution of stannous chlo- v the thus treated gasoline.
ride which contained no stannic salt.‘ The re
JACQUE C. MORREIL'.
-
Документ
Категория
Без категории
Просмотров
0
Размер файла
369 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа