Note: Descriptions are shown in the official language in which they were submitted.
1144177
--1--
Descri~tion
RE~INEMENF 0~ SULFONATED HYDP~OCARBONS
. ... . _
Techn~cal Field
This invention relates to the sulfonation of hydro-
os carbons, e.g., petroleum fractions and cxude oils, and, more
specifically, to a process for the separation of unreacted
hydrocarbons from the final sulfonate product.
Bac~round Art
Prior Art Statement
.. . . ... . _ ...
Single extraction of unreacted hydrocarbons from
petroleum sulfonates is well known in the art, fox example,
U.S. 3,493,048 and U.S. 3,504,744. Re. 22,548 to Brandt uses
water to cause the separation of aqueous sulfuric and sul-
fonic acids and then uses sodium chloride to extract these
acids from organic sulfonic acids. Thereafter, ~.he or~anic
sulfonic acids are neutralized. Brandt also discloses the
use of solvents such as ethyl alcohol, dioxane, acetone, et
cetera, in the extraction process.
Gale, et al. in U.S. 3 ~ 653 r 437 teaches a sin~le solvent
20 process for the removal o unreacted oLls from neutralized
petroleum sulfonate surfactant mixtures. Isopropyl alcohol
is the prefexred solvent of &ale's process. The art also
discloses the extraction of unreacted hydrocarbons from
~ petroleum sulfonates either prior to or after the neutra-
25 lization of the sulfonates, e.g. U.S. 4,144,266. Extraction
solvents of water, alcohol, low molecular weight hydro-
carbons or mixtures of these are generally preferred.
However, the single extractions of unreacted oi'
taught by the prior art are incomplete in that ovex a
30 period of several weeks additional unreacted oil of up to
about 4 percent will separate from the sulonate product.
The presence of this unreacted oil adversely affects the
filterability of a slug containing the sulfonate, e.g., a
114~177
micellar dispersion, which is used in an oil recovery process.
It is an object of the present invention to effect a
complete separation of free unreacted hydrocarbon from the
sulfonate bv a two step separation process. Not only does
this improve the filterability of a slug containing the
sulfonate which is used in an oil reeovery proeess and result
in a savings through the recovery of valuable oil, but as a
result of the incomplete initial separation of the present
process, additional savings are realized through a decrease
in settling times and size of settling tanks required for a
two step separation.
Disclosure of Invention
Sulfonated h~tdrocarbons are refined in a two step
separation process to remove unreacted hydrocarbons. First,
the acidie hydrocarbon sulfonate is subjeeted to a partial
separation from the unreaeted hydroearbon wherein the aeidie
hydroearbon sulfonate phase retains from about 5 to about 15
pereent by volume of free unreaeted hydroearbon. Thereafter,
the aeidic sulfonate is neutralized and the remaining free
unreaeted hydrocarbon is separated from the hydroearbon sul-
fonate produet. If, during the initial separation, a oomplete
separation is obtained between the aeidie hydroearbon produet
and the free unreaeted hydrocarbon, then a portion of the
unreacted hydroearbon should be readded to the acidic sulfonate
prior to the neutralization step in order to obtain a product
eontaining from about 5 to about 15 pereent free unreaeted
hydrocarbon~ The presence of some raffinate in the sulfonated
product after the first separation is necessary to reduee the
separation time needed to separate the neutralized sulfonated
produet fro~ the free unreacted hvdrocarbon.
C -2-
cb/~
1~4~77
According to a specific aspect of the invention
there is provided in a process for the preparation of petroleu~
sulfonates comprising contactin~ sulfur trioxide with a
hydrocarbon selected from the group consistin~ of crude oils,
topped crude oils, gas oils and mixtures thereof in a reaction
zone at a temperature of from about 27C to about 121C and
a pressure of from about 0.01 to about 150 atmospheres for a
reaction time of from ahout 0.001 to about 3600 seconds wherein
from about 5 to about 30 kilograms of sulfur trioxide are
contaeted with each 100 kilograms of hydrocarbon, the
improvement comprising: (a) allowing the sulfonate product
mixture to separate into a free unreacted hydrocarbon phase and
an acid sulfonated product phase; (b) separating the sulfonate
produet mixture into a phase containing a portion of the free
unreacted hydroearbon and an acid sulfonated product phase
eontaining the remainder of the free unreacted hydrocarbon
sueh that the remainder of free unreaeted hvdrocarbon eauses
a faster separation between unreacted hydrocarbon and neutralized
sulfonate product than is possible if a complete separation were
effeeted between the free unreaeted hydroearbon and the sulfonated
produet mixture to be neutralized; (e) neutralizing with a base
the acid sulfonated produet mixture eontaining the remainder of
the free unreaeted hydrocarbon of step (b); and (d) thereafter
removing all of the free unreacted hydrocarbon from the neutralized
sulfonated product mixture at a rate of from about 0.3 to about
0.6 hours per foot of emulsion.
Aeeording to a further speeifie aspeet of the invention
there is provided a process of enhancing the separation of
unreaeted hydrocarbons from the sulfonated product mixture
-2a-
.~ ,.... , ,~,
cb/~\
1144177
~btained by contacting about 5 to about 30 kilograms sulfur
trioxide per lnO kilograms of a hydrocarbon selected from the
group consisting of crude oils, top crude oils, gas oils and
mixtures thereof in a reaction zone at a temperature of from
about 27~C to ahout 121C and a pressure from about 0.01 to
about 150 atmospheres for a reaction time of from about 0.001 to
about 3600 seconds to form a sulfonated product mixture from
which a raffinate comprising free unreacted hydrocarbons
separates, the method comprising the steps of: (a) removing a
portion of the raffinate thereby leaving the remainder of the
raffinate with the sulfonated product mixture; (b) neutralizing
with a base the sulfonated product mixture containing the remainder
of the raffinate to form a neutralized sulfonated product mixture
and a second raffinate; and (c) thereafter removing the second
raffinate from the neutralized sulfonated product mixture, the
remainder of the raffinate in step (a) being in an amountsufficient
to enhance the separation rate of the second raffinate and the
neutralized sulfonated product mixture thereby enabling the
removing of step (c) to take place at a rate faster than that
which would take place if substantially all of the raffinate
has been removed prior to step (b).
The preferred extraction solvents are water and low
molecular weight aqueous alcohols.
The process of the present invention is particularly
useful in the production of crude oil sulfonates. While
2b-
.A,
cb/~
1144177
--3-- .
such sulfonates produced by this invention are intended to
find their primary use in oil recovery processes, they, or
fractions thereof, are also useful in other known appli~
cations of sulfonates, such as flotation, cutting oils and
S insecticide carriers.
Brief Description of Drawings
Figure 1 is a schematic representation of the process
of the present invention..
Figure 2 is a graphic representation of the settling
time o~ the neutrali2ed sulfonate as a function of retained
raffinate.
_st Mode for Carr~ing Out the Invention
The process of the present invention is applicable to
any process for the sulfonation of hydrocarbons wherein
unreacted hydrocarbons are present. It is especiàlly bene-
ficial when mixed hydrocarbons, such as crude oil, aresulfonated to produce petroleum sulfonates. The term crude
oil as used herein includes whole crudes, crude oils which
have been "topped" to remove the lighter ends having boiling
points below about 150 C and preferably below a~out 315 C
and mixtures of whole and topped crude oils. The crude oils
may be pure hyarocarbons or may contain sulfur, halo~en and
nitrogen moieties. Preferred crude oils are those with
aromatic or olefinic portions having molecular weights in
the range of from about 200 to about 1,000, preferably from
about 300 to about 800 and more preferably about 350 to
about 500. The percent aromatics and ole~ins in the crude
oil is preferably from about 10 to about 95, more preferably
from about 20 to about 80 and most preferably from about 25
to about 50 weight percent.
Sulfonation reactoxs which are conventionally utilized
in proce ses for the sulfonation of hydrocarbons including,
for example, the falling of film, scraped.surface and stir-
red tank xeactors, may be used in the process of this inven-
tion. In those instances where a sulfur trioxide diluent is
. . .
li.4417'7 .!
_~ ~
used,, a back mixed tubular reactor is preferred and the
materials introduced into the tubular reactor should he in
turbulent flow.
It is preferred that an anhydrous sulfur trioxide feed
05 that is free oE impurities such as sulfuric acid, which can
cause deleterious side reactions, be used~ From about 5 to
about 30, preferably from about 7 to about 2Q and more
preferably from about 8 to about 15 kilo~xams o~ sulfur
trioxide is fed into ~he sul~onation reactor per 100 kilo~
grams o~ crude oil. The sulfur trioxide can be either a
liquid or vaporized state; however, the vaporixed state is
preferxed.
The sulfur trioxide can be diluted with liquid or
gaseous low molecular weight aliphatics, sulur dioxide,
air, nitrogen or other inert gases. Examples of liquid
diluent solvent include, ethy1ene dichloride, txichloro-
ethylene, nitrobenzene and similar substantially inert polar
solvents. These are introduced into the sulfonation xeactor
to dissolve the sulfonic acids in the unreacted hydrocar-
~0 bons. The desirability of a specific diluent is c~penden~upon the reactivity of the crude oil being sulfonated.
Heavy viscous crudes, such as gas oils, o~ten re~uire a
diluent while less-viscous crudes can be sulfonated with or
without a diluent. A preferred diluent for less viscous
crudes, e.g., whole crude oil, is recycled sul~onic acids
from the sulfonation reactor which contains su~fur dioxide
and light hydrocarbons.
Generally, the diluent solvent is used in a concen-
tration of from about 0 to about 20 kilograms, preferably
from about 1 to about 10 kilograms and more preferably from
about 3 to about 8 kilograms per kilogram of su~fur tri-
oxide. Except when the diluent is a sulfonic acid, it is
preferred that the reaction solvent be removed, e.g., by
steam stripping, prior to the separation o~ any unreacted
hydrocarbons from the sulfonated hydrocarbon.
The reactor conditions are not narrowly critical. The
temperature will normally be in the rang~ of from about
~144~7
-5-
27 C ~o abou~ 121 C, pre~erably from abQUt 38 C to
about 93 C and more preferably from about 55 C to about
82 C. Pressures will range from about 0.01 to about 150,
preferably from about 0.15 to about 75 and moxe preferably
05 from about 0.2 to a~out 5 atmospheres. The xeaction times
will be from about 0.001 to about 3600, prefexably ~rom
about 0.01 to about 360 and more pre~erably from about 0.02
to about 60 seconds.
Additional materials can be introduced into the sul-
fonation reactor~ These include known catalysts which ~onot appear to be needed but may be used i~ desixed, and
sulfonation additives which, inter alia, may aid in control
ling the equivalent weight distribution of the product
mixture. ~he additives are useful in amounts xanging rom
about 0 to about 20, preferably from about l to about 15 and
more preferably from about 2 to about 20 kilogxams of addi-
tive per 100 kilograms o crude oil feed stock. The addi-
tives are of~en sulfonated or sulfated and become a compo-
nent of the product mixture. The additives are i~corporated
in the feed stocks beore or auring sul~onation.
Useful additives include aromatic hydrocarbons, ole-
finic hydrocarbons, or oxygenated hydrocarbons and pre-
ferably have molecular weights in the range of rom 20~ to
about l,OOO, more preferably from about 300 to about 800 and
2S most preferably 350 to about 500. Specific examples of
additives include oxo alcohol bottoms which are describea by
Hatch~ L.F., Higher Oxo Alcohols, Enjay Co., Inc. 1957 and
.
ndustrial and Engineering Chemistry, Vol. Sl, No. 3, pp.
257-258; oxo alcohols alkylated with from about 1 to about
S0 moles of alkylene oxides, such as ethylene or propylene
oxide; catalytic cycle oil axomatics, see ~.S.3,317,44~; and
ultraformer polymer bottoms which are mixtures o~ alkylated
benzenes and asphaltenes.
After the hydrocarbon is sulfonated, it ;s prefexrea
that the water be added to the acid sulonate product mix-
ture in order to expedite the separation ~etween the aci~
~Y;
1~44~77
~6-
sulfonates and unreac~ed hydrocarbons. Water is added in an
amou~t o from a~out 0.1 to a~out 3.0, preferably from about
0.3 to a~out l.S and more preferably from about 0.6 to about
1.O kilograms per kilogram of the acid su~fonate product
05 mixture. T~ereafter, the water and acid sulfo~ate product
mixture is permitted to settle until the acid sulfonate
phase contains from about 5 to abou~ 15 percent b~ volume o
free unreacted hydrocarbon.
After the separation has taken place, the xaffinate is
separated from the sulfonic acids. The resultant sulfonic
acid mixture mus~ contain from about 5 to about 15 percent
of raffinate If the separation is more complete, then
raffinate should ~e readded to the acid sulfonate mixture to
obtain a mixture containing from a~out 5 to about 15 percent
raffinate. q~he presence of greater or lesser amounts of
xaffinate will not prevent the complete se~aration of raf-
finate rom ~he sulfonated product; however, more time wi~
be required for the second separation.
The thus partially xefined sulfonic acid mixture is
then neutralized with sufficient base, prefexably a mono
valent base, such as sodium or potassium h~dxoxide or a~mo-
nia, to form a neutralized pe~roleum sulfonate. Additional
water can be added during the neutraliæation process, as or
example, when it is used as the carrier of the neutralizin~
2S agent.
After neutralization to obtain petroleum sulfonate, the
petroleum sulfonate mixture is allowed to settle to effect
the separation bet~een the remaining raffinate and the
petroleum sulfonates. The raffinate is then remo~ed from
the sulfonate pxoduct. No further separation of unreacted -
oils from the petroleum sulfonates will thereafter occur.
The ~mount of time required for each of the separations
of the present refinement pxocess i5 depen~ent upon several
parameters, for example, size of the settling tank, ~mount
of product being subjected to the process, temperature, and
` 1144177
amount of unreacted hydrocarbon. The amount of unreacted
hydrocarbon is affected, for example, by the composition of
-the feedstock'sulfonated' and the amount of sulfur trioxide
used in the sulfonation process. Since the interaction of
05 these parameters are'understood by those skilled in the art,
the amount of time for each separation in a given pxocess is
readily determined by one skilled in the art. Gener~lly,
the first partial separation of the acidic product ~;- 1 take
from'about 1 to about 2 hours per foot of emulsion. The time
required for the second separation will be a~fected by the
amount of raffinate the neutralized product contains. When
from about 5 to about 15 percent by volume raffinate is
present, the second separation will generally take from
about 0.3 to about 0.6 hours per foot of emulsion.
The separation of the unreacted hydrocarbon from the
'sulfonate can be done as a batch operation or as a conti-
nuous'operation.
Xf the hydro~arbon feedstoc'~ contains wax, then kero- -
sene may be added to the partially separated acidic sul-
fonate prior to the neutralization of the acidic sulfonate.
The ~erosene is added in an amount of from about 0.05 to
about 0.5 kilograms per kilogram of acid sulfonate product.
The reined petroleum sulfonates produced by the
process of this'invention are useful in the formulation of
micellar dispersions comprised of hydrocarbon, water and
petroleum sulfonate, which are utilized in oil recovery
processes. Examples of such micellar dispersions include
micellar flooding of subterranean reservoirs with systems of
the type taught by H. J. Hill, J. Reisberg, and G. L. Stege-
meier, J. Pet T_ch., 186 tFeb~ 1973), wherein relativelydilute aqueous "solutions n o~ sur~actant and/or cosurfactant
are injected, the process of R. L. Reed, et al., U.S.
Patent 3,885,628 wherein a multiphase system is injected;
and U.S. Patent 3,082,822 issued to L. W. Holm et al.,
wherein substantially small slugs of anhydrous-soluble oils
11~4177
--8
are alternately injected with small slugs of ~ater or other
aqueous media. The neutralized sulfonates used in such
micellar dispersions should have an a~erage equivalent
weight of from about 350 to about 525, preferably from about
05 395 to abou-t 440 and more preferably from about ~00 to about
4~0. Ge~erally, the water soluble petroleum su~fonates have
a lower equivalent wei~ht, whereas, the more o-il soluble
petroleum sulfonates have higher equivalent wei~hts. These
petroleum sulfonates are also useful in other t~pes of
sur~actant floods used in oil reco~ery processes.
Figure 1 exemplifies the process of the present inven-
tion. Cruae oil and sulfur trioxide vapor enter a sulfo-
nation reactor 3 through lines 1 and 2, respectively.
The resultant product mixture containing sulfonic acids and
unreacted oils is conducted by conduit 4 to a liquid/~as
separator 5. Sulfur dioxide, light hydrocarbons and diluent
solvent, ~hen it is usea, are separated and xemoved from the
sulfonated product mixture via conduit 6. If desired, these
gaseous proaucts, e.g., sulfur dioxide and light hydrocar-
bons, can be recycled to the sulfonation reactor for use asa reaction solvent. If a diluent solvent is used which re-
mains in the liquid phase, it can be removed by an~ appro~
priate means at any time later in the process. While the
,~ sulfonated product mixture is being conducted throu~h f ~
conduit 7 to settler 8, water is added to the mixtur~ The
water and sulfonated product mixture are then allowed to
separate in settler 8 until the acidic sulfonate pxoduct
mixture contains from 5 to about 15 percent b~ vo~ume o~
free unreacted hydrocarbon. The free unreacted h~drocarbons
are then removed by conduit 10 and ultimately recombined
with the raffinate obtained by the separation of the neu-
tralized petroleum sulfonate. The sulfonic acids from
settler 8 are conaucted by conduit 11 to neutralizer 12,
wherein the sulfonic acids are neutralized by the addition
of a base supplied t~ough conduit 13. Water can be added,
1144177
.
~g
if desired, to the neutrali~er, thxou~h a separate con~it
14 or via conduit 13 as a carrier for the base. The sul-
fonation product is then conducted through line 15 to an-
other settler 16. If needed, kerosene can be added to the
05 sulonated product via conduit 17 prior to i~s introduction
in either settler 8 or settler 16~ The addition of this
kerosene is as an adjunct to extract waxes from the petro-
leum sulfonate. The petroleum sul~onate is then allowed t:o
settle until a complete phase separation has occured between
the unreacted oil and the petroleum sulfonate. Thereafter,
the xaffinate is separated from the sulfonate an~ remo~ed
from the settler via conduit 18. The crude oil s~lfonate is
removed via conduit 19 and thereafter incorporated into a
micellar dispersion for use in an oil xecovery process.
EXAMPLE 1
Sam~les of different crude oils were prepaxed by
sulfonating each crude oil at a rate of a~out 450 kilograms
per hour with 45 kilograms per hour of sulfur trioxide at a
temperature of about 80 CO The vapor stream was then
separated from the liquid stream containing sul~onic acids,
sulfuric acid, sulfurous acid and unreacted oils~ Then, the
liquia stream was mixed with about 400 kilo~rams of fresh
water per hour and enough ammonia to obtain a pH of about 6.
In some cases approximately 220 kilo~rams of kerosene per
hour were also added at this point to reduce the ~inal wax
content of the crude oil sulfonate product. This neutral-
ized liquid stream was allowed to settle ~or about 4 hours
in a settling tank having a 3800 liter capacity in order to
effect a phase separation between the raffinate tunreacted
oil) and the crude oil sulfonate (COS). These two phases
were separated and the crude oil sulfonate contained no
detectable free oil as it left the settler. Thereafter, the
COS was allowed to settle for the time indicated in Table 1. -
The amount of residual raffinate which separated from the
COS during this time period is also ~iven in Table 1. The
1144~77
--10--
raffinate continued to come out of solution ~or ~everal days
and often for several weeks.
TABL~ 1
Residual
05 - Time Period Xaf~inate
Sam~le Cr~de:~il Feedstock ~Iours~ - (vol. ~)
1 Bailey/North Craw- 0 0
ford County, 3 0.5
Indiana (Kerosene 5 1. n
added during 7 1.3
neutralization) 8
~7 1.9
Sl 2.X
121 ~-~
244 ~.6
364 2.7
2 Baile~/North Craw- 0 0
ford County, 3 . 0.5
Indiana ~Kerosene S 1.1
added during 7 1.~
neutralization) 8 1.4
27 l.g
97 2.
~20 ~-~
340 ~.6
3 Muddy Creek 42 . ~. n
4 Indiana 50 0.8
Bailey 111 2.8
6 North Crawford County77 ~.3
30 ~ Bailey/Muddy Creek 216 ~-~
8 Bridgeport 16~ 1.0
.
EXAMPLE 2
~ ... .
A crude oil sulf~ate was prepared by sulfonating 450
kilograms per hour of Craword County, Xllinois cxude oil
with 45 kilograms of sul~ur trioxide at a temperature of
80 C. Samples of the thus obtained acidic crude oil sulfo-
nate (ACOS) were allowed to settle and separate into a
.
1~44~77
raffinat~ and acidic cxude'oi.l sulfonate.phases. The
two phases were then subjected to an incomplete separation
and the amount of raffinate which the separated acidic crude
oil sulfonate containea is given in Fi~ure 2. With some o
05 the samples, additional raffinate was remixe~ into the
already separated acidic crude oil sulfona~e. Thereafter,
all of the samples were neutralized with suf.ic:ient ammonia
to obtain a crude oil sulfonate~rafinate mixture having a
pH about 6-6.5. Each of the samples was allowed to settle
and the time required for complete separation ~etween the
~eutxalized cxude oil sulfonate and the xaffinate is given
in Figure 2.
EXAMPLE 3
Four hundred fifty kilograms per hour of a Crawford
County, Illinois crude oil was reacted with 45 ~ilo.grams per
hour of sulfur trioxide at a temperature of 82 C. A~ter
separating off the vapor stream, composed mostly of light
hydrocarbons and sulfur dioxide, the xemaining stream, i.e.
the sulfonic acid p~ase, co~posed most~y o sulfonic acids,
~- sulfuric acid, sulfurous acid and nnreacted hydrocarbQns,
was processed in the following ways:
Sample l:
The sulfonic acid phase was mixed with ~50 kilograms
per hour of resh water and enough ammonia to ~i~e a pH of
about 6, then allowed to separate over four hours'at 70 C
in a 3800 liter settler. Foux samples of ~he crude oil
sulfonate stxeam fxom the settler were held or varying time
periods at 70 C in volumetric flasks to determine how much
residual rafinate would separate into a top phase. A
residual rafinate layer of 1.1 percent by volume was ob-
tained from a sample held for twenty hours; 1.6 and 1.7
percent by volume residual raffinates were obtained from two
samples held for three'days and a sample hel~ for 28 days
showed a raffinate layer of 2.0 percent by vol~une.
T~e average'time'required for complete settling of the
neutralized stream into a raffinate phase and the pet'roleum
., ~ .
11441~7
~12-
sulfonate phase was 9S minutes. The settling time was
obtained by taking about foot high samples of the neutral-
ized stream in 1000 milliliter gradua~ed cylinders, main
taining the temperature o the samples at 70 C and then
05 measuring the time required to ob~ain the phase separation.
Sample 2:
.
The sulfonic acid phase was treated wi~h ~50 kilo~rams
per hour of fresh water, then ~is mixture was settled ~t
60 C in a 3400 liter settler with a resiclence ~ime of about
3.5 hours. The two streams from the settler, the ra~finate
and acid crude oil sulfonate, were then recombined and
neutralized with ammonia to a pH of about 6. '~his mix,
which containea about 38 percent ~y volume raffinate, was
then put through a second settler o 380Q :Liter capacity at
70 C and a residence time of about 4 hours. ~fter sepa-
ration of the neutralized COS and raffinate, ~amples o the
crude oil sulfonate were held at 70 C in ~olumetri~ flasks
for several hours, at which time a~out 0O~ volume percent
residual raffinate separated to the top o~ the ~rude oil
sulfonate. More raffinate would have separat:ed c>ut had this
sample been held longer at 70 C.
Sample 3:
Fresh water, at a rate of 450 kilo~rams per hour, was
added to the sul~onic acid phase, then this mixture was
allowed to separate in a 3400 liter settler with a xesi~ence
time of about 3.5 hours at a temperature o~ ~0 ~. A
stream of clear raffinate was removed from the top of the
settler. The acid crude oil sulfonate stream from the
bottom o the settler was not clear and it ~ontained about
40% of the total raffinate. This stream was neutraliæed
with ammonia to a pH of about 6, and then put through a
second settler of 3800 liter capacity at 10 ~ and a resi-
dence time of about 5 hours. Samples of this neutrali2ed
stream entering the second settler were ~atch settled at 70
C and showed 10.3 and 16.4 volume percent raffinate.
Samples of the raffinate free crude oil sulfonate stream
44177
-13-
~ere held at 70 C in volumetric flasks for several hours.
No residual raffinate was ohserved. Obser~ation for several
more hours stlll showed no residual raffinate.
Sam~le 4:
S The run conditions were the same as those of Sample 3,
except that the first settler was at abou~ 60 C and the
acid crude oil sulfonate from the first settler con~ained
about 10 percent of the total ~af~inate. Samples o~ the
neutrali~ed stream entering the second settler were batch
settled at 70 C and showed 3.5, 8.8, and 3.3 volume percent
ra~finate. Samples o~ the raffinate free crude oil su~fo-
nate fxom the second settler were held at temperature ~n
volumetric flasks for several hours. No residual raffinate
separated to the top. Observation for several more houxs
still showed no residual raffinate.
EX~MPLE 4
Four hundred fifty kilograms per hour of a Crawford
County, Illinois crude oil was reacted with 45 kilo~rams per
houx of sulfur trioxide at 80 C. After separating off the
vapor stream, composed primarily of light hydrocarbons and
sul~ur dioxide, the remaining stream, i.e. the sulfonic acid
phase, composed mostly o~ sul~onic acids, sulfuric acid,
sulfurous acia and unreacted hydrocarbons was mixed with ~50
kilograms per hour of fresh water and put into a 3400 liter
settler for a residence time of about 3.5 hours. This acid
separation and a second separation at nearly neutral con-
ditions were varied, as described in each of the following
. ~ samples.'
Sample 1: -
In this sample, two separate acid separations were
conducted at a temperature of 50 C (Sample lA) and 70 C
(Sample lB~. Both resulted in a clear rafffina-te stream and
a nearly clear acid crude~oil sulfonate ~ream. Both acid
crude oil sulfonate streams wexe n~ ralized with ammonia to
... . .
~144177
-14-
.
a pH of about ~ and then allowed to reside for a~out 6 hours
in a second settler at a temperature of 70 C. ~ sample o~
about one foot height of each of the neutralized crude oil
sulfonate was taken in a 1000 millilite~ graduated c~linder
S and held at 70 C. Sample lA too~ 45 minutes t~ completely
separate and 2.4 percent by volume of raffinate was removed;
Sample lB took 50 minutes to completely separa~e and 2.9
percent by volume of raffinate was removed.
Samples 2-4:
Additional samples were subjected to the same two step
separation process of Sample 1 with the exception that the
acid separation was not complete. The amount o~ raffinate
left in the acid crude oil sulfonate is in~icatea in Table 2
as are the results of the neutraliæed ~eparation.
TABLE 2
Settlin~ Rafinate
time of ~emo~ed
Temperature Raffinate Neutrali~ea ~n ~nd
of Acid left in COS (min- Separation
20 SeparationACOS (vol.~ tes~ (vol.%)
.._ . . . . .
50 ~ 7-8 24 10.3
70 C 5.5-6.5 ~2 ~.
70 C 14 40 16.4
Sample 5:
In this sample the acid separation was conducted at a
temperature of 60 C. The separated ra~finate was recombined
with all of the acid cxude oil sul~onate stream ana then
neutralized with an~onia to a pH of about 6. This neutral-
ized stream was flowed into a second settler where it
settle~ for 4 hours at a temperature of 70 C. A sample of
one-~oot height taken of this neutrali~ed inlet stream to
the second settler took 135 minutes to completel~ separate
and 38.1 percent by volume of raffinate was removed.
