Note: Descriptions are shown in the official language in which they were submitted.
iOS653Z
This application is a division~l of S,~ 229,96n flled 23 June
1975 and is directed to water-in-oil emulsions wherein the oil phase
includes specific ethylene-vinyl alkanoate copolymers and the use of those
emulsions while the parent application is directed to water-in-oil emulsions
wherein the oil phase includes specific sulfonated polymers and the use
of the emulsions.
This invention relates to novel liquid membrane formulations
which are water-in-oil emulsions wherein the oil phase comprises a sulfonated
polymer having a backbone which is substantially nonaromatic, for example,
less than 10 mole % aromatic, and uses thereof in high temperature liquid mem-
brane processes. The emulsions are useful in liquid membrane water treatin~
processes ~hich are desirabl~ nm at lligh temperatures. In the most preferred
embodiment, these compositions are used in a liquid membrane sour water
treating process wherein a waste water stream containing ammonium sulfide
is contacted with a liquid membrane emulsion, i.e. the emulsions of the
instant invention, at conditions whereby ammonia permeates through the
external phase of the emulsion into an acidic internal phase wherein it
is converted to a nonpermeable form, e.g. ammonium ion, while H2S is
- continuously stripped out of the waste water solution by means of an
inert gas, e.g. steam. Processes of this sort are most effectively
carried out at temperatures greater than 80C wherein (he emulsions of
the instant invention have excellent stability.
In German Patent Publication 2,434,590 published ~ebruary
6, 1975, a process for removing the salt of a weak acid and a weak base
from solution by means of the liquid membrane technology disclosed in
U.S. Patents 3,410,794, 3,617,546 and 3,779j907 is disclosed. The process
disclosed in DOS 2,434,590 utilizes the liquid membrane technology to
remove either the weak acid or weak base or their hydrolysis products
from solution by permeating through the external phase of the liquid
membrane emulsion, and converting same into a nonpermeable form in the
2.
~ ~05653Z
l intPrior phase. Simultaneou~ly the weak acid or weak b~se or
2 hydrolysis product thereof may be stripped f~om solution by
3 means of an inert gas or alternatively by subjecting the sys-
4 tem to subatmospheric pressures This process has been found
to be most e~fectlve when run ~t high temperatures, for ex-
6 ample, 80C. It has been found~ however, th~tg at tempera-
7 tures in this range, many liquld membrane formulations, i,e.
8 water-in-oil emulsions, are unstab~e~ In the process o~ this
q invention, this problem is solved by m~ans of novel formula~
o tions which have been fo~nd to be ~table at temperatures up
ll to 100G.
l2 The in~taTIt inventlon rel~tes to novel liquid mem-
brane formulations which are water~in-oil Pmul~ions wherein
~4 said oil phase comprises a s~l~on~te~ polymer havlng a back-
bone which is substantially non~omatic. ~hese novel compo-
16 sitions also comprise a solvent for said sulfonated polymer
l7 which ~s immiscible with water9 and although not necessary9
l8 an oil-soluble surfactant m~ al~o b~ used in the formulation~
19 The aqueous interior pha~e of these emulsions may comprise a
base or an acid. The emulsion~ of this invention are espee-
21 ially suitable for use in liquid membrane proce~e~ wherein
22 aqueous solutions are treated at high temperatures wlth liq-
23 uid membrane formulations. Eurthermore9 when these emulslons
24 are being utili~ed in the preferred process for treating sour
water, the emulsions will usually comprise elther a strong
26 acid or a regenerable acid. The regener~ble acids used in
27 forming the compositions of the ins~ant invention are fully
28 descr~bed in DOS 2,434,590
29 In general 9 ~ulfonated polymers which are useful in
the compositions and process of the ln~tant inventlon are dis-
~ 3 --
~S653;2
1 closed and claimed in U.S. Patent 3,64~,728. The
2 term "substantially non-aromatic in
3 nature'l means that the b~ckbone will compri~e less than 25
4 mole %, preferably less than 10 mole % arom~tic groups~ This
S is a necessary limitation ~ince it has been found, unexpected-
6 ly, that aromatic containlng sulfonated polymers do not form
7 stable emul~ions with the solvent systems utili~ed in cer--
8 taln higher ~emperature liquid membrane processes, e.g.
9 liquid membr~ne sour ~ater tre~tingO
0 The preferred sulonate~ polymers o~ ~hP ins~ant in-
11 vention are selected from the group con~i~ting of sulfonated
12 butyl polymers and sulfonated e~hylene-propylene copolymers.
13 Mo~t preferably, compositions of the ~nstant invention com-
14 prise a sulfonated butyl polymer~ m e butyl polymer is pre~
pared by copolymerizing isobutylene and isoprene, option~lly
16 with a thlrd monomer, e~g~ cyclopenta~iene~ The preferred
17 sulfobutyl polymers o~ the instant invPntion will contain
8 from about o25 to lO mole % sulfonic ~cid groups9 more prefer-
19 ably from about ~5 to 5 mole % sulfoni.c acid groups. Thls
copolymer may be prep~red by the methods described in U.SO
21 Patent 3,642,728~ The prefErred sulfobutyl polymer of the
22 instant invention will have a number average molecular weight
23 of at le~st 1,000~ preferably from 5,000 to 50J000~
24 Other sulfonated polymers which are useful in making
the compositions of the l.nstant invention may be selected
26 from the group conslsting of sulfonated copolymers of lso-
27 butylene and piperylene, isobutylene and cyclopentadiene, iso-
28 butylene and methylcyclopentadiene~ and lsobutylene and beta-
29 pinene. The diene conten~ of these polymers m~y range from
,5 to 30%~ preferably 1 to 25 mole %O Various sulfonat~d ter-
~056~i3~
1 polymers are also useful in preparing the compositions of the
2 instant invention. For exampleg isobutylene may be copolymer-
3 ized with any two of the above conjugated dienes and the re-
4 sulting copolymer sulfonated in accordance with the teachings
of U.S. Patent 3364~,728 to yield sul~onated polymers useful
6 in the instant invention
7 Other less preferred copolymers for use in the in-
8 start invention are pr~pared by copolym~ri~ing ethylene and
9 propylene with a dlene, e~g~ dicy~lopentadiene, ethylidene
norbornene, or lD6--hexadiene and ~ulfona~ing the copolymer
11 as described above~ These terpolym~rs m~y have ~rom ~2 co
12 10 mole % unsaturation and more preferably from .5 to 7%
l3 prior to sulfonatlon~
l4 Finally, highly unsaturated nonaromatic polymers
may be sulfonated and used in preparing the compositions of
l6 the instant inventionO For example~ polybu~diene and poly-
17 isoprene homopolymer$ m~y be so utili~edO
8 The pol~mers described above~ in general; will con-
19 ta~n from .25 to 20 mole % sulfonlc ~cld groups, pre~erably
from ~5 to 5 mole ~/0 sulfoni~- acid groups, and have a number
21 average molecular weight of at least 1~000, preferably from
22 5,000 to 50,000~
23 The u~e of emulsion~ prepared from sulfonated
24 polymers is not re tricted to sour water treatment~ They have
a very wide util~ty in other liquid membran~ processes. In
26 systems involving strong acids and/or bases, these emulsions
27 are particularly ~dvantageous since the sulfonated polymers,
28 described above9 ac~ as emulsifying agents, and unlike many
29 surfactants are not prone to hydrolysis under the conditions
of use.
lOS6S3~
1 In cases where high temperatures and strong acids
2 or bases are used, it is essential that solvent for the sul-
3 fonated polymer be selected judiciou~ly, ~hus 9 solvents such
4 as esters which can hydroly~e e~sily shDuld not be usedO
Another restriction is volatility o solvents. Thus, hydro-
6 carbons and other solvents which are volatile at 80C, or are
7 steam distillable cannot be used. Another criteria for se-
8 lection of solvents in water-treating processes is toxicityO
9 Solvents which leave a toxic re~idu~ in water must be avoided,
0 It is al~o ~mportant that solvent~ used in this process should
11 be liquids under the operating conditions to provide liquid
12 membranes and should not have a tendency to solidify during
3 use. The solvent should also be selected ~o that the speci-
4 ~ic gravity of the formulated emulsion differs from that of
-the feed stream, with wh~ch it is to be contacted~ by at least
16 .025, to allow easy sep~ration of ~he emulsion from the feed.
~7 Thus, if the difference ~etween the specific gravity of the
18 feed stream and the emulsion is too Sm~ll9 the separation
19 thereof is a tlme-con~uming process, Other con~iderations
will be apparent to those skilled in the art~ For the reasons
21 given above, the preferred solvent will be chosPn from the
22 following group:
23 Petroleum distillates having a boiling point of
24 ~ 200C, Hlgher boiling normal parafflns which have a melt-
2s ing point o~ 70C, or more should not be u~ed, uniess they
26 are mixed with other solvent~ to lower their melting points.
27 Paraffinic solvents, which may be lightly substituted with
28 halogens such as chlorine or ben~ene or cycloalkyl rings,
29 i.e. less than 10 mole %~ Preferred solvents include the
petroleum distillates known ~s isoparaffins having an average
1C356S3Z
1 carbon number of rom abou~ 10 to about 100, most preferably
2 from 30 to 75. Examples of solvents of this type are the re-
3 fined isoparaffins known as Solv~nt Neutr~l*types, available
4 from Exxon Chemical Company. Almos~ all of these are suit-
able in the instant invention, e~g. Solvent Neutral*100,
6 Solvent Neutral*150, Solvent Neutral*~OO and the various
7 grades inbetween. (The numeral reers to the SUS viscosity
8 at 100F.) Other petroleum fractions such as bright stock,
9 Coray gO and the like are also ~uitable~ These are petroleum
~o lubricating oils having v~sco~ities of 479~4 and 41202 centl-
11 stokes, respectively, at 100F. In many applications, it
12 may also be desirable to u~e mixed ~olvents such as, for
13 example, Solvent Neutral 100 and Solvent Neutral 600, in
14 combination.
The most preferred form of the sulfonated polymers
16 used in preparing the composltions of the instant invention
17 is the ~ree acids 9 althGugh long chaln ~mine~ or polyamines
18 can be used as neutraliz~ng agentsO ~he amine~ useful as
19 neutralizing agent~ inclu~e triamines, e~g. cont~ining C~ to
20 C16 hydrocarbyl r~dlcals, such as9for e~ample9 trioctylamine;
21 and diamines, e.g. ccntaining CB ts C16 hydro~arbyl r~dicals~
22 such as, for exampLe 9 dido~ecylamine~ The amines are se-
23 lected on the basis of their lack of solubility in water. If
24 these amines or thelr salts have appreciable solubility in
25 w~ter, they are li~ely to be lost when strong acids and bases
26 are utilized in the intern phase
27 As will be described later, salts o these sulfonic
28 acids such as ammonium, potassiNm, sodium~ etc., are not
29 particularly useful in these applications due to the lack of
their solubility in the solvent system used.
* Tr;~ rk
-- 7 --
105653Z
1 The polymers containing free sulfonic acid groups
2 are prepared by first sulfonating the copolymers such as, for
3 example, isobutylene~isoprene copolymer And then replacing
4 the solvents used in their preparation such a~ methylene
chloride, volatiLe hydrocarbons and ~he methanol quenching
6 agent by the solvent desirable for emulsion ~ormation~ e.g.
7 Solvent Neutral*l00 or Solvent Neutral*600~ This process is
8 kno~n in the art as solvent replacementO Another me~hod is
9 to neutralize the s~lts of ~hese sulfonic acid polymers with
0 an acid, e.g. sulfuric acldD and extract the polymer with the
11 desired solventO Solutions o~ the~e polymers when stored in
12 amber-colored bottles a~e indefin~tely stable~ The concen-
tration of the sul~onic acid polymers used in preparing the
compositions of the instant invention m~y v~ry from 0~05 to
40 wt %, preferably from O.l tO 30 wt~ %~ in the solvent.
16 In many liquld membr~ne p~ocesses9 such as sour
17 water treatment, it is desirable ~o maximi~e rate of ammonia
18 transfer to 1nternal ph~se a~ well ~s the removal of H2S by
19 the iner~ gas, e~g~ ste~mJ or by su~tmospheric pressures.
This is accomplished by carry~ng GUt the process ~t temper-
21 atures higher than ambient wherein the vapor pressure of H2S
22 increases subst~ntially and its solubility in w~ter is de-
~3 creased. Thus, the solub;lity of H2S in ~ater at 25 is O34%
24 and at 90C. it is 0~04/O~ It is eviden~ that when running
this process at a~mospheric pre~sure, a temper~ture of 80 to
?6 85C. would be very pr~ctical~
D One of the outst~nding advantages in using the sul-
28 fonic acid polymers de~cribed above is that no ~dditional sur-
29 fact~nt is needed to stabili~ the emulsion; thus, risk of
hydrolysis and/or decomposition a~ higher operating tempera-
-
1056S3Z
1 tures is avoidPd. m e sulfonated polymer~ provide both addl-
2 tive and surfactant propPrties needed in the liquid membrane
3 processe~. Also, the sulfonic ~cid polymers possess the
4 proper hydrophilic-lipophlli¢ balan~e at the operating temper-
atures, e.g temperatures of from 80 to lOO~C. It h~s been
6 noted that unlike m~ny other ~dditives 9 e,gO p~lyisobutyl-
7 succinic anhydride~tetrae~hylenepent~mine, commonly used at
8 the operating temper~tures described above, the sulfonic ~cid
9 pol~mers ~re inert to hy~rogen ~ulflde attack9 in liquid mem-
o brane process2s.
All of the abo~e factvr~ ~ke th~ sul~onic acid
12 polymers described above p~rticularly suitable for forming
13 emulsions, useful in high temperature liquid membrane pro-
l4 cesses especially liquid membran~ ~our water treating pro-
cesses.
16 The above compollent~ that is sulfonated polymer 9
l7 solvent with or without ~ s~ ctantD are ~elected with con-
8 sideration of ~heir lnter~ction to orm emulslons whieh are
19 stable at high temperature~ and especially in the presence of
strong acids and bases~ e choice of speciflc combinations
21 is within the skill of the artisan ~n the field of emul~ion
22 technology with the ~e~chlng o~ thl~ dlsclo~ure before him~
23 In general, the emulsion of the inst~nt invention are pre-
24 pared by technlques known in the ar~, For example 9 the
sulfonated polymer may be dissolve~ in the solvent followed
26 by the addition and dis~olutlon of the surfac~an~. However,
27 the components can be combined in any order. The aqueous in-
28 ternal phase m~y then be added to the oil ph~se while agltat-
29 ing with any of the devices known in the ~rt for preparing
stable emulsions. For example, paddles with ~ stirrer oper-
`~
~056S3Z
1 able at high speeds m~y be used to emulsify the components.
2 Other well-known emulsion-forming techniques which
3 may be utilized include the use of colloid mills in which
4 large droplets are broken up by the intense shearing forces.
$ Homogenizers can also be used after a preliminary emulsifica-
6 tion in a mixing ves~el, colloid mlll, or other device. In
7 this type of operation9 the co~rse emulsion is pumped at a
8 high velocity through the annular opening o~ a valve~ The
9 droplets are disrupted~ partly by ~he ~imple "s~eving action"
and partly ~y the lntense shearing forces which ~re set up
11 in the annulus~ Other emulsifying devices resemble the in-
12 tense types just described, such as special mixing pumps,
13 centrifugal emulsifiersg ultrasonic generators, slotted
14 mixers, mixing jets inc~uding those in which ultrasonic
vibration occurs and turbulent flow ~evices in which a coarse
16 emulsion is made to flow ~long ~ tube at ~ ~peed greater than
17 the critical velocity for turbl~lence.
8 In general, the compositions of the instant inven-
19 tion will comprise from l0 to 90~ preferab1y 30 to 60 wt. %
oil phase and the remainder the aqueous internal phase,
21 The-internal phase may comprise a strong acid or
22 a strong base or ~ny of th~ other reagents described in U S~
23 Patent 3,779,907. However, these emulsions, as stated above,
24 are especially useful in the process described in DOS
2,434,590. Thus, preferably9 in the composition of the in-
26 stant invention, the internal phase, is as described therein.
27 Most preferably the internal phase will comprise either an
28 acid (strong or regenerabl~) or a strong base The con~
29 centration of acid or base in the internal phase of the emul-
sion is adjusted so tha~ the emulsions may be used economic-
,, , ~ ,r~ ,
lOS6S;~Z
1 ally. In general~ t11e concentration is as high as possible,
2 even up to satur~tion9 t king into consideration the stabil-
3 ity of the emulsion9 e.g. from l. to 30% by weight concentra-
4 tions may be used.
The instant in~ention further relates to novel liq-
6 uid membrane formlllations, i.e~, emulsions~ which comprises
7 an aqueous interior phase and a water-immiscibLe exterior
8 phase, said watèr-immlscib1e exterior phase comprising an
9 ethylene vinyl acetate copolymer and a solvent o~ the type
described above ~or this polymer ~hese compositions pre-
11 erably addition~lly con~ain a w~ter in$oluble ~urfactant to
12 stabilize the emulsionsO In a.preferre~ embodiment, the
13 aqueous interior phase comprises a strong acid, for example,
14 from l to 30, preferably about l to about lO percent by
weight sul~uri.c ~cl~ These emulsions are useful in liquid
16 membrane processe~ ~or the sep~ration o dis~olved components
17 from aqueous solutionO Emulslons o~ the instant invention
18 are characterized as show~ng very low ~welling when contacted
19 with aqueou~ solutions, especially ~t higher temperatures and
thus are especi.~lly effective for use in ~he treatment of
21 sour water feed stream~ by th~ liquid membrane technique.
22 In liquid mem~rane processes, the emulsion is
23 brought into contact with ~n aqueous feed stream containing
24 a dissolved material which is to be removed by permeation
through the external phase of the emulsion ~liquid membrane)
26 into the intern~l phase, at condition~ of constant agitation
27 The emulsion i~ then separ~ted by discontinuing the agitation
28 and allowing the emulsion to settle l~e emulsions useful in
29 watPr treating processes are charaeteri.ed a~ water-in-oil
emulsions and may be stabili~ed by incorpor~ting an oil-
-- ].~. --
,
., ' ' .
-
r~
lQSG532
1 soluble surfactant in the e~ternal phase o~ the emulsion
2 Due to the hydrophilic and lipophilic nature of the surfac-
3 tant, rapid settl m g of the em~lsion after contsct with the
4 aqueous feed stream i~ not always obtained~ Furthermore,
the emulsion9 especially when contacted with the aqueous
6 feed stream at high temperature~, for e~ample 80~C~ has
7 been known to swell and in certain cases the entire mass,
8 i~e. feed stream and emulsion, h~s gelled~ Finally, it has
9 been noted in certaln liquid membrane processes that a~ter
settling of a substantial porticsn o~ ~he emulsion the ~queous
11 feed stream is le~t hazy due to ~he formation of very small
12 emulsion particlesg which do not ~ettle with the bulk of the
13 emulsion. When the liquid membrane proce~s ~s utili~ed for
14 water pollution abatement, haæiness rema}ning in the treated
water is completely unacceptable,
16 The compositions of the instant invention may be
17 used in liquid membrane water t~eating processes to solve all
18 of the above proble~s~ The ethylene vinyl acetate copolymer
19 which is used in forming a co~position of the instant inven-
tion is ch~racte~ize~ ~s having a ~olecular weight of from
21 about 500 to about lO0~000~ preferably from about 500 to
22 lO,000. These polymerg may be prepared by copolymerizing
23 ethylene and vinyl aceta~e ln a free radic~l process at high
24 temperature and pressure. The polymers may be prepared by the
process described in U~SO Patent 3,638,349 and
26 German Patent 1,914,756. The percentage
27 of vinyl acetate in these copolymer~ may vary from 1 to 75
28 percent, but is prefer~bly bet~een S to 40 percent by weight.
~ In the above polymeri~ation, in place of vinyl
acetate, other esters of vinyl ~lcohol containing from l
~ 12 -
iS32
1 to 20 carbon atoms in the alkanoate portion of the ester may
2 be used. Example of such mOnGmerS include vinyl formate3 vi-
3 nyl propionate~ vinyl neopentanoate, vinyl hexanoate, vinyl 2-
~ ethyl hexanoate9 ~inyl decanoate7 vinyl laurate, vin~l stear-
ate, vinyl benzoate, vlnyl salicylate, vinyl thiolacetate,
6 vinyl pivalate, vinyl neodecano~te and the like~ SimiLarly,
7 esters of acrylic acid and methacrylic acid may be copolymer-
8 ized with ethylene in place o or in combination with the a-
9 bove vinyl esters. Examples of such monomers lnclude methyl-
acrylate, ethyl acrylate, butyl ~crylate~ ~-butyl acrylate,do~
11 decyl acrylate, dodecyl methacrylate~ ~-eth~lhexyl methacryl-
12 ate, methyl methacrylate and the likeO In this case, acrylic
13 acid and methacrylic ~cid can also be used in place of or in
14 combination with the above acryllc and methacrylic esters.
Many other vlnyl monomer~ can be copolymeriæed with ethylene
16 and will be app~ren~ to those skilled in the artO Non-vinyl
17 monomers such as allyl aceta~e and ita~onic acid can also be
18 usedO The materials obtained by ccpolymerizing more than one
19 monomer also yield terpolymers ~uitable in thi~ application9
such as for example ethylene in combin~tion with vinyl acetate
21 and methacrylic acid9 vinyl propionate and methacrylic acid,
22 vinyl acetate and dibutyl fllm~rate 9 vinyl acetate ~nd mono-
23 octyl maleate provide copolymers useful in this lnventionO
24 The only limita~ion on t~le above polymers is that
2s they con~ain at least 25%, preferably from 25 to 75~ by
26 welght ethylene ln combina~ion with a polar monomer copolymer-
27 izabl~ therewith. Thls poLar monomer is necessary to achieve
28 the proper hydrophillc-lipophilic ratio in said copolymer.
29 Ihe oil-soluble surfac~sn~ ~7hich may b~ used include
anionic, cationic, or nonionlc surfactants
31 Anionic surfactants useful for ~he process of ~he
- 13 -
JL056S3Z
l instant invention include:
2 Carboxylic acids, including fatty acids, rosin
3 acids, tall oil acids, br~nched alkanoic acids~ etc.
4 Alkali metal ~lkane and alkylaryl sulfonates, in-
cluding alkyl benzene sulfonates, alkyl naphthalene sulfon
6 ates, etc.
7 The cationic suractants useful or preparing the
8 compositions of the instant lnvention include:
q Quaternary amine salt~
o Nonionic surfac~ants which ~re the preferred sur-
ll factant type for preparing the compo~itions of the instant
l2 invention~ include the polyethenoxy-ether deri~atives of
alkyl phenols, alkylmercaptans9 and alcohols, e~g., sorbitol,
pentaerythritol, etc~
Particular preferred nonionic surfactants for use
l6 in the instant invention include compounds having the
l7 general formula
18 Rlo ~ ~ ~H2CH20~m - CH2~H2H
ls wherein Rlo may be C8H17, CgHlg 9 or ClOH21 and m is an i
;20 teger varying from 1.5 to 8
21 The most preferred nonionic surfactant is Span*80
22 manufactured by the Atlas Chemical Company) a ~atty acid ester
23 of anhydrosorbi~ol.
24 Since the number of surfactants is ex~remely large,
it is not intended to burden this application with numerous
26 examples. The following publications may be referred to for
27 further examples: Surr e Ch~ L~ by Lloyd I. Osipow~
28 Reinhold Publishing Company, New York (1962) chapter 8 and
29 Surface Activi~, Moilliet et al, Van Nostrand Company, Inc.
(1961) Part III.
- * Trll(lc M.~rk
- 14 ~
--` ~056532
1 Generally; the aqueous interior phase will comprise
2 from 10 to 80 volume % of such an emulsion, preferably from
3 20 to 60 volume %.
4 The surfactant may be incorporated in the external
phase of the emulsion at from 0.01 to 20, pre~erably from 1
6 to 5 weight %~ The copolymer will be incorporated in said
7 external phase a~ from 1 to 40~ preerably from 3 to 30
8 weight %.
9 The ~ollowing are speci~ic embodiments of the in-
stant invention.
11 E:~:
12 To a vigorously stirred ~1~000 to 2,000 RPM) so-
13 lution o~ 13.6 g. of butyl rubber sulfonated to 2% level in
14 186 5 gO of Solvent Neutral*100 at 85C. was added dropwise
186 ml of 10% aqueous sulfuric acid solution. 180 g. of
16 the emulsion thus produced was ad~ed with stirring (150 to
17 250 RPM) to 740 ml of wa~er containlng 1,720 ppm of NH4~ as
18 ammonium hydroxide and 2,800 ppm of sulfide as H2S~ Samples
19 of water solution were with~rawn by a pipette at 1 minute,
5 minute, 15 minute, 30 minute, 60 minute and 90 minute inter-
21 vals by allowing the emulsion to settle and taking a sample
22 of lower aqueous layer. The temperacure w~s m~intained at
23 80 to 85 t~roughout the r-m.
24 The ammonlum concentration gradu~lly decreased to
42 ppm in 3Q minutes and the emulsion was stable over the en-
26 tire length of experiment (90 minutes~
27 EXAMPLE_2
28 The experiment in Example 1 was repeated. The con-
29 centrations of NH4t and S= were 1,7~0 ppm and 2,240 ppm, re-
spectively. In this experiment, steam was passed at 85 C.
. ~ , .
~ i~)56532
l through the mixture with stirring. The concen~ratlon of am-
2 monium ions was reduced in 30 minutes to 34 ppm and sulfide
3 ions to ~20 ppm, The emulsion was ~gain stable over the en-
4 tire length of th~ experiment (90 minutes~.
5 EXAMPLE 3
6 The experimen~ given in Example 1 was repeated ~Is-
7 ing 2.5 wt. % of the sulfcnated butyl rubber in the oil phase~
8 The internal phase cont~ined 2.13 Wto % sulfuric acid. The
9 emulsion was con~acted with ~eed for 5 minu~es. The concen-
tration o~ NH4~ was determined at the beginning and end o
ll the experimentO A~er thi~ t~me, the feed was removed and
12 the same emulsion was contacted with 8 fresh feed for 5 min-
13 utes. The process w~s repeated two more times. The tempera-
l4 ture was maintained a~ 85C. for the entlre length of the ex-
periment. The concentrations of NH4~ în the four feeds were
l6 118, 137, 143 and 186 ppm ~nd were reduced to l/ 1, 1.75 and
17 2 ppm, respect~velyO
18 This demonstrates the $uitability o~ single emul-
l9 sion in repeated applications.
EXAMPLE 4
_
21 The experiment g~ven in Example 1 was repeated with
22 12% Lubrizol 3702 (a prodwct of Iubrl~ol Corp.) in pl~ce of
23 sulonated butyl rubber in the formulation descrlbed therein.
24 The concentration of ammonium lons wPs 2,040 ppm and that of
sulfide ions 1,970 ppm. Within 15 minute~ of the start of
26 the experiment, the entire mass had ~e]led and samples could
27 not be withdrawn for ammonium an~lysisO
28 EXAMPLE S
29 The experiment glven in Example 1 was repeated wiLh
4% PIBSA-TEPA, the reac~ion product of polyisobutylene-succin-
* T~a ~l o Ma rk
_ lh
~0S6S3Z
l ic anhydride and tetraethylene-pentamine and 1% SPAN*80.
2 Within 15 minutes the en~ire reaction mixture had gelled and
3 it was not possible to withdraw samples for ammonium analysis.
4 _ MPLE_6
S The experiment given in Example 1 w~s repeated
6 with initial NH4+ concentr~tion of 1,900 ppm but no H~S~
7 Within 30 minutes the concentration of N~14~ was reduced to
8 3 ppm,
9 Comparison of Effectivenes~ of Pol~mers Sulfonated to Di~fer-
en~ e_ ls _ _ _ _ __ _ ~ _ __ _
11
12 To a vigorously s~irred ~olution o~ 13.6 g. of
l3 butyl rubber (copolymer of isobutylene with 5 mole % isoprene,
l4 same as was used for preparing sulfonated polymers) and 4 g.
lS of surfactant Span*80 in 182.4 g~ of Solvent Neutral*100 was
16 added, dropwise, 166 g~ of 10% sulfuric acid solutionO The
7 resulting emulsion which looked normal at room temperature
8 was heated to 85C~ in order ~o carry out the treatment of
19 sour water. During heating9 the emulsion started breaking
and as the temperature reached 80C~ organic layer separated
21 out completely rom aqueous layer~ This demonstrate~ that
22 the emulsion does not po~es~ any stability under the oper~
23 ating conditions even though an external surfactant was
24 pre~ent.
EXAMPLE 8 - Po~y~er Sulrona ~
26 The experiment given in Example 1 was repeated us-
27 ing the same concentr~tion of butyl rubber sulfonated to 1
28 mole % level. The initial NH4~ concentration of 1,960 ppm
29 was reduced to 4 ppm within 30 m~nutes and the emulsion was
stable over the length of the experlment ~40 minutes).
- 17 -
i O S6 S3 Z
1 EXAMPLE 9 - Polymer Sulfon~ted to 4 Mole /0 Level
2 The e~periment given in Example l was repeated us-
3 ing the same concentration of butyl rubber sulfonated to 4
4 mole % levelr The resulting emulsion was very thick. The
S initial NH~ concentration in the feed w~s 2,040 ppm~ Within
6 l5 minutes the entire mas~ gelled and it was not possible to
7 carry out the experiment further.
8 ~lese experiments demonstrate that about l mole %,
9 sul~onation is desirable in the sulfonic acid polymers used
0 in preparing the compositions of the instant invention;
11 levels greater than about 4% ~r~ not'as efective.
12 The experiments gîven in Examples 9 7 10 and lL were
13 designed to determine the effect of a smaller amount of poly-
14 mer sulfonated to ~% level, on th~ st~bilîty of the membraner
_ MPLE l0 - ~ ~ eveL
16 An emulsion was prep~red by enr,~psulating 186 g. of
17 10% sulfuric aeid solutlon in a soluticn of lo 5 g~ of butyl
18 rubber sulfonated to 4% level in l98.5 g. o~ Solvent Neutral*
19 l00 at 85C, One-hal of this emulsion w~s contacted with a
feed solution containlng l9960 ppm of ammonlum hydroxide in
21- the usual w~y, l~le ~mulslon had a ~endency to stick too much
22 to the sldes of the reaction vessel ~nd showed very poor
23 separability from ~he feed water. In effect 3 quite a signif-
24 lcant part of the emulslon could not be made to contact the
feed solution~ In order for the emulsion to be workable, it
26 is important that the emulsion can b~ easily dispersed in the
27 form of tiny droplets so as to provi~e a very large surface
28 area to effectively and rapidLy remo~e ~ny contaminant. In
29 this case the concentration of NH4+ w~s reduced to 80 ppm in
30 minutes but increased to l0~ ppm in 60 minutes, indicating
56S32
l a we~kne~s of the membrane.
2 EXAMPLE ll - P_ ymer Sulfonated to 4 Mole ~/O Level
3 The experiment given in Example 9 was repeated with
4 3.0 g. o butyl rubber sul~onated to 4% level instead of 1.5
g. as given in the preceding example. The concentration of
6 NH4+ in the feed was 2,1600 ~is concentrat-Lon was reduced
7 to 90 ppm in 30 minutes~ Ho~ever~ the emulsion gelled com-
8 pletely in 55 minutes.
9 These experiments indicate that levels of sulfonated
polymer of at least 1 w~. % in the external phase are desir~
ll able.
12 Comparison of Effecti~eness of Sulfonated Polymers with Dif-
13 ferent Mol _ular Wei~ht _ __________
14 The experimen~s given in Examples 12-14 were de-
signed to det~rmine the effect of` molecular weight on the mem-
16 brane strength an~ efficacy ln tre~tment of sour water. It
l7 was observed that with ccncen~r~tion of polymer in the range
l8 of 3 to 6% emul~ions were very thLck pastes and could not be
l9 handled while the emulsions containing very low concentrations
of sulfonated high molecular weight polymer lacked dimension-
2l al stabillty and had ~ tendeT-cy to gel ~asily.
22 EXAMPLE 12 - Isobutylene-I~oprene Ccpolymer of Molecular
Weight 150,000 (Number Average) Sulfonated to
23 ~ 1. Mo e % I.evel. _ _
24 An emulsion was prepared according to the procedure
2s given in Example 1, using 0~85% of high molecular weight sul-
26 fobutyl (number average 150~000) instead of 6~8% low molecu-
27 lar weight sulfobutyl (number average 15~000). It was con-
28 tacted with a feed solution containing 2,400 ppm of NH4+.
29 The concen~ration of NH4+ was reduced to 21 ppm in 30 minutes,
but soon after this time the entire-m~ss gelled.
~ / 1
~056S3Z
EXAMPLE 13
2 The experiment given in Example 11 was repeated
3 with 0.40% high molecular weight sulfobutyl. It was contacted
4 with a feed solution containing 2J080 ppm of NH4+~ The con-
centration o NH4+ was reduced to 145 ppm in 15 minutes.
6 However, the entire mass gelled in 25 to 30 minutes.
7 E~MPLE 14
8 The experiment given in Example 11 was repeated
9 using 1 wt~ % sulfoEPT (number average molecular weight
o 80,000; prepared by sulfon~ting ethylene propylene-ethyl~
11 idenenorbornene to 1 mole % level) The concentration of
12 NH4 was reduced from 2,040 ppm to 12 ppm in 15 minutes
13 After 60 minutes, however~ the entire mass had emulsified
14 and the concentration of NH4~ had inereased to 25.4 ppma
These experiments indicate that low molecular
16 w.eight sulfonic acid polymers are desirable in prep~ring
17 compositions o~ the inst~nt invention, e~gç molecular weights
18 of from 5,000 to 50,000~
9 Salts of Sulfonated Pol~mers
In order to study the ef~ic~cy as additives in
21 llquid membranes 9 sodium, ammoni.um, and po~assium salts were
22 prepared by neutraliz~tion of low molecular weight (number
23 average molecular weight 15rO00) isohutylene~-isoprene co--
24 polymer sulfonated to 1% and 2% 1evel with corresponding
bases. Attempts were m~de to prepare a 5% solution of these
26 salts in Solvent Neutral*100. All of these salts were in-
27 soluble at 25C~ and 80C.. Of these) the potassium salt of
28 polymer sulfonated ~o 2% level displayed ~he best solubility
29 behavior~ Its use in liquid membrane is described in
3 Ex~mple 15-
- 20 -
` :~056532
1 EXAMP~E 15
2 A 5% solution of the potassium s~lt of sulfobutyl
3 (containing 2 mole % sulfonate groups) w~s prepdred in Sol-
4 vent Neutral*100 by heating to 85C. and adding 0.5 cc of
Bryj*30 of the Atlas Chemical Company, Wilmington, Delaware.
6 An emulsion was prepared rom the solution by encapsulating
7 83 g. of 1% sulfuric acid solution. This emuLsion was con-
8 tacted w~th a feed containing 109 ppm NH4+. In 60 minutes
9 the NH4~ concentration was reduced to 46 ppm. However, the
lo eed was ~ery cloudyO This demonstrates that these salts may
11 have very m~rginal utility as ~embrane additives in sour water
12 tre~tment.
l3 Use of Acids Other Th n Sulfuric Acid_l _ 7 r~a~enc
)4 EXAMPI.E 16
An emulsion was prepared from 100 g~ of a solution
l6 of 6.8 g. of sulfobutyl in Solvent Neutral* 100 as oil phase
l7 and 83 g. of 16.9% ~olyQ_rylic acid ~number average molecular
l8 weight 50,000, a product of Poly~ciences~ Inc ~ Warrington,
l9- Pa.) as the internal phas~O The emuls;on was contacted wi~h
740 g. of an aqueous feed cont~ining 2~400 ppm of N~l4+ at 85.
2l Within 30 mlnutes the concentration of NH4+ was reduced to
22 37.5 ppm and the emul~ion w~s ~table over the entire length
23 of the experiment (90 minutes)O
24 EX~MPLE 17
The experiment given in Example 16 w~s repeated
26 with 28% squeous glutaric acid as internal r~agent. The
27 temperQture of operation w~s 85Co ~nd the feed contained
28 2,020 ppm of N~4 and 19040 ppm of H2S~ After 29 minu~es the
29 concentration of NH4+ was reduced to 78 ppm and H2S to less
than 20 ppm.
* Trade Mark
~L05~;5~
1 When phosphoric acid or succinlc acids are used in
2 the above example similar results are obtained,
3 EXAMPLE_18
4 An emulsion was prep red from 6% by welght of ~ow
s molecular weight sulfobutylg 4 wto % trioctylphosphine oxide,
6 0.1 wt. % of trioctylamine~ and 90 wt, % of Solvent Neutral;~;
7 100 as membrane phase and 4q2 w~, % sodium hydroxide as the
8 aqueous internal phase. The weight ratio of external to in-
9 ternal pha~e wa~ 190 g. of ~his emulsion was contacted,
with agi~ation, with 800 ml, of feed3 containing 77 ppm of
ll chromium as ~odium dichromate ~t pH 106. Within 5 minutes,
l2 the concentr~tion o chromiwm in the feed was reduced to
13 less than 0.5 ppm.
l4 The following e~amples demonstrate the difficulties
encountered in trying to use $~1fona~ed polystyrene, i.eO
l6 arom~tic sulfonatesO It i~ cle~r that these polymers do not
l7 dissolve in the solvent systems which are desir~bly used and
8 if dissolved in a suitable solvent are precipItated upon the
l9 additlon of the desired ~olvent~
FXAMPLE 19
2l To 100 ml of Solvent Neutral*100 was added 2 g, of
22 po]ystyrene sulfonated to 0.81 mole % level, The mixture
23 was magnetically stirred for 24 hours and then filtered. The
24 residue was wAshed with isopropanol~ It was dissolved in
benzene snd precipitated by addition of propanol, The pre-
26 cipitated solid w~s collected and dried, The weight Gf
27 polymer recovered w~s 2.0 g, which amounts to quantitative
28 recovery.
29 EXAMPI T~ 20
-
A solutlon w~s prepared by dissolving 1,5 g of
. ?2 -
~056S3;~
1 polystyrene sulfonate~ ~o 0.8L mole V/o level in lO0 ml of
2 xylene. To the solution~ 100 ml. of Solvent Neutral 100 was
3 added. The polymer precipi~ated as ~n oil. The supernatant
4 liquid was decanted. The polvmer w~s di~solved in 50 ml of
benzene, reprecipitated by pouring into ;sopropyl alcohol,
6 collected and dried. The weight of recovered polymer was
7 1.1 g.
8 EXAMPLE 21
9 In this example, v~riou~ emulsion~ are utilized
in a liquid membrane pro¢ess for the trea~ment of sour water
11 to compare the e~ectiveness of the emuls.ion formulation~
12 The additives were dis~olved at the wei~ht lndicated in
Table I. In ~he inst~nt ex~mple, 183 g. of an emulsion
14 wherein the exterior phase comprised 55 volume % of the emul-
sion and the interio~ phase comprised l~/o ~y weight sulfuric
16 acid ln water~ was contacted with an aqueous feed stream
17 containing various amo~nt~ of ammoni.a and ammonlum ions~
18 The emulsion and the feed stream ~ere contacted in a volum~
19 ratio of 1:4, This contacting too~ place under condit1Ons
of agitation ~200 RPM'sj and a temperature of 85C, As
21 may be noted from the results ln T~ble I D all the emulsions
22 were effective for the removal of ammonia. I~ese specific
23 emulsion formulations have been found tO be the most effec-
24 tive formulations for ~mmonia removal in terms of transfer
through liquid membrane~ i.eO the ex~.ernal phase of the
26 emulsion, into the interior phase~
- 2~. -
1~653Z
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1C~56S32
1 ~le elllUlSiOII USillg etllylene~vinyl ~cetate copolymer
2 settled very quickly~ Thus, upon stopping the stirrer the oil
3 phase and aqueous feed separated almost ins~antaneously with-
4 out le~ving any of the haze which is produced by suspension
of very fine droplets of oil in the feed~ Wi~h the other
6 additive~, lengthy settling time to give clear feeds was
7 required~
8 EXAMPLE 22
_.___
9 In thl~ exp~riment~ emulsions similar to those
lo tested in Example 21 except that ~ 10~ $ulfuric acid interlor
11 phase was u~llized were comp~red or swelling rate. At this
12 higher concentration o~ sulfuric acid which would be commer-
13 cially significant in a liquld membrane sour water treating
14 process wherein the capacity o~ ~he emul~ion for neutraliza-
tion of ammonia ls important, the ethylene vinyl acetate co-
16 polymer showed superiority The next hest composition, based
17 on sulfon~ted butyl rwbber, showed approximately ~hree times
18 as much swell while the sample based on Lubrizol 3702 was
19 completely inoperativ~ in that it gelled in 5 minutes.
The swell was measured in this example by contacting
21 the emulsions with the ammoni~ containing feed stream in a
22 manner similar ~o Example 21. At intervals the mixing was
23 discontinued and the height o the emulsion measured, after
~4 5 minutes settling~ This is a direct indication of swelling
2s propertles of the emulsion. It is clear from the results
26 shown in Table II th~t the composition in the second column
27 is outstanding with respect to lower rate of swelling As
28 discussed above, this property is very valuable in liquid
29 membrane water treating processes.
25 -
.~
1~56532
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