U.S. patent application number 15/075586 was filed with the patent office on 2016-10-20 for low interfacial tension surfactants for petroleum applications.
The applicant listed for this patent is Soane Energy, LLC. Invention is credited to Rosa Casado Portilla, John H. Dise, Robert P. Mahoney, David S. Soane.
Application Number | 20160304807 15/075586 |
Document ID | / |
Family ID | 50148502 |
Filed Date | 2016-10-20 |
United States Patent
Application |
20160304807 |
Kind Code |
A1 |
Soane; David S. ; et
al. |
October 20, 2016 |
LOW INTERFACIAL TENSION SURFACTANTS FOR PETROLEUM APPLICATIONS
Abstract
The invention relates to a class of novel surfactants that have
utility in the recovery and/or extraction of oil.
Inventors: |
Soane; David S.; (Chestnut
Hill, MA) ; Casado Portilla; Rosa; (Peabody, MA)
; Dise; John H.; (Kirkland, WA) ; Mahoney; Robert
P.; (Newbury, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Soane Energy, LLC |
Cambridge |
MA |
US |
|
|
Family ID: |
50148502 |
Appl. No.: |
15/075586 |
Filed: |
March 21, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14608606 |
Jan 29, 2015 |
9315718 |
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15075586 |
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13669206 |
Nov 5, 2012 |
8969612 |
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14608606 |
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|
12958890 |
Dec 2, 2010 |
8742165 |
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13669206 |
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61285385 |
Dec 10, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 8/584 20130101;
C07C 69/593 20130101; C07C 217/42 20130101; C09K 8/604 20130101;
C09K 8/524 20130101; C10G 21/16 20130101; C11D 1/72 20130101; C02F
1/00 20130101; C07C 235/76 20130101; C07C 69/73 20130101; C10G 1/04
20130101; C10G 31/08 20130101; C07C 235/74 20130101; C10G 2300/206
20130101; C10G 1/047 20130101 |
International
Class: |
C11D 1/72 20060101
C11D001/72; C09K 8/524 20060101 C09K008/524; C07C 217/42 20060101
C07C217/42; C07C 235/76 20060101 C07C235/76; C07C 235/74 20060101
C07C235/74; C09K 8/584 20060101 C09K008/584; C07C 69/73 20060101
C07C069/73 |
Claims
1. A compound having the Formula (I): ##STR00034## wherein A is an
alkyl, alkenyl, alkadienyl, alkynyl, cycloalkyl, or cycloalkenyl,
each optionally substituted; p is 1 or 2; each m and n are
independently 0, 1, 2, 3, 4, or 5; each of G.sub.1 and G.sub.2 are
independently absent, O, S, NR.sub.2, C(O)O, OC(O), C(O),
C(O)NR.sub.2, or NR.sub.2C(O), wherein at least one of G.sub.1 and
G.sub.2 is present; each R.sub.2 is independently H or a lower
alkyl; G.sub.3 is absent, (CH.sub.2).sub.q or G.sub.1; each q is
independently 1, 2, 3, 4 or 5; R is a hydrophilic group; and
R.sub.1 is a saturated or unsaturated hydrophobic aliphatic
group.
2. The compound of claim 1, wherein G.sub.1 is selected from the
group consisting of O, S, NR.sub.2, C(O)O, OC(O), C(O),
C(O)NR.sub.2, and NR.sub.2C(O).
3. The compound of claim 1, wherein A is an alkyl or cycloalkyl,
each optionally substituted.
4. The compound claim 3, wherein A is an optionally substituted
C.sub.3-C.sub.8 alkyl, optionally substituted cyclopentyl or
optionally substituted cyclohexyl.
5. (canceled)
6. (canceled)
7. The compound of claim 1, wherein m is 1 or 2.
8. The compound of claim 1, wherein n is 0 or 1.
9. (canceled)
10. The compound of claim 1, wherein G.sub.1 is selected from the
group consisting of OC(O), C(O)O, C(O), C(O)NR.sub.2 and
NR.sub.2CO.
11. (canceled)
12. The compound of claim 1, wherein R is C(O)OH.
13. The compound of claim 1, wherein R.sub.1 is selected from the
group consisting of C.sub.5-C.sub.20 alkyl, C.sub.5-C.sub.20
alkenyl, and C.sub.5-C.sub.20 alkadienyl.
14. The compound of claim 1 having the Formula (Ia): ##STR00035##
wherein t is 0 or 1; and G.sub.4 is O or NH.
15. A compound of Formula (II): ##STR00036## wherein D is an
aliphatic polymer; p is 1 or 2; each m and n are independently 0,
1, 2, 3, 4, or 5; each of G.sub.1 and G.sub.2 are independently
absent, O, S, NR.sub.2, C(O)O, OC(O), CO, C(O)NR.sub.2, or
NR.sub.2C(O); each R.sub.2 is independently H or a lower alkyl;
G.sub.3 is independently absent, (CH.sub.2).sub.q or G.sub.1; each
q is 1, 2, 3, 4 or 5; R is a hydrophilic group; and R.sub.1 is a
saturated or unsaturated hydrophobic aliphatic group.
16. The compound of claim 15, wherein D is selected from the group
consisting of polyethylene glycol, polypropylene glycol,
polyethylene glycol methyl ether, polyetheramine and ethylene
oxide/propylene oxide block copolymer.
17. The compound of claim 15, wherein p is 1.
18. The compound of claim 15, wherein p is 2.
19. The compound of claim 15, wherein each G.sub.1 is independently
selected from the group consisting of OC(O), C(O)O, C(O),
C(O)NR.sub.2 and NR.sub.2C(O).
20. The compound of claim 15, wherein G.sub.2 is absent.
21. The compound of claim 15, wherein R is C(O)OH.
22. The compound of claim 15, wherein R.sub.1 is selected from the
group consisting of C.sub.5-C.sub.20 alkyl, C.sub.5-C.sub.20
alkenyl, and C.sub.5-C.sub.20 alkadienyl.
23. The compound of claim 15, having the Formula (IIa):
##STR00037## wherein t is 0 or 1; and G.sub.4 is O or NH.
24-33. (canceled)
34. A method for extracting oil from an oil mixture comprising: (a)
adding a compound of claim 1, to an oil mixture, and (b) collecting
the oil.
35. A method for extracting oil from an oil mixture comprising: (a)
adding a compound of claim 15, to an oil mixture, and (b)
collecting the oil.
36. The compound of claim 23, wherein D is polyethylene glycol.
37. The compound of claim 23, wherein R.sub.1 is selected from the
group consisting of C.sub.5-C.sub.22 alkyl, C.sub.5-C.sub.22
alkenyl, and C.sub.5-C.sub.22 alkadienyl.
38. (canceled)
39. The compound of claim 38, wherein R.sub.1 is a C.sub.5-C.sub.22
alkenyl.
40. The compound of claim 39 having the Formula (IIb):
##STR00038##
41. The compound of claim 40, wherein the compound is:
##STR00039##
42. A surfactant composition comprising a compound of claim 23 in
an aqueous solution having a pH greater than 8.
43. The surfactant composition comprising a compound of claim 40 in
an aqueous solution having a pH greater than 8.
44. The surfactant composition of claim 42, wherein the solution
comprises sodium hydroxide.
45. The surfactant composition of claim 42, wherein the solution
comprises sodium hydroxide.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/608,606, filed on Jan. 29, 2015, which is a divisional of
U.S. application Ser. No. 13/669,206, filed Nov. 5, 2012 (now U.S.
Pat. No. 8,969,612), which is a continuation-in-part of U.S.
application Ser. No. 12/958,890, filed Dec. 2, 2010 (now U.S. Pat.
No. 8,742,165), which application claims the benefit of U.S.
Provisional Application No. 61/285,385, filed Dec. 10, 2009. The
entire teachings of the above applications are incorporated herein
by reference.
FIELD OF THE APPLICATION
[0002] The application relates generally to surfactants useful for
petroleum applications.
BACKGROUND
[0003] A number of problems in the petroleum industry derive from
the viscosity, surface tension, hydrophobicity and density of crude
oil. Heavy crude oil in particular, having an API gravity of less
than 20 degrees, is difficult to transport due to its viscosity,
and is difficult to remove from surfaces to which it has adsorbed,
due to its hydrophobicity and immiscibility with water. Extra-heavy
crude oil or bitumen, having an API gravity of less than 10
degrees, is heavier than water, so that it can sink to the bottom
of a water formation, causing subsurface contamination.
[0004] The properties of crude oil contribute to the limitations of
oil recovery from traditional oil fields. Conservative estimates
suggest that 30% of the technically recoverable oil in U.S. oil
fields is inaccessible due to the adsorption of the residual oil to
porous geologies. Technologies to unlock the oil in these so-called
"dead" wells presently involve the use of hot water injections with
expensive surfactants, chemistries that are applied to overcome the
hydrophobicity of the adsorbed oil so that it can be mobilized.
[0005] The properties of crude oil also contribute to the
difficulty of environmental remediation following, for example, an
oil spill onto a body of water. The high interfacial tension causes
the oil to float on the water and adhere to plants, animals and
soil. As the aromatic constituents of the oil evaporate, the
heavier residues can sink, contaminating the subsurface structures.
Current treatment of spilled oil on water surfaces relies on
time-consuming and expensive biological degradation of the oil.
Thick, adherent crude oil cause environmental problems in the oil
fields as well. Oil deposits attached to vehicles and equipment
must be cleansed with jets of hot water and caustics.
[0006] The viscosity of heavy crude oil makes the substance
difficult and expensive to transport to upgrading facilities.
Because of its viscosity, a significant amount of energy is
required to pump it through pipelines to a refinery. Furthermore,
the viscosity affects the speed at which the heavy crude oil can be
pumped, decreasing the overall productivity of an oil field.
Exploiting certain oil fields or other oil deposits may be
economically unfeasible to develop at present because of the
transportation-related costs.
[0007] Crude oil, as it is produced, is typically associated with
connate water that can form a stable emulsion with the oil in
multiple phases, including solid-in-oil dispersions, water-in-oil
emulsions, and oil-in-water-in-oil emulsions. Certain hydrocarbon
molecules found in heavy crude oils can act as emulsifiers to
stabilize the various species of water plus oil emulsions. As an
example, asphaltenes and high naphthenic acids, along with
submicron sized solid particles such as silica, clay or other
minerals, can stabilize emulsions such as water-in-oil emulsions
where the heavy crude oil fluid comprises the continuous phase.
Asphaltenes are high-molecular weight, complex aromatic ring
structures that can also contain oxygen, nitrogen, sulfur or heavy
metals. As polar molecules, they tend to bond to charged surfaces,
especially clays, leading to formation plugging and oil wetting of
formations. Asphaltenes tend to be colloidally dispersed in crude
oils, stabilized by oil resins.
[0008] Asphaltenes, paraffinic waxes, resins and other
high-molecular-weight components of heavy crude exist in a
polydisperse balance within the heavy crude fluid. A change in the
temperature, pressure or composition can destabilize the
polydisperse crude oil. Then the heavy and/or polar fractions can
separate from the oil mixture into steric colloids, micelles, a
separate liquid phase, and/or into a solid precipitate. The
asphaltene micelles can be destabilized during well treatments,
e.g., acidizing or condensate treatments, leading to asphaltene
precipitation. Asphaltene precipitation causes problems all along
the crude oil process. Asphaltene precipitation becomes
increasingly problematic when crude oil is processed, transported,
or stored at cooler temperatures, because the heavier components of
crude oil (e.g., asphaltenes and naphthenic acids) that remain
dissolved in the heavy crude under high temperatures and pressures
are no longer supported in that state as the conditions change.
When the heavy crude oil cools to ambient atmospheric temperatures,
these components can precipitate out of the crude oil itself and
lodge at the bottom of a storage vessel or tank to form a viscous,
tarry sludge. These components also become available as emulsifying
agents to sustain water-in-oil emulsions. The emulsion layer has a
higher density than light crude, so that it tends to sink to the
bottom of storage vessels along with the heavy oil components and
associated clay/mineral solids, contributing to the buildup of oil
sludge, a thick waste material formed from the various deposits
sedimenting out from a crude oil mixture.
[0009] As mentioned previously, sludge forms when heavier
components of crude oil separate from the liquid hydrocarbon
fractions by gravity and sink to the bottom of the vessel.
Components of the sludge can include usable hydrocarbons along with
the aforesaid entrained water as a water-in-oil emulsion, along
with a multitude or organic and inorganic components and
contaminants. As the heavier elements in the stored oil continue to
migrate to the vessel bottom, the sludge becomes increasingly
viscous over time. Any given storage vessel can thus contain a
significant amount of sludge, which can diminish storage space for
useful crude oil and which can otherwise reduce the efficiency of
storage tank operation. Sludge may also require removal if the
storage vessel is to be maintained, repaired or inspected.
[0010] Many approaches have been proposed for preventing the
formation of sludge in oil storage vessels such as oil tanks and
oil tankers, and for removing sludges and oily sediments that have
formed. In particular, it is desirable to recapture valuable
hydrocarbons from the sludge as part of the removal process. The
two dominant systems for sludge removal are surfactant-based
approaches and solvent-based approaches. In surfactant-based
systems, aqueous solutions are used to treat the sludge and
coalesce the water droplets emulsified within the oil matrix. The
particular surfactant is designed to overwhelm the surface energy
that is created by the asphaltene/naphthenic acid molecules and
return the aqueous portion to a more-native interfacial tension
with organics. Current surfactant additives have been shown
effective but have commercial limitations because of either high
dosage requirements or ineffective solids interactions. Solvent
systems typically use a mixture of known aromatic and
aliphatic-based organics to decrease the viscosity of the heavier
oil fractions and cause phase separation. Issues of cost and
toxicity, however, have been raised with the use of solvent-based
approaches.
[0011] The development of a technology that can provide emulsion
and favorable transport properties while maintaining the ability to
demulsify on demand, all under variable conditions of salinity,
temperature, pH, etc., remains unmet in the art. Such a technology
would have wide reaching impact across the oilfield chemical sector
in applications such as those mentioned above, particularly if the
material could be inexpensively produced and could be applied to a
variety of oil types.
[0012] Additional uses for a surfactant technology in the oil
industry arise from the problems posed by oil well drilling. When
drilling oil or gas wells, a drilling fluid, referred to as a
"drilling mud," is circulated downwardly through a pipe to reach
the drill bit, lubricating it and carrying away the cuttings from
the drilling process. The clean drilling mud is injected through a
series of pipes called the drill string to reach the bit, and then
flows back up to the surface in the annular area between the drill
string and the inside of the wellbore carrying the cuttings and
other particulate matter. The drilling mud can be water-based or
oil-based. Oil-based drilling fluids include as their base material
any of a number of natural or synthetic oils, including petroleum
fractions, synthetic compounds, blends of natural and synthetic
oils, along with a variety of performance-enhancing additives.
Following drilling, the wellbore annulus must be cleaned to remove
drilling fluids, gelled drilling fluid, residual additives from
drilling fluids, and the like. One cleaning process can take place
before the casing and cementing operations are done, and another
cleaning process is done after the casing is installed. The casing
must be cleaned to a water-wet condition with no oil sheen.
Oil-based drilling fluids, especially synthetic based muds (SBMs),
are particularly difficult to remove from the surfaces they
contact. These oil-based fluids can form invert emulsions upon
contact with water, where the continuous phase is predominantly
organic, and the discontinuous phase is aqueous. This emulsion will
tenaciously coat any surface that it contacts, leading to oil
wetting of borehole surfaces, casing surfaces, and the surfaces of
other equipment that it contacts.
[0013] Wellbore cleaning can involve the use of a sequence of
fluids, each having a specific purpose. In designing the sequence
for the cleaning process, formulations are selected that give
maximum performance while using minimum amounts of material. Also,
the fluids must be chemically and physically compatible, so that an
earlier one does not interfere with the function of subsequent
ones. Cleaning operations must be conducted carefully, so that the
clay components of the drilling mud residue do not come into
contact with water, thereby forming a thick paste that adds to the
difficulty of removal. There remains a need in the art, however,
for a cleaning system that is effective and efficient in removing
drilling mud films and residua from wellbore surfaces. This need is
exacerbated by the prevalence of SBMs, which produce
harder-to-remove films. There is also a need for a cleaning system
that requires less fluid volume than those systems presently in
use. In addition, there is a need for a cleaning system that does
not require or produce hazardous materials.
SUMMARY
[0014] The invention relates to the discovery to surfactant
compounds with utility in recovering or extracting oil, such as
fossil fuels.
[0015] Accordingly, in some embodiments, the invention relates to a
compound having the Formula (I):
##STR00001##
wherein A is an alkyl, alkenyl, alkadienyl, alkynyl, cycloalkyl, or
cycloalkenyl, each optionally substituted; p is 1 or 2; preferably
2; m and n are independently 0, 1, 2, 3, 4, or 5; each of G.sub.1
and G.sub.2 are independently absent, O, S, NR.sub.2, (CO)O, O(CO),
CO, CONR.sub.2, or NR.sub.2CO; each R.sub.2 is independently H or a
lower alkyl; G.sub.3 is absent, (CH.sub.2).sub.q or G.sub.1; q is
1, 2, 3, 4 or 5; R is a hydrophilic group; and R.sub.1 is a
saturated or unsaturated hydrophobic aliphatic group. In certain
aspects, m is 1 or 2 and n is 0 or 1. In some embodiments, at least
one of G.sub.1 and G.sub.2 are present.
[0016] In some embodiments, the invention is compound having the
Formula (Ia): (II):
##STR00002##
wherein t is 0 or 1; G.sub.4 is O or NH; and A and R.sub.1 as
defined above.
[0017] In an additional embodiment, the invention is directed to a
compound of Formula (II):
##STR00003##
wherein D is an aliphatic polymer; p is 1 or 2; preferably 2; m and
n are independently 0, 1, 2, 3, 4, or 5; each of G.sub.1 and
G.sub.2 are independently absent, O, S, NR.sub.2, (CO)O, O(CO), CO,
CONR.sub.2, or NR.sub.2CO; each R.sub.2 is independently H or a
lower alkyl; G.sub.3 is absent, (CH.sub.2).sub.q or G.sub.1; q is
1, 2, 3, 4 or 5; R is a hydrophilic group; and R.sub.1 is a
saturated or unsaturated hydrophobic aliphatic group.
[0018] In certain embodiments, the invention encompasses a compound
having the Formula (IIa);
##STR00004##
wherein t is 0 or 1; G.sub.4 is O or NH; and D and R.sub.1 are as
defined above.
[0019] In a further aspect of the invention, the compound has the
Formula (IIb):
##STR00005##
[0020] In an additional embodiment, the invention relates to a
compound of Formula III:
##STR00006##
wherein E is alkyl, alkenyl, alkadienyl, alkynyl, cycloalkyl,
cycloalkenyl, aryl and heteroaryl;
G.sub.5 is CONH;
[0021] D.sub.2 is a hydrophilic aliphatic polymer; and p is 1 or
2.
[0022] In yet another aspect, the invention encompasses a compound
having the Formula (IV):
D.sub.2-N(J).sub.2;
wherein D.sub.2 is a hydrophilic aliphatic polymer; wherein each J
is independently selected from the group consisting of hydrogen and
the Fragment (A) having the structure shown below;
##STR00007##
wherein E is a hydrophobic group selected from the group consisting
of alkyl, alkenyl, alkadienyl, alkynyl, cycloalkyl, cycloalkenyl,
aryl and heteroaryl; and wherein at least one J is the Fragment
(A).
[0023] The invention also encompasses a compound having the Formula
(V):
(J).sub.2N-D.sub.2-N(J).sub.2;
wherein D.sub.2 is a hydrophilic aliphatic polymer; each J is
independently selected from the group consisting of H and the
Fragment (A):
##STR00008##
wherein E is a hydrophobic group selected from the group consisting
of alkyl, alkenyl, alkadienyl, alkynyl, cycloalkyl, cycloalkenyl,
aryl and heteroaryl; and wherein at least two of J are Fragment
(A).
[0024] The invention also relates to methods for extracting oil
from an oil mixture comprising:
(a) adding a compound of any one of Formula (I), Formula (Ia),
Formula (II), Formula (IIa), Formula (IIb), Formula (III), Formula
(IV) and Formula (V), or a combination of any of thereof, to an oil
mixture, and (b) collecting the oil.
[0025] An oil mixture is a mixture comprising oil and at least one
other component. The oil mixture can comprise oil sands, waterborne
oil slicks or oil deposits. Further, the methods of the invention
can comprise the additional steps of adding water or transporting
the mixture via a pipeline. In another embodiment, the compounds
and compositions of the invention can be used in methods of
degreasing machinery, such as those used in oil or bitumen
production.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 shows comparison photographs of phase separation.
[0027] FIG. 2 shows comparison photographs of solutions prepared at
neutral and acidic pH.
DETAILED DESCRIPTION
General Formulations
[0028] Disclosed herein are compositions, systems and methods
related to ultra-low interfacial tension ("IFT") surfactants for
applications in the petroleum industry. In certain embodiments, the
present disclosure is based on the discovery that multiple
aliphatic-based functionalities can be incorporated onto a single
surfactant molecule. This molecule can include functionality that
allows it to be either surface-active or surface-inactive by
adjusting or "tuning" the surfactant by means of an adjustment of a
parameter such as temperature or pH. Preferably, the application of
a single-molecule, switchable surfactant system is prepared in
aqueous solution. Suitable surfactant solutions for application in
enhanced oil recovery will also display very low interfacial
tension values with both crude oil as well as organics with
aliphatic and aromatic character. Additionally, surfactant
solutions exhibiting only pH switchability will remain in solution
at elevated temperatures, so that they can be inserted into
underground wells, where temperatures may range between
70-100.degree. C.
[0029] For such applications as enhanced oil recovery, the ability
to deactivate a surfactant (i.e., "turn it off") would enable the
user first to create an emulsion of the petroleum to be recovered,
then to transport the oil in an emulsified state, then to easily
separate the oil from the emulsion when it has reached its desired
destination. Controlling the phase state of an oil deposit could
potentially be a useful tool in recovering difficult to access, yet
desirable, sources of oil.
[0030] In one embodiment, compositions of particular use in these
systems and methods can include at least one compound of the
Formula (I), Formula (Ia), Formula (II), Formula (IIa), Formula
(IIb), Formula (III), Formula (IV) or Formula (V) as described
above.
[0031] In some aspects of the invention, the compound has the
Formula (I), (Ia), (II) or (IIa). The invention encompasses
compounds having the Formula (I) or Formula (Ia), wherein A is an
alkyl (e.g., a C.sub.3-C.sub.8 alkyl) or cycloalkyl, each
optionally substituted. In another embodiment, A is an
alkyl-substituted cyclopentyl or cyclohexyl. Examples of
alkyl-substituted cyclohexyl is propylcyclohexyl and
ethylcyclohexyl. In additional aspects, the compound has the
Formula (I), wherein G.sub.1 is selected from the group consisting
of O, S, NR.sub.2, C(O)O, OC(O), C(O), C(O)NR.sub.2 and
NR.sub.2C(O). In yet additional aspects, the compound has the
Formula (I), wherein G.sub.1 is selected from the group consisting
of C(O)O, OC(O), C(O), C(O)NR.sub.2 and NR.sub.2C(O). In yet
further aspects, G.sub.1 is selected from C(O)O and C(O)NR.sub.2.
In additional aspects, the compound has the Formula (I) wherein p
is 1. In yet additional aspects, the compound has the Formula (I)
wherein p is 2. In a further aspect, the invention is a compound of
Formula (I) wherein m is 1 or 2. In yet additional aspects, the
invention is a compound of Formula (I), wherein n is 0 or 1. In yet
another aspect, the invention is a compound of Formula (I), wherein
R is C(O)OH. In a further aspect, the invention is a compound of
Formula (I), wherein R.sub.1 is selected from the group consisting
of C.sub.5-C.sub.20 alkyl, C.sub.5-C.sub.20 alkenyl, and
C.sub.5-C.sub.20 alkadienyl.
[0032] In other embodiments, the compound has the Formula (II) or
(IIa), wherein D is selected from the group consisting of
polyethylene glycol, poly(ethylene glycol)/poly(propylene glycol)
copolymers, polyethylene glycol methyl ether, polyetheramine and
ethylene oxide/propylene oxide block copolymer. In additional
aspects, the compound has the Formula (II), wherein p is 1. In a
further aspect, the compound has the Formula (II), wherein p is 2.
In yet an additional aspect, the compound has the Formula (II),
wherein m is 1 or 2, or n is independently 0 or 1, or a combination
thereof. The invention also includes the compound of Formula (II),
wherein each G.sub.1 is independently OC(O), C(O)O, C(O),
C(O)NR.sub.2 or NR.sub.2C(O). In an additional aspect, the compound
has the Formula (II) wherein G.sub.2 is absent. In a further
aspect, the compound has the Formula (II) wherein R is C(O)OH.
[0033] In certain additional aspects, the compound has the Formula
(IIa) wherein D is polyethylene glycol. In yet another aspect, the
compound has the Formula (IIa) wherein R.sub.1 is selected from the
group consisting of C.sub.5-C.sub.22 alkyl, C.sub.5-C.sub.22
alkenyl, and C.sub.5-C.sub.22 alkadienyl. In yet an additional
embodiment, the compound has the Formula (IIa) wherein D is
polyethylene glycol, R.sub.1 is selected from the group consisting
of C.sub.5-C.sub.22 alkyl, C.sub.5-C.sub.22 alkenyl, and
C.sub.5-C.sub.22 alkadienyl, G.sub.4 is 0 and t is 0. In yet
additional aspects, the compound has the Formula (IIa) wherein D is
polyethylene glycol, R.sub.1 is a C.sub.5-C.sub.22 alkenyl, G.sub.4
is 0 and t is 0. In a further aspect of the invention, the compound
has the Formula (IIb):
##STR00009##
[0034] In further aspects, the compound has the structure shown
below:
##STR00010##
[0035] As described above, compounds of Formula (I), (Ia), (II) and
(IIa) comprise a hydrophilic portion (substituent R) and a
hydrophobic aliphatic group (substituent R.sub.1). In some
embodiments, the aliphatic groups include saturated or unsaturated
carbon chains, preferably between five and twenty units in length,
or five and eighteen units in length, or eight and twenty units in
length, fifteen and twenty-two units in length, or hydrogen. The
carbon chains can optionally be unsaturated and, when present,
reside anywhere along the carbon chain. The hydrophilic portion of
the inventive compounds can comprise one or more hydrophilic groups
or substituents. Hydrophilic portions or groups can be an ionizable
groups, including, for example, amines and carboxylic acids. In
certain aspects of the invention, the hydrophilic group is C(O)OH.
Hydrophilic groups also include hydrophilic polymers, including,
but not limited to, polyalkylamine, poly(ethylene glycol) or
poly(ethylene glycol)/poly(propylene glycol) copolymers. Nonionic
hydrophilic materials such as polyalkylamine, poly(ethylene glycol)
or poly(ethylene glycol)/poly(propylene glycol) copolymers can be
used to increase hydrophilicity or aid stability in salt
solutions.
[0036] In some embodiments, the surfactant compound has the Formula
(III). In certain aspects, D.sub.2 is a polymer or copolymer
containing ether groups. The invention also encompasses a method
for the preparation of a compound having the Formula (III)
comprising reacting an aliphatic or aromatic diacid with a
polyetheramine. In an additional embodiment, the compound has the
Formula (III), wherein E is C.sub.1-C.sub.6 alkyl.
[0037] In an additional embodiment, the surfactant compound has the
Formula (IV) or Formula (V) as described above, wherein D.sub.2 is
a polyether. In certain aspects, E is a C.sub.5-C.sub.20 alkyl,
C.sub.5-C.sub.20 alkadienyl or C.sub.5-C.sub.20 alkenyl.
[0038] The invention also is directed to methods for the
preparation of a compound having Formula (IV) or Formula (V)
comprising reacting an amino-containing polyether with an
epoxy-containing compound. An example of an amino-containing
polyether is a polyetheramine. Non-limiting examples of
epoxy-containing compounds are styrene oxide, 2,3-diphenyloxirane,
phenyl glycidyl ether, 1-naphthyl 2-oxiranylmethyl ether, and
poly[(o-cresyl glycidyl ether)-co-formaldehyde.
[0039] In certain aspects, a lower alkyl is a C.sub.1-C.sub.10
alkyl, C.sub.1-C.sub.6 alkyl, or C.sub.1-C.sub.4 alkyl.
[0040] The compounds described herein can be used as surfactants.
In embodiments, these compounds can demonstrate switchable behavior
under conditions where pH and/or temperature is varied.
Switchability
[0041] In embodiments, the inventive surfactants, such as a
compound of Formula (I), (Ia), (II), (IIa), (IIb), (III), (IV) or
(V), can demonstrate switchable behavior based on pH, where the
surfactant is capable of sustaining an emulsion at a higher pH, but
loses its emulsification properties at a lower pH. In embodiments,
pH switchable surfactants can comprise an ionizable group and a
hydrophobic portion, or an ionizable portion and a hydrophilic and
a hydrophobic portion. The ionizable group on the surfactant reacts
to changes in pH that impact its emulsification properties. For
example, with a decrease in pH, the ionizable group will be in the
protonated form and the surfactant molecule will lose its
solubility in water solution, thereby losing its emulsification
properties. Conversely, if the pH increases, the ionizable group
will be in the ionic form and the surfactant molecule will increase
its solubility in water solution, thus being capable of sustaining
emulsions of oil in water. This behavior is reversible because no
functional groups are cleaved in the process. Non-limiting examples
of surfactants demonstrating this behavior include surfactants
prepared in accordance with Examples 1, 2 and 3 shown below.
[0042] In embodiments, surfactants can demonstrate switchable
behavior based on changes in temperature, whereby they are able to
stabilize emulsions at temperatures below their cloud points but
lose their emulsification properties at temperatures above their
cloud points. In embodiments, temperature switchable surfactants
will have a hydrophobic portion and a hydrophilic portion mainly
containing, for example, ethoxylated groups. Such surfactants can
display solubility in water solutions at temperatures below the
cloud point and will be able to emulsify oil in water. However,
upon increasing the temperature above the cloud point, the
surfactants will lose solubility in water solutions and will lose
their emulsification properties. The behavior is reversible because
no functional groups are cleaved in the process. Non-limiting
examples of surfactants demonstrating this behavior are those
prepared in accordance with Examples 9, 10, 11 and 13.
[0043] In embodiments, surfactants can demonstrate switchable
behavior based on changes in temperature and pH. There are trigger
points for emulsification capability that are determined by pH and
by temperature. Non-limiting examples of such surfactants are those
prepared in accordance with Examples 4, 5, 6 and 7 below.
[0044] In certain embodiments, temperature switchable behavior can
be elicited in compounds having ether groups. For example, PEG or
hydroxyl-terminated ethers such as PPO and PEO (e.g., Pluronics)
can be reacted with anhydrides such as alkene succinic anhydride
(for example, 8, 9, 12 units), and styrene maleic anhydride
copolymers. For example, the surfactant can be the product of a
reaction between PEG and an alkenylated succinic anhydride. In an
additional example, the reaction can be as shown below
##STR00011##
wherein it is understood that
##STR00012##
is a polyethylene glycol.
[0045] In certain embodiments, the polyethylene glycol has a chain
length of 3 to 22. Such a reaction is shown below:
##STR00013##
[0046] Such a reaction is described in the Exemplification section
below, in Examples 4 and 5, for example.
[0047] In other aspects of the invention, the hydrophilic portion
of the surfactant compounds of the invention include one or more
polymers or copolymers containing ether groups. These polymers
impart the compounds with a cloud point. The compounds will display
solubility in water at temperatures below the cloud point and, as a
consequence, are able to emulsify oil. However, upon increasing the
temperature over the cloud point, the compounds become less soluble
in water and show a decrease in emulsification properties. It is
believed that this behavior is reversible because no functional
groups are cleaved in the process. Some non-limiting examples of
these kinds of compounds can be obtained by reacting:
[0048] (i) Amino (primary or secondary)-containing polyethers with
epoxy compounds. Examples of amino-containing compounds are:
polyetheramines, such as JEFFAMINES.RTM. from Huntsman, and other
PEG and PPO/PEG containing primary, secondary amines. Examples of
epoxy compounds include aryl glycidyl ether, such as: styrene
oxide, 2,3-diphenyloxirane, phenyl glycidyl ether, 1-naphthyl
2-oxiranylmethyl ether, and poly[(o-cresyl glycidyl
ether)-co-formaldehyde;
[0049] (ii) Acid groups with amines or alcohols. Examples include
reacting aromatic diacids with a polyether containing (primary or
secondary) amine or hydroxy units. Another embodiment is the
reaction of a polyethylene glycol-diacid terminated with and
aromatic amine or alcohol;
[0050] (iii) Copolymerizing monomers that can form polymers with
LCST such as N-vinylcaprolactam, isopropyl acrylamide or
diethylacrylamide with acrylic acid, followed by reacting the acid
with a alcohol or amine groups, preferably the alcohol or amine
will be slightly hydrophobic (hexyl alcohol, hexyl amine, octyl
alcohol, octyl amine, phenethyl alcohol, etc.).
[0051] In some aspects of the invention, the hydrophilic portion of
compounds of the invention is a combination of: (i) one or more
copolymers containing ether groups, and (ii) one or more ionizable
carboxylic acid groups. In this case, the obtained compound has
emulsification capabilities that are triggered by a change in pH or
temperature. Below a specific pH, the surfactant compound has
emulsification properties under certain temperature conditions.
However, above that pH, the temperature at which the surfactant has
emulsification properties increases. The surfactants are thus
tunable based on changes in pH or temperature.
[0052] In some embodiments, the hydrophilic portion of the compound
comprises an ionizable carboxylic acid group. In yet additional
embodiments, the surfactant composition comprises a compound of the
invention in a basic, aqueous solution. In certain additional
embodiment, the surfactant composition comprises a compound of
Formula (II), (IIa) or (IIb) in a basic, aqueous solution. In yet
another aspect, the surfactant composition comprising a composition
comprises a compound of Formula (II), (IIa) or (IIb) in a solution
comprising sodium hydroxide (NaOH). An example a compound with
ionized carboxylic acid groups is shown below:
##STR00014##
[0053] Exemplary surfactants can be synthesized by reacting: [0054]
(i) PEG and PPO/PEG (hydroxyl terminated) with aromatic anhydrides.
Examples of PEG and PPO/PEG are the PLURONICS.RTM.. Examples of
aromatic anhydrides are phenyl succinic anhydride; [0055] (ii)
Copolymerizing monomers that can form polymers with LCST such as
N-vinylcaprolactam, isopropyl acrylamide or diethylacrylamide with
acrylic acid followed by reacting a fraction of the acid with a
alcohol or amine groups, preferably slightly hydrophobic (hexyl
alcohol, hexyl amine, octyl alcohol, octyl amine, Phenethyl
alcohol, etc.).
Applications
[0056] Environmental Remediation
[0057] By taking advantage of the low IFT behavior of the
surfactant compounds disclosed herein, such surfactants can be
suitable for applications where undesired petroleum products pose
an environmental problem. Oil cleanup using surfactants may be
required for two different types of contamination. First, as an oil
slick dispersant, the surfactant family can be used on waterborne
slicks, acting as a dispersing agent. It will act to disperse the
oil into the water body itself and encourage biodegradation through
natural decomposition means. Additionally, a solution of surfactant
can be used to remove physiosorbed crude or refined oils from
inorganic rocks, sand, or other substrates as an emulsion.
[0058] Oil Sands Extraction
[0059] Oil sands comprise heavy petroleum products coating sand and
clay, an assemblage that is similar to certain artificial
composites that are formed during a man-made oil spill, as
described above. The surfactant compounds and compositions thereof
described herein may be useful for extracting bitumen from the
other components of the tar sands material. Currently, mined oil
sands are extracted using hot water, a process that causes the less
dense bitumen to flow off the sand and float to the surface of a
settling tank. This so-called "primary froth" is contaminated with
various materials derived from the mined products (solid particles,
clay, and sand). Current froth treatment utilizes naphtha, a
valuable fraction of purified petroleum, to dilute the bitumen and
decrease the viscosity to the point of flowability. This allows
solids and water to be removed by settling and centrifugation
methods. By using an aqueous solution of surfactant as the dilution
medium instead of naphtha, the latter solvent can be replaced with
water and surfactant, thus decreasing the cost of purifying the
froth. Additionally, when the surfactant-diluted bitumen is
recovered from the water, the hydrophilic portions associated with
the froth (clay, water, salts) will preferentially partition to the
water phase and be separable from the bitumen.
[0060] Use of the inventive surfactants in accordance with these
systems and methods may further be applied to other aspects of the
extraction process, for example in the oil sands strip mining or
in-situ operations, where the ability to emulsify the petroleum
component of the oil sands ore may enhance the efficiency or
economy of separating the bitumen from the insoluble
byproducts.
[0061] Oil Field Transport Emulsions
[0062] Transporting petroleum precursors for further processing is
a necessary, though expensive, part of obtaining usable crude oil.
When petroleum is obtained as a heavy crude, it needs to be
transported to an upgrading facility for conversion to useful
petroleum products. Typically, pipeline transport is the most
economical means to accomplish this. When oil sands are used as
precursors in the production of synthetic crude oil, they are
transported for further processing after extraction and froth
treatment through pipelines as a naphtha-diluted bitumen so that
they can undergo further upgrading processes, including cracking
and coking, amongst other standard refining operations. For these
types of applications in the petroleum and tar sands industries,
the heavy oil or oil precursor materials (respectively) may be
transported through pipelines as oil-in-water mixtures or
emulsions. It is understood that more viscous matter being sent
through pipelines has a greater resistance to flow and consequently
requires more energy to move an equivalent distance. Hence,
decreasing the viscosity of the flowable matter decreases the
amount of pumping energy required, and potentially improves the
transit time and the productivity of the overall process. Mixing
water with crude oil or bitumen can decrease the viscosity of these
latter substances towards the viscosity of water, but only if a
water-continuous emulsion is created. The surfactants described
herein can compatibilize oil and water into an emulsion that can be
pumped with greatly decreased energy requirements and/or increase
the throughput of crude oil or oil precursors to their
destinations.
[0063] Auxiliary Petroleum Applications
[0064] There also exist many other opportunities in the oilfield
chemical sector for degreasing applications, as can be accomplished
with the systems and methods disclosed herein. Periodically,
machinery used in oil and bitumen production must be cleaned for
maintenance and performance reasons. With petroleum production
heading towards heavier crude reserves, the need for an effective
degreaser becomes even more acute: exposure to heavier crude oils
results in thicker, more adherent oil residues that must be removed
during the cleaning/degreasing processes. The surfactants described
herein can be an active ingredient in an industrial degreasing
formulation for these purposes.
[0065] Enhanced Oil Recovery (EOR)
[0066] Tertiary oil recovery, also known as "enhanced" or
"improved" oil recovery, makes use of low IFT polymers to produce
oil from wells that have stopped producing of their own accord.
Injection of a low IFT surfactant into one of these less productive
wells can stimulate production from the residual oil left adhered
to the surface of porous rocks. The compounds described herein are
useful as low IFT surfactants for EOR.
[0067] Desalting
[0068] Desalting refers to the process of removing salts from oil,
making the oil more suitable for further refining. Salts, including
magnesium chloride, sodium chloride and calcium chloride can be
found in crude oil. If allowed to remain in the crude oil during
the refinery operation, the salts can dissociate and the chloride
ion can ionize to form hydrochloric acid, which, along with various
organic acids found in crude oil, contributes to corrosion in
refinery equipment. In addition, other metal salts (e.g.,
potassium, nickel, vanadium, copper, iron and zinc) can be found in
the crude oil, also contributing to fouling of the equipment and
end-product degradation. Crude oil also contains emulsified water,
which contains dissolved salts.
[0069] Desalting crude oil takes advantage of the fact that the
salts dissolve in a water phase, which is separable from the oil
phase. Crude oil naturally contains water in emulsion, as mentioned
above. For certain techniques of desalting, additional water may be
added to the oil (e.g., in an amount between 5-10% by volume of
crude) so that the impurities can further dissolve in the water.
The water-in-oil emulsion can be broken with the assistance of
emulsion-breaking chemicals and/or by exposing the emulsion to an
electrical field that polarizes the water phase, so that the water
phase bearing the impurities separates from the petroleum phase.
Ethoxylated nonylphenols are a class of nonionic surfactants that
have been used for desalting crude oil according to these
principles.
[0070] The surfactant compounds disclosed herein can facilitate the
demulsification of the water-in-oil emulsion, so that the oil phase
separates from the water phase, with the water phase carrying the
soluble impurities (i.e., the salts). In embodiments, the
hydrophilic portion of the surfactant compound can include one or
more ionizable carboxylic acid groups that can be ionized at a
basic pH (e.g., >8) to produce an emulsion-sustaining material.
In another embodiment, the carboxylic acid groups of a compound of
Formula (IIa) or (IIb) is ionized at a basic pH (for example, at a
pH greater than 8). To destabilize the emulsion, acid may be added,
removing the charge stabilization and allowing the two phases to
segregate from each other.
[0071] Sludge and Tank Bottoms Clean-Up
[0072] In accordance with these systems and methods, an aqueous
surfactant solution comprising an amphiphilic surfactant can be
used to emulsify heavy crude oil components that have settled as a
sludge at the bottom of the oil containment vessel. Such a
surfactant can be injected into the sludge, thereby forming an
oil-in-water emulsion comprising the heavy crude oil components of
the sludge, which emulsion can then be removed from the oil
containment vessel, thereby desludging it. In embodiments, the
sludge to be treated comprises an oil-contaminated sediment that
was created by accidental discharge of hydrocarbons onto the ground
or a body of water. In embodiments, the sludge to be treated
comprises asphaltenes, or it comprises a water-in-oil emulsion.
[0073] In embodiments, the aqueous surfactant includes a
switchable, "smart" surfactant, which can be injected as an aqueous
solution into an oil storage vessel to emulsify the heavy oil
sludge into the water phase with minimal agitation. Establishing
water as the continuous phase of the emulsion for the sludge can
decrease the sludge viscosity so that it can be pumped out of the
storage vessel into an alternate containment system. For example,
the sludge-in-water emulsion can be directed to a distinct
separation vessel, where the emulsion can then be broken, yielding
a phase-separate two-component system comprised of crude oil
fractions suitable for further refining and recovered water
suitable for reuse in similar or other projects.
[0074] In embodiments, several steps will be required for the
surfactant system. First, the surfactant will be injected into the
heavy oil sludge (including the rag layer), so that the surfactant
can destabilize the heavy oil-water interface to invert the
emulsion into the water phase. In this initial phase, an
amphiphilic, water-soluble polymer can be used that is effective at
low concentrations. After this is accomplished, the resulting water
emulsion can be removed from the subject vessel and relocated, for
example to a separation vessel. This may take place as a separate
step after the first step has been completed. In other embodiments,
however, this can take place during the first step. For example,
the water emulsion can be siphoned off as it is formed. As a final
step, the water emulsion containing the stabilized oil droplets can
be demulsified. A change in the conditions of the water emulsion
can change the conformation of the surfactant, so that it breaks
into an oil-soluble component and a water-soluble component. The
oil-soluble component thus demulsifies the heavy oil droplets,
while the water-soluble component remains in the water phase.
Surfactant molecules can be designed so that the water-soluble
byproduct is non-toxic and environmentally safe. The emulsification
and/or separation processes might be carried out at temperatures
above ambient, to facilitate flow and emulsification or to cause
switching of the surfactant properties.
[0075] In embodiments, a surfactant in accordance with these
formulations and methods can be formulated as a polymer that can
emulsify the heavy crudes, but can decompose into one or more
oligomers capable of effecting demulsification. Oligomers suitable
for demulsifying can include: polyethylene oxide/polypropylene
oxide copolymers, cellulose esters, polyethylene/ethylene oxide
copolymers, ethoxylated nonylphenols, and the like. In embodiments,
a random linear copolymer can act as the emulsifying agent. Such a
copolymer can contain regions of ionic charge, such as a quaternary
amine or sulfonate, that would be resistant to the high-salt
environment in the sludge. To create the surfactant effect, the
copolymer could further contain nonionic regions having
hydrophobicity, such as polycarbonate, polystyrene or styrene
maleic anhydride. In the copolymer, a demulsifying oligomer (as set
forth above) can be covalently attached to the nonionic hydrophobic
regions. As a first step using these formulations, the sludge would
be emulsified using the surfactants to form an oil-in-water
emulsion. The emulsion could then be pumped from the subject tank
or other vessel to a suitable separation vessel. Heat could be
optionally added. In the separation vessel, the pH could be altered
so that the covalent linkage holding the demulsifying moieties in
place would be broken. If the covalent bond is a weak one (e.g., an
ester bond), it may be altered by adding heat only. For other
covalent linkages (e.g., ethers and amides), alkali may need to be
added to the emulsion. With the release of the demulsifying agent
from its attachment to the polymer, phase separation of oil and
water would occur. Water and oil could then be directed for further
processing as separate fluid streams.
[0076] Wellbore Cleaning
[0077] Disclosed herein are compounds and methods that have utility
in cleaning wellbores and the like with a multipurpose water-based
formulation that can remove films left behind from the use of
synthetic base muds, and at the same time leave the wellbore
surface in a hydrophilic state. Advantageously, the disclosed
formulations can minimize volumes of cleaning materials utilized
for wellbore cleanout, reduce the amount of waste material produced
and offer tailored formulations for specific films left by
different drilling muds. The hydrophilic regions of the surfactant
compounds disclose herein can attract aqueous fluids to wash away
or break up the oil and the hydrophobic portion can be designed to
have high oil affinity.
[0078] Contaminated Cuttings
[0079] During the drilling process, cuttings are formed that are
contaminated with oil. In many situations, they are considered
hazardous waste because of their oil content, whether from
oil-based drilling fluid or from formation-produced oil. Disposal
of these contaminated cuttings is specialized and expensive,
because of their hazardous waste status. In embodiments, cuttings
generated during the drilling operations can be cleaned using
surfactants disclosed herein. Cleaning the cuttings by removing the
oil may reduce their hazard burden. The use of switchable
surfactants for cleaning cuttings is especially advantageous
because the emulsion can be demulsified in a manner that minimizes
the contaminated wastewater produced and allows recovery of
oil.
[0080] The invention is illustrated by the following examples which
are not meant to be limiting in any way.
EXAMPLES
Materials
[0081] All materials were purchased from Aldrich except those
listed below: PLURONIC.RTM. L64, L35 and L31 were obtained from
BASF Corporation, Florham Park, N.J. 07932, USA. JEFFAMINE.RTM.
ED-900, M-1000, ED-2003, ED-600 were obtained from HUNTSMAN,
Austin, Tex. 78752, USA.
Eka SA 210: EKA Chemicals, Inc., Marietta, Ga. 30062, USA.
Example 1
Reaction Between Alkenylsuccinic Anhydride and Aliphatic
Alcohol
[0082] A reactor was charged with 1,3-butanediol (0.64 g, 7.14
mmol) (Aldrich) and Eka SA 210 brand alkylated succinic anhydride
(5 g, 14.28 mmol). The mixture was stirred for about 4 hours at
130.degree. C. under nitrogen. The product was then analyzed by an
AVATAR 360 FT-IR ("IR"). The sample was run in the "Attenuated
Total Reflectance mode" placing the sample over a Germanium
crystal. The IR spectra showed the almost complete disappearance of
the initial anhydride peaks due to the carbonyl groups (peaks at
1859 and 1778 cm-1), and the appearance of carbonyl peaks at 1735
and 1704 cm-1 due to the formation of ester and acid
respectively.
[0083] Other properties of the product were identified as
follows:
[0084] Solubility in water at 25.degree. C..about.1%.
##STR00015##
Example 2
Reaction Between Alkenylsuccinic Anhydride and Aliphatic
Alcohol
[0085] A reactor was charged with neopentyl alcohol (3.482 g, 33.4
mmol) (Aldrich) and 2-(1-nonenyl) succinic anhydride (15 g, 66.87
mmol) (Aldrich). The mixture was stirred for about 1.5 hours at
130.degree. C. under nitrogen. The product was then analyzed by IR.
The sample was run in the "Attenuated Total Reflectance mode"
placing the sample over a Germanium crystal. The IR spectra showed
the almost complete disappearance of the initial anhydride peaks
due to the carbonyl groups (peaks at 1859 and 1778 cm-1), and the
appearance of carbonyl peaks at 1735 and 1704 cm-1 due to the
formation of ester and acid respectively.
[0086] The product had very limited solubility in water.
##STR00016##
Example 3
Reaction Between Alkenylsuccinic Anhydride and
Cyclohexylethanol
[0087] A reactor was charged with 2-cyclohexylethanol (5.716 g,
44.58 mmol) (Aldrich) and 2-(1-nonenyl) succinic anhydride (10 g,
44.58 mmol) (Aldrich). The mixture was stirred for about 1.75 hours
at 130.degree. C. under nitrogen. The product was then analyzed by
IR. The sample was run in the "Attenuated Total Reflectance mode"
placing the sample over a Germanium crystal. The IR spectra showed
the almost complete disappearance of the initial anhydride peaks
due to the carbonyl groups (peaks at 1863 and 1781 cm-1), and the
appearance of carbonyl peaks at 1734 and 1703 cm-1 due to the
formation of ester and acid respectively.
[0088] Other properties of the product were identified as
follows:
[0089] Solubility in water at 25.degree. C.>1%.
##STR00017##
Example 4
Reaction Between Alkenylsuccinic Anhydride and Polyethylene
Glycol
[0090] A reactor was charged with Poly(ethylene glycol), Mn=1000,
(6.839 g, 6.839 mmol) (Aldrich) and Eka SA 210 brand alkylated
succinic anhydride (4.822 g, 13.68 mmol). The Polyethylene glycol
was dried beforehand in a vacuum oven at about 80.degree. C. for 6
hours. The mixture was stirred for about 6 hours at 130.degree. C.
under nitrogen. The product was then analyzed by IR. The sample was
run in the "Attenuated Total Reflectance mode" placing the sample
over a Germanium crystal. The IR spectra showed the almost complete
disappearance of the initial anhydride peaks due to the carbonyl
groups (peaks at 1859 and 1782 cm-1), and the appearance of
carbonyl peaks at 1731 cm-1 due to the formation of ester.
[0091] Other properties of the product were identified as
follows:
[0092] Solubility in water at 25.degree. C.>10%.
[0093] Cloud point (1% aqueous, pH>5)>90.degree. C.
[0094] Cloud point (1% aqueous, pH<5) 10-40.degree. C.
##STR00018##
Example 5
Reaction Between Alkenylsuccinic Anhydride and Polyethylene
Glycol
[0095] A reactor was charged with Poly(ethylene glycol) (Fluka)
(molecular weigh 380-420) (12.82 g, 32 mmol) and Eka SA 210 brand
alkylated succinic anhydride (22.58 g, 64 mmol). The mixture was
stirred for about 3 hours at 130.degree. C. under nitrogen. The
product was then analyzed by IR. The sample was run in the
"Attenuated Total Reflectance mode" placing the sample over a
Germanium crystal. The IR spectra showed the almost complete
disappearance of the initial anhydride peaks due to the carbonyl
groups (peaks at 1859 and 1778 cm-1), and the appearance of
carbonyl peaks at 1735 cm-1 due to the formation of ester.
[0096] The primary constituent of the product mixture obtained has
the structure shown below:
##STR00019##
[0097] Other properties of the product were identified as
follows:
[0098] Solubility in water at 25.degree. C.>10%.
[0099] Cloud point (1% aqueous, pH>5)>90.degree. C.
##STR00020##
Example 6
Reaction Between an Ethylene Oxide/Propylene Oxide Block Copolymer
and Alkenylsuccinic Anhydride
[0100] A reactor was charged with PLURONIC.RTM. L64 (BASF) (8.8248
g, 3.04 mmol) and 2-(1-nonenyl) succinic anhydride (1.36 g, 6.09
mmol) (Aldrich). The mixture was stirred for about 6 hours at
130.degree. C. under nitrogen. The product was then analyzed by IR.
The sample was run in the "Attenuated Total Reflectance mode"
placing the sample over a Germanium crystal. The IR spectra showed
the almost complete disappearance of the initial anhydride peaks
due to the carbonyl groups (peaks at 1859 and 1782 cm-1), and the
appearance of carbonyl peaks at 1731 cm-1 due to the formation of
ester.
[0101] Other properties of the product were identified as
follows:
[0102] Solubility in water at 25.degree. C.>10%.
[0103] Cloud point (1% aqueous, pH>5)>90.degree. C.
##STR00021##
Example 7
Reaction Between Alkenylsuccinic Anhydride and Polyethylene Glycol
Methyl Ether
[0104] A reactor was charged with Poly(ethylene glycol)methyl ether
(Mn-550) Aldrich (10 g, 18.18 mmol) and 2-(1-nonenyl) succinic
anhydride (4.843 g, 18.18 mmol), Aldrich. The mixture was stirred
for about 3 hours at 130.degree. C. under nitrogen. The product was
then analyzed by IR. The sample was run in the "Attenuated Total
Reflectance mode" placing the sample over a Germanium crystal. The
IR spectra showed the almost complete disappearance of the initial
anhydride peaks due to the carbonyl groups (peaks at 1855 and 1781
cm-1), and the appearance of carbonyl peaks at 1731 cm-1 due to the
formation of ester.
[0105] Other properties of the product were identified as
follows:
[0106] Solubility in water at 25.degree. C.>10%.
[0107] Cloud point (1% aqueous, pH>5)>90.degree. C.
[0108] Cloud point (1% aqueous, pH<5)<90.degree. C.
##STR00022##
Example 8
Reaction Between Polyetheramine and Alkenylsuccinic Anhydride
[0109] A reactor was charged with JEFFAMINE.RTM. ED-900 (XTJ-501)
with MW=900 (HUNTSMAN) (10 g, 11.1 mmol), noneyl succinic anhydride
(5.919 g, 22.2 mmol) (Aldrich) and 15 ml of THF (Aldrich). The
mixture was stirred for about 3 hour at room temperature. Then the
solvent was stripped off under vacuum in a rotary evaporator. The
product was analyzed by IR, which showed complete disappearance of
the anhydride carbonyl peaks (1859 and 1778 cm-1) and the
appearance of the amide and acid carbonyl bands (1645 and 1540 for
amide I and II respectively, and 1731 cm-1 for acid).
[0110] Other properties of the product were identified as
follows:
[0111] Solubility in water at 25.degree. C.>10%.
[0112] Cloud point (1% aqueous, pH>5)>90.degree. C.
##STR00023##
Example 9
Reaction Between an Aliphatic Diacid and a Polyetheramine
[0113] Under a nitrogen atmosphere, an oven-dried reactor was
charged with anhydrous tetrahydrofurane (15 ml) (Aldrich), adipic
acid (0.73 g, 5 mmol) Aldrich, JEFFAMINE.RTM. M-1000 (XTJ-506) with
MW=1000 (HUNTSMAN) (10 g, 10 mmol) and dicyclohexylcarbodiimide
(Aldrich) (2.269 g, 11 mmol). The mixture was stirred overnight at
room temperature. A white precipitate was formed and was removed by
vacuum filtration and discharged. The clear liquid residual that
was obtained was stripped of from solvent under vacuum in the
rotary evaporator and analyzed by IR. The IR spectra showed the
almost complete disappearance of the initial acid band due to
adipic acid (peak at 1692 cm-1), and the appearance of new peaks at
1653 and 1540 cm-1, corresponding to amide.
[0114] Other properties of the product were identified as
follows:
[0115] Solubility in water at 25.degree. C.>1%.
[0116] Cloud point (1% aqueous)>90.degree. C.
##STR00024##
Example 10
Reaction Between Polyetheramine and Hydrophobic Glycidyl Ether
[0117] A reactor was charged with Glycidyl hexadecyl ether
(Aldrich) (5.97 g, 20 mmol), JEFFAMINE.RTM. ED-2003 (XTJ-502) with
MW=2000 (HUNTSMAN, Austin, Tex. 78752, USA) (9 g, 4.5 mmol) and 25
ml of isopropanol. The mixture was stirred for 5 hours under reflux
and under nitrogen. Then the solvent was stripped off under vacuum.
The reaction was monitored by IR following the disappearance of the
915 cm-1 peak (epoxy group) and the appearance of the broad peak at
3500 cm-1 (hydroxy group) The peak at 915 cm-1 disappeared almost
completely with only very small traces left, indicating that the
starting materials have reacted.
[0118] Other properties of the product were identified as
follows:
[0119] Solubility in water at 25.degree. C..about.0.5%.
##STR00025##
Example 11
Reaction Between Polyetheramine and Hydrophobic Glycidyl Ether
[0120] A reactor was charged with Glycidyl hexadecyl ether
(Aldrich) (2.9851 g, 10 mmol), JEFFAMINE.RTM. M-1000 (XTJ-506) with
MW=1000 (HUNTSMAN) (10 g, 10 mmol) and 25 ml of isopropanol. The
mixture was stirred for 5 hours under reflux and under nitrogen.
Then the solvent was stripped off under vacuum. The reaction was
monitored by IR following the disappearance of the 915 cm-1 peak
(epoxy group) and the appearance of the broad peak at 3500 cm-1
(hydroxy group) The peak at 915 cm-1 disappeared almost completely,
with only very small traces left, indicating that the starting
materials have reacted.
[0121] Other properties of the product were identified as
follows:
[0122] Solubility in water at 25.degree. C.>10%.
[0123] Cloud point (1% aqueous) 80-90.degree. C.
##STR00026##
Example 12
Reaction Between Polyetheramine and Hydrophobic Glycidyl Ether
[0124] A reactor was charged with Glycidyl hexadecyl ether
(Aldrich) (5.97 g, 20 mmol), JEFFAMINE.RTM. ED-600 (XTJ-500) with
MW=600 (HUNTSMAN) (6 g, 10 mmol) and 24 ml of isopropanol. The
mixture was stirred for 5 hours under reflux and under nitrogen.
Then the solvent was stripped off under vacuum. The reaction was
monitored by IR following the disappearance of the 915 cm-1 peak
(epoxy group) and the appearance of the broad peak at 3500 cm-1
(hydroxy group) The peak at 915 cm-1 disappeared almost completely,
with only very small traces left, indicating that the starting
materials have reacted.
[0125] Other properties of the product were identified as
follows:
[0126] Solubility in water at 25.degree. C.>1%.
[0127] Cloud point (1% aqueous) 50-57.degree. C.
[0128] The scheme below illustrates this synthesis:
##STR00027##
Example 13
Reaction Between Polyetheramine and Hydrophobic Glycidyl Ether
[0129] A reactor was charged with Glycidyl hexadecyl ether
(Aldrich) (2.985 g, 10 mmol), JEFFAMINE.RTM. ED-2003 (XTJ-502) with
MW=2000 (HUNTSMAN) (10 g, 5 mmol) and 26 ml of isopropanol. The
mixture was stirred for 5 hours under reflux and under nitrogen.
Then the solvent was stripped off under vacuum. The reaction was
monitored by IR following the disappearance of the 915 cm-1 peak
(epoxy group) and the appearance of the broad peak at 3500 cm-1
(hydroxy group) The peak at 915 cm-1 disappeared almost completely,
with only very small traces left, indicating that the starting
materials have reacted.
[0130] Other properties of the product were identified as
follows:
[0131] Solubility in water at 25.degree. C.>10%.
[0132] Cloud point (1% aqueous) 57-60.degree. C.
[0133] The scheme below illustrates this synthesis:
##STR00028##
Example 14
Surfactant Solutions Surface Activity
[0134] Surfactant molecules were tested for their ability to
decrease the surface tension across the aqueous-organic interface.
Interfacial tension (IFT) measurements were conducted using a KSV
Sigma 702 tensiometer with a Du Nouys ring. Surfactant solutions
were prepared at 1% by weight in accordance with Examples 4, 8, 13,
3 and 9, and adjusted to neutral pH with 5 M NaOH. Each aqueous
surfactant solution was tested interfacing with air, toluene, Exxon
ISOPAR M (blend of C.sub.13-C.sub.15 aliphatics) and light crude
oil (API=37.4.degree.). IFT values are reported in Table 1.
TABLE-US-00001 TABLE 1 Interfacial Tension Values for
Aliphatic-based surfactants. IFT IFT IFT IFT w/ w/ w/ w/ air
Toluene ISOPAR Crude Oil Surfactant Name [mN/m] [mN/m] [mN/m]
[mN/m] Deionized Water 71.88 33.12 72.38 a Poly(ethylene
glycol)-bis-[3- 39.10 8.13 6.18 3.69 (2-nonen-1-yl)succinic acid]
ester Polyetherdiamine-bis-[3- 43.20 1.50 10.60 7.37
(2-dedecen-1-yl succinic acid] amide N,N'-bis(3-hexadecyl ether-2-
38.40 6.67 15.95 7.61 hydroxypropyl)polyetherdi- amine
2-(nonen-1-yl)succinic acid 28.68 <0.01 b 0.09 <0.01 mono
(2-cyclohexylethyl) ester N(1),N(6)-dipolyether hexane 40.05 12.90
7.58 7.89 diamide a Interfacial tension exceeded maximum device
limit of XXX mN/m. b Interfacial tension below minimum device limit
of 0.01 mN/m.
[0135] As observed in Table 1, the 1% solution of the molecule
prepared in accordance with Example 3 is of particular interest
because of its low IFT values with all three organic liquids. For
certain applications, such as EOR, it is desirable to have such low
interfacial tensions with crude oils because EOR surfactant
solutions are often used to recover crude oil that is trapped
within the capillaries of rock formations.
Example 15
Surfactant Stability
[0136] Application of the synthesized surfactants are tested for
their ability to emulsify different density oil samples while also
yielding a stable mixture that does not phase separate. In the
experiments listed below, a 2 mL sample of heavy oil
(API=15.0.degree.) was combined with 2 mL samples of 1% by weight
surfactant solutions, including a test surfactant solution, and two
commercial surfactants. The test surfactant solution was prepared
by dissolving 1.01 grams of the molecule prepared in accordance
with Example 3 in 100 mL of deionized water, and neutralizing it
with 0.547 grams of 5M NaOH. The mixture was then shaken by hand
for 10 minutes and set aside. The commercial surfactants Igepal
DM-970 and Tergitol 15-S-30 were used to form 1% by weight
surfactant solutions to compare with the test surfactant. Deionized
water was used as the control. Photographs and phase height
measurements were taken at 5, 30, and 60 minutes as well as 24
hours after mixing. Table 2 displays the percentage of the solution
occupied by emulsion phase over time for each surfactant (test
surfactant and two commercial surfactants). FIG. 1 shows the
behavior of the emulsion over time, and shows a control sample
containing DI-water (without surfactant). This example demonstrates
that the synthesized surfactant of the present invention are
capable of stabilizing heavy oil over long periods of time.
TABLE-US-00002 TABLE 2 Phase stability of surfactant solutions
compared to commercial products. Surfactant % mixture volume
occupied by emulsion solution 5 min 30 min 60 min 1 day Test 93 79
64 36 surfactant (Example 3) Igepal DM-970 21 14 14 14 Tergitol
15-S- 21 14 14 7 30 Deionized 21 14 14 7 water control
Example 16
Surfactant Switchability by pH Variation
[0137] Surfactant switchability can be induced by the adjustment of
mixture pH. Surfactant solutions that exhibit emulsifying
characteristics at neutral pH can be deactivated from surface
activity when the pH becomes acidic. This will allow for controlled
recovery of oil from an otherwise stable emulsion. A test
surfactant was compared to the commercial surfactant Tergitol
15-S-7. The surfactant solution was prepared by dissolving the
molecule prepared in accordance with Example 3 in deionized water
and adjusting the pH to neutral by the addition of 5 M NaOH. Two
oil mixtures were prepared for each surfactant solution: initially
the two mixtures had neutral pH, but after the vials were agitated
and emulsion was formed, a few drops of HCl 10M was added to one of
the vials to decrease the pH to -3.
[0138] In each case, 2 mL of heavy oil (API=15.0.degree.) was added
to 2 mL of 1% by weight surfactant solution, and the vial was
agitated to mix the components. Photographs of the vials were taken
after 5, 30, 60 minutes and 24 hours after mixing, along with
measurements of the height of vial occupied by water phase and
emulsion phase. Table 3 displays the percentage of the solution
occupied by the emulsion phase over time for the test surfactant
solution, the commercial surfactant (Tergitol 15-S-7), and a
control sample containing deionized-water and oil (without
surfactant). The example shows that the surfactants of this
invention can emulsify-demulsify oil depending on the pH of the
mixture.
TABLE-US-00003 TABLE 3 Comparison of emulsion stability at neutral
and acidic pH. % mixture volume occupied Surfactant by emulsion
solution Acid pH 5 min 30 min 60 min 1 day Test (Example 3) No 9
100 99 93 43 Test (Example 3) yes 1 0 0 0 0 Tergitol 15-S-7 No 6 96
93 86 36 Tergitol 15-S-7 Yes 1 93 64 50 29 DI-Water No 6 0 0 0 0
DI-Water Yes 1 0 0 0 0
[0139] FIG. 2 shows the behavior of the emulsion with and without
acid after 5 minutes along with a control sample containing
DI-water (without surfactant) and a 1% solution of a commercial
surfactant Tergitol 15-S-7.
[0140] In addition, a 105 mL sample of heavy oil (API=15.0.degree.)
was combined with 45 mL of a 1% by weight solution of the test
surfactant (prepared in accordance with Example 3), producing a
70:30 oil to water mixture. The mixture was gently stirred until it
was observed it achieved a single liquid phase. Previously, the
viscosity of the neat heavy oil sample was measured at 3431 cP
using a Brookfield DVIII+Rheometer. The 70:30 mixture exhibited a
viscosity of 100.2 cP. Next, 1 mL of 10 M HCl was added and the
mixture was stirred gently, while observing phase separation of the
oil and water. The oil sample was decanted from the container and
obtained the same viscosity measurement as the untreated heavy oil
sample.
Example 17
Removal of Crude Oil from Sand Surfaces
[0141] Samples of oil-contaminated sand were prepared by mixing
50/70 mesh sand with a sample of light crude oil
(API=28.6.degree.). 100 grams of sand were mixed with 10 grams of
oil using a stir rod, until the solid sand was thoroughly coated
and the sample appeared uniform. A muffle furnace set at
650.degree. C. was used to heat a 5 gram sample of oil-contaminated
sand for 3 hours to determine the total organic content.
Additionally, 1% by weight solutions of molecules prepared in
accordance with Example 13 and Example 3 were prepared at neutral
pH by the addition of small amounts of 5 M NaOH. Samples were
stirred using magnetic stir bars until each surfactant was
completely dissolved in solution. In a separate 200 mL jar, 150 mL
of each surfactant solution was added to 30 grams of
oil-contaminated sand.
[0142] After addition of the 1% solution from Example 13, it was
observed that, after moderate agitation by shaking, the contaminant
crude oil was significantly removed from the sand surface. Upon
initially shaking the jar, the oil separated from the sand surface
and became emulsified in the aqueous solution. After leaving the
jar stationary for approximately 5 minutes, the oil remained
emulsified in the aqueous phase, leaving a clean, settled layer of
sand at the bottom. After approximately 30 minutes, slight phase
separation began to occur with oil forming on the top layer of the
water phase.
[0143] Similarly, 30 grams of oil-contaminated sand (10% by weight)
was washed with 150 mL of a 1% surfactant solution from Example 3.
Upon initially adding the aqueous solution to the jar, it was
immediately observed that oil droplets began to separate from the
sand on the bottom of the jar and rise to the water-air interface.
Even with only slight agitation of the jar by tipping, nearly all
of the contamination on the sand was removed. Total oil removal
percentages are presented in Table 4.
TABLE-US-00004 TABLE 4 Oil Removal from Oily Sand % Oil Solution
used remaining in % Oil to wash Oily- Oily-sand Recovery by sand
After Wash Washing None 9.17% DI Water 7.90% 13.86% 1% Example 13
0.75% 91.81% 1% Example 3 0.53% 94.19%
Example 18
Reaction Between an Ethylene Oxide/Propylene Oxide Block Copolymer
and Phenyl Succinic Anhydride
[0144] A reactor was charged with phenyl succinic anhydride (0.564
g, 10.52 mmol) and Pluronic L35 (10 g, 5.26 mmol). The mixture was
stirred for about 4 hours at 130.degree. C. under nitrogen. The
product was then analyzed by IR which showed almost complete
disappearance of the anhydride carbonyl peaks (1859 and 1785 cm-1)
and the appearance of the ester and acid carbonyl band (1731
cm-1).
[0145] Other properties of the product were identified as
follows:
[0146] Solubility in water at 25.degree. C.>10%.
[0147] Cloud point (1% aqueous, pH-8)>100.degree. C.
[0148] Cloud point (1% aqueous, pH-2) 60-100.degree. C.
[0149] The scheme below illustrates this synthesis:
##STR00029##
Example 19
Reaction Between an Ethylene Oxide/Propylene Oxide Block Copolymer
and Phenyl Succinic Anhydride
[0150] A reactor was charged with phenyl succinic anhydride (0.9746
g, 18.2 mmol) and Pluronic L31 (10 g, 9.1 mmol). The mixture was
stirred for about 2.5 hours at 130.degree. C. under nitrogen. The
product was analyzed by IR which showed almost complete
disappearance of the anhydride carbonyl peaks (1859 and 1785 cm-1)
and the appearance of the ester and acid carbonyl band (1731
cm-1).
[0151] Other properties of the product were identified as
follows:
[0152] Solubility in water at 25.degree. C.>10%.
[0153] Cloud point (1% aqueous, pH-8)<64.degree. C.
[0154] The scheme below illustrates this synthesis:
##STR00030##
Example 20
Reaction Between an Aromatic Diacid and a Polyetheramine
[0155] Under a nitrogen atmosphere, an oven-dried reactor was
charged with anhydrous dichloromethane (25 ml), terephthalic acid
(0.831 g, 5 mmol), Jeffamine M-1000 brad polyethermonoamine (10 g,
10 mmol) and dicyclohexylcarbodiimide (2.269 g, 11 mmol). The
mixture was stirred overnight at room temperature. A white
precipitate was formed. This material through a Buchner funnel. The
clear liquid residual that was obtained was stripped of from
solvent under vacuum. The liquid residual product was analyzed by
IR, which showed that a fraction of the starting terephthalic acid
peak was present at 1700 cm-1, and that new amide peaks appeared at
1653 and 1536 cm-1, consistent with the reaction between the
aromatic diacid and the polyetheramine proceeded partially. The
scheme below illustrates this synthesis:
##STR00031##
Example 21
Preparation of Secondary Amine by Reacting a Polyetheramine and
Phenyl Glycidyl Ether
[0156] A reactor was charged with phenyl glycidyl ether (3 g, 20
mmol), Jeffamine M-1000 brand polyethermonoamine (10 g, 10 mmol)
and 25 ml of isopropanol. The mixture was stirred for 5 hours under
reflux and under nitrogen. Then the solvent was stripped off under
vacuum.
[0157] The reaction was monitored by IR following the disappearance
of the 915 cm-1 peak (epoxy group) and the appearance of the broad
peak at 3500 cm-1 (hydroxy group).
[0158] Other Properties:
[0159] Solubility in water at 25.degree. C.>10%.
[0160] Cloud point (1% aqueous) 57-60.degree. C.
##STR00032##
Example 22
Interfacial Tension (IFT) Measurements of Surfactants
[0161] Solutions of surfactants, listed in Table 5 below, were
dissolved in aqueous solution at 1% by weight. Deionized water was
used as the control. Each surfactant was formulated as described
above. The pH of each solution was adjusted to 9 by the addition of
1 M sodium hydroxide. Using a KSV Sigma 702 tensiometer, the
interfacial tension was measured for each solution at the interface
with air, toluene and Exxon ISOPAR M fluid. Values are reported in
Table 5.
TABLE-US-00005 TABLE 5 Table 5: Interfacial tension measurements
for 1% surfactant solutions at the interface of air, toluene and
ISOPAR IFT IFT IFT w/ w/ w/ Exam- air Toluene ISOPAR Compound ple
[mN/m] [mN/m] [mN/m] 1 Deionized Water Control 71.88 33.12 72.38 3
1- 21 41.50 0.93 5.84 [methoxypoly(oxyethylene/ oxypropylene)-
2-propylamino]-3-phenoxy- 2-propanol 4 N,N-bis(3-phenoxy-2- 18
45.77 0.18 7.41 hydroxypropyl)polyether- amine
Example 23
Surfactant Properties
[0162] A solution prepared in accordance with Example 21 was
dissolved into aqueous solution at 1% by weight and the pH was
adjusted to 9 by the addition of 1 M sodium hydroxide, to form a
surfactant solution. 2 mL of light crude (API gravity index=28) was
emulsified at 50:50 volume ratio with the surfactant solution. The
mixture was amply shaken and then left to sit for one hour. After
an hour, no phase separation had occurred. After 2 days of leaving
the emulsion to rest, about 1 mL of water had been separated and
about 0.5 mL of oil had been separated. An emulsion layer remained
in between the separated water and oil layers.
Example 24
Oily Sand Treatment
[0163] 30 grams of washed sand (50/70 mesh) was mixed with 3 grams
of light crude oil (API gravity index=28) by stirring until the oil
was evenly distributed over the surface of the sand. For this
experiment, the surfactant prepared in accordance with Example 21
(Surfactant B) was tested. 150 mL of a 1% surfactant solution was
mixed with the oily sand by sealing in ajar and shaking by hand at
a moderate pace for 5 minutes. The contents of the jar were left to
sit for 1 hour and then the liquid layer was decanted from the
sand. The jar was placed in an oven under vacuum at 100.degree. C.
for 3 hours, then cooled to room temperature. A sample of the dried
sand was weighed and placed in a muffle furnace at 650.degree. C.
for 3 hours, then reweighed to determine the total remaining weight
of hydrocarbon on the sand surface. Table 6 summarizes the effect
of the surfactant solutions.
TABLE-US-00006 TABLE 6 Solution used to wash % Oil remaining in
Oily- % Oil Recovery by Oily-sand sand After Wash Solution None
8.83% Deionized water 7.90% 10.54% 1% Surfactant B 1.60% 81.93%
Example 25
Surfactant Compound in Sodium Hydroxide Solution
[0164] 75.57 g of tap water and 3.10 g of 50% Sodium hydroxide were
added to a beaker. The solution was mixed until homogeneous. 21.33
g product obtained in Example 5 was slowly added while stirring the
solution. The mixing was continued until a homogeneous solution is
obtained. The primary constituent in the solution has the structure
shown below:
##STR00033##
EQUIVALENTS
[0165] While specific embodiments of the subject invention have
been discussed, the above specification is illustrative and not
restrictive. Many variations of the invention will become apparent
to those skilled in the art upon review of this specification.
Unless otherwise indicated, all numbers expressing quantities of
ingredients, reaction conditions, and so forth used in the
specification and claims are to be understood as being modified in
all instances by the term "about." Accordingly, unless indicated to
the contrary, the numerical parameters set forth herein are
approximations that can vary depending upon the desired properties
sought to be obtained by the present invention.
[0166] While this invention has been particularly shown and
described with references to preferred embodiments thereof, it will
be understood by those skilled in the art that various changes in
form and details may be made therein without departing from the
scope of the invention encompassed by the appended claims.
* * * * *