Demulsifiers for separating oil and water mixtures

Details Demulsifiers for separating oil and water mixtures Demulsifiers for separating oil and water mixtures

1999-07-30

2001-01-09

Lovering, Richard D. (Department: 1712)

Colloid systems and wetting agents; subcombinations thereof; pro

Compositions containing an agent for breaking ; processes of...

Continuous liquid phase colloid system and discontinuous...

C210S708000, C507S921000, C516S161000, C516S180000, C516S191000

Reexamination Certificate

active

06172123

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to the separation of oil and water mixtures, and more particularly to the use of demulsifiers to accomplish the separation.
BACKGROUND OF THE INVENTION
In the production of petroleum (crude oil) from underground sources, water flooding is frequently used to increase recovery of the crude oil. In addition, ground water can also be present in the crude oil deposits. It is both essentially and economically advantageous to remove the water before transporting and processing the crude oil. Separating the water from the crude oil is often time consuming and expensive due to the presence of an interlayer positioned at the interface between the oil and water layers. This interlayer is an intimate mixture of oil and water, typically a water-in-oil emulsion, and usually cannot be removed successfully by mechanical procedures such as setting, centrifuging, heat treatment, and electrical fields.
Demulsifiers have been used to aid in the collapse of this interlayer to separate the oil and water present therein with more or less success.
However, there is a continuing need for demulsifiers that are both effective and economical. Demulsifiers currently in commercial use are usually complex mixtures of ingredients, often containing cationic nitrogen compounds that significantly increase the cost of treating the interlayers.
SUMMARY OF THE INVENTION
There has now been discovered low foaming surfactants that have been found to be highly effective when used alone as demulsifiers for preventing or breaking mixtures of oil and water, and which are especially useful in preventing or breaking the above-described interlayer present between oil and water layers obtained in the recovery of petroleum crude oil from underground sources.
The surfactants used in the method of the invention are the branched reaction products of
A) at least one linking compound of formula I
R
1
(X)
3
  (I)
wherein each X group is a halogen atom or one X group is a halogen atom and two X groups with two adjacent carbon atoms in the R
1
group and an oxygen atom from an epoxy group, and R
1
is an alkanetriyl group containing from 3 to 10 carbon atoms;
B) at least one compound of formula II and/or formula III
R
2
(OA)
n
OH  (II)
wherein R
2
is an aliphatic group containing from 3 to 36 carbon atoms, n is a number of from 0 to 200, preferably from 1 to 20, and each OA group is independently an ethyleneoxy, 1,2-propyleneoxy, or 1,2-butyleneoxy group.
R
2
(OA)
n
NH
2
  (III)
wherein R
2
, OA and n have the meanings given above for formula II; and, optionally, one or more of the following components;
C) a polyol containing at least 2 hydroxyl groups, one or more of which can be optionally alkoxylated; and
D) a polyamine containing at least two amine groups, e.g. 2, 3, 4, 5 or 6 amine groups or more, and which can optionally contain alkyleneoxy groups, e.g., a polyether backbone based on ethylene oxide (EO), propylene oxide (PO), or both ethylene oxide and propylene oxide(EO/PO).
It is preferred in the above compounds that when at least one of components C) or D) is present, the ratio of moles of component A) to the sum of the OH and amine equivalents in components B), C), and D) is from 0.5:1 to 0.99:1, and more preferably from 0.8:1 to 0.95:1. However, when the reaction products contain only components A) and B) it is preferred that the mole ratio of component A) to component B) is from 0.5/1 to 5/1, preferably from 0.80/1 to 2/1.
The method of the invention is carried out by adding to an oil and water mixture a quantity of the above branched reaction product or a mixture of two or more of such products in a quantity sufficient to prevent or break the oil and water mixture into its separate components. By the term “break(ing) the oil and water mixture” is meant either complete breaking or separation of the mixture into its separate components or providing a significant reduction in the quantity of the oil and water mixture remaining after the addition of the branched reaction product(s) of the invention such that the oil and water components can be economically separated from each other for oil production.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood as modified in all instances by the term “about”.
In the above reaction products, the linking compound of formula I is preferably epichlorohydrin although other epihalohydrins can be used. Also, trihaloalkanes can be used, such as 1,2,3-trichloropropane, 1,2,4-trichlorobutane, 1,3,6-trichlorohexane, and the like. Instead of chlorine in the epihalohydrins and the trihaloalkanes, the corresponding bromine and iodine compounds can also be used, including compounds containing two or even all three of the above halogens.
The compound of formula II is an aliphatic (optionally alkoxylated) alcohol. The R
2
group in formula II and formula III is preferably a straight or branched chain alkyl group containing from 3 to 36 carbon atoms, more preferably from 8 to 16 carbon atoms. However, the R
2
group can also be a linear or branched alkenyl or alkynyl group, a saturated carbocyclic moiety, an unsaturated carbocyclic moiety having one or more multiple bonds, a saturated heterocyclic moiety, or an unsaturated heterocyclic moiety having one or more multiple bonds. The number of alkyleneoxy groups, i.e. the value for n in formula II and formula III, is preferably from 0 to 100, more preferably from 1 to 20, and most preferably from 2 to 10. The OA groups are preferably all ethyleneoxy groups.
The compounds of formula III are aliphatic (optionally alkoxylated) monoamines. These compounds can be readily prepared from the corresponding alcohols wherein the terminal hydroxy group is replaced by an amino nitrogen. For example, a compound of formula II can be subjected to a catalyzed ammoniation (with ammonia, or a lower alkylamine or lower acylamide) for replacement of the hydroxyl, or to a capping of the hydroxyl with epichlorohydrin followed by ammoniation (with ammonia, or a lower alkylamine or lower acylamide) of the resulting glycidal group. Many of these compounds are available under the tradename Jeffamine, from Texaco Chemical Company, Houston, Tex. as the Jeffamine M series.
The polyols of optional component C) include compounds of formula IV
H(OA)
m
—OH  (IV)
wherein OA is as defined above for the compounds of formula II, and m is a number of from 1 to 500, preferably from 2 to 10.
Also included in the polyols of optional component C) are polyols of formula V
R
3
((OA)
x
OH)
y
  (V)
where R
3
is a straight or branched chain C
3
-C
36
alkyl group, each OA group is independently an ethylenoxy, 1,2-propyleneoxy, or 1,2-butyleneoxy group, each x in each y group is independently a number of from 0 to 200, and y is a number of at least 3, e.g. from 3 to 1,000, preferably from 3 to 74. In formula V, x is preferably a number of from 1 to 200 more preferably from 5 to 100, and the OA groups are preferably all EO groups. Examples of compounds of formula IV include glycerin alkoxylates, trimethylol propane alkoxylates, pentaerythritol alkoxylates, and polyvinyl alcohols, especially those of low viscosity, i.e. having a molecular weight of from 25,000 to 35,000.
The polyamines of optional component D) are preferably those of formula VI
H
2
N(OA)
n
OA—NH
2
  (VI)
in which each A group is independently an ethylene or, 1,2-propylene group, preferably ethylene groups, and n is a number of from 1 to 200, preferably 1 to 5. Compounds of formula VI are commercially available from Huntsman Chemical Company, Houston, Texas as Jeffamine™ D and Jeffamine™ ED series.
In addition, polyamines of the formula VII are also preferred
in which R
4
is a straight or branched chain C
3
-C
35
alkyl group, each OA group is independently an ethyleneoxy or 1,2-propyleneoxy group, and x, y, and z are each independently a number of from 1 to 200,

Affiliated with

Also associated with

Rating

Demulsifiers for separating oil and water mixtures does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Demulsifiers for separating oil and water mixtures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Demulsifiers for separating oil and water mixtures will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2472698