Dewatering compositions and methods
10202551 ยท 2019-02-12
Assignee
Inventors
Cpc classification
International classification
Abstract
The present invention is drawn to dewatering components and methods for their use. As particularly preferred, the invention relates to dewatering components comprising a cationic starch and/or a tannin capable of separating and/or resolving oil-in-water emulsions, water-in-oil emulsions, particularly in crude petroleum oil.
Claims
1. A petroleum-dewatering component comprising a tannin component and a starch component, said starch component consisting essentially of a starch having a cationic charge and a degree of substitution (DS) of greater than 0.3, wherein said petroleum-dewatering component efficiently demulsifies a mixture of oil and water into a water phase having reduced oil, and an oil phase in which water is substantially removed.
2. The petroleum-dewatering component of claim 1 in liquid form.
3. The petroleum dewatering component of claim 2 wherein said starch has a cationic charge has a degree of substitution from 0.31 to about 0.4.
4. The petroleum dewatering component of claim 3 wherein said starch has a cationic charge has a degree of substitution from about 0.32 to 0.4.
5. A petroleum dewatering component comprising a tannin component and a starch component, said starch component consisting essentially of a starch having a cationic charge and a degree of substitution (DS) of greater than 0.3 and at least one additional component selected from the group consisting of: an acid-catalyzed phenol-formaldehyde resin, a base-catalyzed phenol-formaldehyde resin, an epoxy component, an oxide, a polyamine, a quaternized condensate amine, a di-epoxide, a polyol, a metal salt, and an acrylamide, wherein said petroleum-dewatering component efficiently demulsifies a mixture of oil and water into a water phase having reduced oil, and an oil phase in which water is substantially removed.
6. The petroleum-dewatering component of claim 5 comprising a polyol.
7. The petroleum-dewatering component of claim 5 wherein said at least one additional component comprises a metal salt.
8. The petroleum-dewatering component of claim 5 wherein said at least one additional component comprises an oxide.
9. The petroleum-dewatering component of claim 5 wherein said at least one additional component comprises a quaternary condensate amine.
10. The petroleum-dewatering component of claim 5 comprising a synthetic demulsifier other than tannin.
11. The petroleum-dewatering component of claim 5 comprising a biocide.
12. The petroleum-dewatering composition of claim 6 comprising a metal salt.
13. The petroleum-dewatering composition of claim 6 comprising an oxide.
Description
EXAMPLE 1
(1) TABLE-US-00001 Formula 1 Soft Water .3814 LB Cargill Plus 05035 Starch (acid hydrolyzed corn starch) .2318 LB Sodium Hydroxide 50% membrane grade .0570 LB Sodium Hydroxide 50% membrane grade .0308 LB Quat 188 (65%) Cationic Monomer (Dow) .2912 LB Hydrochloric Acid .0058 LB Kathon LX 1.5% .0020 LB
(2) Quat 188 (64%) Cationic Monomer is an aqueous solution of N-(3-chloro-2-hydroxypropyl)trimethylammonium chloride. This reagent can be converted to its epoxide form by treatment with strong base (NaOH); the resulting epoxide is highly reactive with, for example, the hydroxyl groups of carbohydrates such as starch. Kathon LX 1.5% is a microbiocide.
(3) The water and 0.0570 lb of NaOH are combined and heated within a closed container in a water bath to between about 50 C. and about 85 C.; the powdered starch is then added and slurried for 5 minutes. The addition of base at this optional step causes hydrolysis of the polysaccharide and prepares the starch for the subsequent derivitization; it is also thought to open the sheaf of raw starch, thereby causing the granule to become more soluble in water. The treatment with base also degrades the starch backbone and de-protonates hydroxyl moieties within the starch so they will be more susceptible to reaction with the epoxide form of the Quat 188 reagent.
(4) The Quat 188 is then mixed with the second aliquot of NaOH (0.0308), and this solution is slowly added to the suspended starch; because the Quat/NaOH reagent generates heat upon dilution it is added slowly at a rate determined by the overall temperature of reaction; the reaction temperature is preferably not permitted to rise above about 80 C. to about 85 C. The reaction is allowed to continue for about 4 hours with stirring. After the reaction is deemed completed, the hydrochloric acid is added to bring the pH to about 7.5 to about 8.5, and the Kathon LX 1.5% is added as a preservative.
(5) Following reaction, the product cationic starch comprises the ether-linked hydroxypropyl trimethylammonium moiety as follows:
Starch(C)OCH.sub.2CH(OH)CH.sub.2N.sup.+(CH.sub.3).sub.3
EXAMPLE 2
(6) TABLE-US-00002 Formula 2 Soft Water .2994 Cargill Gum 05039 Starch (acid hydrolyzed corn starch) .1692 Sodium Hydroxide 50% membrane grade .0416 Quat 188 (65%) Cationic Monomer (Dow) .0842 Soft Water .3801 Muriatic/Hydrochloric Acid .0205 Kathon LX 1.5% .0050
(7) These reagents are used to produce the cationic starch in much the same manner as for Formula 1, except in this case the partially hydrolyzed starch is not pre-treated with NaOH before addition of the Quat 188 reagent and NaOH. As above hydrolysis is halted by neutralization with HCl, then the Klathon LX 1.5% is added to the solution.
(8) Following reaction and washing, this product cationic starch also comprises the ether-linked hydroxypropyl trimethylammonium moiety as follows:
Starch(C)OCH.sub.2CH(OH)CH.sub.2N.sup.+(CH.sub.3).sub.3
(9) One of ordinary skill in the art will immediately realize that there are myriad ways in which starch may be given a positive charge. For example, and without limitation, reagents such as 1,1,1,n-Tris(3-chloro-2-hydroxypropyl) amine and glycidyl trimethyl ammonium acetate, other ammonium-containing reagents and agents containing amino, imino, euphonium or phosphonium groups can be used in place of the Quat 188 reagent to modify starch and render it cationic. Furthermore, while the above reaction scheme takes place in aqueous solution, there exist many different methods to make cationic starch; see e.g., Kuo et al., C
(10) Similarly, the person of ordinary skill in the art will recognize that starch may be obtained from many different vegetable sources other than corn (including but not limited to potato, wheat, rice, cassava, and tapioca); any such starches may be used in the dewatering components of the present invention. Although not absolutely necessary, it is often desirable that the starch be modified (for example by hydrolysis) prior to derivitization. For example, acid and enzymatic hydrolysis of starch results in the formation of pores within the starch granule, greatly increasing the surface area of the starch granule and thus increasing the potential degree of substitution of the starch with a cationic moiety.
(11) The degree of substitution (DS; number of cationic groups per 100 starch monomers) of the cationic starches of the present invention may range from about 0.0075 to about 0.4 or more. In certain applications it may be desired that the degree of substitution is, for example, from about 0.01 to about 0.4; or from about 0.015 to about 0.4; or from about 0.02 to about 0.4; or from about 0.025 to about 0.4; or about 0.03 to about 0.4; or from about 0.035 to about 0.4; or from about 0.04 to about 0.4; or from about 0.05 to about 0.4; or from about 0.06 to about 0.4; or from about 0.07 to about 0.4; or from about 0.08 to about 0.4; or from about 0.09 to about 0.4; or from about 0.1 to about 0.4; or from about 0.15 to about 0.4.
(12) In other applications it may be desired that the DS is from about 0.01 to about 0.4; or from about 0.01 to about 0.35; or from about 0.02 to about 0.3; or from about 0.01 to about 0.25; or from about 0.01 to about 0.2; or from about 0.01 to about 0.15; or from about 0.01 to about 0.1; or from about 0.01 to about 0.05.
(13) It will be understood that the disclosure of ranges such as those listed above in this specification are intended to disclose, and do disclose and provide a written description of, each and every point between the listed endpoints provided, as expressed as decimal fractions to the nearest 0.01.
(14) In other preferred embodiments of the present invention the dewatering component comprises a cationic starch in combination with a tannin component. Tannins are a family of polyphenolic compounds containing hydroxyl groups and often carboxyl groups; tannins in general tend to form complexes with proteins and other organic compounds and macromolecules. In nature tannins are found in a large number of plant species, including both gymnosperms (such as pines) and angiosperms (such as oaks), molecules called pseudo tannins (which may include gallic acid, flavan-3-ols, clorogenic acid) are found in coffee, cacao, and tea. Additionally, synthetic tannins (synthetic polyphenolic compounds) have been made, such as phenol-formaldehyde based resins, particularly those termed novolacs having a formaldehyde to phenol ratio of less than one and cross-linked with methylene or dimethylene bridges. The presence of tannins can be tested by the ability to precipitate proteins.
(15) Generally, tannins occur in three major classes, classified by the monomer unit of the tannin. In one class, the hydrolysable tannins, the monomer comprises a gallic acid monomer unit. The second class, the non-hydrolysable (or condensed) tannins, the monomer unit is flavone. Both of the first tannin classes can be extracted from plants. The third tannin class, the phlorotannins, is extracted from brown algae, and comprises a phlorogluconol subunit. Particularly in the flavone-derived tannins, the monomer is polymerized and further hydroxylated in order to yield the relatively high molecular weight polyphenol motif characteristic of tannins. A tannin must generally have at least about 12 hydroxyl groups and at least about five phenyl groups to bind proteins substantially. Tannins are generally completely water-soluble. Tannins may have molecular weights ranging from about 500 Da to over 20,000 Da.
(16) Although aqueous tannin solutions are generally at least lightly acid, in certain applications in a dewatering component the tannins may be present in solution as acidified tannins at a pH of about 2. For example, commercially available tannin aqueous solutions such as Floquat FL 5323 (SNF Inc., Riceboro, Ga.), may comprise acidified tannic substances at a concentration of about 25% to about 35% by weight at a pH of as low as about 2. However, tannins can be modified to comprise cationic charges as well; a commercial product called Floccotan comprises amine-modified wattle bark tannins having active amine groups appended thereto to create an amphoteric tannin, depending upon the pH of the solution.
(17) In certain embodiments the dewatering component of the present invention comprises at least one of a cationic starch and a tannin, in combination with at least one additional demulsifier.
(18) Metal demulsifiers include, without limitation, aluminum demulsifiers and iron demulsifers. Aluminum demulsifers include, without limitation, aluminum sulfate, aluminum choride, aluminum chlorohydrate, sodium aluminate, polyaluminum chloride, polyaluminum sulfur chloride, polyaluminum silicate chloride, and forms of any of these salts in conjunction with organic polymers. Iron demulsifers include, without limitation, ferric sulfate, ferrous sulfate, ferric chloride, ferric chloride sulfate, polyferric sulfate, and forms of any of these salts in conjunction with organic polymers.
(19) Additional demulsifiers may also include, without limitation, polymeric demulsifiers. Polymeric demulsifers or derivatives hereof include, without limitation, activated silica, extracts from seeds of the Nirmali tree (which comprise an anionic, mainly proteinacious, demulsifier), natural starches, anionic oxidized starches, amine-treated starches and starch derivatives, guar gums, chitosan, alginates. An advantage of such polymers is that they are biodegradable and virtually toxin free. Synthetic polymers may include, without limitation, acrylate and polyacrylamide-based compounds, pDADMAC-based quaternary ammonium compounds, polyethyleneimine (PEI), other polyamines, and quaternized condensate amines (such as, without limitation, those described in U.S. Pat. Nos. 4,197,350 and 5,750,492).
(20) In preferred (and non-exclusive) embodiments, the dewatering components of the present invention comprise a cationic starch; or comprise a cationic starch and a tannin; or comprise a cationic starch in the absence of a metal salt; or comprise a cationic starch in the absence of an aluminum salt; or comprise a cationic starch in the absence of an iron salt; or comprise a cationic starch and a naturally occurring polymer; or comprise a cationic starch and a synthetic polymer other than tannin; or comprise a cationic starch in the absence of an naturally occurring polymer other than tannin; or comprise a cationic starch in the absence of an synthetic polymer.
(21) In additional preferred (and non-exclusive) embodiments, the dewatering components of the present invention comprise an acidified unmodified tannin; or comprise an acidified modified tannin; or comprise a tannin in the absence of a metal salt; or comprise a tannin in the absence of an aluminum salt; or comprise a tannin in the absence of an iron salt; or comprise a tannin and a different naturally occurring polymer; or comprise a tannin and a synthetic polymer; or comprise a tannin in the absence of another naturally occurring polymer; or comprise a tannin in the absence of an synthetic polymer.
(22) In additional preferred (and non-exclusive) embodiments, the dewatering components of the present invention comprise a cationic starch and at least one additional demulsified component; or a cationic starch and at least two additional demulsifer components, or a cationic starch and at least three additional demulsifer components; or a cationic starch and at least four additional demulsifer components.
(23) In additional preferred (and non-exclusive) embodiments, the dewatering components of the present invention comprise a tannin and at least one additional demulsifer component; or a tannin and at least two additional demulsifer components, or a tannin and at least three additional demulsifer components; or a tannin and at least four additional demulsifer components.
(24) In additional preferred (and non-exclusive) embodiments, the dewatering components of the present invention comprise a tannin and at most one additional demulsifer component; or a tannin and at most two additional demulsifer components, or a tannin and at most three additional demulsifer components; or a tannin and at most four additional demulsifer components.
(25) In additional preferred embodiments the dewatering components of the present invention comprise a cationic starch having a degree of substitution (DS; number of cationic groups per 100 starch monomers) from about 0.0075 to about 0.4 or more, or from about 0.01 to about 0.4; or from about 0.015 to about 0.4; or from about 0.02 to about 0.4; or from about 0.025 to about 0.4; or about 0.03 to about 0.4; or from about 0.035 to about 0.4; or from about 0.04 to about 0.4; or from about 0.05 to about 0.4; or from about 0.06 to about 0.4; or from about 0.07 to about 0.4; or from about 0.08 to about 0.4; or from about 0.09 to about 0.4; or from about 0.1 to about 0.4; or from about 0.15 to about 0.4.
(26) In additional preferred embodiments the dewatering components of the present invention comprise a cationic starch having a degree of substitution from about 0.01 to about 0.4; or from about 0.01 to about 0.35; or from about 0.02 to about 0.3; or from about 0.01 to about 0.25; or from about 0.01 to about 0.2; or from about 0.01 to about 0.15; or from about 0.01 to about 0.1; or from about 0.01 to about 0.05.
(27) In additional preferred embodiments the dewatering composition of the present invention comprises a cationic starch and at least one anionic component.
EXAMPLE 3
(28) TABLE-US-00003 Exemplary Dewatering Component 1 Cationic Starch Preparation of Formula 1 60% (by weight) Floquat FL 5323 acidified tannin preparation 40% (by weight)
EXAMPLE 4
(29) TABLE-US-00004 Exemplary Dewatering Component 2 Cationic Starch Preparation of Formula 2 60% (by weight) Floquat FL 5323 acidified tannin preparation 40% (by weight)
EXAMPLE 5
(30) TABLE-US-00005 Exemplary Dewatering Component 3 Cationic Starch Preparation of Formula 1 50% (by weight) Aluminum Sulfate 50% (by weight)
EXAMPLE 6
(31) TABLE-US-00006 Exemplary Dewatering Component 4 Cationic Starch Preparation of Formula 2 50% (by weight) Polyaluminum chloride 50% (by weight)
EXAMPLE 7
(32) TABLE-US-00007 Exemplary Dewatering Component 5 Cationic Starch Preparation of Formula 1 60% (by weight) Quaternized Amine Condensate 30% (by weight) Aqueous Tannin preparation (25-35% by weight) 40% (by weight)
EXAMPLE 8
(33) TABLE-US-00008 Exemplary Dewatering Component 6 Cationic Starch Preparation of Formula 1 60% (by weight) Anionic polyacrylamide preparation 40% (by weight)
EXAMPLE 9
(34) TABLE-US-00009 Exemplary Dewatering Component 7 Cationic Starch Preparation of Formula 1 30% (by weight) Quaternized Amine Condensate 30% (by weight) Aqueous Tannin preparation (25-35% by weight) 40% (by weight)
EXAMPLE 10
(35) TABLE-US-00010 Exemplary Dewatering Component 8 Cationic Starch Preparation of Formula 1 50% (by weight) Quaternized Amine Condensate 50% (by weight)
EXAMPLE 11
(36) TABLE-US-00011 Exemplary Dewatering Component 8 Cationic Starch Preparation of Formula 1 25% (by weight) Quaternized Amine Condensate 25% (by weight) Polyaluminum chloride 50% (by weight)
EXAMPLE 12
(37) TABLE-US-00012 Exemplary Dewatering Component 9 Cationic Starch Preparation of Formula 2 60% (by weight) Quaternized Amine Condensate 30% (by weight) Aqueous Tannin preparation (25-35% by weight) 40% (by weight)
EXAMPLE 13
(38) TABLE-US-00013 Exemplary Dewatering Component 10 Cationic Starch Preparation of Formula 2 60% (by weight) Anionic polyacrylamide preparation 40% (by weight)
EXAMPLE 14
(39) TABLE-US-00014 Exemplary Dewatering Component 11 Cationic Starch Preparation of Formula 1 30% (by weight) Quaternized Amine Condensate 30% (by weight) Aqueous Tannin preparation (25-35% by weight) 40% (by weight)
EXAMPLE 15
(40) TABLE-US-00015 Exemplary Dewatering Component 12 Cationic Starch Preparation of Formula 1 50% (by weight) Quaternized Amine Condensate 50% (by weight)
EXAMPLE 16
(41) TABLE-US-00016 Exemplary Dewatering Component 13 Cationic Starch Preparation of Formula 1 25% (by weight) Quaternized Amine Condensate 25% (by weight) Polyaluminum chloride 50% (by weight)
EXAMPLE 17
(42) Heavy, hydrated crude oil is fed into the bottom of a gunbarrel tank through a distributor. Simultaneously, Exemplary Dewatering Component 1 is fed into the distributor at a rate calibrated to that of the crude oil flow. The oil, water and dewatering components are dispersed using a spreader plate, if necessary. The rate of oil inflow is calibrated to the residence time required for separation of dewatered oil and water phases. The less dense oil phase rises in the tank, while the water phase occupies the bottom layer; as crude oil is fed into the tank, the dewatered oil reaches an oil outlet at the top of the tank, where it is then permitted to flow to storage. Water outlets at the bottom of the tank are opened as necessary (while flow of crude oil is temporarily halted) to permit the water phase to be removed. Sensors within the tank (or windows built into the tank) indicate the oil level and water level.
(43) The addition of Exemplary Dewatering Component 1 results in one or more of the following advantages obtained as compared to the use of prior art dewatering chemicals: permits the dosage level of chemicals to be reduced, little or no heat to be required during the separation, higher percentage of oil recovery, reduced or absent solids settling after separation, reduced cost of chemicals, biodegradable dewatering components, and less environmentally toxic waste following use of chemicals.
EXAMPLES 18-34
(44) The process of Example 9 is repeated with each of Exemplary Dewatering Component 2-16, with at least one of the following advantages obtained as compared to the use of prior art dewatering chemicals: permits the dosage level of chemicals to be reduced, little or no heat to be required during the separation, higher percentage of oil recovery, reduced or absent solids settling after separation, reduced cost of chemicals, biodegradable dewatering components, and less environmentally toxic waste following use of chemicals.
EXAMPLE 35
(45) Hydrated oil is fed into an induced gas flotation tank. Simultaneously, feed water containing one of Exemplary Dewatering Components 1-16 is also fed into the bottom of the tank. Bubbles are generated in the emulsion using an impeller pump. (Other methods of bubble induction may include an eductor or sparger.) The bubbles adhere to the suspended oil droplets, causing the suspended hydrocarbons to float to the surface and form a froth layer, which is then removed by a skimmer. The froth-free water exits the float tank as the clarified effluent.
(46) The use of the dewatering components of the present invention results in at least one of the following advantages obtained as compared to the use of prior art dewatering chemicals: permits the dosage level of chemicals to be reduced, little or no heat to be required during the separation, higher percentage of oil recovery, reduced or absent solids settling after separation, reduced cost of chemicals, biodegradable dewatering components, and less environmentally toxic waste following use of chemicals.
(47) Those of ordinary skill in the art are aware that the dewatering components of the present invention make be used in methods using other equipment as well, for example, gravity separation or oil/water or API oil and water separators.
(48) Any and all patents, patent publications, or printed publications (including internet publications) cited in this patent application are each hereby individually incorporated by reference herein in its entirety.
(49) While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.