Notes on Demulsification- Theory and Application
Compiled by Chandran Udumbasseri
Demulsifiers – Theory and applications Demulsifier is a chemical used to break emulsions and separate into two phases. Water is separated from crude oil by dozing demulsifier and breaking the emulsion. The emulsion of water in crude oil is thermodynamically unstable but kinetically very stable. Natural surfactants, wax and solids (inorganic salts, zinc, iron, aluminum sulfate, calcium carbonate, silica and iron sulfide) stabilize such emulsions. Asphaltene compounds were found to be one of the contributing materials to the stability of crude oil. Asphaltenes are condensed aromatic rings containing saturated carbon chains and naphthenic rings as substituents along with hetero atoms and metals. Asphaltenes are capable of cross linking at the water drop oil interface and preventing water droplets from coalescence. They are surface active agents present in the oil water interface. Demulsifiers reduce surface tension at the water-oil interface. Demulsifiers are polymers that act as surfactants and counteract the effect of asphaltenes. The polymers have both hydrophilic and hydrophobic groups. The polymeric surfactant, when added to the crude emulsion locates itself in the interface between water and oil molecules. The hydrophilic groups orient themselves towards water while the hydrophobic ones orient themselves towards the oil. At the interface the demulsifier either replaces the emulsifying surfactant or it provides additional steric forces within the film interface. In either case, this absorption causes a random film thickness fluctuation. This random film thickness fluctuation results in an increase in the film surface area and also results in a localized decrease in the absorbed stabilizing emulsifier. Hence causing a local increase in interfacial surface tension and thinning of the film. The following process takes place during the absorption of the demulsifier at the interface: 1. The demulsifier absorbs the stabilizing emulsifier at the water liquid interface and decreases the film forming capability of the emulsifying additives. 2. The demulsifier may render the additives soluble in the water phase and hence less surface active. 3. The demulsifier may mix with the emulsifying additive and reduce the interfacial tension at the water oil interface, there by creating less stable water dispersion. The demulsifiers used for water separation from crude oil are a combination of compounds having demulsifying activity and compounds that assist demulsification but without demulsifying activity. 1. Compounds with demulsifying activity. 1.1. Polyethylene imine alkoxylate. 1.2. Mono or oligo-amine alkoxylate. 1.3. Alkoxylated alkylphenol formaldehyde resin. 1.4. Alkoxylated amine modified alkyl phenol formaldehyde resin. 1.5. Co or ter polymers of alkoxylated acrylates or methacrylates with vinyl compounds. 1.6. Condesates of mono- or oligo- amine alkoxylates, dicarboxylic acids and alkylene oxide block polymers (may be quaternized at nitrogen). 1.7. Cros linked products of 1 to 6.
2. Compounds acting as demulsifying assistant. 2.1. Poly alkylene glycol ethers 2.1.1. General Formula, [R’(OA1)a ..OH]n , R’ = C7 to C20 alkyl group, phenyl group, alkyl phenyl group: A1,A2,A3 = 1,2 alkylene group with 2 to 4 carbon atoms, phenyl ethyl group ( there should be one 1,2 alkylene group with 4 carbon atoms); a = 1 to 50; n = 1 to 10. 2.1.2. General Formula H-(OA1)b-(OA2) c-(OA3) d-OH (where b, c and d each has value from 0 to 50 and b+c+d is >3). Action of Demulsifier. The demulsifier tend to act on the emulsion by: ? Flocculation of oil droplets. ? Dropping of water. ? Coalescence of the water droplets. ? The speed and efficiency at which this occurs can be improved by process equipment design and operating condition (e.g.: Increasing the temperature, separator design, etc.). The components of the demulsifier formulation are characterized according to their primary function. But components can provide multipurpose function in a particular crude oil. Also inclusion of surface wetters can assist in the treating of emulsion problem. Function of different demulsifiers Oxyalkylated Phenolic Resins High molecular weight phenolic resin oxyalkylates have been found to be highly effective as crude oil emulsion breakers. Resins are used on emulsions of the waterin-oil type and work by counteracting the stabilizing influence of naturally present emulsifying agents. They are classified as nonionic surface-active organic chemicals that will not interact with ionic type chemicals. Applications phenolic resin oxyalkylates are generally used in dilute form in aromatic solvent or blended with chemicals of different generic structures to give synergistic formulas which may have greater efficiency. Polyalkylene Glycols Polyalkylene glycols are non-ionic in character. Polyols work by counteracting naturally occurring emulsifiers. Polyols have been found to be particularly effective when used in low salt water brine or in fresh water emulsions. In these cases, polyols are often formulated with sulfonates or used as is. Polyols are stable to hydrolysis. Polyols exhibit exceptional ability to lower interfacial tension and, as a result, have a high degree of wetting activity. For this reason, polyols can effectively disperse or deflocculate solids.
Applications Polyalkylene glycols can be used with effectiveness in synergistic blends with oxyalkylated phenolic resins or with sulfonic acid salts, or in blends of all three, to break crude oil emulsions of the water in oil type. Polymeric Elastomers Polymeric elastomers are used in a variety of geographical locations in standard emulsion breakers. Rapid penetration through the oil phase to finely emulsified water droplets has made them indispensable in many areas. This penetration is vividly demonstrated by the rapid blackening of cream colored emulsions and the quick brightening of water-hazed emulsions. Being extremely oil soluble in nature, polymeric elastomers exhibit great tenacity for finishing the dehydration of crudes where more water-soluble compounds can “wash out” with the water phase of a partially resolved emulsion. Applications Polymeric elastomers may require blending with other emulsion breaker intermediates to achieve complete treatment of water-in-oil emulsion. Polymeric elastomers can be formulated in toluene, xylene, or heavy aromatic solvent, and are compatible with other emulsion breaker intermediates. If necessary, alcohols can be used as brightening or stabilizing agents in these field strength blends. Polymerized Polyols Polymerized polyol intermediates are used in a variety of geographical locations in standard emulsion breakers. Rapid penetration through the oil phase to finely emulsified water droplets has made them indispensable in many areas. This penetration is vividly demonstrated by the rapid blackening of cream-colored emulsions and the quick brightening of water-hazed emulsions. They are extremely oil soluble in nature and exhibit great tenacity for finishing the dehydration of crudes where more water-soluble compounds can “wash out” with the water phase of a partially resolved emulsion. Applications Polymerized polyols typically require blending with other emulsion breaker intermediates to achieve complete treatment of water-in-oil emulsion. Polymerized polyols can be formulated in toluene, xylene, or heavy aromatic solvent, and are compatible with other emulsion breaker intermediates. If necessary, alcohols can be used as brightening or stabilizing agents in these field strength blends. Polyol Esters Polyol esters are a reaction product of a polyalkylene oxide block polymer and a polyfunctional organic acid. Polyol esters are particularly effective on fresh-water emulsions and tend not to cause emulsion inversion or oil-in-water emulsions. Polyol esters act, as do most emulsion breakers, by counteracting the effect of naturally occurring emulsifiers. Applications Polyol esters are an effective emulsion breaker when used separately or in blends with oxyalkylated phenolic resins. This high molecular weight chemical is non-ionic in character.
Resin Esters Resin ester intermediates are reaction products of an oxyalkylated phenolic resin and an organic carboxylic acid. Resin esters are unusually effective when used as a detergent or as a wetting agent in emulsion breaker formulations. Applications Despite resin ester’s high detergency, they do not cause inversion to oil-in-water emulsion. Resin esters have also been used in limited applications as a desalting chemical and in treating slop oils. Sulfonates Sulfonates have outstanding characteristics that include low cost and a resistance to “burning” or “overtreating” when used in formulations to treat crude oil emulsions of the water-in oil type. Sulfonates aid in emulsion breaking by counteracting naturally occurring emulsifiers and are extremely effective in resolving loose water emulsions stabilized by solids. Sulfonates are often used in treating refinery “slop” emulsions as well as tank bottoms. Applications Sulfonate intermediates are generally used in conjunction with oxyalkylated phenolic resins and with polyglycols. The solubility characteristics of sulfonates enable them to work at the oil/water interface where they are extremely effective in resolving loose water emulsion stabilized by solids. Classification Water droppers Water droppers coalesce water droplets in the crude oil and release free water. Predominant type is based on alkyl phenol formaldehyde resins with low levels of addition of ethylene oxide or propylene oxide. These demulsifiers also show excellent desalting properties. Treaters The primary function of these compounds is to flocculate the large number of submicron water droplets dispersed in the crude oil. Water droplets are thus concentrated at the base of the oil column prior to coalescence and the crude is dehydrated above the settling level of the flocs. This can be noticed by the brightening of the top oil in contrast to its dull appearance when the water dispersion existed. The predominant type is based on high molecular poly propylene glycol molecules with hydrophilic ‘tips’which solvate into the water droplets and facilitate gathering. Hybrids These compounds incorporate a balance of molecular design features such that both ‘dropping’and ‘treating’characteristics are exhibited. Hybrids are more cost effective than blends of droppers and treaters.
Desalters The emulsions coming along the crude to the desalting stage have low amounts of water and are less stable. Some of the naturally occurring emulsion stabilizers have been removed at the 1st stage demulsification process. The droplet size is not very small. High potential electric field applied coalesce these polar salt water droplets. A good desalter demulsifier would achieve rapid water separation at low level addition rates. Products from “Uniqema” (Datas are from website) Most of the Uniqema resin alkoxylates (alkylphenol formaldehyde resin alkoxylates) are good water droppers and desalters. Some of them are hybrids of ‘dropping’ and ‘treating’(flocculating water droplets and breaking emulsion). Abbreviations: D: water dropper; S: Desalter; H: hybrid of water dropper and desalter; T: Treater Resin Alkoxylates Product- Kemelix 3501X 3535X 3570X 3575X 3627X D303 D304 D308 D309 D310 D311 D313 D322
RSN 15 19 7 17 12 23 24 17 29 20 18 21 14
Function D D D H D,S H D,S D,S D,S D H,S D D,S
The polyimine derivatives from Uniqema are mostly treaters (flocculants of water droplets) Poly imine derivatives Product- Kemelix 3216X 3422X 3515X 3549X 3551X D510 D513
RSN 9 8 9 9 10 11 8
Function H T,S T T T T,S T
The polyols from Uniqema show mixed primary functions and modified polyols function as treaters and hybrids. Polyol Product- Kemelix D501 D502 D503 D511 Synperonic T701 Synperonic PEL 64 Synperonic PEL 101
RSN 22 13 19 12 16 22 12
Function D T H T H,S D H
Modified Polyol Product- Kemelix 3503X 3504X 3566X 3584X D317 D400 D401
RSN 8 16 7 10 9 6 7
Function T H H T T H H
RSN 16
Function D, unusual base, can be used anywhere Excellent resin blnds withDP318 and DP215 D, better water dropper than DP280 Works better with DP318 and DP188 Similar to DP479 Specific for Arabian gulf and north Africa
Products from “Majorchem” Resin alkoxylates Product DP 196 DP280
16
DP 292
17
DP 479
9
DP493 DP510
9 8
Polymer initiated Block Polymers Product RSN DP188 16 DP314
8
DP318
8
EO/PO Co-Block Polymers Product DP215
RSN 13
DP216
22
DP285
15
DP336
20
Function Hydrophilic version of DP318 More hydrophobic than DP318 Good emulsion breaker Blends well with Block polymers and resin bases
Function Main base for water soluble formulations Very hydrophilic; chief use is low percentage component to improve water drop and interface. Spectacular at water dropping but tend to leave B.S. Instant and complete treatment on some crude, but higher dosage than normal
Formulation Product DP193
RSN N/A
Function Unusual base
Diepoxides Product DP751
RSN 6
Function Mostly for Arabian gulf and particularly useful when DP-188 and DP318 are not good enough on any specific crude
Special functions of Uniqema products Low temperature demulsification These products are designed to treat crude oil at ambient or low temperature with greatest efficiency. Polyimine alkoxylates-Kemelix Product RSN D510 11 D513 8 3418X 14 3422X 8 3515X 9 3551X 10
Desalters from Uniqema These products are good at desalting Product -Kemelix D308 D309 D310 D311 D510 D511 3501X 3575X 3678X
Chemical type Resin ethoxylate Resin ethoxylate Resin alkoxylate Resin alkoxylate Polyimine alkoxylate Polyol Resin alkoxylate Resin ethoxylate Resin ethoxylate
RSN 17 29 20 18 11 12 15 17 21
Chemical type Resin alkoxylate Resin alkoxylate Modified Polyol Polyol Imine Polyol Polyimine alkoxylate Polyimine alkoxylate Polyimine alkoxylate Polyimine alkoxylate Polyimine alkoxylate
RSN 20 16 6 19 11 12 8 14 8 9 10
Uniqema Dehazers Product -Kemelix D310 D311 D400 D503 D510 D511 D513 3418X 3422X 3515X 3551X
Heavy Oil demulsifiers from Uniqema Product -Kemelix D310 D311 D313 D322 D400 D401 D501 D510 Synperonic T701 3422X 3424X 3501X 3515X 3551X 3575X 3627X 3678X
Chemical type Resin alkoxylate Resin alkoxylate Resin alkoxylate Resin ethoxylate Modified Polyol Modified Polyol Polyol Polyimine alkoxylate Polyol Polyimine alkoxylate Resin alkoxylate Resin alkoxylate Polyimine alkoxylate Polyimine alkoxylate Resin ethoxylate Resin alkoxylate Resin ethoxylate
RSN 20 18 21 14 6 7 22 11 16 8 20 15 9 10 17 11 21
Note RSN is the Relative Solubility Number of the solvent stripped demulsifier. Products with an RSN<13 are insoluble in water. Products with RSN 13 – 17 are dispersible and products with RSN >17 are considered soluble in fresh water.
Preparation of demulsifier bases The methods of preparation of demulsifiers are taken from various U.S. Patents that were developed in their laboratories. Initially the intermediate product, resin (alkyl phenol formaldehyde resin, Polyalkylene poly imine resin, Polyalkylene resin, intermediate amine, polyoxyalkylene glycol, polyoxyalkylene glycol-diglycidyl ether condensate, polyamidoamine, vinyl polymers) is prepared. This product is then condensed with ethylene oxide, propylene oxide or butylenes oxide or their mixture to make oxyalkylate. As the number of molecules of alkylene oxide increases the solubility of the resin in water increases. Depending on the requirement of degree of solubility in oil/water the ratio of resin to alkylene oxide is varied.
Alkyl phenol formaldehyde resin ethoxylate/propoxylate Phenol reacts with formaldehyde at ortho and para sites allowing 3 molecules of formaldehyde to attach to the ring. Further reaction takes place between mono, di ant tri hydroxymethyl phenol, phenol and formaldehyde and eliminating water molecules and causing polymerization.
Resin ethoxylate/propoxylate The free phenolic groups in the resin are reacted with ethylene oxide and propylene oxide to form resin ethoxylate / propoxylate. More ethylene oxide undergoes condensation reaction with more phenolic groups giving resin alkoxylates with higher molecules of alkylene oxides. The hydrophilic nature of the resin increases as the number of alkylene oxide molecules attached to the resin increases.
Example Preparation of p-t-butyl phenol formaldehyde resin from p-t-butyl phenol and para formaldehyde A reactor was charged with 24.5 lbs. of para-tert-butyl phenol, 6 lbs. of para formaldehyde and 57.25 lbs. of xylene. The above charge was heated to 50oC. and 0.213 lbs. of 50% aqueous sodium hydroxide was added. The product was now heated to 90oC and held there for 0.5 hour, then heated to reflux. Reflux began at 135oC. and gradually increased to 145oC under azeotropic conditions to remove 4.0 lbs. aqueous layer and 2.25 lbs. solvent. Total time at reflux was 41/2 hours. After cooling to 50oC, the product was dropped. Some solid stayed behind because it had caked out on the coils. Analysis of the material so obtained indicated 77-80% yield of the desired cyclic tetramer. Preparation of Resin oxyalkylate General procedure for the oxyalkylation of cyclic phenol-formaldehyde tetramers Pure cyclic tetramer and 3 to 5% by weight of KOH, dissolved in an equal amount of water, are heated together with two to four times their weight of xylene, under azeotropic reflux, until catalyzation is complete and no more water can be removed. This usually takes from 3 to 6 hours depending upon the batch size. Since the tetramer is very poorly, if at all, soluble in the xylene, it is essential that efficient rapid stirring is needed to keep the very finely dispersed solid homogeneously distributed throughout the liquid. The mixture is then transferred to a pressure reactor or autoclave equipped with a means of external (electric) heating, internal cooling and efficient mechanical agitation. The resin is heated to 120oC -140oC and the alkyleneoxide or mixture of oxides is charged into the reactor until the pressure is 2575 p.s.i. During the ensuing oxyalkylation reaction the original suspension gradually clears up and after all the oxide has been added and the reaction has been completed, which usually takes from 2 to 12 hours depending upon the nature of the reactants, the resulting product solution, the oxyalkylated derivative of the cyclic tetramer, now completely soluble in xylene, is cooled and ready to be applied for demulsifier use.
Polyethylene imine oxyalkylate
Polyethylene-imine Polyalkylene-polyamines may be obtained from ethyleneimine and/or propyleneimine by the conventional method. Preferably, ethyleneimine is used as the starting material. The polyalkylenepolyamines have at least two recurring alkyleneimine units per molecule. Polyethyleneimines comprising from 10 to 3,000 recurring ethyleneimine units are used for oxyalkylate preparation. n
CH2-CH2
? -[CH2-CH2- NH]n-
NH Ethylene imine ? Polyethylene polyimine Where “n” can have values from 10 to 3000
Polyethylene imine oxyalkylate The oxyalkylation of polyethylene imine may be carried out with any common alkylene oxide, e.g. ethylene oxide, 1, 2-propylene oxide, 1, 2- and 2,3-butylene oxide, isobutylene oxide, styrene oxide or cyclohexene oxide, amongst which propylene oxide and ethylene oxide should be singled out particularly. - [CH2-CH2- NH] n- +
CH2-CH2 ? O
Poly(ethylene imine)
Ethylene oxide
- [CH2-CH2- N] n CH2-CH2-O-H Polyethylene imine oxyalkylate . The polyalkylenepolyamines can be reacted with the various alkylene oxides by using these either individually or as a mixture and (in the latter case) the reaction can take the form of a block copolymerization or a random copolymerization. If the reaction is carried out in two steps, the alkylene oxide may, in the first step, again be used individually using the same procedure. Preferably, either propylene oxide alone is used, or propylene oxide and ethylene oxide are used and are reacted by block copolymerization. In the latter case, 1, 2propylene oxide is introduced in the first step in order to form the corresponding propanolamine, and thereafter further propylene oxide and, finally, ethylene oxide are
introduced, satisfactory results being obtained with a ratio of propylene oxide to ethylene oxide of up to 1:15. However, the converse procedure can also be used, i.e. ethylene oxide can be introduced first, followed by propylene oxide, in which case the ethylene oxide: propylene oxide ratio is advantageously from 20:1 to 1:20. Both embodiments can be carried out in one step or in two steps. Preparation (by the 2-step method) of component B, containing about 100 recurring propylene oxide units per nitrogen valency First Step: 172 g (2 mole equivalents) of a 50% strength aqueous solution of a polyethyleneimine containing about 100 recurring ethyleneimine units are introduced into a stirred autoclave and 116 g (2 moles) of propylene oxide are introduced in portions at 90oC to 100oC Time: 3 hours; pressure: 6 atmospheres gauge; temperature; 90oC to100oC. The water is then removed by distillation at 100oC /15-20 mm Hg. Second step: 15.6 g (0.15 mole) of the product from step 1 and 0.624 g (4 percent by weight, based on 1.) of KOH powder are introduced into a stirred autoclave and thereafter 687 g (11.85 moles) of propylene oxide are introduced in portions at 135oC and 132 g (3 moles) of ethylene oxide are introduced in portions at 125oC. Time: 6 hours (PrO); pressure: 6-8 atmospheres gauge; temperature: 135oC (PrO), 2 hours (EO); 125oC (EO). The mixture is then stirred for 4 hours until the pressure remains constant. The product obtained can be used directly. It consists of the polyethyleneimine which now contains about 80 moles of propylene oxide and 20 moles of ethylene oxide as adduct.
Amine Oxyalkylates: Into a stainless steel autoclave with the usual devices for heating, heat control, stirrer, inlet, outlet, etc., which is conventional in this type of apparatus was charged 500 grams of triethylene tetramine, 300 grams of xylene, and 15 grams of sodium methylate. The autoclave was sealed, swept with nitrogen gas and stirring started immediately and heat applied. The temperature was allowed to rise to approximately 145oC. At this particular time the addition of butylene oxide was started. The butylene oxide employed was a mixture of the straight chain isomer substantially free from isobutylene oxide. It was added continuously at such speed that it was absorbed by the reaction as added. The amount added in this operation was 1500 grams. The time required to add the butylene oxide was two hours. During this period the temperature was maintained at 130 to 145oC. using cooling water through the inner coils when necessary and otherwise applying heat if required. The maximum pressure during the reaction was 50 pounds per square inch. (NH2) 2CH-CH2-CH2-CH2-CH2-CH (NH2) 2 +
CH3CH-CH2 ?
O Triethylene tetramine Propylene oxide (NH2) 2CH-CH2-CH2-CH2-CH2-(H2N) CH NH - (CH3)CH-CH2-OH Triethylene tetramine mono propoxylate
Polyalkylene oxyalkylate Block polymers 1. Preparation of Low Molecular Weight Pentaerythritol Polyol with Propyleneoxy and ethyleneoxy block polymers. A 5-gallon pressure reactor equipped with mechanical stirrer was charged with 3 lb. of pentaerythritol 24-molar propoxylate and 14 g KOH. Water was removed by vacuum treatment at 100 to 100oC, followed by addition of 4 lb. propylene oxide at 115 to 120oC. This product had hydroxyl number of 88.2. Three pounds of this material was charged to a 5-gallon pressure reactor and treated with 7 pounds ethylene oxide at 115oC. The final product had a molecular weight of 8400, basis the hydroxyl number and contained 70% ethylene oxide by weight. C[CH2O-{CH(CH3)-CH2-O}6-H] 4 + (CH3)CH-CH 2 ? Polymer product O Pentaerythritol 24 propoxylate + CH2-CH2 ? O Polyalkylene propoxy ethoxylate Block polymer 2. Preparation of High Molecular Weight Pentaerythritol Polyol with Propyleneoxy and ethyeleneoxy block polymers Four pounds of the product of Example I was charged to a 5-gallon pressure reactor, contents purged with N.sub.2, and treated with 8 pounds ethylene oxide at 120oC. The product had a molecular weight, basis the hydroxyl number of 18,900 and containing 90% by weight ethylene oxide. 3. Preparation of Low Molecular Weight Sucrose Polyol with Propyleneoxy and ethyeleneoxy block polymers A 5-gallon pressure reactor equipped with mechanical stirrer was charged with 3 pounds sucrose 8-molar propoxylate and 8 g potassium hydroxide. The mixture was vacuum stripped for one hour at 120oC, nitrogen purged and treated with 3 pounds propylene oxide at 110 to 125oC, followed by treatment with 12 pounds ethylene oxide at 125oC. The product had a molecular weight of 4,900, basis the hydroxyl number and contained 66.7% ethylene oxide. 4. Preparation of Sucrose Polyol with Alternating Blocks of Propyleneoxy and ethyeleneoxy block polymers To 5 pounds of the product of Example 3 in a 5-gallon pressure reactor were added successively at 125oC, 4 g KOH (H.sub.2 O subsequently removed in vacuum), 3 pounds propylene oxide, and 12 pounds ethylene oxide. To 5 pounds of this product were added 1.5 pounds propylene oxide and then 6 pounds ethylene oxide at
135.degree. C. The final product had a molecular weight, basis the hydroxyl number 30,000 and contained 79% ethylene oxide. 5. Preparation of Hydrophobic Sorbitol Polyol with Propyleneoxy and ethyeleneoxy block polymers Using the alkoxylation methods described in Examples 1-4, sorbitol 174-molar propoxylate was treated with 85 moles ethylene oxide to prepare a product of about 14,000 molecular weight hydroxyl number=24.5 having 26.6 weight percent ethylene oxide content.
Polyoxyalkylene glycol-diglycidyl ether block polymers Condensation Products prepared with diglycidyl ethers CH2-CH-CH2-O-Polyoxyalkylene glycol-O-CH2-CH-CH2 O Di glycidyl ether of polyoxyalkylene glycol
O
Polyoxyalkylene glycols to be used in condensates with diepoxides were prepared by addition of the desired alkylene oxide or a mixture of two or more oxides to a suitable monohydric or polyhydric compound. The reaction conditions vary somewhat depending on the alkylene oxide used, but generally the temperature employed will be within the range of about 90o-160oC. A small amount of alkaline catalyst is needed for polyglycol formation. Preferred catalysts include potassium hydroxide, sodium hydroxide and sodium hydride with a concentration of about 0.1 to 0.8 weight percent, based on finished product. A non-exclusive list of suitable alcohols, phenols and glycols includes normal and branched alcohols, phenols, propylene glycol, ethylene glycol, butylene glycol, glycerin, pentaerythritol and the like. (Refer Polyalkylene oxyalkylate block polymer) Diepoxide condensates Preparation of diepoxide condensates with polyoxyalkylene glycols is carried out according to the following general procedure. Reaction of polyoxyalkylene glycols with diglycidyl ethers take place at temperatures from 70o -160oC, preferably between about 80o -120oC. Generally, the reaction is carried out without solvent, although the reaction can also be carried out in the presence of an inert organic solvent. Normally the molar ratio of polyoxyalkylene glycol to diglycidyl ether is from about 1:0.5 to about 1:1. At the 1:1 ratio, crosslinking may become pronounced and may result in insoluble lumpy material. To minimize insolubles, the total amount of diglycidyl ether is preferably added in two or three steps, rather than all at once. The reaction takes place in the presence of alkaline catalysts. Usually, the catalyst that is present in the freshly prepared polyoxyalkylene glycols is all that is needed to prepare the condensate with the diglycidyl ether. The reaction can also be catalyzed by Lewis acid-type catalysts, such as ZnCl2, BF3 -etherates and the like. In this case, the residual catalyst from the initial oxyalkylation is first neutralized, followed by the subsequent addition of the Lewis
acid. The reaction time depends on the temperature and is generally stopped when the epoxy number of the condensate has decreased to 2 or less. Oxyalkylation Polyoxyalkylene glycol/diepoxide condensates can be further oxyalkylated using a procedure similar to that for the polyoxyalkylene glycol preparation
Polyamido oxyalkylate Preparation of the polyamido component 918.4 g (7 moles) of dipropylenetriamine and 2,377.2 g (21 moles) of caprolactam were heated at 180oC in a stream of nitrogen. The mixture was stirred for 17 hours at 180 oC , after which the temperature was increased to 190oC and the mixture was stirred for a further 5 hours. 3246.6 g of a polyamidoamine of MP 110oC were obtained. The amine number was 7.27meq/g and the product contained about 11% of 6aminohexanoic acid. Oxyalkylation Example 1 947 g (16.32 moles) of propylene oxide were forced a little at a time, in the course of 6 hours, under 6-10 bar and at 135oC into a stirred stainless steel autoclave containing 72.5 g (0.154 moles) of the polyamido component prepared as described above and 1g of KOH powder. Stirring was then continued for a further 4 hours until the pressure remained constant. The product can be used directly. As adduct of about 106 moles of propylene oxide with one mole of the polyamidoamine was formed. Example 2 1,128 g (19.4 moles) of propylene oxide and then 365 g (8.3 moles) of ethylene oxide were forced a little at a time, in the course of 10 hours at 135oC and under 6-10 bar, into a stirred stainless steel autoclave containing 84.7g (0.18 mole) of the polyamido component and 1 g of KOH powder, and the mixture was then stirred for a further 4 hours until the pressure remained constant. The product can be used directly. An adduct of about 108 moles of propylene oxide and 46 moles of ethylene oxide with one mole of the polyamidoamine was formed. Example 3 The procedure described in Example 2 was followed, and 108 g (0.23 mole) of the polyamido component were reacted with 1,040 g (17.9 moles) of propylene oxide and then with 304g (6.9 moles) of ethylene oxide. The product can be used directly. An adduct of about 78 moles of propylene oxide and 30 moles of ethylene oxide with one mole of the polyamidoamine was formed.
Example 4 197.5 g (0.03 moles) of the oxypropylate described in Example 1 and 1 g of KOH powder were reacted with 53 g (1.2 moles) of ethylene oxide in a stirred stainless steel autoclave in the course of 3 hours under a pressure of from 6 to 10 bars at 125oC. The mixture was then stirred for a further 4 hours until the pressure remained constant. Analysis showed that the resulting adduct contained about 106 moles of propylene oxide and about 40 moles of ethylene oxide per mole of polyamidoamine.
Vinyl polymer alkoxylate Vinyl polymer with a site capable of being alkoxylated should be used. The vinyl polymer contains a hydrophobic monomer and a hydrophilic monomer. The monomer may contain heteroatoms, like nitrogen, sulfur and phosphorous. Percentage hetero atom (PHA) is calculated as follows. E.g. A molecule of dimethyl aminoethyl acrylate has a formula C7H13O2N and an estimated molecular weight of 143. The weight % attributable oxygen and nitrogen is, Nitrogen: 14 and Oxygen: 32 (2molecules) and Total 14+ 32= 46. %PHA = 46x100/143 = 32.3% or 32.2. Hydrogen bonding is also estimated like this E.g. A molecule of Hydroxyethyl acrylate with formula C5H8O3 and Mol.wt = 116 has one hydroxyl group (OH = 17). So %PHB is 17x100/116 = 14.7 Hydrophobic monomers are which having PHA less than 27 and hydrophilic monomers are those which have PHA > 27. Hydrophobic monomers are butyl acrylate, styrene, decyl acrylate, lauryl acrylate, etc. Hydrophobic monomers are compounds such as hydroxyethyl, hydroxypropyl, methoxyethyl acrylate and methacyrlates, methyl methacrylate, acrylamide, vinylpyrolidine, acrylic acid, maliec anhydride methacrylic acid, vinyl pyridine and vinyl acetate. Vinyl polymers Butyl acrylate = BA Hydroxyl ethyl acrylate = HEA Methyl methacrylate = MMA Hydroxy ethyl methacrylate = HEMA Lauryl acrylate = LA Decyl acrylate = DA Polymers BA/HEA copolymer BA/HEA/MMA terpolymer BA/HEMA copolymer BA/HEMA/DA terpolymer BA/HEMA/LA terpolymer BA/HEA/LA terpolymer The preferred polymer is placed in an autoclave with inhibitor and heating to -160oC. The polymerized vinyl polymer is thereafter reacted with alkylene oxide.
Vinyl polymer alkoxylates with small % of alkylene oxides are good demulsifiers than non-alkoxylated vinyl polymer. BA/HEA copolymer with ratio 93:7 and ethylene oxide 4% or more are found better demulsifiers than those having ethylene oxide 0-2%. Prepared by Chandran Udumbasseri
