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Section 11. Chemistry
Mirzaakhmedova Mavlyuda Ahmedjanovna, Institute of General and Inorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan E-mail: [email protected]
Technology of extracting demulsifiers for nonionic oil-water dispersions
Abstract: In this article reviewed the scientific and practical experience of laboratory synthesis of non-ionic demulsifiers to the synthesis of individual functional compounds. As well as local synthesis of ampholytic demulsifiers, which, thanks to the strong ionic interactions with mineral ions solution “brine" in the dispersed oil-gas-condensate system can effectively desalt hydrocarbons from local refineries.
Keywords: Demulsifier, oil and gas condensate
The process of dehydration and desalting of crude oil, gas condensate (GC), oil and gas mixtures are particularly relevant, as mined in our country these raw materials have a high content of water and dissolved salts.
The salt content in oils often reaches 2000-3000 mg/l and in some cases it reaches 0.4%, which cause a lot of of severe complications on their processing. During processing of such crudes above mentioned salts are deposited mainly in the hot process plant equipment. Salts dissolved in water released during the evaporation ofwater [1, 216]. Since the process takes place largely on the heating surface or on nearness of the portion, crystallized salt adheres to these surfaces, settling on it in the form of a solid cake. Sometimes these salt crusts are braking off flow of oil extracted and deposited in a subsequent apparatus. Corrosion i.e. refinery equipment corrosion during processing salty oils causes the release of free hydrochloric acid in the hydrolysis of certain chlorides.
At the processing plant, saline oil and gas condensate from Kokdumalak oil-fields forming residual products, because the chloride content of 10.0 g/l, which results
in an increase in the ash content of tar upto 1.5%. Processing of petroleum into oil increases its ash content of more than 0.3%. In these cases, fuel oils and tars are not suitable for the production of not only any of the final products, but even as a fuel, since the salts cause clogging of nozzles, chimneys: form deposits on the surface of the heating elements causing corrosion [2, 143]. Therefore, the for processing oils with high salt content it is necessary to refuse receipt of these combustion products, which is directed to the production of bitumen, which reduces the range of production of fuel products.
A stable emulsion of saline water leads to the presence of high-molecular hydrocarbon gas condensate and oil and gas mixtures of compounds able to form dispersed systems to be demulsified with demulsifiers [3, 119].
Oil with high content of water entering the AVT violates technological mode of work; increased pressure in the apparatus is reducing its performance, as well as an additional amount of heat is consumed on its preparation.
Table 1. - The content of the disperse phase related to Kokdumalak Gas and Oil refinery
The composition of dispersed phase Volume of gas condensate, ml Contents % (mass.) from mixture mass Density in 20°С, g/cm3
Aggregates in aqueous hydrocarbon dispersions: 27,67 2,812 0,8483
including:
- water 18,534 2,22 1,105
- volatile organic impurities (upto 125°С) 6,2929 0,545 0,723
- dry remainder (mineral salts, resin, etc.). - 0,0466 -
Finely dispersed water 12,787 1,532 1
Combined water 2,145 0,257 1
The data in Table 2 shows that gas condensate from Kokdumalak oilfields contains quite a considerable amount of finely dispersed (1.532%) and combined (0.257%) water, indicating its inability to dewatering
to the desired degree by conventional mechanical methods. The chemical composition separated from the condensate water from Mubarekneftegaz UDP oilfields is shown in Tables 3 and 4.
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Technology of extracting demulsifiers for nonionic oil-water dispersions
Table 2. - The content of the mineralized water in gas condenstaes
№ TS* from wells Pressure in plume kg/cm2 Pres- sure kg/ cm2 Temp. of plume C° Oil density, kg/m3 Water content in product, % volume The content of chloride salts mg/dm3 Mineralization of free water, mg/dm3
Related Sum- mary In emulsion Sum-mary
1 24 30 69 868 24,7 24,7 19230,4 19230,4 77855,9
2 15 30 48 877 3,5 3,5 2799,6 2799,6 79989,9
3 N/A N/A 40 883 37,1 37,1 31527,8 31527,8 84980,5
4 25 N/A 61 910 27,7 88 22380,5 73630,8 84992,2
5 40 50 70 884 38,2 38,2 35708,8 35708,8 93478,5
* OP test sample; N/A-undefined
These tables shows a fairly high content of salty water mixtures in oil and gas condensates.
Table 3. - The chemical composition of calcium chloride salt in salty water containing oils
№ TS. Specific weight of TS, g/cm3 рн TS Содержание ионов, мг/дм3 Total mg/ dm3
Na++K+ Ca2+ Mg2+ Cl- HCO- SO24-
Kokdumalak oil field
1 1,055 6,05 22919,7 4937,9 899,8 46257,2 103,7 528,4 75646,7
2 1,062 6,10 26984,5 4623,2 842,7 51568,7 85,4 859,8 84964,3
3 1,064 6,00 26414,4 5462,9 995,9 52820,3 85,4 590,8 86869,7
4 1,67 6,00 27136,3 6010 1095,6 55266,8 79,3 494,7 90082,7
5 1,071 6,20 28626,1 6549,1 1192,9 58762,9 115,9 518,8 95765,7
* TS - Test Sample
This shows that slightly acidic environment dissolved including emulsion breakers (Table 1). For the basic
in number of backup ions 7,5-9,6 g/l of brine water. process of the preparation of oil and gas condensate at
Therefore, the preparation of brine water emulsified oil the Kokdumalak oil fileld uses imported demulsifier -in the tanks of their pre-treatment in the fields of UDP “K-1” produced in China.
“Mubarekneftegaz" uses various foreign-made chemicals,
Table 4. - The use of surface active substances in various technologies in the oilfields of UDP “Mubarekneftegaz”
№ Description of SAS Type Consumption*, ton/y Price mln. UZS/ton Amount, mln UZS Areas of use
1. Imported demulsifier (China) «К-1» 232,0 3951 916,68 In preparation stations of oil and gas condensate
2. Corrosion inhibitor (Russia) «Do- dikor-4543» 561,7 3191 1792,35 In the production and processing plants
3. Scale inhibitor (Germany) Dodiscal and «VI-2870 K» 140,0 2447 342,580 Oil dehydration stations
4. Dehydrate adjuster (Russia) DEG 1600,0 1363 2181,280 Preliminary gas preparation
5. Foam forming Anaion SAS 27,0 1184 31,986 For firefighting in oil wells
6. Corrosion inhibitor (Italy) Danox- AF-200 248,9 - - For inhibiting the wells and gas condensate
* - Statistics of 2005y, now increased for 1.5 times
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Section 11. Chemistry
“K-1" is dissolved in the solvent in the secondary raw-oil and gas condensate mixtures in any proportions and the solution is pumped into pipelines after a separator-dehydrators stations dehydration process.
At the stage of pre-storage tanks, before sending gas condensate for recycling from the fields there are problems related to the presence of crystallized and dispersed water [4, 222].
In such cases, a hydrated water from the brine dispersion and gas mixture should be in dehydrated in prior separators (SP-1), where its content therein is reduced to 3.5-5.5%, as well as the presence of crystallized water. This dispersion of the water-oil-gas emulsion is destroyed, stratified and can interlocked with a solution of an effective demulsifier. Thus its
concentration in the oil does not exceed 100 gr/ton and does not affect the quality of the oil obtained from them.
For dehydration used raw gas condensate from Kok-dumalak oilfield. The data of the water content in the test sample Kokdumalak gas condensate is upto 4.5%, which is subjected to demulsification process.
On this basis, demulsification process of different crude oils, the most interesting solution to the problem is, in our opinion, is the selection of demulsifiers and choosing their right application. It is necessary, that it should be taken into consideration the Kokdumalak oilfields characteristics. Which requires the creation of technology of nonionic demulsifiers water-oil emulsion dispersions based on local raw materials.
Table 5. - Structure and properties of demulsifiers for the selection to demulsification water and gas condensate dispersions
Conventional demulsifiers, from which semiproducts it’s made SAS formula and avg. mol/weight Optimal consumption, emulsion. gr/ton Emul-sion concen- tration (water/oil dispersions) Demul- sifica-tion grade,%
«OP-7-10» (geksomer e esterification ethyl with alcylphenols) R^])—O(C2H4O)7H where R-C8H15 avg. mol. weight up to 1000 90 8,5-9,0 90
«Proxanol» ethylene and propene bloc oligomer Н (СА °)„- avg. mol. weight up to 1800 70-80 9,0-10 88
«Proxamin» block oligomers of ethylene oxide and propylene with ethylene H (C,H4O),nN (CH«)«N (C3H5 0) mH where n and m=17-20, avg. mol. weight up to 2000 40-80 6,5-7,0 92
«Reagent demulsifier» a mixture of polyethylene glycol ethers of alkylphenols R^^^O(C2H4O)nH where: n=30-36 and R-C12H25 avg. mol. weight up to 1400 80-90 7,5-8,0 85
«Hercules»-esters oligomers aminocarbonium acids H-R-COO- (C3H6O)n where: R-C10H25 and n-20-25 avg. mol. weight up to 2000-2200 30-40 6,5-7,0 93
«Dissolvans»-condensates of propylene oligomers with diamins and spirts R (C3H6 °)„-N (CH> (C,H« °)H where: R-C.H17 and n=7-8 and avg. mol. weight up to 2600 40-45 6,0-65 94
As seen from the table above, all varieties of demulsifiers are nonionic surfactants; esters inventories oligomers of ethylene and propylene with alcohols, amines and organic acids. They are characterized by good solubility of both water and in oils with simultaneous formation of their complex ions mixtures of compounds
capable of dissociation and salinity complex in medium water-oil-gas dispersions and causes blocking of water droplets.
To select the conditions of use of demulsifiers was prepared model 10% emulsion, aqueous dispersion of a mixture of oil and gas condensate oil and condensate
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Technology of extracting demulsifiers for nonionic oil-water dispersions
flowing into the tank. The content of chloride salts in the emulsion was 5.94 g/dm3. Samples of the emulsion with demulsifier additives in a concentration of 6.8 mg/kg were analyzed for the contents of water and salt after the thermal settling after 1, 2 and 3 hours. At this stage, it was determined the optimal residence time of oil in thermotank, which turned out to be 3 hours, and found that each demulsifier has its head start. For example, a sample of the emulsion with a demulsifier “Dissolvan” already after 1 hour a residual water content of 0.18% and with time the amount of water remaining almost unchanged. The other two samples is the gradual separation of water and 3 hours they are almost entirely absent. Further studies were to determine the optimal concentration of the reactants and achieving a minimum water content and residual salts in the oil. The demulsifier was injected at a concentration of 10; thirty; 50; 60 and 80 gr/ton. The laboratory results showed:
• All demulsifiers have a fairly high degree of desalination to 91-92%;
• the greatest degree of demineralization (91%) when administered minimum-amount of a (1 mg/kg) has demulsifier “Proxomin”;
• dependence of the residual content of chloride salts on the concentration of the demulsifier is an extreme character;
• with increasing concentrations of the demulsifier (up to a certain amount) increases the degree of removal of chlorides;
• operating range of demulsifiers “SS-7-10” and “Proxamin” is 1-3 mg/kg, “Dissolvan” is 1-5 mg/kg of
oil.
To carry out pilot tests of demulsifier “OP 7-10” was recommended:
• to set the initial reagent consumption of 50 g/m, as at this concentration it exhibits the greatest degree of demineralization;
• in the case of stable quality desalted crude oil in the future to reduce the flow rate to 30 g/tonne of oil.
Fig.1. — The dependence of the degree A combination of laboratory synthesis of non-ionic demulsifiers to the synthesis of individual functional compounds (dimethyl sulfate, monochloroacetic acid, hydroxy acid, etc.) can solve the problem of the local synthesis of ampholytic, emulsion breakers, which, thanks to the strong ionic interactions with mineral ions solution “brine” in the dispersed oil and gas condensate the system can effectively desalted hydrocarbons. The choice of high quality demulsifier that meets the requirements ofthe
of desalting concentration of demulsifier above demulsification emulsions of oil and gas condensate produced in various technological cycles, is a necessary requirement prior preparation of hydrocarbons for transport. Development and introduction of technologies of such demulsifiers is realizeable in enterprises of UDP “Mubarekneftegaz.” It is therefore recommended technology for producing nonionic demulsifiers for aqueous dispersions can be made from oil-based chemical raw materials and wastes produced in domestic companies.
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Section 11. Chemistry
References:
1. Vladimir Loginov. Oil dehydration and desalting.//“Chemistry”, M.: 1979. P. 216.
2. Petrov A. A. The nonionic-demulsifiers for oil dehydration.//“Kuibyshev book. ed. “, 1965. P.143.
3. Myshkin E. A.. Preparation of oil and fuel for processing.//Gostoptekhizdat, M.: 1946. P. 119.
4. Pozdnyshev G. N. Stabilization of emulsions and destruction. “Nedra”, M.: 1982. 222 p.
Muhamadiev M. G., National University of Uzbekistan, Associate Professor the Faculty of Chemistry Khazratkulova S. M., National University of Uzbekistan, teaching assistant the Faculty of Chemistry Mahkamov M. A., National University of Uzbekistan, teaching assistant the Faculty of Chemistry E-mail: [email protected]
Physic-chemical characteristics of polymers on the basis N- replaced acrylamides of natural ox acids
Abstract: Studying the influence of pH and the temperature of the environment to viscosity of water solutions, swelling kinetics and collapse of cross-linked polymers and copolymer on the basis of natural ox acids there are founded the presence of pH and heat-sensitive qualities. It is revealed that the existence of polymers as a form of amides and as well as carboxyl groups leads to the appearance of a unique quality of having a little interval of temperature of two critical mixed temperatures.
Keywords: PAA-N-MLA — Acrylamide N is methylene of laced acid, PAA-N-MGA — Acrylamide N is methylene of glekilev acid, PAA-N-MLA and PAA-N-MGA are dissolved in water, methanol, ethanol, DMFA, DMCO and some other polar dissolvent. They are not dissolved in ether, benzol, and hydrocarbon.
It is known that physic -chemical characteristics of macromolecular repulsive forces between charged groups solutions of polyelectrolytes particularly differ with their ofthe same name lead to considerable change conformation
peculiarities from non electrolyte polymer. Presence ofmolecules in solution. The consequence of it is deflection
of ionized groups have an effect on viscosity by ionizing of the rectilinear dependence. qyA/C=f (С).
а) б)
PAA-N-MGA from polymer concentration. concentration.
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