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Section 15. Chemistry
Список литературы:
1. Месропен Э. Г., Аветисян А. А., Галстян А. С., Арутюнов И. Р., Шахнзарян Г. А., Синтез новых производных пропанолов-2 с разными гетероциклическими заместителями//Химический журнал Армени, 2006. 59, № 1.
2. Краюшкин М. М. Яровенко В. И., Ширинян В. З., Заварзин И. В., Способ получения n- (циклогексилтио) фталимида. Патент RU № 2091371, 2005.
3. Батыршин И. Р., Юмабаева В. М., Сахаутдинов И. М. Синтез новых производных пиразола на основе алленов с фталимидным фрагментом.//Материалы Международной XIX Молодежной конференции студентов, аспирантов и молодых ученых «Ломоносов», секция «Химия», 9-13 апреля, Москва, 2012.
Jumaeva Dilnoza Jurayevna, Ph. D., senior scientist of the laboratory “Colloid Chemistry”, doctoral institute of General and Inorganic Chemistry Institute of the Academy of Sciences of Uzbekistan
E-mail: [email protected] Mutalov Shuxrat Axmadjonovich, Ph. D., Senior Research Fellow applicant Tashkent Institute of Chemical Technology, Vice-Rector for Academic institute
E-mail: [email protected] Jumabaev Berdakh Aytbaevich, Ph. D., head of department of «General Chemistry» of Nukus State Pedagogical Institute of the Republic of Uzbekistan
E-mail: zara.1976@ mail.ru Agzamkhodjaev Anvarxodja Ataxodjaevich, doctor of chemistry, professor, international academy of ecology and life protection sciences (IAELPS), manager laboratory «Colloid chemistry »Institute of General and Inorganic Chemistry Institute of the Academy of Sciences of Uzbekistan E-mail: [email protected]
Pyrolysis products angren coal of Uzbekistan and the possibilities of their use for wastewater treatment
Abstract: In the research, by the thermal pyrolysis of coal Angren Uzbekistan marked as 2BPK (lignite, stove, large) without air access within temperatures of 500-600°C there obtained hydrophobic carbon adsorbent with wetting angle a>900 and porosity of 30% and an absorbing fuel (oil product) to 24%. The obtained product of the pyrolysis of coal — a hydrophobic carbon adsorbent is recommended for purifying wastewater from oil. It was found that in the wastewater treatment of Mubarek Gas Processing Plant of the Republic of Uzbekistan with hydrophobic carbon adsorbent degree of purification of the water from the oil and gas processing products is 96.0-97.0%. Defined exit gases during pyrolysis of coal, which is 57 m 3/t with content of CO2-78.0%; CO — 12.0%; H2-4.0%; CH4-3.0% and calorific value of4300 kcal/Nm 3. The obtained gas is recommended to be used as a domestic fuel.
Keywords: Angren coal, industrial wastewater, purification, pyrolysis, carbon adsorbent, gas, calorific value.
Introduction. In recent decades, over the world there have been noted the intensive growth of manmade chemical pollution of water bodies used by the public. The development of the chemical and oil and gas industries, chemicals in agriculture, the widespread use of new drugs in the home and at work drastically exacerbated the issue of prevention of getting elevated
concentrations of unwanted organic and inorganic contaminants in the human body with water. The main source of water pollution are industrial enterprises, and especially the chemical industry, oil and gas processing enterprises industry, production of new synthetic materials, pesticides, detergents, heat treatment plants for solid and liquid fuels. Their discharges of untreated
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Pyrolysis products angren coal of Uzbekistan and the possibilities of their use for wastewater treatment
or poorly treated sewage can pose a significant threat to public health [1-2].
Wastewater of oil and gas processing industry, released into ponds contain various dissolved inorganic substances and products that degrade water quality (contamination and salinity of water bodies), and having a negative impact on flora and fauna of water reservoirs. The content of impurities exceeds the norms of maximum permissible concentration (MPC). Therefore, treatment of industrial wastewater using adsorbents is one of the most effective methods of treatment, which allows for deep cleaning of water [3-4].
In connection with the above stated, the preparation of new carbon adsorbents based on Angren brown coal by pyrolysis of coal and the use of obtained pyrolysis products in industry and everyday life has great scientific and practical interest and it is very relevant.
Objects and methods of research. Previous [5-9] we have obtained a number of carbon adsorbents on the basis of brown and stone-coal of the Republic of Uzbekistan for the treatment of industrial wastewater of metallurgical and chemical industries. In continuation of these studies, the aim of this work is to obtain new carbon adsorbents by pyrolysis based on Angren brown coal for purifying and softening industrial sewage of oil-gas processing enterprises. In the work as a research object was used Angren brown coal of Uzbekistan marked as 2BPK with ash content of 12.7%. It is known that the Angren brown coal differs from stone-coal in physical and chemical properties. They contain reactive acidic (carboxyl and hydroxyl, phenolic) groups. To increase the adsorption capacity of coal, we used the method of pyrolysis at temperature 500-600oC without air for 30 minutes [10-12]. It is established that during the heat treatment of coal there derived hydrophobic (contact angle with a = 990), highly porous (pore volume 30%) adsorbents with capacity of 25% to benzine and with specific surface area of 150 m 2/g, suitable for the purification of wastewater from oil products.
We used the set of physical and colloid-chemical methods of investigation such as adsorption, analysis and so on and the object of study for the purifying and softening — industrial wastewater of Mubarek gas processing plant in Uzbekistan. The amount of oil products in the water was determined by the method that was developed by the State Specialized Inspection ofAnalytical Control (SSIAC), approved by the State Committee for Nature Protection of the Republic of Uzbekistan.
Results and discussion. For purifying wastewater from oil products in the work [9] there was proposed
using thermally processed (about 500 °C) Shargun stone-coal as the adsorbent. In this connection, there is a great interest to investigate the possibility of using adsorbents based on Angren brown coal for treatment of sewage of oil processing [6,7,13]. It should be noted that for adsorption of oil from the surface of wastewater, it is necessary that the adsorbent should possess high porosity and hydrophobic properties, i. e. adsorbent surface should be well wetted by oil products and not to be moistened with water.
Angren coal — hydrophilic, well moistened with water, due to the presence oxygen-containing groups in it. Therefore, the original coal can not be directly used for the purification of wastewater from oil products. The coal must be given hydrophobic properties, for example, by its pyrolysis without air access. During the pyrolysis process existing coal carboxyl and hydroxyl groups in the coal are decomposed, which leads to hydrophobisation of its organic mass. Therefore, we studied the effect of pyrolysis temperature on the physicochemical properties of the Angren coal. For the study was taken Angren coal with a moisture content of 15% and an ash content of 12.7%, with a volatile content of 35%. Deselected pulverized coal size 2-5 mm was subjected to heat treatment without access of air at temperatures of from 300 °C to 800 °C in a laboratory (Figure 1.) consisting of a vertical furnace (1) with electric heating, the reactor (2), a thermocouple (3) with a millivoltmeter (4), a glass tube (5) which diverts gases and liquid products from the reactor, gas collector (7), a glass flask of Wurtz (6) cooled with ice (8) for collecting the resin and pyrogenetic water, measuring device (9) for measuring the gas outlet and the gas analyzer VTI-2 (10) for gas analysis.
The experiments were carried out as follows. A charge of air-dried sample at 50 g poured into the reactor, which is a cylindrically shaped container made of refractory material closed at one end. The sample in the reactor was heated to a predetermined temperature and held for about 30 minutes (until the evolution of gases from the reactor). The gases collected in the gas collector, and the resin and pyrogenic water trapped in the glass flask of «Wurtz», which from the outside was cooled with ice. The gases were analyzed on the device VTI-2 consecutive absorption in the vessels filled with different solvents: CO2 was absorbed by KOH, O2 — by the solution of pyrogallol, CO — by ammonia solution Cu2Cl2 On CuO at 300-350°C degree there burned CO and H2, at a temperature 850-900°C methane and its homologs, formed during combustion of CO, H2 and CH4 were determined with adsorption method [2; 3;
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5]. The solid decarbonized products released during the further research and testing to determine the possibility heat treatment of Angren coal and gas is subjected to of their practical use.
Fig. 1. Laboratory installation for thermal treatment of Angren coal without air access 1. Electric furnace 2. Thermocouple 3. Reactor 4. Milli-voltmeter 5. The outlet pipe for gas and liquid products 6. glass flask of Wurtz 7. Gas collector 8. Ice for cooling 9. Measuring tank for measuring gas 10. Gas analyzer VTI — 2.
The solid decarbonized product was studied in order to use it as a carbon adsorbent for the purification of wastewater from oil products. Adsorption of oil products on a firm surface of coal complicated by the presence of water, molecules that can also be adsorbed on the surface of the adsorbent and therefore be a competitor of molecules of adsorbent.
The intensity of interaction between the molecules is determined by the phenomenon of wetting, which is a prerequisite for the adsorption [14]. A natural measure of wetting is the contact angle or angle of wetting. To measure the contact angle formed by water on a solid
surface it is applied a small drop of water, it designs side image of the drop on the screen. Then the screen outline contour drops sitting on a solid surface and through the point at which all three phases in contact, tangent to the contour ofthe drop, the angle of inclination of which determines the angle of contact.
Then on the screen there delineated the contour of the drop sitting on a solid surface and through the point at which all three phases in contact, tangent to the contour of the drop, the angle of inclination of which determines the angle of contact. On Fig. 2 Here is shown droplets forming on the solid surface.
Fig. 2. Various cases of incomplete wetting: a) a < 90 °; b) a = 90 °; c) a > 90 °.
On the surface, the acute angle of contact (a <900), the contact angle equal to 900 and a blunt edge angle (a> 900). Full wetting is not, then there is the case where the contact angle is equal to 1800, almost never
observed as there is always attractive force between the liquid and the solid. Following values: contact angle formed by water at the surface of different solids in air [14]:
Surface Quartz MalaShite Galena Graphite Talc Wax
Angle of wetting, a 0 ° 17 ° 47 ° 60 ° 69 ° 106 °
Wetting is a process in which in a system of three adjacent phases there decreases the free energy. When spreading liquid around the solid surface it is replaced with a high surface tension at the surface with a smaller surface tension. As wetting accompanied by a decrease of the surface energy, it is always accompanied by heat. The heat of wetting of the surface of 1 sm 3 typically ranges
from 10-3 to 10-5 cal. If it is impossible to determine the contact angle, for example when wetting liquid powders, the heat of wetting can serve to characterize the ability of liquid to wet the surface of the solid [10].
About the liquid which wets the surface better, it is said that it has greater selectivity with respect to the wetting of the surface. If the surface is selectively
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Pyrolysis products angren coal of Uzbekistan and the possibilities of their use for wastewater treatment
wetted with water, the contact angle a <90°, the surface is called the hydrophilic. If the body is better wetted by a non-polar hydrocarbon, ie water a> 900, the surface is referred to as hydrophobic. The substances with a hydrophobic surface are all hydrocarbons — oil products. When contact angle a = 90° there will be an intermediate case, and there
will be no selective wetting. From the above, in solid decarbonized residues obtained by heat treatment of coal Angren at 300, 400, 500, 550, 600, 700, and 800°C on a laboratory setting there was measured the contact angle of wetting. Below there presented are the results of determining the contact angle of the heat-treated samples of Angren coal:
Temperature of heat treating, °C 300 400 500 50 600 700 800
Угол смачивания, a 70° 0 ° 97° 99° 98° 70° 60°
The initial sample ofAngren coal is well wettable due to its hydrophilic properties of its high content in the organic part of its molecules polar carboxyl, hydroxyl, and other groups. The latest ones during the heat treatment, as the temperature rises, leave as CO2 and CO, the obtained decarbonized product will get hydrophobic properties and the wetting angle will increase reashing a maximum value at 500-600 °C. A further increase in temperature of the pyrolysis results aromatization and graphitization of the decarbonized product, to decrease of the contact angle (see above). And so, with increasing treatment temperature of Angren coal the angle of wetting increases and reaches a maximum value (a = 99o) during heat treatment — 550 °C. Further increase in the treatment temperature (up to 800 °C) reduces the wetting angle (a = 60°).
Therefore, the optimum temperature of pyrolysising Angren coal is 500-600 °C at which the angle of contact is the largest (a> 97-990), and accordingly, it to turns hydrophobic decarbonized residue — carbon adsorbent. To establish its capacity to petroleum products, it is necessary to determine its porosity.
The porosity of the adsorbent obtained from Angren coal was determined by acetone in accordance with state standart 6217-52. [14]. For comparison, there also determined the porosity of the heat-treated Shargun coal at 500 °C. In parallel with the study of porosities
of adsorbents there was determined their capacity to benzine. The studies found that if the porosity and capacity of adsorbents, which are derived from coal Shargun, to benzine respectively equal to 12 and 9%, these characteristics of adsorbents Angren coal is 30 and 24%, it’s almost 2.5 times higher.
Thus the obtained carbon adsorbent based on pyrolysis (at 550 °C) Angren coal, during its use in treatment processes wastewaters from oil processing industries shows 2.5 times more effectiveness compared to Shargun coal and certainly it can be recommended for use in industry.
The analysis of the initial industrial wastewater of Mubarek gas processing plant revealed that the oil content in the initial water was 14.6 mg/l. Table 1 shows the experimental data to determine the oil content in the process of adsorption treatment of wastewaters of Mubarek gas processing plant using a carbon adsorbent. It should be noted that for the purification there were used adsorbents amount of from 1.0 g to 6.0 g per 1 liter of purified water. From the data of Table 1 it is clear that if the oil content of the original waste water is 14.6 mg/l, it is enough to use carbon adsorbent up to 5 g/l in the adsorption treatment, because at such a concentration of the adsorbent water becomes almost pure (oil content 0.43 mg/l), meets the standards of MPC.
Table 1. - The content of residual amount* of oil products in adsorption treatment process of wastewater of Mubarek Gas Processing Plant using a carbon adsorbent
Amount of used adsorbents, g/l The content of residual amount of oil products in the waste water, mg/l
1 0,91
2 0,85
3 0,69
4 0,58
5 0,43
6 0,41
*content of oil products in the original sewage 14,6 mg/l
For purifying the industrial wastewater of Mubarek Gas Processing Plant from oil products and inorganic
mineral impurities we also tested the carbon adsorbent obtained by pyrolysis of coal at 550 °C and by composite
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carbon adsorbent obtained by the addition of the carbon calcium hydroxide [7]. The results are shown in Table. 2. From the data it is clear that in the purification of waste water with carbon adsorbents, the degree of its purification from both oil-gases processing products and inorganic mineral impurities meet the standards
of MPC. Oil products are mainly adsorbed on the heat-treated carbon adsorbent (to 96.0-97.0%), and in the composite carbon adsorbent there are adsorbed remaining small amount of oil products (about 3.04.0%) and cations dissolved inorganic contaminants from water hardness reduction of up to 0.5 mg/l.
Table 2. - The results of treatment of wastewaters of Mubarek Gas Processing Plant from oil and gas processing and inorganic mineral impurities using carbon adsorbents
№ Name of pollution types Content of the initial sewage of the plant, mg/l After purification using heat-treated carbon adsorbent, mg/l After purification using composite carbon adsorbent, mg/l
11 Oil products 14,6 0,43 0,03
22 Potassium 3,2 2,8 1,0
33 Sodium 24,0 18,6 10,3
44 Calcium 40,8 35,8 18,4
55 Magnesium 22,7 20,6 5,1
66 Chloride 53,2 52,0 8,4
77 Sulfates 129,8 127,0 32,0
88 pH 7,9 8,0 8,0
99 Solids 512,0 470,6 178,6
110 Total hardness, mg.eq./l 8,9 8,4 0,5
Thus, the above set of studies on the development of technology for production of new high-carbon adsorbents based on local Angren coal by pyrolysis of their allowed that in the purification of industrial waste water Mubarek Gas Processing Plant carbon adsorbent, the degree of cleaning and softening up to the ceiling standards. It should be noted that when using a heat-activated carbon adsorbent purification rate of oil and gas processing products purified almost to 96.0-97.0%, that is, if the source water, these products were 14.6 mg/l, after adsorption treatment values of these products was reduced to 0.43 mg/l. It should be noted that in this case the oil and gas processing products are available on the surface of the waste water is almost completely adsorbed thermally activated carbon adsorbent. The composite carbon adsorbent adsorbs mainly products of inorganic mineral matter and wherein the water in the exact content of calcium, magnesium, chlorates, sulfates, nitrates, and the dry residue is reduced by 4-5 times, and the hardness values are also reduced from 8.9 mg.ekv./l to 0.5 mg. ekv./l, besides carbon composite adsorbent and adsorbs the remaining quantity of oil and gas processing products (approximately 3-4%, which is 0.43 mg/l), which are in dissolved form in the volume of waste water
It should also be noted that during the pyrolysis of coal at 550 °C Angren release gases, which can not be released into the atmosphere and zagazovyvat environment. It is necessary to dispose of them for practical use.
These studies established that the overall yield of the gases of about 57 m 3/t, and the percentage of CO2, CO, CH4 and H2, respectively, are 78, 12, 4 and 3%. The calorific value of gas is low due to the high content of CO2
Combustible gases, such as natural and passing, coke gases, refinery gases, gases of generators etc., in most cases gas must be purified from CO2, SO2 and other contaminants. In most cases gas is cleaned from carbon monoxide and nitrogen oxides. On a large scale in the industry to clean emissions from CO2 [15]. Ifthe gas, produced during the pyrolysis of Angren coal, is cleaned of CO2 by one of the existing industrial methods, the caloric content can be increased up to 4300 kcal/Nm 3. Industrial methods for treating gas by CO2, described in the literature are based on a chemical raw material (ethanolamine, potassium carbonate (K2CO3), NaOH, etc.) instead of them there can be used quicklime, milk of lime at 10% concentration. For 1 m 3 purification of quicklime gas it’s required 2.0 kg burnt lime or 110 kg for cleaning 57 m 3 gas produced during the pyrolysis of1 t Angren coal. The calculation is based on the reaction: СО2 + Са (ОН)2 ^ СаСО2 + Н2 О.
In literatures, there are widely covered industrial adsorption units for gas purification from impurities. In practice, one can use these materials when selecting plants for gas purification from CO2 [15] using lime milk.
After purification by CO2 gas with lime milk, the gas outlet is reduced up to 12.5 m 3/t, and the percent-
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Pyrolysis products angren coal of Uzbekistan and the possibilities of their use for wastewater treatment
age of CO, H2 and CH4, respectively, is increased to 58, 20 and 23%, resulting in a gas with a calorific value of 4300 kcal/Nm 1 This gas can be used for both domestic use and for chemical synthesis.
On the basis of experimental data developed technological scheme of pyrolysis Angren coal without air at 550 °C. From 1 ton of Angren coal taken in the dry air, it is possible to receive about 57 m 3 of gas, or 12.5 m 3 purified from CO2 and 750 kg — decarbonized material — hydrophobic carbon adsorbent. To clear the 57 m 3 of gas from the CO2 it is required 110 kg of quicklime.
As a result of the pyrolysis of Angren coal and purification of gases there revealed the following characteristics of the obtained product:
1. Gas output — 57 m 3/t, gas composition: CO2-78.0%; CO — 12.0%; H2-4.0%; CH4-3.0%.
2. Gas output purified from CO2-12.5 m 3/t calorific value of the gas — 4300 kcal/nm 3, gas composition: CO — 58.0%; H2-20.0%; CH4-23.0%.
3. Output of the decarbonized product (hydrophobic carbon adsorbent) — 750 kg/m, porosity to acetone — 30%, the capacity to benzine — 24%.
After removal of oil products from the wastewater it’s necessary to clean them from the oil products which are in the form of colloidal particles and dissolved inorganic impurities. For this it’s proposed to use of hydrophobic and composite adsorbent of Angren coal. After removal from the wastewater oil products with hydro-
phobic adsorbent, the water is cleaned from dissolved inorganic impurities in it composite adsorbent that can reduce water hardness and the content in the wastewater cations Ca, Mg, etc. up to the norms of maximum permissible concentration (MPC).
Conclusion
By thermal pyrolysis of Angren coal of Uzbekistan marked 2BPK without air access within temperatures at 500-600oC there has been obtained decarbonized residue having a hydrophobic property (wetting angle a> 900), a porosity of 30% and absorbing benzine (oil products) up to 24%. The obtained product of the pyrolysis of coal as a hydrophobic carbon adsorbent is recommended for purification of wastewater from oil. It was found that in the purification of industrial waste water of Mubarek Gas Processing Plant of the Republic of Uzbekistan received by a hydrophobic carbon adsorbent the degree of purification of the wastewater reaches up to the standards of the maximum permissible concentration (MPC), where the degree of purification of the water from the oil and gas processing products is 96.0-97.0%. Defined exit gases during pyrolysis of coal, which is 57 m 3/t with content of CO2-78.0%; CO — 12.0%; H2-4.0%; CH4-3.0%. The caloric content of the gas after cleaning CO2 with lime milk is 4300 kcal/nm 3 with content of CO — 58.0%; H2-20.0%; CH4-23.0% in it. The obtained gas can be used as a household fuel.
References:
1. Jukov A. I., Mongait I. L., Rodziller I. D. Techniques for treating industrial wastewater. Moscow: Stroyizdat. 1989. - 223 p.
2. Borisov I. A. Methods of wastewater treatment. Book 1, Moscow: Stroyizdat. 2008. - 196 p.
3. Proskuryakov V. A., Schmidt L. I. Wastewater treatment in the chemical industry. Leningrad: Chemistry. 1977. P. 372-391.
4. Krichko A. A., Lebedev V. V., Farberov I. L. Non-fuel use of coal. Moscow: Nedra. 1978. P. 94-106.
5. Shimkovich V. V. Wastewater refineries and petrochemical plants. Moscow: Oil TSNIIE 1973, P. 11-16.
6. Shi-syan V. V., Jumaeva D. J., Gumarov A. D. Agzamhodjaev A. A. Treatment of industrial wastewater with new carbon adsorbents//Collection ofarticles ofscientific and practical seminar on World Environment Day “ Protection of the environment in Uzbekistan: its status in real time with the development of “Tashkent. 2012. P. 143-145.
7. An application for a patent of the Republic of Uzbekistan IAP 20120235 from 18.06.2012, the method for producing a composite adsorbents for reducing the hardness of the water (Agzamhodjaev A. A., Gumarov A. D., Jumaeva D. J., Shi-syan V. V., Eshmetov I. D., Salihanova D. S.).
8. Jumaeva D. J., Eshmetov I. D., Agzamhodjaev A. A. Process Wastewater Treatment carbon adsorbents obtained on the basis of the Angren coal//Uzbek chemical journal. Tashkent. 2014. № 5. P. 38-42.
9. Shi-syan V. V., Jumaeva D.J, Gumarov A. D., Agzamhodjaev A. A. Process of wastewater treatment using local coal adsorbents//catalog of innovative projects and developments presented at the VI Republican fair of innovative ideas, technologies and projects in the “technology transfer”. 2013. P. 9-10.
10. Jumaeva D. J., Eshmetov I. D., Agzamhodjaev A. A. Adsorption treatment and mitigation of industrial wastewater//Journal of Chemical Industry. Russia. 2014. Vol. 91. № 3. P. 150-154.
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11. Jumaeva D. J., Eshmetov I. D., Agzamhodj aev A. A. Process Wastewater Treatment carbon adsorbents//Materials Resp. Scientific conference on technics “The ingredients are from local and recycled materials to produce new composite materials.” Tashkent. 2014. P. 114-115.
12. Jumaeva D. J., Eshmetov I. D., Agzamhodjaev A. A. Wastewater production of carbon adsorbents//Proceedings of IV Republic Scientific Practical Conference “Actual issues of chemistry” Termiz. Part 2: 2014, P. 301-303.
13. Kalendarev I. Y. Influence of physical and chemical properties of coal in the compressibility and conditions for briquettes and molded adsorbents.//Abstract of dissertation work. Candidate of Science. Tashkent., 1984. - 22 p.
14. Voyutsky, S. S. Course of Colloid Chemistry, Graduate School, Moscow, 1964. -356 p.
15. Serpionova E. N. Industrial adsorption of gases and vapors, Moscow: Higher School, 1969, -324 p.
Toghasharov Ahat Salimovich, Institute of General and Inorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan,
Senior Researcher E-mail: [email protected]. Tukhtaev Saidahral, Institute of General and Inorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, head of the laboratory "Defoliations" E-mail: [email protected].
Study of the Solubility of Components in the System Ca(ClO3)2-2NH2C2H4OH-H3 С6 Н507-Н2О
Abstract: The solubility of components in the system Ca(ClO3)2-2NH2C2H4OH-H3C6H5O7-H20 was studied from the complete freezing temperature -43.6°C to 40.0°C. A polythermal solubility diagram was constructed, in which the crystallization fields were determined for ice, Ca(ClO3)2^6H2O, Ca(ClO3)2HH2O, Ca(ClO3)2^2H2O, 2NH2C2H4OH-H3C6H5O7-H20, 2NH2C2H4OThH3C6H5O7, and new compound, (C6H5O7)2Ca3-4H2O, which were identified by chemical and physicochemical analysis methods.
Keywords: solubility, system, the diagramme, concentration, crystallization, temperature, calcium chlorate,
citric acid.
In this report the results of studies of solubility of the water system consisting of calcium chlorate and di-monoetanolamina citrate, which are absent in the literature, but have a certain scientific and practical interest in obtaining polifunktsionalnodeystvuyuschih defoliants.
For research was used calcium chlorate - the active ingredient calcium chlorate-chloride defoliant inorganic origin. However, its effect on plants in excess hectare application rate results in drying of leaves and burns young unopened cotton bolls. Moreover, the drug has no effect polyfunctional. In the synthesis of new effective defoliants is ofconsiderable interest to use monoethanolamine salt of citric acid, a plant growth stimulator. It has biological activity, enhances oxidation-reduction processes, carbohydrate biosynthesis and action enzymatic activity [1,2].
For physico-chemical study of the process of obtaining an effective defoliant based on chlorate calcium and citrate dimonoetanolamina investigated the
solubility of the components in the system Ca(ClO3)2-2H2NC2H4OH-H3C6H5O7-H2O in a wide temperature and concentration range.
Dimonoetanolamin citrate synthesized based on citric acid and monoethanolamine, taken at a molar ratio of 2:1.
Solubility in the system 2H2NC2H4OH-H3C6H5O7-H2O We studied in the temperature range from -23.0 to 70.0 °C. Polytermic solubility diagram is characterized by its branches crystallization ice, 2HNCHOH.HCHO-HO and 2HNCHOH.
224 36572 224
H3C6H5O7, which intersect at two points of double coexistence of two solid phases. The first double point meets co-crystallization of ice and citric acid monohydrate dimonoetanolamina at -23.0 °C and a concentration of 67.0% 2H NC H OH-H C H O and 33.0%
2 2 4 3 6 5 7
H2O. The second double point corresponds to co-crystallization dimonoetanolamina citrate monohydrate and
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