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ХИМИЧЕСКИЕ НАУКИ
THE OBTAINING AN ADSORBENT FROM COAL OF THE FIELD SHOPTYKOL DEPOSIT OF THE MAYKUBEN BASIN ON EXPERIMENTAL INDUSTRIAL INSTALLATION
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Yermagambet B.T. , Kazankapova M.K. , Zhenisova A.K. , Nauryzbayeva A-Т.4 (Republic of Kazakhstan) Email: [email protected]
1Yermagambet Bolat Toleukhanuly - Doctor of Chemical Sciences, Professor, Director; 2Kazankapova Maira Kuttybayevna - PhD, Leading Researcher, LLP "INSTITUTE OF COAL CHEMISTRY AND TECHNOLOGY"; 3Zhenisova Akmaral Kamzievna - Undergraduate, KAZAKH UNIVERSITY OF TECHNOLOGY AND BUSINESS, Junior Researcher, LLP "INSTITUTE OF COAL CHEMISTRY AND TECHNOLOGY"; 4Nauryzbayeva Assemay Turlankyzy - Undergraduate, KAZAKH UNIVERSITY OF TECHNOLOGY AND BUSINESS, Junior Researcher, LLP "INSTITUTE OF COAL CHEMISTRY AND TECHNOLOGY", NUR-SULTAN, REPUBLIC OF KAZAKHSTAN
Abstract: in the article, experiments on heat treatment of coal at the Shoptykol deposit of the Maykuben basin were carried out by its carbonization and activation on a pilot-laboratory installation. First, carbonization of coal was carried out in an inert atmosphere of nitrogen in the temperature range of25-600 ° C and then the activation of coal with water vapor at a temperature of600 ° C for 1 hour. With the help of energy dispersive X-ray spectroscopy on a SEM instrument (Quanta 3D 200i) with an attachment for energy dispersive analysis from EDAX its chemical composition was determined. BET method determined adsorption characteristics of samples. It was found that the specific surface area and specific pore volume significantly increased as a result of high-temperature treatment of coal. Tests on testing the obtained activated carbon as an adsorbent for the purification of water and gas.
Keywords: coal, adsorbent, "Shoptykol", carbonization, activation, cleaning.
ПОЛУЧЕНИЕ АДСОРБЕНТА ИЗ УГЛЯ МЕСТОРОЖДЕНИЯ «ШОПТЫКОЛЬ» МАЙКУБЕНСКОГО БАССЕЙНА НА ОПЫТНО-ПРОМЫШЛЕННОЙ УСТАНОВКЕ Ермагамбет Б.Т.1, Казанкапова М.К.2, Женисова А.К.3, Наурызбаева А.Т.4 (Республика Казахстан)
1 Ермагамбет Болат Толеухащлы - доктор химических наук, профессор, директор;
2Казанкапова Майра Куттыбаевна - PhD, ведущий научный сотрудник, ТОО «Институт химии угля и технологии»;
3Женисова Акмарал Камзиевна - магистрант, Казахский университет технологии и бизнеса, младший научный сотрудник, ТОО «Институт химии угля и технологии»;
4Наурызбаева Асемай Турланцызы - магистрант, Казахский университет технологии и бизнеса, младший научный сотрудник, ТОО «Институт химии угля и технологии», г. Нур-Султан, Республика Казахстан
Аннотация: в статье проведены эксперименты по термической обработке угля месторождения «Шоптыколь» Майкубенского бассейна путем его карбонизации и активации на опытно-лабораторной установке. Сначала проводили карбонизацию угля в инертной среде азота в интервале температур 25-600 °С и затем активацию угля водяным паром при температуре 600 °С в течение 1 часа. С помощью энергодисперсионной рентгеновской спектроскопии на приборе SEM (Quanta 3D 200i) с приставкой для энергодисперсионного анализа от EDAX определен его химический состав. Методом БЭТ определены адсорбционные характеристики образцов. При этом установлено, что удельная поверхность и удельный объем пор существенно повышаются в результате высокотемпературной обработки угля. Проведены испытания по апробации полученного активированного угля в качестве адсорбента для очистки воды и газа. Ключевые слова: уголь, адсорбент, «Шоптыколь», карбонизация, активация, очистка.
УДК 661.66
Due to the rapid development of "green energy", the production of solid fuels in the world, as energy raw materials is reduced. This leads to the search for highly efficient technologies for the complex processing of combustible minerals into products with high added value and high conversion, which is an urgent task for science and industry. Thus, the cost of carbon nanotubes in the world market ranges from $ 30 to $ 100 per 1 kg., the cost of nanosorbents is 450 times higher than the cost of raw materials with a huge market volume, and the total world production of porous carbon materials is currently about 1 million tons per year [1].
Activated carbon (activated carbon, "carbol") is a porous substance that is obtained from various carbon-containing materials of organic origin. Activated carbon contains a huge amount of pores and therefore has a very large specific surface area per unit mass, as a result of which it has a high adsorption.
The preservation of the planet's water resources is considered one of the main objectives of the development of modern science, and the purification of drinking and industrial wastewater is an important stage in its solution. There are various solutions to water purification methods, but the most simple and widely known is the adsorption method based on the use of solid sorbents. It should be noted that the level of production of domestic brands of carbon materials, suitable as adsorbents, remains not high. There are various schemes for obtaining carbon materials, which include the preparation and modification of the original coal, carbonization and subsequent activation by gas or chemical reagent.
The Maykuben lignite basin, which includes the Shoptykol, Sarykol, and Taldykol deposits, has been known since the beginning of the 19th century. Since 1941, coal has been developed on a small open-pit mine for local needs at the Shoptykol deposit, and since 1987, with a large open pit of Maykuben design capacity of 20 million tons/year.
The coals of the basin are humus, brown of a high degree of coalification (B3), medium salt (25-28%). Ash is refractory, with a high content of A12O3 (up to 30%), low-sulfur coals (0.5-1.0%) and polyphosphorous (0.1%). The heat of combustion to a combustible mass of 77.5 thousand kcal / kg. The yield of tar is 4-7%, rarely 10%, humic acids 5% on dry coal for Shoptykol suite and bitumen about 2.5%. The total reserves of coal in the basin are estimated at 5.3 billion tons, including those suitable for open pit mining with overburden up to 10 m3 / t are 1.8 billion tons [2].
As is known, the main characteristic of the adsorption capacity of materials during the adsorption of gases, vapor, solid and liquid substances is the surface development, the total pore volume, pore size distribution, high specific surface, which gives them a number of unique properties. Being an excellent sorption material, coal can be used for the purification of gases, liquid media, including sewage from petroleum products, phenols and salts of heavy metals.
The purpose of this work is to obtain porous carbon materials (adsorbents) based on coal from the Shoptykol deposit of the Maykuben basin for cleaning the gas phase from acidic components and wastewater.
Samples of activated carbon were obtained at the "Institute of Chemical and Coal Technology" LLP (Astana). Carbonization (at 600 °C in a nitrogen environment) and activation of water vapor in accordance with the procedure described in [3]. To obtain activated adsorbents, the previously obtained product is crushed to fractions of 0.1 mm, then crystalline samples are obtained from the extruder (d = 0.2-0.3 cm). The determined optimal composition of the adsorbent from the Shoptykol coal deposit, which amounted to (wt.%): Coal - 77.5; starch - 5; sodium hydroxide - 0.5; water - 17. Next, the product passes the stage of heat treatment (carbonization) and activation in an inert atmosphere of nitrogen (Figure 1). Samples should be obtained in the following way: final drying due to heat is obtained from the walls of the retort (final drying zone); distilling of volatile, resinous products and gaseous substances at a temperature of 450-600 °C (carbonization zone); activation due to the interaction of coal with superheated steam at a temperature of 600 °C for 1 hour (activation zone).
The main chemical reactions occurring in the activation zone:
2 H2O ^ 2 H2 + O2 - Q
C + H2O ^ CO + H2 - Q
C + CO2 ^ 2 CO - Q
C + 2 H2 ^ CH4 + Q
The first three reactions are dominant and take place with the absorption of heat. Therefore, to maintain the conditions for the reactions, an influx of heat is required, which occurs due to the combustion of gas in the furnace and the afterburning of activation gases in the collecting manifold.
Humidity, ash content and volatility of the samples were determined on a Thermoster Eltra thermogravimetric analyzer (according to ASTM D7582-12 Standard Test Methods for Thermogravimetric Analysis Standard Test Methods). The technical characteristics of the initial and activated adsorbent are (%): Ad - 23.44; Wr - 12.11; Vd - 40.66 and Ad - 16.97; Wr - 16.97; Vd -32,10 respectively.
Chemical analysis of activated carbon was performed by energy dispersive X-ray spectroscopy on a SEM instrument (Quanta 3D 200i) with an attachment for energy dispersive analysis from EDAX. The energy of the exciting electron beam in the analysis was 15 keV. The results of elemental analysis are presented in Table 1.
Table 1. The chemical composition of activated carbon Maykuben basin
Element, % Source, % Activated, %
C 60.51 53.98
O 25.24 22.12
Na 0.38 0.42
Mg 0.49 0.73
Al 3.82 6.33
Si 7.02 11.55
S 0.24 -
K 0.82 1.49
Ca 0.41 1.27
Fe 1.07 2.10
After carbonization, the number of elements such as carbon, oxygen and sulfur decreases, this is due to the fact that during the high-temperature treatment removes of volatile components (including burnout of unstructured carbon) occurs. At the same time, develop the structure of flat aromatic rings, uniting in graphite-like crystallites.
The adsorption characteristics of the samples (specific surface area, specific pore volume by limiting filling) were studied by the Brunauer-Emmett-Teller method (BET). The measurements were carried out on a KATAKON Sorbtometer M. The bulk density, the pH of the aqueous extract, the adsorption activity according to methyl orange was determined in accordance with the methods [4, 5].
The results of the study to determine the main physico-chemical characteristics of the original coal and activated adsorbent are shown in Table 2.
Table 2. Physical and chemical characteristics of the source and activated carbon of the Shoptykol deposit of
the Maykuben basin
Name pH of the aqueous extract Adsorption activity by methyl orange, mg/g Specific surface, m2/g (single point BET method) Specific pore volume, cm3/g (on the limit of filling)
Source 7,03 0,5 5.114 -
Activated adsorbent 7,40 48,5 241,945 0,104
As can be seen from the obtained data, in activated adsorbents compared to the initial carbon (Table 2), the specific surface area significantly increases by ~ 47.31 times.
Also, the physicochemical properties of the activated adsorbent were studied in the testing laboratories of the "Research and Development Center" "Coal" LLP (Karaganda). The research results are presented in Table 3.
Table 3. The results of tests ofphysico-chemical properties
Units of Value of the
№ Name of indicator measure ment indicator ND on test methods
1 Water content % 1,55 ST RK 2407-2013
2 Ash content % 17,51 ST RK 2406-2013
3 Structural strength % 80,42 ST RK 2243-2012
4 Total pore volume of water % 0,48 ST RK 2404-2013
5 Iodine adsorption activity % 20,30 ST RK 2402-2013
6 Bulk density r/sm3 0,69 ST RK 2408-2013
7 Mass fraction of chlorine % 0,01 GOST 9326-2002
8 Mass fraction of arsenic % 0,0006 GOST 10478-93
9 Mass fraction of total sulfur % 0,62 GOST 8606-93
Grading: more than 5 mm 18,61
3-5 mm 73,26
10 1-3 mm % 6,82 ST RK 2405-2013
0.1-1 mm 0,36
less than 0.1 mm 0,95
Total 100,00
According to the quality standards, such indicators as mass fraction of water, which by ST RK 2246-2012 is not more than 4.0%, mass fraction of ash not more than 23% and grain size distribution, correspond to the indicators.
The obtained sample of activated carbon "Shoptykol" was tested as an adsorbent for water purification, taken under the faucet. Chemical analysis of drinking water before (control) and after cleaning with an adsorbent was carried out in an accredited analytical laboratory in the RSE "Center for Sanitary and Epidemiological Expertise", in which the main indicators of water treatment were identified. The results of the analysis are shown in Table 4, in which for comparison the degree of purification is also given, and the norms for ND (normative documents) are indicated.
The data obtained show that the values of indicators such as chlorides, potassium, sodium and COD after purification with activated carbon significantly decrease in 1.17; 1.18; 1.02 and 1.01 times as appropriate.
In the laboratory of the Institute of Coal Chemistry and Technology, the resulting carbon porous adsorbent was tested to purify gases (composition: H2S, CO, CO2, CH4, N2, H2) from harmful substances H2S, CO2, N2 to obtain mainly combustible components CO, CH4, N2. The results of elemental analysis before and after gas purification showed a degree of purification of CO2 -78.99% and H2S - 97.7%.
Table 4. Results of chemical analysis of water before and after cleaning with activated adsorbent
Name of indicators Results ND on test methods
Water from the tap Water after cleaning with adsorbent
Smell at 20.0 ° C, points 0 2 GOST 3351-74
Taste, points 0 1 GOST 3351-74
Chromaticity, hail 15 15 GOST 3351-74
Turbidity, mg / dm3 0,47 0,52 GOST 3351-74
Total hardness mmol / dm3 3,2 3,2 GOST 26449.1-85
pH 7,92 8,12 GOST 2874-82
Sulfates , mg / dm3 51,29 54,62 ST RK ISO 10304-1-2009
Ammonia, mg / dm3 0,0 0,0 GOST 33045-2014
Chlorides, mg / dm3 63,35 53,98 ST RK ISO 10304-1-2009
Potassium, mg / dm3 5,26 4,45 ST RK GOST R 513092003
Sodium, mg / dm3 45,61 44,57 ST RK GOST R 513092003
Permanganate oxidation, mg / dm3 1,2 1,3 GOST 23268.12-78
COD, mgO2 / dm3 6,8 6,7 GOST 31859
Residual free chlorine, mg / l 0,0 0,09 GOST 18190
Thus, as a result of high-temperature carbonization processes (in an inert environment) and activation (with water vapor) of the Shoptykol coal from the Maikuben basin, porous carbon material was obtained with a specific surface area of 241.945 m2/g and a specific pore volume of
0.104.cm3/g, which has a more developed and an ordered surface structure, as well as higher adsorption properties. In this regard, activated carbon can be considered promising, in particular, as an adsorbent for the purification of liquid media and gases.
The work was performed according to program No. BR05236359 "Scientific and technological support for coal processing and production of high-quality coal chemistry" and project No. AP05130707 "Development of technology and production of carbon nanocomposite materials based on domestic mineral raw materials for gas phase and wastewater treatment" MES RK.
References / Список литературы
1. Yermagambet B.T., Kassenov В.К., Nurgaliev N.U., Nabiyev А.А., Kasenova Zh.M., Kazankapov М.К., Zikirin А.М. Electrophysical properties and heat capacity of shale Kendyrlyk field // Chemistry of solid fuel, 2018. № 1. Р. 68-72.
2. Azizov T.M., Vlasov V.I. Pools and deposits of coal and combustible shale of Kazakhstan // Reference book. Almaty, 1997. Р. 91-101.
3. Sanchez A.R., Elguezabal A.A., Saenz L.T. CO2 activation carbon from wood waste // Carbon, 2001. V. 39. P. 1367-1377.
4. GOST 4453-74 Charcoal active lightening charcoal powder. Technical conditions.
5. Kabulov A.T., Nechipurenko S.V., Efremov S.A. // Proceedings of the Kola Scientific Center of RAS, 2015. № 5 (31). P. 527.
