Synthesis and characterization of high molecular weight amphoteric terpolymer based on acrylamide, 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt and (3-acrylamidopropyl)trimethylammonium chloride for oil recovery

High molecular weight amphoteric terpolymer based on a nonionic monomer, acrylamide (AAm), an anionic monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS), and a cationic monomer, (3-acrylamidopropyl) trimethylammonium chloride (APTAC), was prepared using free-radical copolymerization in an aqueous solution and characterized by 1H NMR, FTIR, GPC, DLS, zeta potential and viscometry. The polymer was shown to be viscosifying, and therefore can be utilized as a polymer flooding agent in the high salinity and temperature conditions of oil reservoirs. Injection of 0.25 wt.% of amphoteric terpolymer, dissolved in 200-300 g∙L-1 brine, into high and low permeability sand pack models demonstrated that the oil recovery factor (ORF) increases by up to 23-28% in comparison with saline water flooding. This is explained by an increase in the viscosity of brine solution due to disruption of intra- and interionic contacts between oppositely charged AMPS and APTAC moieties, demonstrating the antipolyelectrolyte effect. In high saline water, the anions and cations of salts screen the electrostatic attraction between positively and negatively charged macroions, resulting in expansion of the macromolecule. This phenomenon leads to an increase in the viscosifying effect on the brine solution, thus decreasing the mobility factor (M), which is defined as the ratio of displacing phase mobility (water) to displaced phase mobility (oil).

Изучение кинетики высвобождения липофильных ингредиентов из капсул с использованием синтетических и природных систем

В работе была изучена кинетика высвобождения витамина Е и полифитового масла из капсул с использованием синтетических и природных систем. Высвобождение активных ингредиентов исследовали на УФ-спектрофотометре Cary 50 Cons, оснащенного программным обеспечением CaryWinUV. Кинетика высвобождения витамина Е из капсул, стабилизированных казеинатом натрия и затем покрытых хитозаном показывает замедленное пролонгированное высвобождение 20% витамина Е в течение 1 ч, в течение 5 ч высвобождается около 45%, в течение 48 ч около 80%. Установлено, что эффективность капсулирования витамина Е выше, чем полифитового масла, высвобождение витамина Е более замедленное и пролонгированное по сравнению с полифитовым маслом. Также исследовано высвобождение витамина Е из капсул, стабилизированных синтетической системой полимер-ПАВ / витамин E) хитозан) полистирол сульфонат PSS. Определено, что высвобождение витамина Е из капсул, стабилизированных синтетической системой (полимер-ПАВ и покрытых двумя слоями противоположно заряженных полиэлектролитов методом Layer-by-Layer) пролонгированное, в течение 1 ч – 23% высвобождается витамина Е, 70 % – в течение 12 ч и 100% – в течение 80 ч.

Распределение растворенных и взвешенных форм тяжелых металлов в воде реки Сырдарьи (Южный Казахстан)

Река Сырдарья является основным источником пресной воды Южного Казахстана, использующейся в сельском хозяйстве. Применение этой воды для орошения селькохозяйственных полей сказывается на изменении ее химического состава, что отражается в показателях класса качества воды, приведенных в информационных бюллетенях Министерства экологии, геологии и природных ресурсов Республики Казахстан. В настоящей работе изучено распределение взвешенных и растворенных форм тяжелых металлов в воде Сырдарьи на двух участках – верховье реки от Шардаринского водохранилища до моста «Коксарай» и низовье реки от г. Туркестана до п. Теренозек. Концентрацию тяжелых металлов и металлоидов определяли методом масс-спектрометрии с индуктивно-связанной плазмой (ИСП МС Agilent 7500A, США). Общая концентрация групп металлов (V, Cu, Mn, Fe, Sr) превышает значения предельно-допустимых концентраций, установленных для вод рыбохозяйственных водоемов. Оценена роль взвешенной формы в геохимической миграции ряда металлов в воде реки и показано, что взвешенная форма для большинства тяжелых металлов составляет значительную долю от общей концентрации металла. Наблюдается тенденция распределения взвешенных форм металлов аналогично значению мутности воды реки.

Recovery of zinc from copper smelter slag by sulfuric acid leaching in an aqueous and alcoholic environment

The content of zinc in copper smelter slags obtained from pyrometallurgical copper production is comparable to the content of this metal in zinc ores. Therefore, these slags are considered a valuable secondary resource for zinc recovery. At the same time, the features of the mineralogical composition of the slag make the extraction of zinc from it very problematic. Most of the zinc is concentrated in the refractory zinc ferrite (ZnFe2O4). To avoid the formation of a viscous pulp when leaching copper smelter slag with an aqueous solution of sulfuric acid, in this work, the slag was leached with sulfuric acid also in isopropanol and n-pentanol, under the following conditions: 0.5 M H2SO4, pulp density 50 g/L, magnetic stirrer rotation speed 600 rpm. The influence of the duration and temperature of leaching milled (≤100 μm) copper smelter slag of the Balkhash copper smelter on the extraction of zinc into solution was investigated. It was found that the maximum zinc recovery into an aqueous solution was 75 ± 2% at 363 K and 210 min. Replacing water with isopropanol or n-pentanol led to an increase in zinc recovery to 82 ± 2% at 210 min and a lower temperature (353 K) than in an aqueous environment. An increase in temperature to 383 K during leaching in n-pentanol made it possible to extract 92 ± 2% of zinc. A shrinking core model was used to describe the kinetics of the zinc leaching process. It was found that the limiting stage of the process under all investigated conditions is the chemical leaching reaction. Some kinetic characteristics of the leaching process were calculated, in particular, the apparent reaction rate constants, as well as the activation energy.

Selection of sorption materials for the extraction of nickel and cobalt from the ore of the Gornostaevskoye deposit

Oxidized nickel ores account for the majority of industrial ores suitable for nickel production. The processing of such ores using traditional pyrometallurgical technology is not economically viable due to the low nickel content. One of the most cost-effective methods of processing oxidized nickel ores is sulfuric acid leaching technology followed by sorption extraction. The aim of this work is to establish the kinetic and thermodynamic parameters of the sorption extraction of nickel and cobalt using iminodiacetate chelating ion-exchange sorbents from various manufacturers, to select a desorbing solution and to determine the degree of desorption. The sorption of nickel and cobalt was carried out in a weakly acidic medium from a model solution containing impurities of other metals in static and dynamic modes. The limiting sorption capacity for the studied sorbents is 18-26 mg/g for nickel and 1-2 mg/g for cobalt in the static mode. The sorption capacity in the dynamic mode for nickel is equal to 25.5 g/L for Purolite S 930, 29.2 g/L for Lewatit TP 207, 1.4 g/L, and 1.8 g/L for cobalt, respectively. The best desorption parameters are achieved when using a 2 M sulfuric acid solution. The degree of desorption for sorbents Purolite S 930 and Lewatit TP 207 exceeds 90%. The use of the Lewatit TP 207 sorbent for the extraction of nickel from the leaching solution of nickel ore of the Gornostaevskoye deposit in 5 cycles made it possible to obtain a commercial desorbate with a nickel content of 18 g/L. The use of a part of the commercial desorbate obtained in the previous cycle, further strengthened to the initial concentration of sulfuric acid, for re-extracting nickel from the saturated sorbent during a cyclic process leads to a deterioration in desorption characteristics. It is recommended to remove the commercial desorbate from the process after several cycles of desorption and supply new solution of sulfuric acid for desorption to restore the sorption parameters.

Preparation and study of the physicochemical characteristics of multilayer polymer composites based on poly(ethyleneimine)-stabilized copper nanoparticles and poly(sodium 2-acrylamide-2-methyl-1-propanesulfonate)

Multilayer films were synthesized from a complex of branched polyethyleneimine (PEI) with copper nanoparticles (PEI-CuNPs) and sodium poly-2-acrylamide-2-methyl-1-propanesulfonate (PAMPSNa), applied layer-by-layer (LbL) on a solid support in an acidic medium. Protonation of the amino groups of PEI in an acidic medium increases the positive charge of the PEI-CuNPs system to +43.5 mV and promotes the formation of an interpolyelectrolyte complex between the positively charged PEI-CuNPs and the highly charged anionic polyelectrolyte PAMPS, the ζ-potential of which was -141 mV. AFM images and SEM micrographs showed a uniform distribution of spherical copper nanoparticles in the homogeneous structure of the multilayer film. The optical characteristics and hydrodynamic dimensions of PEI-CuNPs indicate the formation of PEI-CuNPs nanoparticles with sizes of 60-300 nm, with an average size of up to 100 nm. Copper nanoparticles distributed uniformly in a multilayer PEI-CuNPs/PAMPS film may be of interest for applications in the field of membrane catalysis, biochips, sensor membranes, and controlled drug delivery.

Synthesis of nanocomposite material through modification of graphene oxide by nanocellulose

Intensive research of nanocomposites contributes to the development of new materials in the fields of medicine, nanoelectronics, energy, biotechnology, information technology. Therefore, the synthesis of new materials by modifying of graphene oxide (GO) with nanocellulose and the study of its properties are of great interest. In this study synthesized nanocomposite material by modifying of graphene oxide (GO) from activated carbon (BAU-A) in a 1:1 volume ratio with nanocellulose (NC) from hemp stems belonging to the annual plant, and their chemical structure was studied by FTIR and UV-spectroscopy. The results of the study showed the absorption of the etheric bond C = O in the UV spectrum at full length 243 nm. The IR spectrum showed all the new etheric bonds O = C - OH at a wavelength of 1625 cm-1. The average particle sizes of GO was 352 nm and NC was 470 nm in length and 80 nm in width. The SEM analysis indicating the NC as a contact layer between ultralow thicknesses of the GO layers. The XRD analysis indicated GO-NC composite film is a substance comprising GO and NC. According to the results, modification of graphene oxide showed that its scope can be expanded as much as possible.

Powder bismuth-based anode material for magnesium-ion batteries and its properties

In this work an intercalation anode material synthesized on the base of the powdered bismuth is presented. The uniformly distribution of carbon paste suspension over the substrate surface was found out by scanning-electron microscopy. The regularities of electrochemical intercalation and deintercalation of magnesium ions into the electrode created on the base of powdered bismuth in a solution of 0.25 mol/L Mg(N(SO2CF3)2)2 on the base of acetonitrile were studied. The cyclic voltammograms with the results of scanning electron microscopy and atomic emission analysis indicate that in the cathode area the reduction processes proceed with the formation of an intermetallic compound – MgxBiy; two peaks were observed at the reverse course which were conceivably corresponding to two-stage magnesium oxidation. According to cyclic voltammograms by the difference in the potential of peaks in the forward and reverse directions it was established that the processes of reduction and oxidation of magnesium ions into intercalation material were irreversible. The diffusion coefficients of intercalation and deintercalation into the electrode material were calculated using the Rendles-Shevchik equation; they were 3.12·10-11 sm2/s and 1.85·10-11 sm2/s, respectively. X-ray diffraction (XRD) results demonstrated the cubic structure of the bismuth crystal lattice with altered parameters corresponding to inter-metallide formation. At galvanostatic cycling of the synthesized anode material a capacity of up to 104 mA·h·g-1 at current load 1C was achieved. Such results can be a good indicator for the development of magnesium-ion power sources.

Recycling of waste plastics to liquid fuel mixture over composite zeolites catalysts

Plastic waste production and consumption is increasing at an alarming rate with the increase of the human population, rapid economic growth, continuous urbanization, and changes in lifestyle. In addition, the short life span of plastic accelerates the production of plastic waste on a daily basis. Plastic waste recycling is carried out in different ways, but in most developing countries, open or landfill disposal is a common practice for plastic waste management. Plastic recycling into feedstocks, also known as chemical recycling, is encouraged all over the world. One such area is the thermal and catalytic thermal degradation of plastics into hydrocarbon fractions, which can be used as high-quality motor fuel after appropriate processing. Hydrocracking in the presence of a catalyst is a promising method of converting waste plastic materials to high quality liquid transportation fuels with decreased amounts of olefins and heteroatoms such as S, N, Cl, N, and O. The article deals with the study of hydrocracking of waste plastic into high quality liquid fuel on various catalysts based on natural zeolite deposits Taizhuzgen. The aim of the work is to determine the effect of new composite catalysts on the yield of liquid products by studying the specific surface and porous structure based on natural zeolite modified with Mо salt. It is established that the modification of natural zeolite with Mo affects the morphology of the catalyst, therefore, the obtained catalysts have different effects on the yield and composition of liquid fractions during the hydrogenation thermocatalytic transformation of hydrocarbons. The highest yield of liquid products (61.56%) was achieved using the 2% Mo/Taizhuzgen zeolite catalyst, which was chosen as optimal.

Ultrasound-assisted dewatering of crude oil from Kumkol oilfield

Reducing the water content of crude oil is a necessary step in preparing oil for transportation and processing. This task is complicated by the presence of stable water-in-oil emulsions. The most widely used approach to oil demulsification is exploring chemical demulsifiers. However, the high cost and impossibility of regenerating the latter require the search for new ways to destroy water-oil emulsions. One of the promising areas is the use of ultrasound. This paper presents the results of studies on the ultrasonic treatment of four samples of emulsions with different water content (8.74; 15; 25 and 30 vol.%) based on oil from the Kumkol oilfield (Kazakhstan). Samples of emulsions were subjected to ultrasonic action at a frequency of 40 kHz for 5-60 min at a temperature of 70±1°C, followed by settling for 40 min at the indicated temperature. The influence of the initial water content in the emulsion, the acoustic intensity, as well as the duration of ultrasonic treatment on the dewatering ratio was investigated. It was found that the residual water content in the oil was 5.04- 7.82 vol.%. Ultrasonic treatment of crude oil from the Kumkol oilfield can be used for preliminary dewatering, to subsequently reduce the consumption of chemical demulsifiers.