Wettability Changes Due to Nanomaterials and Alkali—A Proposed Formulation for EOR

We investigated the usage of two silica nanomaterials (surface-modified) and alkali in enhanced oil recovery through Amott spontaneous imbibition tests, interfacial tension (IFT) measurements, and phase behavior. We evaluated the wettability alteration induced by the synergy between nanomaterials and alkali. Moreover, numerical analysis of the results was carried out using inverse Bond number and capillary diffusion coefficient. Evaluations included the use of Berea and Keuper outcrop material, crude oil with different total acid numbers (TAN), and Na2CO3 as alkaline agent. Data showed that nanomaterials can reduce the IFT, with surface charge playing an important role in this process. In synergy with alkali, the use of nanomaterials led to low-stable IFT values. This effect was also seen in the phase behavior tests, where brine/oil systems with lower IFT exhibited better emulsification. Nanomaterials’ contribution to the phase behavior was mainly the stabilization of the emulsion middle phase. The influence of TAN number on the IFT and phase behavior was prominent especially when combined with alkali. Amott spontaneous imbibition resulted in additional oil recovery ranging from 4% to 50% above the baseline, which was confirmed by inverse Bond number analysis. High recoveries were achieved using alkali and nanomaterials; these values were attributed to wettability alteration that accelerated the imbibition kinetics as seen in capillary diffusion coefficient analysis.

Geopolymers Based on Mechanically Activated Fly Ash Blended with Dolomite

This study reports the effect of natural dolomite addition to fly ash and the mechanical activation of this blend on the geopolymerization process. Dolomite was replaced with fly ash at 1, 3, 5, and 10 wt.%. Geopolymers were synthesized at ambient temperature using NaOH solution as an alkaline agent. The geopolymerization process, reactivity of the raw material, compressive strength, and microstructure were studied using X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetry, and scanning electron microscopy. It was shown that blending fly ash with dolomite and mechanical activation improved the geopolymer strength, especially during the early age of curing. For geopolymers prepared using a 90% fly ash + 10% dolomite blend cured for 7 d, the strengths were 8.2-, 2.3-, and 1.4-fold higher than those for geopolymers prepared using 100% FA for 30 s, 180 s, and 400 s milling times, respectively. A simple method for evaluating the increments of mechanical activation, carbonate additives, and the synergistic effect in the increase in the compressive strength of the composite geopolymer is proposed.

Influence of fly ash and blast furnace slag on characteristics of geopolymer non-autoclaved aerated concrete

Geopolymer materials are known as sustainable and environmental material. The main constituents of geopolymer material are alumina and silicon, which can be activated in an alkaline environment. In this paper, the reaction of alumino-silicate materials in the alkaline agent is investigated on geopolymer non-autoclaved aerated concrete (GNAAC). The main constituents of GNAAC are fly ash (FA), blast furnace slag (BSF), lime, gypsum, aluminium powder, and alkaline solution. In the mix proportions, FA and BSF are used to replace crushed sand and cement. The results indicate that the GNAAC can be produced similarly as traditional autoclaved aerated concrete. Besides, the flow diameter of the mixture using blast furnace slag is lower than that of fly ash. The temperature and expansion ability decrease with an increase in FA/BFS – Lime and alkaline content. Furthermore, the compressive strength of GNAAC can be determined by synthesizing geopolymer without steam and pressure curing conditions.

Intensification of the process of decomposition of oil-water emulsions stabilized with hydrochloric acid

The major goal of oil and gas companies working in the oilfields on the late stages of development is to maintain a high level of hydrocarbon production. Analysis of well intervention techniques (WITs) in the oilfields of the Samara Region shows that most often the bottomhole area is treated with reagents containing hydrochloric acid, which significantly effects the efficiency of well fluid preparation processes. The paper summarizes the results of studies of the impact of hydrochloric acid on the rheological and near-surface properties of water-in-oil emulsions (WOEs). It is shown that the presence of acid and/or products of its reaction with the oil increases the stability of the water-in-oil emulsion. To enhance the process of decomposition of the water-in-oil emulsion stabilized with hydrochloric acid, a reagent was developed based on the non-ionic surfactants, alkaline agent and solvent, providing a significant reduction of the viscosity of water-in-oil emulsions and improving the efficiency of their decomposition.

Synthesis of Fly Ash-Based Geopolymers: Effect of Calcite Addition and Mechanical Activation

Blends of fly ash and natural calcite, mechanically activated for 0–400 s in a planetary mill, were used to synthesize geopolymers at ambient temperature. The calcite content in the blends was 0–10 wt.%. Sodium hydroxide solution was used as an alkaline agent. Mechanical activation of the raw material considerably enhanced its reactivity with respect to the alkaline agent, as was observed using Fourier-transform infrared spectroscopy, isothermal conduction calorimetry, thermogravimetry coupled with mass spectrometry analysis of the evolved gas, and SEM/EDS. The addition of calcite to the fly ash improved the compressive strength of the geopolymers, especially during the early age of curing. For 7 d aged geopolymers based on the 90% fly ash + 10% calcite blend, the strength was 8.0-, 3.5- and 2.9-fold higher than that for the geopolymers based on the unblended fly ash for 30 s, 180 s and 400 s mechanical activation time, respectively. Using Mössbauer spectroscopy, it was revealed that iron present in the fly ash did not play a significant part in the geopolymerization process. The dominant reaction product was sodium containing aluminosilicate hydrogel (N-A-S-H gel). Calcite was found to transform, to a small extent, to vaterite and Ca(OH)2 in the course of the geopolymerization.

Arsenic (III) Removal from a High-Concentration Arsenic (III) Solution by Forming Ferric Arsenite on Red Mud Surface

Arsenic (As) is considered one of the most serious inorganic pollutants, and the wastewater produced in some smelters contains a high concentration of arsenic. In this paper, we purified the high-concentration arsenic solution with red mud and Fe3+ synergistically. In this system, arsenite anions reacted with Fe(III) ions to form ferric arsenite, which attached on the surface of red mud particles. The generated red mud/Fe1−x(As)x(OH)3 showed a better sedimentation performance than the pure ferric arsenite, which is beneficial to the separation of arsenic from the solution. The red mud not only served as the carrier, but also as the alkaline agent and adsorbent for arsenic treatment. The effects of red mud dosage, dosing order, pH, and molar ratio of Fe/As on arsenic removal were investigated. The efficiency of arsenic removal increased from a pH of 2 to 6 and reached equilibrium at a pH of 7. At the Fe/As molar ratio of 3, the removal efficiency of arsenic ions with an initial concentration of 500 mg/L reached 98%. In addition, the crystal structure, chemical composition, and morphological properties of red mud and arsenic removal residues (red mud/Fe1−x(As)x(OH)3) were characterized by XRD, XPS, X-ray fluorescence (XRF), SEM-EDS, and Raman spectroscopy to study the mechanism of arsenic removal. The results indicated that most of the arsenic was removed from the solution by forming Fe1−x(As)x(OH)3 precipitates on the red mud surface, while the remaining arsenic was adsorbed by the red mud and ferric hydroxide.

Development of a regime of disinfection of milking equipment and milk inventory with the acid detergent “Milkodez”

The material for the reseach were the washes that were taken from the milk utensils, portable milking machines, surface of the cooler, milking unit with the UDM 200 “Bratslavchanka” and milking parlor “Yalinka”. Washing of milking equipment and milk equipment was carried out with 0.5% hot solution (70 ± 5 ℃) of alkaline “Hyprochlor” and acid detergents disinfectant “Milkodez” and “Hypracid”. Processing of milk dishes, portable milking machines and cooler with acidic means was carried out for 2 and 5 minutes, cooler for 5 and 10 minutes, and installations of milking machine with UDM 200 “Bratslavchanka” milking parlor and “Yalinka” milking parlor – for 15 minutes by pumping the solution several times using a vacuum unit. The equipment, sanitary treatment of which was carried out by means of “Hyprochlor” and “Hypracid”, used as control. The disinfectant effect of the investigated agents was evaluated by the number of mesophilic aerobic and optional anaerobic microorganisms (MAOanM) in washings selected after washing and in milk. It was found that for the use of “Milkodez” dairy utensils for sanitary treatment, the amount of MAOanM on the surface of milking buckets and glass jars was smaller compared to their treatment with “Hypracid”, and the difference was for 2 and 5 min respectively 86.5% and 57.7% and 97.3 and 95.7%, respectively. Microbial contamination of fresh milk was reduced by 50.5% and 91.3%, respectively. The smallest amount of MAОanM in washes from milking rubber, milk hose, collector and milking tank of portable milking machines was in 5 minutes of their washing “Hyprochlor” and “Milkodez” and were respectively 0.6, 0.3, 0.5 and 0.2 thousand CFU/sm3, which allowed to obtain milk with the content of microorganisms 26 thousand CFU/sm3. The number of microorganisms per 1 sm3 of flushing from the walls of the cooler for 10 min of sanitary treatment by means of “Hyprochlor” and “Hypracid” was 5.8 thousand CFU/sm3, while for 5 min of exposure of the preparations “Hyprochlor” and “Milkodez” their number was 1.1 thousand CFU/cm3, and for 10 min – 0.4 thousand CFU/cm3. Thus, the number of microbial cells in 1 sm3 of milk was respectively 248000, 41000 and 29000 CFU. It is proved that for the sanitary treatment of UDM 200 “Bratslavchanka” and milking parlor “Yalinka” it is advisable to use the acid detergent disinfectant “Milkodez”, which provided 11.7 and 20.3 times less total amount of microorganisms in the washes from the elements and in 3.6 and 7.1 times in fresh milk, compared to “Hypracid”. The optimal mode of application of 0.5% solution of acid detergent disinfectant “Milkodez” for the effective sanitary treatment of milk utensils is 5 minutes, milking equipment – 10 minutes, and for the treatment of milking installations with milk pipeline and milking parlor – 15 minutes, after the previous washing them with an alkaline agent “Hyprochlor”.

A novel low add-on technology of dyeing cotton fabric with reactive dyestuff

A novel low add-on dyeing process of cotton fabric with C.I. Reactive Black 5 has been implemented successfully with the assistance of dye-jet ejector units to produce precise wet pick-up ranging from 20% to 50%. The steaming process of the low add-on technology was investigated through evaluating the effects of relative humidity, steaming temperature, steaming time and water ratio on the surface temperature of the wet fabric and their influence on the dye properties, as well as the effect of the wet pick-up on dye properties. The optimal dyeing process was also conducted, including build-up properties and the concentrations of the alkaline agent and the electrolyte via the evaluation of the color strength ( K/ S value) and dye fixation rate. A comparison was made between the novel low add-on dyeing process and conventional dyeing process by assessing the dye properties, color shade and color levelness. The results indicated that the fabric dyed with the low add-on process had excellent washing fastness, rubbing fastness, a similar color shade and superior levelness in comparison with conventional one-bath pad-steam dyeing.