دوماهنامه مهندسی شیمی ایران
پیاپی 129 (مهر و آبان 1402)

The success of drilling hydrocarbon reservoirs is inextricably linked to the efficiency of the drilling fluid. Polymers and nanopolymers as effective additives have great potential to improve the properties of drilling fluids. However, the role of polymeric materials in this field is in its beginnings and had significant progress in recent years. The present study reviews the drilling fluids improved and modified by various polymers and nanopolymers. Also, the effects of new polymers, seawater-based and environmentally friendly polymer systems, cationic and anionic polymer systems, the role of surfactants and nanopolymers in improving the properties of drilling fluids are described and their technical and economic advantages are studied. This research reviews recent advances in the synthesis and applications of polymers and nanopolymers in drilling fluid systems while discussing the role of polymers in modifying rheological properties and controlling drilling fluid loss, mud cake thickness, filtration properties, and thermal stability. The most important findings of this review show that environmentally friendly polymer systems reduce costs by up to 30% and reduce the transport and disposal of drilling fluid waste. The use of cationic and anionic polymer systems neutralizes the rock charge and reduces its electrostatic interaction with water, which prevents water from penetrating the clay and can, like PHPA polymer, reduce the drilling problems of clay layers. As a biopolymer, terminalia mantaly (TM gum) and CMC are desirable additives to increase viscosity. Also, the ability to withstand high pressure and sealing of drilling fluids based on nanopolymers prevents pressure transfer and minimizes the interaction of fluids between the drilling bit and the formation, thus improving the stability of the oil and gas wells.

In this paper, main effects and the interactions of operating conditions were investigated using response surface methodology and statistical analysis in the presence of Co/Al2O3 catalyst in a CSTR reactor. Analysis of variance demonstrated that the second-order polynomials adequately predicted the responses. The selectivity of CO2, CH4, and CO conversion increased by the decrement of syngas flow rate. Increasing the pressure to 22 bar led to the increasing of CO conversion and CO2 selectivity; indicating the promotion of the water-gas-shift reaction in these conditions. Rising syngas flow rate caused decreasing the CO conversion and increasing C5+ selectivity. Minimum CO2 selectivity was achieved at the syngas flow rate and pressure of 61.9 Nl/h and 15 bar, respectively. Multi-objective optimization showed that minimum CO2 selectivity (2%) and methane selectivity (16.4%), as well as maximum CO conversion (53.8 %) and C5+ selectivity (68.3%) obtained at the syngas flow rate and pressure of 47.8 Nl/h and 15 bar, respectively.

One of the ore dressing steps in Gol Gohar Mining and Industrial Company is dewatering from slurry containing 60 weight percent of the iron concentrate. At present, this dewatering step is carrying out by a continuous strip filter, which is a kind of vacuum filter. At the present research the role of ionic and non-ionic surface activators in reducing the moisture, content of the iron ore particles, after filtration, has been investigated. Surface activators used were sodium dodecyl sulfate (SDS), polyethylene glycol 4000 (PEG4000), sodium dodecyl ether sulfate (SLES) and acetyl tri methyl ammonium bromide (CTAB). In this work amount of 30, 45, 60, 75 and 90 g/ton of the mentioned surfactants were added to the slurry. To evaluate effect of each surfactant, in addition to amount of filter cake humidity, other experiments including filtration kinetics, Zeta potential, contact angle measurement, and FTIR analysis on the samples were carried out. The results showed that SDS and SLES anionic surface activators have a significant effect on the reducing cake moisture. The best results obtained at 75 g /ton of the surfactants and the average moisture reduction in filter cake obtained about 2%. On the other hand, polyethylene glycol 4000 had a negligible effect, 0.5%, on the final cake humidity. The results from addition of acetyl tri methyl ammonium bromide (CTAB) showed that using this chemical reagent does not help to the slurry dehumidification.

In this study, a magnetic metal-organic framework functionalized with 8-aminoquinoline was synthesized to monitor and measure arsenic in rice and tuna samples consumed in the Iranian market. After identifying the nanoadsorbent by FT-IR, SEM, TEM, VSM, XRD, CHN, DLS, Zeta potential and BET methods, parameters affecting adsorption and desorption were optimized. Optimization of the extraction process was performed by the experimental design method based on a three levels Box-Behnken design. Then the desired method was validated and finally, the synthesized adsorbent was used to monitor and measure arsenic in rice and tuna samples consumed in the Iranian market. The optimal extraction conditions were: pH of the sample solution, 3.6; adsorption time, 12 minutes; nanoadsorbent dose, 16 mg; type and concentration of elution solvent, 0.06 M nitric acid; elution time, 8.5 minutes; eluent volume, 0.8 ml. Under the optimal conditions, the detection limit of the method was equal to 0.01 μg/l, and the method exhibited good accuracy in the analysis of the sample with the confirmed concentration. Under the optimal conditions, the desired method was evaluated in order to monitor and measure arsenic in rice and tuna samples available in the Iranian market, and very good results were obtained.The most important advantages of the present method are its simplicity, easiness, time saving and high accuracy.

Emulsifying porous polymers have many pharmaceutical and industrial applications and are considered as new materials for separation. In this research, first the emulsion synthesis of poly (styrene-di vinylbenzene) was performed and then the effect of increasing the functional group of sodium styrene sulfonic acid on the hydrophilicity of the emulsion porous polymer poly (styrene-divinylbenzene) was investigated. Scanning Electron Microscope to study surface morphology and determine the size distribution of surface cavities and Energy Dispersive X-ray analysis test to investigate the presence of sulfur and sodium atoms in the surface of functionalized porous polymer and contact angle measuring device with Coupled-Camera Devise(CCD) and with software for measuring the contact angle of droplet contact with the surface to evaluate the hydrophilicity of the surface of polymerized emulsion polymer poly (styrene-divinylbenzene) were used. Increasing sodium styrene sulfonic acid has no effect on the shape and size of the cavities formed, but the hydrophilicity of the samples increased with increasing sulfone factor in the aqueous phase and the appropriate percentage of sodium styrene sulfonic acid in the aqueous phase was about 2%. With an increase of more than 2%, a slight increase in the hydrophilicity of the surface of the emulsion porous polymer poly (styrene-divinylbenzene) was activated and the graph became almost flat with slope changes insignificant.

In this study, we developed artificial neural network-based model for prediction of equilibrium solubility of carbon dioxide in the amine solvent system of (triethanolamine + piperazine + water) for the purpose of carbon dioxide uptake. In the MLP model, the solubility data (CO2 loading in the amine solution) were investigated as functions of CO2 partial pressure, system temperature, and amine composition. The Levenberg–Marquardt back-propagation (LMP) algorithm was used to predict the partial pressure of carbon dioxide. The final ratio of training, validation, and test datasets was approximately 70:15:15. The optimum multilayer perceptron (MLP) structure in Levenberg-Marquardt algorithm for CO2 partial pressure is created with 20 neurons in the first hidden layer and 10 neurons in the second hidden layer. There was a 0.99546 correlation coefficient between the experimental results and the artificial neural network (ANN) calculations, demonstrating excellent compatibility between them. The best validation performance was 0.0043497 from epoch 13. In general, the results show that the applied model can provide an accurate prediction of partial pressure or solubility for different operating conditions.

ZnO-ZnS nanocomposite was synthesized by sol-gel method with thiourea precursor. Nanocomposite properties were evaluated by XRD, SEM, FTIR and UV-vis DRS. XRD and FTIR results confirmed the presence of the crystalline structure of ZnO and ZnS in the nanocomposite. SEM analysis confirmed the synthesis of photocatalyst in nanometer dimensions. The fabrication of nanocomposite increased the light absorption efficiency compared to pure ZnO and the band gap ofZnO-ZnS photocatalyst decreased to 3 eV. ZnO-ZnS nanocomposite was investigated for the photocatalytic degradation of direct red 80 (DR80) under ultraviolet light irradiation. The DR80 degradation reached 98.76% after 60 minutes irradiation, which is 40% higher than that of ZnO nanoparticles. Reducing the band gap of nanocomposite and proper charge transfer in the created heterojunction caused a significant increase in the photocatalytic activity. A mechanism for the ZnO-ZnS nanocomposite performance was presented. Stability of nanocomposite was evaluated after 4 times of recycling.

The energy crisis and environmental concerns in recent decades are a serious challenge to human life. The fuel cell, especially the solid oxide type, has been welcomed due to its features such as fuel flexibility, good efficiency and no need for precious metals. However, the problems of hydrogen fuel, such as the low energy density of the gas phase, difficult storage and portability, have suggested ammonia as a suitable alternative fuel. In this research, tubular all porous solid oxide fuel cell ammonia fueled has been simulated and investigated. Therefore, the equations of conservation of mass, momentum, energy, species and electric flux are defined, coupled and solved in the form of finite element code. The results show that the presence of electrolyte porosity increases the efficiency of fuel cell ammonia fueled. It was also observed that the power and current density of the fuel cell have a direct relation with the operation temperature and flow rate and an inverse relation with the porosity of the electrodes.

The present study investigates the performance of CO2 absorption in the presence of amino acid L-arginine (ARG) as a promoter in an aqueous solution of triethanolamine (TEA) in a micro-reactor. In order to experimentally evaluate the absorption process, the aqueous solution of 30% TEA and a mixture of TEA and arginine were used in four concentrations of ARG-TEA (0+30 wt%), (4+26 wt%), (8+22 wt%), and (12+18 wt%) under the solvent flow rate of 3-9 ml/min and the inlet gas flow rate of 120-300 ml/min at the temperature of 45 ℃. The experimental mass transfer performance was evaluated in terms of the overall volumetric gas-phase mass transfer coefficient (KGaV), absorption efficiency (AE), and volumetric mass transfer flux (NAaV). The results of this investigation illustrated that in the medium flow rate of solvent and gas, by increasing the arginine concentration in the aqueous solution (30 %wt TEA) up to 12 wt% in the TEA+ARG (12+18%wt), the values of KGaV increased from 11.09 to 83.37 kmol/m3 kPah so that the absorption efficiency improves up to about 40%.