Kinetic and thermodynamic study of a traditional dye as catalyst for thiol oxidation in sour kerosene and Nawras Sabeeh Al Qadisiyah Journal for Engineering Sciences, 2025 The oxidation process of thiols with air is industrially used to treat light petroleum products in the presence of an alkaline solution and a supported catalyst. A low-cost, traditional dye, cobaltous phthalocyanine salt, was used as the active component for catalyst preparation. The supported catalyst was experimentally prepared by impregnation the activated carbon (dp = 1.971 mm) with the uric dye solution in a laboratory batch unit. The prepared catalyst was tested for the oxidation of thiols present in row kerosene. All kinetic experiments were carried out at constant pressure concurrent fixed-bed unit. The effect of temperature and LHSV on conversion percent was investigated. Attempts were made to correlate the data with first and second-order reactions, and it was found that the first-order kinetics correlates the data well with an activation energy of 24.48 kJ/mol. This indicates that the synthesised catalyst is effective and necessary for the reaction to proceed at moderate temperatures with a sufficient rate. Also, the change of enthalpy and entropy were found to be equal to 21.94 kJ/mol and 0.153 kJ/mol K, respectively, with an average Gibbs free energy change of -24.802 kJ/mol. These values indicate that the reaction is weakly spontaneous and thermodynamically favourable, and could proceed at a suitable rate in the presence of the prepared catalyst. Furthermore, the Thiele modulus and internal effectiveness factor were examined, and it was found that the internal diffusion is the major resistance for the oxidation reaction proceeding, and the oxidation reaction takes place only on the outer layer of the surface of the pellets.
Bio-based synthesis of a sustainable Nano drag reducing agent for sprinkler irrigation systems Nawras S Sabeeh, Abbas K Mohammad Iop Conference Series Earth and Environmental Science, 2023 High-grade silica Nano particles were extracted from rice husk using a straightforward thermochemical method. The specifications of the isolated Nano particles were verified using a variety of material characterization techniques. Siloxane and silanol groups were notably visible in the spectra obtained using Fourier transform infrared spectroscopy. Scanning Electron Microscopy images revealed main Nano particles alongside secondary Micro particles. The size of the particles varied from 14.56 to 33.72 nm. The drag reduction experiments were took place in a facility that uses a forced closed loop. The extracted Nano silica was mixed with faucet water at a weight concentration of 50 to 400 mg/l to reduce drag. Records of pressure loss were obtained along a 186 cm carbon steel tube with internal diameters of 1.6 and 2.7 cm and variable flow rates of solutions at a comfortable temperature of 25 °C. The friction factor values were found to be around Blasuis asymptote for pure water but they were found to be near maximum drag reduction asymptotes when using the Nano material. A maximal drag reduction of nearly 68 % was achieved by using 400 ppm of Nano silica. It was observed that there is a crucial Reynolds number around 96000 that should not be surpassed since any additional increase results in a drop in drag reduction. Furthermore, a relationship between wall shear stress and velocity of the fluid was established.
Ultrasound assisted extraction of carotenoids from Sargassum Angustifolium algae Abbas Khalaf Mohammad, Nawras Shareef Sabeeh Periodicals of Engineering and Natural Sciences, 2022 An experimental batch extraction method was studied to obtain a carotenoid pigment from dried Sargassum Angustifolium algae using ultrasound as an enhancer and a mixture of ethanol-isopropanol as a solvent. The purpose of this work is to investigate the extraction kinetics as well as the temperature effects (303 to 333) K, solvent concentration (40% ethanol - 60% isopropanol to 60% ethanol - 40% isopropanol) and particle size (250 - 500, 500 - 710 and 710 - 1000) micrometer. Also, the effect of collecting, drying and transporting Sargassum Angustifolium algae on the total carotenoids extraction from dried algae was studied. The ultimate extraction value of the carotenoids was found to be 0.29% from algae. A batch model for extraction was created and numerically solved. The model parameters were calculated using existing empirical correlations and data gathered during this project. The model predicts the mass transport rate constant and saturation capacity at various temperatures. Furthermore, the energy of activation and frequency factor of the extraction process were enumerated and it was found that the process is endothermic with activation energy equals 28.9 kJ/mol. The utilized mathematical model agreed well with the experimental data, allowing it to be used in modeling and improving the carotenoids extracting process from Sargassum Angustifolium algae.
Microstructure, thermal, and mechanical properties of friction stir welded 6061 aluminum alloy with 10% SiCp reinforcement H. Dawood, Kassim Alshemary, Abbas Mohammad, Nawras Sabeeh Egyptian Journal of Chemistry, 2022 After 10 vol. % SiC particles from the welding volume were inserted into the joint line, the mechanical properties of friction stir-welded joints were assessed. During the Friction Stir Welding (FSW) process, three different rotational speeds (1300, 1750, and 2000 rpm) were used. Field Emission Scanning Electron Microscopy (FESEM) was used to examine the microstructure across the Stir Zone (SZ), revealing a banded structure between the particle-rich and particle-free portions of the SiCp. When the joint was constructed at 1750 rpm, it displayed better mechanical properties. Because of the presence of SiCp, the Ultimate Tensile Strength (UTS) was enriched by 79.6% at 1750 rpm. Because of the pinning effect and larger nucleation sites caused by the SiC powder, this strength significantly increased. Furthermore, the hardened particle powder cracked the initial grains. When compared to the SiC-free sample, the SiC-rich sample had higher ductility at 1750 rpm. Finally, the fracture surface showed a good agreement with the equivalent ductility marks.
Rotational speeds and preheating Effect on the friction stir butt welding of Al-Cu joints H. Dawood, Abbas Mohammad, Kanaan Musa, Nawras Sabeeh Egyptian Journal of Chemistry, 2022 Friction Stir Welding (FSW) used for welding similar and dissimilar materials especially to join sheet Al alloys. In this study, commercial pure aluminum and copper sheets (Al/Cu) with a thickness of 3mm were joined. We first preheated on the Cu side by pinless welding tool. Three different tool rotational speeds of 700, 1000 and 1500 rpm were used while the axial load and transverse speed were kept constant at 7.5 KN and 30 mm/min, respectively. We measured different parameters to determine the best rotational speeds for welding. Such as Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD) analysis which showed that at 700 rpm there are three elements: Al, Cu and oxygen are present. While at 1500 rpm formation of different Intermetallic Compounds (IMCs). At 1000 rpm the interface has only Al and Cu in a uniform structure this result is due to the sufficient frictional heat generated at 1000 rpm and it considered perfect welds with acceptable mechanical properties.
Treatment of oily wastewater by using polysulfide polymer Fatima Mohammed Taha, Abbas Khalaf Mohammad, Nawras S. Sabeeh Al Qadisiyah Journal for Engineering Sciences, 2021 The discharge of water from oil fields is become one of the most significant environmental concerns associated with the oil sector. This study features a low-density polysulfide polymer prepared by Sulfur and used sunflower oils react directly. Because both sulfur and cooking oils are hydrophobic, the polymer can easily extract hydrocarbons like crude oil and diesel fuel from saltwater. Sulfur is a petroleum industry by-product, and leftover sunflower oil may be utilized as a raw material. 150 g food-grade used sunflower oil, 150 g sulfur, and 700 g finely powdered sodium chloride were used in an experiment to make polysulfide. The reaction temperature was adjusted at 180°C. The resulting polymer (a soft rubber) is friable; therefore, it was ground down using a mechanical grinder and screened for particles between 0.5 and 3 mm. The polymer was repeatedly rinsed with DI water to eliminate the sodium chloride porogen. The polymer was filtered through a sieve (0.5 mm) and pressed with a piece of flat plastic to remove surplus water after the final wash. The polymer was then dried in a sieve by putting it in a drying oven (UNB400, Germany) for 24 hours at 42 degrees Celsius. Kinetics of adsorption was examined with pseudo−first order, pseudo−second order and intra particle diffusion models. The experimental results show good fitting with pseudo−second order model for south oil adsorption on polysulfide polymer. Adsorption of north and south oils onto the prepared polysulfide polymer was done experimentally using batch apparatus with controlled conditions of temperature and stirring. Effects of temperature and initial oil concentration for the adsorption process were examined for the ranges (20−40) ◦C and (10−90) (g/l), respectively. The experimental data follows the Freundlich isotherm model with coefficient of variance (R2) equals, according to the study of adsorption equilibrium isotherms (0.99). According to the findings of the study, the greatest g/l of south oil removal equals 93 percent at the lowest temperature of 20 degrees Celsius.
Comparative study for adsorption of hydrogen-methane mixtures on activated carbon and 5A molecular sieve Abbas Khalaf Mohammad, Nawras Shareef Sabeeh Brazilian Journal of Chemical Engineering, 2018 Equilibrium adsorption isotherms were obtained experimentally by a static method for a binary component hydrogen-methane mixture on activated carbon and 5A molecular sieve adsorbents. The temperature range 303-333 K and pressure range 0 - 4 MPa were examined. Methods for predicting gas-mixture equilibrium adsorption data from the pure-component isotherms were evaluated. Extended Langmuir model correlated the adsorption of binary mixtures fairly well. In all cases mutual interference was found, that is, the amount of a given gas adsorbed at a given partial pressure was always less in the mixture than it would have been if the other gaseous component had not been present. It was found that the amount adsorbed of gases per unit bulk volume for 5A molecular sieve was higher than for activated carbon. Furthermore, 5A molecular sieve showed better adsorption characteristics than activated carbon in mass transfer properties, affinity, selectivity and heat of adsorption.
