Experimental Investigation and CFD Simulation of Top Spray Fluidized Bed Coating System

Experimentally investigated in this work is the hydrodynamics of particulates motion in a cylindrical fluidized bed equipped with a pneumatic nozzle jet flow. Subsequently, the computational fluid dynamics (CFD) is combined with the Eulerian formulation of multiphase flow to describe the hydrodynamics of particulates motion. Similar to free spray jet velocity profile, the velocity profile of output gas from nozzle is obtained based on the Schlichting equation. Particle trajectories, time dependent fluidization height, gas and solid particles velocity distributions and the fluidization height distribution of particles in different radial positions within the bed have been also considered in the course of experimental and modeling studies. The comparison between the predicted and experimental height of fluidized bed indicates a good agreement between simulation results and experimental data

Potential of Acid-Activated Bentonite and SO3H-Functionalized MWCNTs for Biodiesel Production From Residual Olive Oil Under Biorefinery Scheme

Application of acid-activated bentonite and SO3H-functionlized multiwall carbon nanotubes (SO3H-MWCNTs) for lowering free fatty acids (FFAs) content of low-quality residual olive oil, prior to alkali-catalyzed transesterification was investigated. The used bentonite was first characterized by Scanning Electron Microscopy (SEM), Inductively Coupled Plasma mass spectrometry (ICP-MS), and X-ray fluorescence (XRF), and was subsequently activated by different concentrations of H2SO4 (3, 5, and 10 N). Specific surface area of the original bentonite was measured by Brunauer, Emmett, and Teller (BET) method at 45 m2/g and was best improved after 5 N-acid activation (95–98°C, 2 h) reaching 68 m2/g. MWCNTs was synthesized through methane decomposition (Co-Mo/MgO catalyst, 900°C) during the chemical vapor deposition (CVD) process. After two acid-purification (HCl, HNO3) and two deionized-water-neutralization steps, SO3H was grafted on MWCNTs (concentrated H2SO4, 110°C for 3 h) and again neutralized with deionized water and then dried. The synthesized SO3H-MWCNTs were analyzed using Fourier-Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM). The activated bentonite and SO3H-MWCNTs were utilized (5 wt.% and 3 wt.%, respectively), as solid catalysts in esterification reaction (62°C, 450 rpm; 15:1 and 12:1 methanol-to-oil molar ratio, 27 h and 8 h, respectively), to convert FFAs to their corresponding methyl esters. The results obtained revealed an FFA to methyl ester conversion of about 67% for the activated bentonite and 65% for the SO3H-MWCNTs. More specifically, the acid value of the residual olive oil was decreased significantly from 2.5 to 0.85 and 0.89 mg KOH/g using activated bentonite and SO3H-MWCNTs, respectively. The total FFAs in the residual olive oil after esterification was below 0.5%, which was appropriate for efficient alkaline-transesterification reaction. Both catalysts can effectively pretreat low-quality oil feedstock for sustainable biodiesel production under a biorefinery scheme. Overall, the acid-activate bentonite was found more convenient, cost-effective, and environment-friendly than the SO3H-MWCNTs

The correlation of trihalomethanes with other disinfections by-products and fractionation of dissolved organic carbon in Dez River water

This work assesses the correlation between trihalomethanes (THM) and the formation potential (THMFP) of other disinfections by-products and the fractionation of natural organic matter in Dez River water in Iran. The THMFP of Dez River water was well correlated with the haloacetonitriles (R2 = 0.796) and haloacetic acids (R2 = 0.907) formation potential. The most abundant fraction of natural organic matter in the river was hydrophobic acid fraction (49.4 μg/L). The study demonstrated that however the THMFP of Dez River water was relatively high but a usual waterworks could effectively reduce THMFP

Effect of water quality and operational parameters on trihalomethanes formation potential in Dez River water, Iran

This study assesses the influence of the total organic carbon (TOC) content, chlorine quantity, water temperature, bromide ion concentration, and seasonal variations on trihalomethanes (THMs) formation potential (THMFP) in Dez River water in Iran. The water temperature and TOC content had a significant effect on THMFP. Further, the experimental results showed that increasing the concentration of bromide ions enhances the formation of dibromochloromethane and bromoform. It was found that the THMFP in Dez River water during summer times was relatively higher than 100 µg/L, maximum contaminant level for THMs in drinking water. By increasing the reaction time until 80 h, the THMFP was gradually increased and reached to 177.4 µg/L. The most abundant fraction of natural organic matter in the river was hydrophobic acid fraction (49.4 μg/L). Overall, our study demonstrated that however the THMFP of Dez River water was relatively high but a usual waterworks could effectively reduce THMFP

Efficient phenol removal from petrochemical wastewater using biochar-La/ultrasonic/persulphate system: characteristics, reusability, and kinetic study

This research has analysed the physiochemical properties of a catalyst that has been developed–biochar-La, including BJH, BET, EDX, SEM, FTIR, pHpzc, and iodine number. The catalyst consisted of effective functional groups, including C=S, C–O, C=C, –COOH and O–H, with a specific surface area of 31.2 m2/g. The catalyst was used in the biochar-La/ultrasonic/persulphate system to remove phenol from wastewater. The kinetics, mechanism, and reusability of the catalyst for the phenol removal from synthetic wastewater were determined. The results suggested that phenol removal kinetics follows pseudo-first-order model (k = 0.0386 1/min), and the catalyst can be reused three times. The potential of operation of the biochar-La/ultrasonic/persulphate system–with the effective removal of phenol and other organic compounds from real petrochemical wastewater–was tested. The results indicated that the removal of phenol from the petrochemical wastewater with a relatively high total dissolved solid is >99%. The gas chromatography–mass spectrometry (GC-mass) test revealed that the complete decomposition of some contaminants in the petrochemical wastewater had occurred, as H2O and CO2 were detected. The contribution of a heterogeneous mechanism for phenol oxidation by biochar-La/ultrasonic/persulphate was calculated to be 60%. Overall, the results showed that the biochar-La/ultrasonic/persulphate system is very effective and promising for the removal of phenol from the petrochemical wastewater

Microchannels Effective Method for the Extraction of Oleuropein Compared with Conventional Methods

Different methods of oleuropein extraction from olive leaf were investigated, including maceration, soxhlet, ultrasonic-assisted extraction, and microchannel. In current research, a response surface methodology (RSM) was used for prediction of the optimal values of parameters affecting the extraction of oleuropein through two methods of ultrasound and microchannel. Frequency (F), temperature (T), and power of ultrasound (P) were the parameters which were studied in ultrasound method, but in microchannel system effects of pH and temperature (T), volumetric flow rate ratio of two phases (VR), and contact time (CT) of two phases were optimized. UV detector device at 254 nm was used to recognize oleuropein through comparison of the retention time of the extracts with standard compound in chromatogram. The analysis of extracts was performed using HPLC. Optimum conditions for ultrasound were obtained as follows: F=80 kHz, T = 25°C, and P=100 w. Using these optimum conditions, the extraction of oleuropein was 81.29%. Amount of oleuropein extraction by microchannel method in optimum conditions was 96.29%, which was way more than other applied methods. Microchannel system as a continuous method has many advantages including low solvent consumption, being environment friendly, short time for extraction, and high efficiency

Efficient phenol removal from petrochemical wastewater using biochar-La/ultrasonic/persulphate system: characteristics, reusability, and kinetic study

This research has analysed the physiochemical properties of a catalyst that has been developed – biochar-La, including BJH, BET, EDX, SEM, FTIR, pHpzc, and iodine number. The catalyst consisted of effective functional groups, including C=S, C–O, C=C, –COOH and O–H, with a specific surface area of 31.2 m2/g. The catalyst was used in the biochar-La/ultrasonic/persulphate system to remove phenol from wastewater. The kinetics, mechanism, and reusability of the catalyst for the phenol removal from synthetic wastewater were determined. The results suggested that phenol removal kinetics follows pseudo-first-order model (k = 0.0386 1/min), and the catalyst can be reused three times. The potential of operation of the biochar-La/ultrasonic/persulphate system – with the effective removal of phenol and other organic compounds from real petrochemical wastewater – was tested. The results indicated that the removal of phenol from the petrochemical wastewater with a relatively high total dissolved solid is >99%. The gas chromatography–mass spectrometry (GC-mass) test revealed that the complete decomposition of some contaminants in the petrochemical wastewater had occurred, as H2O and CO2 were detected. The contribution of a heterogeneous mechanism for phenol oxidation by biochar-La/ultrasonic/persulphate was calculated to be 60%. Overall, the results showed that the biochar-La/ultrasonic/persulphate system is very effective and promising for the removal of phenol from the petrochemical wastewater

Innovative α‑MnO₂/Nanocarbon Ball Additive for Enhancing the Molecular Structure, Emission Control, and Engine Performance of Diverse Biodiesel Generations

This study investigates the utilization of an α-MnO2/nanocarbon ball (NCB) additive to enhance the performance of second-, third-, and fourth-generation biodiesels (SSGB, PVB, and GMCB). Various tests including XRD, XPS, TEM, HRTEM, BET, torque and power measurements, EGT, BTE, emissions analysis (CO2, CO, HC, soot, and NOx), and BSFC were conducted. The combination of GMCB5N50 with α-MnO2/NCB yielded the highest torque (35.77 N m) and power (6.47 kW), indicating an improved engine performance. GMCB5N50 exhibited efficient combustion with a peak pressure of 76.04 bar. The nanoadditive also demonstrated significant reduction in BSFC, achieving up to 34% improvement in fuel efficiency. When GMCB20N50 was used, the highest BTE values were observed, reaching approximately 39.5%. EGT values for GMCB5N50 were only slightly elevated compared to pure diesel. Notably, GMCB20N50 showcased substantial decreases in emissions, including carbon dioxide (CO2: 55% reduction), carbon monoxide (CO: 35% reduction), hydrocarbons (HC: 58% reduction), and soot (98% reduction), indicating a promising direction for the development of low-emission alternative fuels. The investigation of the effects of the oxygen lattice, surface area, and oxygen adsorption on engine performance and emission reduction revealed their positive contributions. These findings highlight the potential of the studied α-MnO2/NCB additive for improving biodiesel performance and advancing the development of sustainable and environmentally friendly fuels

Polybenzimidazole/ BaCe0.85Y0.15O3-δ nanocomposites with enhanced proton conductivity for high temperature PEMFC application

The present work reports the synthesis of polybenzimidazole ﴾PBI) / BaCe0.85Y0.15O3-δ nanocomposite membrane. The obtained membranes were investigated to use as novel electrolytes in high temperature proton exchange fuel cells. The PBCYx membranes were prepared with dispersing BaCe0.85Y0.15O3-δ into the polyimidazole membrane by solution casting method. The obtained membranes were used as novel proton conductors. The thermal stability and structural properties were investigated. The conductivity and morphology of the obtained materials were studied using impedance spectroscopy AC ﴾IS) and scanning electron microscope ﴾SEM) equipped with energy dispersive X-ray spectroscopy ﴾EDX). The maximum phosphoric acid adsorption ﴾175%) and protonic conductivity ﴾ 0.092 S/cm at 180 ̊C in dry condition) were observed for all of the PBI nanocomposite membranes containing 5 wt.% of BaCe0.85Y0.15O3-δ in the membrane matrix. The polarization and power density curves were studied at 150 and 180 ̊C operation temperature. The power density of about 0.42 W/cm2 and current density of about 0.84 A/cm at 0.5 V and 180 ̊C were achieved in dry condition. The data obtained from our studies showed that the physicochemical properties of the novel nanocomposites were enhanced for using in the high temperature proton transfer fuel cells.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Sustained release Curcumin loaded Solid Lipid Nanoparticles

Purpose: curcumin is poorly water soluble drug with low bioavailability. Use of lipid systems in lipophilic substances increases solubility and bioavailability of poorly soluble drugs. The aim of this study was to prepare curcumin loaded Solid Lipid Nanoparticles (SLNs) with high loading efficiency, small particle size and prolonged release profile with enhanced antibacterial efficacy. Methods: to synthesize stable SLNs, freeze- Drying was done using mannitol as cryoprotectant. Cholesterol was used as carrier because of good tolerability and biocompatibility. SLNs were prepared using high pressure homogenization method. Results: optimized SLNs had 112 and 163 nm particle size before and after freeze drying, respectively. The prepared SLNs had 71% loading efficiency. 90% of loaded curcumin was released after 48 hours. Morphologic study for formulation was done by taking SEM pictures of curcumin SLNs. Results show the spherical shape of curcumin SLNs. DSC studies were performed to determine prolonged release mechanism. Antimicrobial studies were done to compare the antimicrobial efficacy of curcumin SLNs with free curcumin. DSC studies showed probability of formation of hydrogen bonds between cholesterol and curcumin which resulted in prolonged release of curcumin. Lipid structure of cholesterol could cause enhanced permeability in studied bacteria to increase antibacterial characteristics of curcumin. Conclusion: the designed curcumin SLNs could be candidate for formulation of different dosage forms or cosmeceutical products