Iranian Journal of Chemistry and Chemical Engineering
Volume:35 Issue: 4, Jul-Aug 2016

A novel sulfur nanocomposite was fabricated based on graphitic mesoporous carbon.The graphitic mesoporous carbon was synthesized using sucrose as carbon precursor, nano CaCO3 as a hard template and nickel nitrate as graphitization catalyst. The structural properties of the prepared material were characterized using powder X-Ray Diffraction (XRD), N2-adsorption/desorption and Scanning Electron Microscopy (SEM) techniques. The mesoporous solid with the high surface area of 710 m2/g, average pore size of 2.7 nm and high graphitization degree was applied as the nanoreactor for infiltration of molten sulfur at 150 ºC in an inert gas atmosphere. The properties of prepared nanocomposite were investigated by XRD, BET, SEM and cyclic voltammetry methods. The obtained results showed that the desired nanocomposite with enhanced conductivity successfully was synthesized.

In this work, the template, monomer, and cross-linker with the ratio of 1:8:40 were used to synthesize Molecularly Imprinted Polymers (MIPs) for extraction of the bioactive chemical compounds from some traditional herbs as a sorbent material. Quercetin, Methacrylic Acid (MAA), Trimethylolpropanetrimethacrylate (TRIM) and Tetrahydrofuran (THF) were used as a template, functional monomer, cross-linker, and porogen, respectively. Polymer particles have been evaluated by Atomic Force Microscopy (AFM), Field Emission Scan Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and Brunauer–Emmett–Teller (BET). The produced nanoporous MIPs, with a good specific surface area 167.899 m2/g comparatively to Non-Imprinted Polymers (NIPs), exhibited a good affinity to quercetin with the binding capacity of 392.08 mg/g in acetonitrile-water (1:1v/v). The results showed that the MIPs can be used as a sorbent. Thus, direct extraction of certain pharmacophoric components from herbal plants is considerable by MIPs technology.

The copper(II) complex [Cu(pic)2]·2H2O was synthesized with 2-picolinic acid (Hpic) and copper acetate as reactants by room temperature solid-solid reaction. The composition and structure of the complex was characterized by elemental analyses, single crystal X-ray diffraction, X-ray powder diffraction, FT-IR spectroscopy and thermogravimetry-differential scanning calorimetry. The crystal structure of the copper(II) complex belongs to triclinic system and space group , with cell parameters of a = 5.1274(16) Å, b = 7.641(2) Å, c = 9.209(2) Å,α = 74.91(2)°, β = 84.56(2)°, γ = 71.58(3)°, V = 338.48(15) Å3, Z = 1, F(000) = 175, R1 = 0.0530, and wR2 = 0.1141. The Cu(II) ion is six-coordinated through two nitrogen atoms from two pyridine rings and four carboxyl oxygen atoms from four different 2-picolinic acid anions, forming an elongated octahedral geometry. The interaction of carboxylate O and Cu(II) forms an one-dimensional chain structure, and the complex exhibits a two-dimensional layered structure by hydrogen bonds. The thermal decomposition processes of the complex under air include dehydration and pyrolysis of the ligand, and the final residue at about 400 °C is copper oxide.

A facile and efficient one-pot three-step process for the synthesis of 5-acetyl-2-imino-4-methylthiazoles via the cyclocondensation of 3-thiocyanatoacetylacetone with various hydrazine or hydrazide derivatives in EtOH has been developed. 3-Thiocyanatoacetylacetone itself has been synthesized as the intermediate from substitution reaction of thiocyanate with 3-chloroacetylacetone. Better results were obtained by three-step procedures vs one-step reaction. The proposed method does not require techniques such as extraction and chromatography. Surprisingly, 3,5-dimethyl-4-thiocyanato-1H-pyrazoles were not produced in this reaction, it was proved based on the existence of the acetyl group in the products. The molecular structures of newly synthesized compounds were elucidated on the basis of elemental analysis and spectral data.

In the current study, a magnetic inorganic–organic nanohybrid material (HPA/TPI-Fe3O4) was produced and used as an efficient, highly recyclable and eco-friendly catalyst for the one-pot and multicomponent synthesis of 3,4-dihydroquinoxalin-2-amine, diazepine-tetrazole and benzodiazepine-2-carboxamide derivatives with high yields and in a short range of time (20–35 min). The nanohybrid catalyst was prepared by the chemical anchoring of H6P2W18O62 onto the surface of modified Fe3O4 NPs with N-[3-(triethoxysilyl)propyl]isonicotinamide (TPI) linker.The magnetically recoverable catalyst was easily recycled at least ten times without any loss of catalytic activity. The structures of obtained products are certified by 1H and 13C NMR spectra.

Modified Bubble Column Extraction with Ultrasonic Bath (BCE-UB) method was used to extract atropine from the stem and leaves of Atropa belladonna. Optimum condition were obtained with Kamada solvent which was chloroform-methanol-ammonia 15:15:1(v/v/v) as extraction solvent, the particle size of less than 350 µm, an extraction time of 23.95 min, a liquor to material ratio of 15.08 mL/g and an air flow of 6.31 mL/min.g. In this state, percent of extracted atropine was calculated which was equal to 6.81%. Percent of extracted atropine was 6.31% that showed a little difference compared to the predicted value. In order to study the effect of bubbles on the extraction rate, the same extraction with the previous method was performed in a stirred tank. Percent of atropine was 5.59%.

To improve the corrosion protection of copper metal, 0.01M concentration of 1H-1,2,4-triazole-3-thiol (TAT) was incorporated into the hybrid sol-gel monolayers containing 3-glycidoxypropyltrimethoxysilane (GPTMS) and Tetraethoxysilane (TEOS). It was further subjected to hydrolysis and condensation reaction to form a sol-gel matrix. The TAT-doped hybrid sol-gel coating was applied over the copper surface by Self-Assembled Monolayer (SAM) method. The resultant coating was characterized by Fourier Transform Infrared (FT-IR), X- RayDiffraction (XRD) analysis, Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX) spectroscopy. The corrosion protection ability of these coatings was evaluated by Electrochemical Impedance Studies (EIS) and Potentiodynamic Polarization (PP) measurements in 3.5% NaCl medium. The EIS and PP results showed that TAT doped hybrid sol-gel coating exhibit better corrosion protection than the undoped hybrid coating alone. Thus these studies revealed the enhancement of corrosion protection of TAT doped hybrid sol-gel coating on the copper metal surface.

In this study, Microwave-Assisted Solvent Extraction (MASE) was used to recover oil residues from pomace olive using acidic hexane. Results obtained demonstrated that oil extraction yield increased with time, the amount of acetic acid in hexane and power radiation. For both radiation powers used (170 and 510W), the optimal extraction time and most interesting content of acetic acid in hexane are 1.5 minutes and 5.0% respectively. Oil yield obtained at power 510 W was slightly higher than those corresponding to 170 W. Compared to results obtained with pure hexane, the yield increases were 8.4 % at 170 W and 6.0% at 510 W. However, the oil extracted from pomace olive was found to be of poor quality; indeed only phenolic compounds concentration increased significantly with acetic acid content.

A lab-scale SBR equipped with a flat sheet membrane in submerged configuration that is named MSBR was used for the treatment of composting leachate. It was fed by biologically treated leachate with overall 70-1360 mg/L Chemical Oxygen Demand (COD). The values of pH, Electrical Conductivity (EC), and Dissolved Oxygen (DO) were monitored routinely. However, analysis of total COD, Soluble COD (SCOD), Biological Oxygen Demand (BOD5), Total Suspended Solids (TSS) and Volatile Suspended Solids (VSS) was done in feed and filtrate, whenever the system reached steady state twice a week for about 6 months.In all loading rate, BOD5 concentration was less than standard limit. The removal efficiency of total COD increased in the bioreactor with time in all experiments was up to 80%.Influent SCOD varied spectacularly (50-1050mg/L) due to the leachate collection during different seasons but in the effluent, it remained relatively stable. About 60% of the feed SCOD was the non biodegradable type that was separated by the membrane.Up to 99 % further solids was removed with micropore membrane which might be mainly included in colloidal solids. The value of EC for the leachate sample was 0.86-4 mS/cm at 22 °C which decreased by membrane significantly.It was concluded that MSBR as a versatile technology with high throughput could treat composting leachate belowthe standard limit if used after proper processes.

We study copper corrosion inhibition by ethanolamine (ETA)with (0, 0.2 ,0.3,0.4,0.5) vol.% concentrations in 100 ppm NaCl solution. This work is carried out by potentiodynamic measurements and Electrochemical Impedance Spectroscopy (EIS). The substrate's surface morphologies are examined by Scanning Electron Microscopy (SEM). ETAis characterized by NMR spectra of ETA1H and 13C and Fourier Transform InfraRed Spectroscopy (FT-IR).Quantum chemical calculation (DFT) is conducted to correlate the adsorption mechanism with ETAmolecule structure. The results show thatETA acts as a mixed inhibitor; so at 0.4 vol. %, the current density ( i ) and the polarization resistance (Rp) are respectively 0.8µA/cm2 and 28.62 Ω.cm2 with 99.78% corresponding efficiency . ETA adsorption obeys to Langmuir isotherm and takes place on the copper surface through chemical and physical mixed-type adsorption.

In the present work, the electrooxidation of formic acid and formaldehyde; potentially important fuels for future fuel cells, was investigated on the Fe3O4@Pt core-shell nanoparticles/carbon-ceramic electrode (Fe3O4@Pt/CCE). The Fe3O4@Pt nanoparticles were prepared via a simple and fast chemical method and their surface morphology, nanostructure properties, chemical composition, crystal phase, and electrochemical behavior were investigated by scanning electron microscope, transmission electron microscope, X-ray diffraction, energy dispersive X-ray spectroscopy and electrochemical methods, respectively. Then the electrocatalytic activity of the Fe3O4@Pt/CCE toward the oxidation of formic acid and formaldehyde was studied in details. The primary electrochemical analysis shows that the Fe3O4@Pt/CCE has superior catalytic activity and stability for formic acid and formaldehyde oxidation compared to Pt-alone nanoparticles on the carbon-ceramic electrode (Pt/CCE). The present investigation demonstrates that the Fe3O4@Pt/CCE electrocatalyst may play a significant role in future fuel cell applications.

This study investigates the degradation of sodium dodecylbenzenesulfonate (SDBS) in aqueous solution by the Fenton-like oxidation process. The effects of different parameters such as concentrations of ferric chloride and hydrogen peroxide, pH and reaction time on the SDBS removal and Chemical Oxygen Demand (COD) reduction were evaluated. Response Surface Methodology (RSM) with Central Composite Design (CCD) was used to study and optimize the oxidation process. A quadratic polynomial equation could accurately model the SDBS removal with an R2 of 0.98. The results showed that pH and time were the most significant parameters affecting SDBS removal and COD reduction, respectively. A high SDBS (90.5%) and COD (70.7%) reduction efficiency were obtained at the optimal conditions of 60 min, pH 4 and 8.82 mM of H2O2 and 3.67mM of Fe. In this work, the effects of some organic compounds on the degradation of SDBS by the Fenton-like process were examined. The results showed that 50 mgL-1of oxalic acid slightly enhanced the SDBS degradation efficiency while acetic acid and Ethylenediaminetetraacetic acid (EDTA) reduced it.

The present paper concerns on the selective and very efficient transport of thorium(IV) ions from aqueous solutions through an emulsion liquid membranes composed by paraffin and a surfactant, without carrier requirement. The influence of pH of the external aqueous phase, the surfactant concentration in the membrane phase, the type, and concentration of the acid used in the receiving phase, the emulsification and mixing speed on the process efficiency were examined and discussed. The optimized conditions were: liquid paraffin as diluent, 5% surfactant (nonionic polyamine surfactant span-80), emulsification rate 5250 rpm, 15 min of stirring at 750 rpm in the extraction step, pH 5, oil/aqueous ratio of 3 in emulsions and using 0.3 M solution of sulfuric acid as stripping phase. Under optimized experimental conditions, thorium ions were selectively and quantitatively transported from its mixture solution with lanthanides La(III), Sm(III), Eu(III) and Er(III). The concentration of thorium ions, in single component transport experiment, was measured spectrophotometrically using ArsenazoIII as the indicator at 655 nm, and the analysis of metal ions in competitive experiments was performed by an ICP-OES instrument under recommended conditions provided by the instrument’s manufacturer.

In the present study, the production of low-salt water from salty water by nanofiltration as well as membrane fouling was investigated. Furthermore, a new method was proposed and tested experimentally for creating the backpulse in order to minimization of fouling and increase of the filtration efficiency. In the proposed method, the permeate was used instead of gas for creating the backpulse. To test the quality of this method, experiments were conducted using NaCl solution.
In these experiments, the backpulse interval was changed and in constant backpulse duration, the effect of this parameter on the permeate flux was investigated. The results confirmed the effectiveness of the proposed system, especially when the concentration of the saline solution was increased.

Clean hydrogen is the major energy carrier for power production. The conversion of CO to CO2 and zero emission during hydrogen energy production causes high capital cost. It is a matter of prestige to optimize the process in order to make zero emission and cost effective production of clean hydrogen energy and electric power. In this era, coal gasification is the most promising technology for the clean hydrogen energy and electric power production with simultaneously capturing of CO2. The experimental set up used in this scheme consists of Fluidized Bed Coal Gasifier (FBCG), syngas treatment unit, electricity generation unit, CO2 capturing unit and clean hydrogen adsorption unit. This paper shows the analysis of low sulphur Makarwal (Pakistan) coal. The Oxygen to Steam (O/S) ratio is optimized in order to produce syngas efficiently in the FBCG. The desulphurization unit reduces the H2S contents below than 1ppm. In this experimental plant, the feed rate 37.5 tons/hr of coal is used and clean hydrogen is produced at the rate of 1.30-1.40 tons/h.

Quantitative assessment is the most important means to identify hazard potential and manage risk for an industrial process. The implement of quantitative assessment in the early stage will help to develop inherently safer process, eliminating the hazard and reduce the possibility of accidental chain events and the magnitude of consequences. In this paper, after reviewing the presently available assessment method, we present the disadvantages of current technology in several aspects. Focusing on the main disadvantage of subjectivity in two aspects of index valuing and weighting, which is a serious barrier to measure the real level of process safety, we propose a quantitative assessment method integrated fuzzy inference and Analytic Hierarchy Process(AHP) to quantify safety and health hazards of chemical process route in preliminary design stage. The purpose of integrating fuzzy inference into it is to reduce the subjectivity of index valuing system. The fuzzy inference system is designed without medium variable in order to eliminate its negative effect on assessment result. Index weighting is determined by AHP more objectively based on the ordering of inherent safety guidewords. Finally, the proposed method is applied to assessment nine competing routes of acetic acid manufacture to present its improvement.