Iranian Journal of Chemistry and Chemical Engineering
Volume:32 Issue: 1, Jan-Feb 2013

Iranian Journal of Chemistry & Chemical Engineering(IJCCE), English Edition, has 31 years old. IJCCE is the first Iranian scientific journal indexed in many international data bases including Science Citation Index-Expanded (SCIE) in Thomson Reuters since 1994. According to SCIE data base, 937 items has been published during 19 years indexed in SCIE, which obtained 803 total citations. 92% of citations are non self-citations. The average citations per item is 1.26. The h-index of IJCCE is 12. The average authors per published item equals to 3.

Benzazolo [2,1-b]quinazolinones and triazolo[2,1-b]quinazolinones were synthesized in high yields by the condensation reaction of an aldehyde and a cyclic β-diketone with 2 - aminobenzimidazole, 2 - aminobenzothiazole or 1, 2, 4 - triazole derivatives in 1 - butyl - 3 -methylimidazolium bromide as an ionic liquid under classic heating conditions within 5-60 minutes

An extensive study of Higher Alcohols Synthesis (HAS) from syngas using alkalized MoS2 catalysts supported on Carbon Nanotubes (CNTs) is reported. Up to 30wt.% of Mo and 8wt.% K are added to the CNTs by impregnation method. The catalysts were characterized by different methods and the performance of the catalysts was assessed in a micro-reactor. TEM images showed that most of the metal particles were homogeneously distributed inside the tubes and the rest on the outer surface of the CNTs, with particle sizes in the range of 3 to 16 nm. Temperature Programmed Reduction (TPR) tests showed that increasing the amount of Mo decreased the first TPR peak from 518 to 503oC and increased the second TPR peak temperature from 782 to 825oC. The diffraction peaks representing the characteristic K-Mo-O phase (these species can enhance formation of higher alcohols) were observed in the XRD of catalysts. The catalyst with 20 wt.% Mo and 8 wt.% K showed the highest conversion. The total alcohol selectivity reached a maximum of 45.3 wt.% on the catalyst with 15 wt.% Mo. The catalyst with 15 wt.% Mo exhibited selectivity of 35.3 wt.% towards higher alcohols.

An extensive study of Higher Alcohol Synthesis (HAS) from synthesis gas using cobalt (Co) promoted alkalized MoS2 catalysts supported on Carbon NanoTubes (CNTs) is reported. Up to 5wt.% of Co is added to the 15wt.% Mo-8wt.%K/ CNTs by incipient wetness impregnation method. Most of the metal particles were homogeneously distributed inside the tubes and the rest on the outer surface of the CNTs. The catalysts are extensively characterized by different methods and the activity and selectivity of the catalysts were assessed in a fixed bed micro-reactor. Temperature Programmed Reduction (TPR) tests showed that addition of cobalt decreased the second TPR peak temperature from 801 to 660oC. The diffraction peaks that represent the characteristic K-Mo-O phase (i.e. K2Mo2O7, K2MoO4, K2Mo7O20, KMo4O6, and K0.33MoO3; these species can enhances formation of higher alcohols) were observed in the X- Ray Diffraction (XRD) patterns of unpromoted Mo-K/CNTs and to a greater extent in the XRD patterns of Co-promoted Mo-K/CNTs catalysts. Co addition to Mo-K/CNTs not only increased the number of surface sites, but also decreased the average active metal particle sizes from 7.53 to 5.33 nm and increased the percentage dispersion from 51.1 to 68.2%. Among the catalysts with different Co loadings, catalyst with 5 wt.% Co showed the highest %CO conversion of 38.8%. The total alcohol selectivity reached a maximum of 59.7 wt.% on the catalyst promoted with 3 wt.% cobalt. The catalyst with 3 wt.% Co exhibited selectivity of 41.65 wt.% towards higher alcohols.

The NO removal over oxide sorbents (K2O/Al2O3, CaO/Al2O3 and BaO/Al2O3) at a loading of up to 25 wt.% was investigated using a synthetic diesel exhaust gas containing 1,000 ppm NO, 1000 ppm iso-butane (i-C4H10), 8% O2 and N2 balance. The reactor was operated at 250 oC to 450 oC for the activity study. NO was effectively stored (removal efficiencies between 30-60 %) as nitrate under experimental conditions after surface oxidation to NO2; and the maximum removal efficiency decreased in the order of K2O/Al2O3 (55.4 %) > BaO/Al2O3 (39.0 %) > CaO/Al2O3 (37.0 %). K2O/Al2O3 had higher mobility; but loadings higher than 15 wt.% were detrimental to the morphological properties. Despite higher basicity, CaO/Al2O3 showed lower removal efficiency of NO compared to BaO(10)/Al2O3 due to low catalytic NO2 formation activity. Unlike K2O(10)/Al2O3, BaO(10)/Al2O3 showed increasing NO removal between 350 oC and 450 oC. K2O(5)BaO(5)/Al2O3 resulted in better surface area and volume leading to about 65 % of NO removal. This was attributed to synergic effects between physicochemical, catalytic and NO removal properties of the components. The high performance of K2O(5)BaO(5)/Al2O3 was successfully elucidated based on the characteristics of the sorbent.

A highly efficient method for the oxidation of aldehydes to carboxylic acids using PolyVinylPolyPyrrolidone supported - Boron Trifluoride (PVPP-BF3) in the presence of 35% hydrogen peroxide has been developed in acetonitrile at 60 °C. This procedure cleanly oxidizes variety of aldehydes to the corresponding carboxylic acids. Oxidative esterification of benzaldehyde utilizing PVPP-BF3/H2O2(35%) is also reported in good to excellent yields in acetonitrile at 60 °C.

A complex of Cu(II) with 1-(6-HydroxyNaphthalen-2-yl) Butane-1,3-Dione (HNBD) was synthesized and characterized by elemental analysis, IR, UV and DTA-TG-DTG techniques. IR spectra as well as UV-visible absorption measurements indicated that Cu(II) ion was coordinated to the HNBD ligand. The TG-DTA-DTG curves showed that thermal decomposition of the anhydrous complex was a two-stage process and the residue of decomposition was CuO. The decomposition mechanism and non-isothermal kinetic parameters of the complex were obtained from the analysis of TG-DTG data using three kinds of integral methods (Coat-Redfern equation, HM equation, MKN equation) and differential method (Achar equation). The results indicate that the kinetic equations with parameters describing the thermal decomposition reaction are with E = 417.78 kJ/mol, A = 3.531038/s, S = 487.55 J/K•mol and n =3 for the first stage, with E = 88.76 kJ/mol, A = 4.74105, S = -144.59 J/K /mol and n =2 for the second stage.

Photocatalytic decolorization of Methyl Orange (MO) solution has been studied using phosphotungstic acid (HPA) as photocatalyst. The decolorization reaction of MO solution is photocatalysis. The paper reveals that the optimal loading of photocatalyst for decolorization of MO solution (10 mg/L) is 0.6 g/L. The results show that the photocatalytic decolorization reaction of MO with HPA in a homogenous solution can be described by Langmuir-Hinshelwood equation; the results manifest that the reaction is first order with lower concentration, the limiting rate constant and the adsorption constant in this case are 0.3378 mg/(Lmin) and 0.5988 L/mg, respectively. The effect of pH value on the decolorization efficiency was also demonstrated, where special attention was paid on the nature of photocatalyst itself. Several observations indicate that only hydroxyl radicals participate the photocatalytic decolorization of MO with HPA under UV irradiation.

Antioxidants act as free radical scavengers in the oxidation processes. Thus, they will certainly play diverse roles in the biological systems and the therapy of a wide variety of diseases. Regarding this fact, in the present study, we synthesized two new salen ligand compounds by the condensation of ethylendiamine and salicylaldehyde derivatives in excellent yields. The structures of these ligands were confirmed by IR, 1H NMR and mass spectroscopy techniques. Furthermore, we evaluated the relative dismutase, catalase and peroxidase activities of the newly synthesized complexes named as EUKs 131, 132, 141 and 142 relative to EUKs 108 and 8, as the reference compounds. The results demonstrated that all Mn-salen complexes (EUKs) illustrated significant dismutase, catalase and peroxidase activities. EUKs 131 and 8 showed the most catalase and peroxidase activities while their dismutase activities were almost the same as the other compounds. In addition, our data indicated that the biological activities of the EUKs are modulated by manganese element as well as the types and the positions of substituents on the ligand.

In this paper, aggregation behaviors of aqueous solutions of short chain hydrophilic Ionic Liquids (ILs), 1 – allyl - 3 - methylimidazolium chloride ([Amim]Cl), 1 - ethyl - 3 - methylimidazolium chloride ([Emim]Cl), 1 - butyl - 3 - methylimidazolium chloride ([Bmim]Cl), 1 - butyl - 3 - methylimidazolium tetrafluoroborate ([Bmim]BF4) were investigated using conductivity and laser light scattering. The measurements of conductivity and light scattering were conducted over the whole liquid range, and the Critical Aggregation Concentration (CAC) of aqueous ILs solution determined with the conductivity, was in the order of 2.35mol/L([Amim]Cl) > 2.32mol/L([Emim]Cl) > 2.29mol/L([Bmim]Cl) < 2.54mol/L([Bmim]BF4). The CAC vaule of [Bmim]BF4 determined with conductivity was consistent with the result of light scattering. In addition, we proposed aggregation model for illustrating the structural change in the aqueous ILs solutions.

Drying of green peas in a Fluidized Bed Dryer (FBD) with inert particle, heated by combined sources of hot air and InfraRed (IR) radiation, has been experimentally and theoretically studied. For this purpose, an experimental set up was constructed. This setup was composed of a cylindrical bed dryer containing some inert particles which are fluidized by hot air. Some infrared lamps were also placed around the bed for heating assistance. A sample of green pea was hung in the fluidized bed and its moisture content, surface and central temperature were measured with time. A mathematical model, based on the two layers concept of penetration and conduction was also proposed for this process. The results obtained by the proposed model were compared with the experimental data. Once the validity of the model was checked, it was used to investigate the effects of parameters such as inlet air velocity and temperature, drying sample size and the amount of inert particles on the rate of drying.

This paper presents efflux time experiments performed in the absence and presence of aqueous solutions of Drag Reducing Agents (DRAs) when a liquid is emptied from a large open cylindrical storage tank through an exit piping system. The drag reducing agents studied are Dodecyl benzene sulfonate anionic surfactant and a mixed solution of surfactant and sodium chloride counter ion. The variables studied are initial height of liquid in the tank, diameter of storage tank, and length of exit pipe. Drag reduction (i.e reduction in efflux time) is found be more significant in presence of mixed solutions of surfactant and its counter ion. It has also been observed that Froude umber remains constant during draining and increases upon addition of surfactant solution and also in case of mixed solutions of surfactant and its counter ion.

UV/TiO2 photocatalysis of chelated copper in aqueous solutions has been performed starting from Cu(II)-tartaric acid, Cu(II)-citric acid, Cu(II)-EDTA and Cu(II)-DTPA, in the presence of oxygen and at acidic pH. The photocatalytic reaction obeys first-order kinetic equation. The influence of Cu(II) on photocatalytic oxidation of organic ligands and how the various organics will affect the treatment of Cu(II) were described. A significant synergistic effect was observed between the reduction of Cu(II) and oxidation of organic ligands. The results prove that TiO2 photocatalysis is an effective approach for removing chelated copper from wastewater.

Four different alkaline earth metal oxides i.e. MgO, CaO, SrO and BaO were used as heterogeneous catalysts for biodiesel production from palm oil. Effects of critical process variables i.e. reaction time, methanol to oil ratio and temperature were investigated. The results were then fitted to a historical design to study the Analysis of Variance (ANOVA), to characterize interactions between variables and to simulate the process. MgO did not show good catalytic activity while CaO produced undesired products at longer reaction time. BaO showed the best biodiesel result with a yield of up to 95 %, followed by SrO with a yield of 91 %. A methanol to oil ratio of 9:1 and 60 ºC were found to be the optimum conditions. The experimental data were satisfactorily predicted at 99 % confidence level under various conditions with R2 values higher than 0.92. Characterizations of the catalysts before and after the transesterification process were also performed using a surface analyzer, scanning electron microscopy, Hammett indicator and Atomic Absorption Spectrophotometeric (AAS) methods. The catalytic activity was in the order of BaO > SrO > CaO. However, due to lixiviation of BaO in the product, SrO was found to be the most potential catalyst

In order to increase the productivity of human interleukin-2 (IL-2) as a model protein in the recombinant E.coliBL21 (DE3), the effect of magnesium acetate and manganese acetate was studied based on full factorial design experiments magnesium acetate and manganese acetate and their interaction exhibited an increasing effect on IL-2 expression level upto 25.24%, 16.80% and 23.30%, respectively,in comparison to 10.76% for the standard M9 medium(as usual defined medium in high cell density culture). Magnesium acetate was the most effective salt. Other experiments were performed to investigate the effect of magnesium and acetate ions separately. Results revealed that M9 medium with 1.5 times of magnesium ion concentration resulted in the highest expression level.