Papers by Keyword: Cyclohexane

Abstract: The growth of vertically aligned ZnO Nanorods arrays using Zinc Nitrate hexahydrate and Hexamethylene Tetramine (HMTA), by Chemical Bath Deposition on Silicon Wafer was investigated. The growth is conducted under influence of Ethane-1,2-diamine, the amine based enhancer was evaluated based on three different ratios (1:0.5, 1:1, 1:1.5) of enhancer to the precursor (Zinc Nitrate and HMTA). The effect different ratios of enhancers on morphology aspect ratio and crystallinity of the as grown Nanorods were studied under Scanning electron microscope (SEM) and X-ray powder diffraction (XRD). Electrical Properties such as current–voltage characteristics were investigated, its correlation to the morphology and aspect ratio of the Nanorods in the presence of 100μL-500μL of Aromatic Compound Cyclohexane and at different applied voltages.

Abstract: Isothermal Vapour-liquid equilibrium for cyclohexane (1) + benzene (2) binary system, cyclohexane (1) + benzene (2) dimethylformamide (3) ternary system and cyclohexane (1) + benzene (2) dimethylformamide (3) + cosolvent (4) quaternary systems were obtained. The effects of cosolvents (diethyl glycol, dimethylsulfoxide, N-methylformamide) on the performance of dimethylformamide in benzene-cyclohexane separation were studied. The result shows the selected cosolvents suppress the effectiveness of dimethylformamide. The result also shows that the ratio of cosolvents to dimethylformamide affects the separation factor.

Abstract: Cyclohexane dehydrogenation is an important process in the petrochemical industry, chemical raw material such as cyclohexanol, cyclohexanone,benzene and cyclohexene can be produced from which.Divided cyclohexane dehydrogenation into catalytic dehydrogenation or oxidative dehydrogenation, homogeneous or heterogeneous reaction. Summarized vary catalysts, active constituent and process conditions in dehydrogenation process.

Abstract: Degradation performances of Klebsiella spp. for Cyclohexane was studied by using the method of single factor in the paper. The influences of temperature, pH, initial concentration of Cyclohexane, oxygen supply, culture time etc. were studied and the optimum conditions were determined. The results show that the activated strains of Klebsiella spp. are inoculated in the liquid culture medium of 100 ml which contained cyclohexane, the initial concentration of cyclohexane is 2490 mg/L, the culture temperature is at 28°C, pH is 6, the number of Klebsiella spp. is about 9×10⁵ ml^-1 in the liquid culture medium, the speed of rotary shaker is 120 r/min, and the degradation rate of Cyclohexane reaches 70.1% in 96 hr. The results could provide the theoretical basis in the field of pollution treatment of petroleum hydrocarbons.

Abstract: Cyclohexane is mainly produced by catalytic hydrogenation of benzene, and the separation of unreacted benzene is very important process. However, the separation of benzene and cyclohexane mixture is one of the difficult separation processes in petrochemical industry. Presently, extractive distillation is commercially used to separate benzene and cyclohexane using molecular solvents. However, the current process suffers from process complexity and high-energy consumption. In this work, new ionic liquid, 1-propanenitrile-3-butylimidazolium dicyanamide was synthesized and applied for separation benzene and cyclohexane mixture. Some of the thermophysical properties of the ionic liquid were measured. The vapour- liquid equilibrium and relative volatility of the components were determined. The ionic liquid breaks the azeotropic mixture and increased the relative volatility of cyclohexane to benzene.

Abstract: The effect of steam, fed to the fixed-bed microreactor reactor, on the oxidative dehydrogenation of cyclohexane over Mg₃(VO₄)₂ catalyst was reported. The catalyst characterization results showed that the crystal structure, the electron cloud distributions of the active species and the oxygen species, and the reducibility of the active species are not influence by the introduction of steam. It was observed that steam added to the oxidative dehydrogenation of cyclohexane competes for sites required for gas-phase oxygen activation, which catalyst lattice oxygen utilization is not affected. The shorter residence time and the competition for sites with oxygen causes a decrease in cyclohexane conversion and a corresponding increase in selectivity to cyclohexene.

Abstract: The oxidation of cyclohexane in the microchannels not only improves the safety of the reaction, but also the performance of the oxidation reaction. Different gas-liquid micro mixers were used for the mixing of gas and liquid before entering into microchannels, and SIMM-V2 performed best of all. Excellent slug/plug flow can be formed in the microchannels after mixing in the gas-liquid micro mixer when the molar ratio of oxygen to cyclohexane is less than 0.5:1. The conversion of cyclohexane increased as the residence time increased, but the selectivity of cyclohexanol and cyclohexanone increased first and then decreased. At the reaction temperature of 200 °C, with the flow rate of the solvent isopropanol being 1 mL/min and the molar ratio of oxygen to cyclohexane being 0.15:1, both the conversion of cyclohexane and selectivity of cyclohexanol and cyclohexanone increased with the increase of pressure. The conversion of cyclohexane and selectivity of cyclohexanol and cyclohexanone reached 10.10% and 66.93% respectively at the pressure of 8 MPa. It is indicated that the new process by use of uncatalyzed cyclohexane oxidation in the microchannels will have very attractive prospects in the improvement of the safety, intensification of the gas-liquid mass transfer and obtaining good reactive performance. Therefore, the technology shows good potential in industrial applications.

Abstract: A new route to substitute for the traditional two-step method for adipic acid production has been investigated. Supported nano metal catalysts Au/C and Co/C were prepared and used for liquid phase oxidation of cyclohexane to adipic acid with oxygen as an oxidant. These catalysts were characterized by XRD, TEM and ICP-AES. The reactions were carried out in an autoclave with solvent and radical initiator at 373~423K and 1.5 MPa. Au/C (1.25%) was found to be a highly efficient catalyst for the oxidation of cyclohexane with a high conversion (44.93%) of cyclohexane and more than 54.85% selectivity to adipic acid. It is indicated that there was a potential application prospect for the nano-catalysts in one-step oxidation of cyclohexane to adipic acid.

Abstract: Cobalt and/or manganese incorporated berlinites (CoMnAPO₄) and aluminophosphate molecule sieve (CoMnAPO-5) were hydrothermally synthesized, characterized by XRD, FT-IR, XPS and SEM, and employed as catalysts in the oxidation of cyclohexane with molecular oxygen at 348 K under atmospheric pressure. It was found that the berlinite-based catalysts were more selective for the production of KA oil, stable during the reaction, but slightly less active for the conversion of cyclohexane, when compared to their molecular sieve counterparts. The CoMnAPO₄ exhibited a better catalytic performance, due to a synergic effect, than the CoAPO₄ or MnAPO₄.

Abstract: Abstract. The solubility of hydrogen in styrene-butadiene-styrene (SBS) block copolymer-cyclohexane solution was determined under 3, 6 and 10 MPa pressures and at temperatures from 50°C to 150°C respectively. The experimental results showed that the solubility of hydrogen increases with risen pressure, temperature as well as concentration of SBS polymer in the cyclohexane solvent. The measured data of gas solubility could be successfully correlated by PRSV equation of state.