Advanced Materials Research Vol. 772

Abstract: The K/Cu-Zn catalyst has been synthesized by the co-precipitation method coupling with impregnation method and the catalytic performances for the reverse water gas shift (RWGS) reaction and mixed alcohols synthesis from CO₂ hydrogenation have been investigated. The catalytic activity and product distribution depend strongly on reaction temperature, pressure, space velocity and the molar ratio of H₂/CO₂. These results indicated that the optimal conditions for CO₂ hydrogenation over K/Cu-Zn catalyst were as follows: 350 K, 6.0 MPa, 5000 h^-1 and H₂/CO₂ = 3.0, under which the selectivity of CO and mixed alcohols reach 84.27 wt% and 7.56 wt%, respectively. The outstanding performances for RWGS reaction and mixed alcohols synthesis of K/Cu-Zn catalyst can be due to the well dispersion of Cu active component.

Abstract: Citronellal, citronellol and geraniol are the main components of the natural plant citronella oil, and their vapor-liquid phase equilibrium relationship is the critical data to separate, purify the citronella oil and design rectifying column. Citronella oil is a thermo-sensitive material, so the separation under high vacuum conditions could lower its boiling point and maintain its quality. This paper adopts the precise vapor-liquid phase equilibrium instrument to collect the binary system of citronellal-citronellol, citronellal-geraniol and citronellol-geraniol with the absolute pressure of 1.2kPa. Meanwhile, the corresponding phase equilibrium diagrams are drawn, which provide data support for the distillation of citronella oil.

Abstract: The anti-oxidation stability of rapeseed biodiesel (RME) was evaluated on an oxidation simulator set up by the author. The results showed that oxidative stability of RME was worse than that of petrodiesel by exhibiting higher acid values and peroxide values, as well as greater viscosity increases after oxidation. Furthermore, a conjecture was taken about the configurational changes and the oxidation mechanisms of unsaturated fatty acid methyl ester molecules in the oxidation process, according to the principles of free radical reactions and the results of both infrared and ultraviolet spectroscopic analysis. An idea was put forward that, during oxidation, cis-trans isomerization might occur in unsaturated fatty acid methyl ester molecules and conjugated double-bond might produce due to transfer of double-bond.

Abstract: Process of terpolymerization of basic unsaturated components of liquid products of pyrolysis of straight-run gasoline in toluene solution has been studied as model of oligomerization of C₉ fraction under the action of catalytic system TiCl₄Al (C₂H₅)₂Cl. Relative reactivity of styrene, indene and dicyclopentadiene (80-85 % from total amount of monomers) was established. On the basis of data of adiabatic thermometry, IR and ¹H NMR spectroscopy we revealed possibilityto synthesize polymeric and oligomeric products.These products basically correspondto the industrial petropolymericresinsobtained from C₉ fraction.

Abstract: Concerning the fact that the in-situ aquathermolysis reaction of heavy oil is affected by the limit of formation temperature, a simulated experiment is made by means of thermochemistry on promoting the aquathermolysis reaction of heavy oil through increasing formation temperature via in-situ heat generation. The results show that after the injection of 5mL concentration of 5mol/L NaNO₂/NH₄Cl exothermic system to the reaction kettle, the reactor temperature rises from 200°C to over 240°C, increasing the pressure almost by 0.4MPa. After the reaction, the viscosity reduction ratio of the heavy oil decreases by about 40%, with saturated hydrocarbons and aromatic content increased significantly, but resin and asphaltene content significantly obviously lowered, which proves that thermochemincal heat generation can promote the aquathermolysis reaction of heavy oils. The analysis also shows that the field injection process through the thermochemical system is feasible, that the exothermic reaction speed and the thermal peak position are controllable and that no formation damage is done. Besides, it also proves the feasibility of promoting the aquathermolysis viscosity reduction of heavy oil through increasing temperature by thermochemical heat generation. In specific application, an in-depth analysis of the factors that affect the thermochemical temperature increase should be made and the relevant parameters of the operation should be optimized.

Abstract: onic liquid is a green catalyzer and solvent which can be designed by changing the structure of its cation or anion. Ionic liquid has been used in diverse chemical reactions. Especially, Ionic liquids as environmentally friendly catalysts were applied in biodiesel production. Preparation of biodiesel catalyzed by ionic liquids have many merits, such as no corrosion to equipment, no pollution to environment, and reusability. In this paper, the advances in the base ionic liquids catalysts and their application in biodiesel production were reviewed. The characterization of the ionic liquids were summarized. In addition, the prospect for the application of the basic ionic liquids to catalyze biodiesel production was also stated. Since the cost of ionic liquid may be an issue, there are some challenges to be faced, such as the production of ionic liquids with low cost, easy recovery and with the possibility of reutilization of the catalyst for several cycles.

Abstract: The luminescence of rare earth composite micelles was measured in different polarity. The polarity of complexes was changed with the molar ratios of block copolymers, trivalent europium (Eu (III)) ions and 1,10-phenanthroline (Phen). When 4-vinyl pyridine (4VP) coordinated with central ions Eu (III), the improved asymmetry of composite micelles resulted in higher polarity. The higher polarity strengthened the ability of electron transition, which improved the luminescence of complexes. When Phen participated in coordination, the polarity was improved further. The strongest luminescence of complexes could be obtained by changing the molar ratios of block copolymers, Eu (III) ions and Phen.

Abstract: The larch bark was examined by non-isothermal means to determine the mass loss kinetics of the thermal decomposition with linear temperature programming in nitrogen atmosphere. In this work, mechanism equation of = was used for Coats-Redfern integral method at the different heating rates. The apparent activation energy, pre-exponential factor and the pyrolysis kinetic equations at the different heating rates were obtained. The pyrolysis temperature area was divided into two separate temperature regions for the pyrolysis kinetic equation and the two components were decomposed respectively at the two separate temperature regions. The global mass loss rate of the bark is considered as controlled respectively by the reactions of the two components respectively during the lower and higher temperature ranges. The kinetics of the two components are found to abide by the mechanism equation of =, which gave the best fits to the experimental data. The obtained kinetic equations of the bark at the different heating rates were additionally validated by the reasonable agreement between the experimental and calculated results.

Abstract: In this paper, the orthogonal experiments of three factors and three levels, pH Value (4.1,7.0,9.1), surfactants concentration (10,50,200mg/L), temperature (15,30,45°C) were used to investigate lubricants biodegradation . An L₉ (3⁴)) orthogonal table has been used for experiment arrangement in order to find out the major influencing factors. The results showed that in the three factors temperature was the first influencing factors, the second was surfactants concentration, the last is pH value.

Abstract: Strontium appears to be one of the most effective substances for the treatment of osteoporosis and other bone-related conditions. Since calcium and strontium share the properties of group 2A elements, strontium can replace calcium in bone without much difficulty. Additionally, non-radioactive strontium also deposits in bones and behaves like calcium; therefore it enhances bone density and resistance to osteoporotic fractures. In this study, 10 wt% strontium doped hydroxyapatite (SrHA) nanopowders were synthesized through a sol-gel method. The obtained gel was dried and subsequently subjected to 500, 600, 700, 800 and 900 oC calcination. At 500°C calcining temperature, the SrHA nanopowders are still in amorphous state but starting to become crystalline when heated to 600°C, 700°C and 800°C. Increasing the temperature to 900 °C originates more intense and sharp peaks, corresponding to an increase in the mineral crystallinity, which is compatible with particle growth. Morphological evaluation by FESEM shows that the nanopowders calcined at 500°C and 700°C are in spherical shape and highly agglomerated. At 900°C the SrHA particles are still in globular shape with a mean diameter of 1-2 μm. The primary particles have diameter of 30-50 nm in average. No secondary phase was detected in these nanopowders, correlated to nearly 100 % presence of HA.