Advanced Materials Research Vols. 396-398

Abstract: Based on detailed chemical kinetics, a combustion model for ADN was established first. The mechanism used consists of 33 species and 173 reactions. Results obtained from the model match the experimental data reasonably well. Then the model was carried out many times at various heat feedbacks from gas to condensed phase. And the calculations show that heat feedback is crucial to create a dark zone and determine the length of it.

Abstract: Experiments were carried out on the heat resistance, corrosion-resistance and adhesion performance of the nano-modified urushiol titanium antiseptic paint on the top heat exchanger of Atmospheric Tower. Through the experiment, it can be found that the corrosion resistance in the environment of HCl-H2S-H2O can be effectively improved by adding a certain amount of nano-SiO2 into urushiol coating made of titanium the top heat exchanger of Atmospheric Tower for modification.

Abstract: The synthesis of methylal from methanol and trioxane was investigated by using acidic resin as a catalyst, and a variety of solvents were also tested such as toluene, 1,4-dioxane, N,N-dimethylformamide. Comparatively, the organic solvent was suitable for obtaining the better catalytic performance. Among the acidic resin tested, Amberlyst15 showed the highest conversion. Moreover, the reaction conditions were optimized over the modified β zeolite. As a result, the proper reaction conditions are 1,4-dioxane as solvent, reaction temperature 70°C, n(methanol):n(trioxane) =2.2:1, with catalyst 5 wt% and reaction time 3 h. Under the above condition, the yield of methylal may reach about 62 % with Amberlyst 15.

Abstract: Using 5-bromosalicylaldehyde, 4, 4’-Diaminodiphenylamine and MgCl2•6H2O as starting materials, a new Mg (II) complex material was synthesized. This method is a convenient and efficient way to the synthesis of Mg (II) complex materials. The luminescent properties of the Mg (II) complex material were studied in solid state and in organic solvents. The effect of organic solvents and three carboxylate derivatives on the luminescent properties are also investigated. The results show that the Mg (II) complex material emits light green fluorescence 550 nm when excited at 328 nm at room temperature.

Abstract: The paper develops a new ammonia synthesis process based on Brayton cycle, successfully solving the problem of low heat recovery efficiency of reaction heat by conventional Rankine cycle. In the new process, a gas turbine expander is introduced to drive the multistage compressor coaxially instead of raising steam in a waste heat boiler to drive a steam turbine. Such a process represents a typical reaction-separation system with a recycle stream and cold separation of the product from the recycle loop. Through thermodynamic analysis, it is found that the ammonia synthesis system has the innate convenience and conditions to use the actual improved Brayton cycle. Moreover, since the cold separation is always influenced by gas-liquid equilibrium of pure ammonia, absorption separation is integrated in the process to achieve better use of the reaction heat, which can be driven by the low temperature heat. Flow sheets of the new process are described with the pressure and temperature parameters according to the actual operation conditions. For this special case, thermodynamic calculation and analysis are carried out by a software. The calculated results show that the expansion work is much larger than the required compression work. Even if the utilization efficiency is relatively low, the output work can meet the need of gases compression.

Abstract: the nonlinear bending problem of the shallow spherical shells with rectangular bottom was studied under the boundary condition of moved fixed-edges based on the nonlinear deformation foundational equations of shallow reticulated shells, the trigonometric series solution satisfies boundary condition of the deflection was derived first, the stress function was solved by substitution of the solution into the nonlinear compatibility equation, the nonlinear characteristic formula of the loads and the deflection was obtained by the energy equation, then the critical point was given. The critical load was given by the characteristic curves. The nonlinear characteristic formula in the paper can be reference by the engineering designers.

Abstract: Solubility, metastable zone width and induction period of (R)-3-(methylamino)-1-phenylpropanol hydrochloride (MPH) in ethanol were determined by synthetic method at atmospheric pressure. The measured induction period data are also used to estimate the interfacial tension values of the system. The determined interfacial tension values have been also used to evaluate the nucleation parameters, such as the radius of the critical nuclei, the free energy change per unit volume, the critical free energy barriers.

Abstract: As the core component of synthetic ammonia process, ammonia synthesis takes place in a loop in which hydrogen and nitrogen are converted to ammonia per pass through the ammonia converter. Its nonlinear mathematic model is built in this paper, based on partial data from literatures. The research focus on four types of unit: synthesis converter, ammonia separator, synthesis gas compressor and ammonia chiller, and dynamic simulation under fault conditions is carried out. Results show that the model has enough precision to meet fault simulation requirements. This work establishes the research foundation for future quantitative fault modeling, diagnosis algorithm selection and fault effect analysis.

Abstract: The Cobalt (II) Complex constructed with 5-nitroisophthalic acid and 2,2’-bibenzimidazole, [Co(H2bibim)3](5-nipa)•H2O (1), (H2bibim =2,2’-bibenzimidazole, 5-nipa=5-nitroisophthalic acid) have been synthesized by hydrothermal methods and structurally characterized by elemental analysis, IR and X-ray single crystal diffraction. Complex 1 possesses distorted CoN6 octahedrals linked by the H2bibim ligands in a bidentate chelating mode and the 5-nitroisophthalic acid groups act as counterions, and there exists a 2D supramolecular network linked by intermolecular O−H•••O and N−H•••O hydrogen-bonding interactions.

Abstract: In this paper, the hydrogen distribution network of a complex refinery is optimized by the hydrogen surplus pinch method. By plotting the hydrogen purity profiles and hydrogen surplus diagrams, the hydrogen pinch with hydrogen purity of 87% is identified. The corresponding minimum hydrogen utility consumption is 17730.5 Nm3/h. Moreover, the optimal hydrogen distribution network with minimum utility consumption is designed. Compared with the current hydrogen network, the hydrogen utility consumption can be reduced by 10.45%.