The effects of temperature and hydrogen partial pressure on 4-Carboxybenzaldehyde (4-CBA) hydrogenation over Pd/TiO2 catalyst were investigated in a batch reactor. The results show that 4-CBA hydrogenation is a consecutive reaction. And 4-CBA hydrogenation to 4-hydroxymethylbenzoic (4-HMBA) is a reversible exothermic reaction. Meanwhile, a parallel reaction of 4-CBA decarbonylation occurs during the process. The hydrogenation rate of 4-HMBA is more sensitive to temperature and hydrogen partial pressure than that of 4-CBA. Macro-kinetics of 4-CBA reaction over Pd/TiO2 was obtained from the experimental data using the power-law kinetics model. The apparent activation energies of 4-CBA hydrogenation, 4-HMBA hydrogenation, 4-CBA decarbonylation and 4-HMBA dehydrogenation are 29.65 kJ/mol, 42.55 kJ/mol, 74.32 kJ/mol and 69.34 kJ/mol, respectively. The reaction orders with respect to 4-CBA and 4-HMBA are both first-order.
The formed TiO2supports were prepared by compression method and then used in the Pd/TiO2 catalytic hydrogenation of 4-carboxybenzaldehyde (4-CBA). Supports and catalysts were characterized by the intensity test, BET, XRD, SEM and ICP techniques. Results showed that the pore-forming agent can adjust both the specific surface and average pore diameter. The suitable content is 4 wt.%. Silicon additive inhibits the growth of TiO2grain and the anatase-rutile phase transformation. Forming pressure brings out a certain crushing strength and pore characteristic. The crushing strength of support significantly increases with increasing support calcination temperature. However, the specific surface and pore volume decrease. The TiO2support has the side crushing strength of 122 N/cm and the specific surface of 38 m2/g at the optimum preparation conditions of silicon additive of 4 wt.%, forming pressure of 150 MPa and calcination temperature of 700 °C. A series of Pd/TiO2 catalysts were prepared by incipient wetness of impregnation and liquid-phase chemical reduction method. On Pd/TiO2700 (Pd, 0.5 wt.%) catalyst, the 99.5% conversion of 4-CBA is obtained after reaction for 90 min at reaction temperature of 280 °C and hydrogen partial pressure of 0.6 MPa.
This paper introduces a new bamboo wood composite board structure, which board uses little diameter class bamboo as raw material. Bamboos cut into segments and remove part of the bamboo surface from double sides or four sides. Make the bamboo segments have two or four smooth surfaces. Through arrange the bamboo segments reasonably, minimize the impact of differences in bamboo segments straightness to the bamboo wood composite board. And then rolling brush the smooth bamboo segments surfaces with adhesive. Gluing between the bamboo segments from left and right sides and gluing bamboo segments with fiberboard from top and bottom sides. After the hot pressing and cutting edges, the bamboo wood composite board shaping.
Infrared thermal imaging technology in various fields has been widely used. This paper firstly sets up the three-dimensional targets infrared radiation models and the atmospheric transmission model, and then generates the associated radiation data; Secondly building target 3D geometric model, the radiation data is mapped to the three-dimensional model, target in the 3D space is reconstructed of the infrared radiation characteristics; Finally it is using OGRE image engine rendering technology and GPU programmable pipeline technology that generate the target infrared image. This will have important significance to the next step to construct complex infrared scene.
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