Influence of support properties on selective oxidation of 2-methylnaphthalene on vanadia-molybdena based catalyst

In this work,the catalytic performance of vanadia-molybdena loaded on TiO_(2),MgO,ZSM-5,NaY and Mordenite was investigated in the selective oxidation of 2-methylnaphthalene(2-MN)to 2-naphthaldehyde(2-NA).Results show that strong interactions between supports(TiO2,ZSM-5)and active components can promote the dispersion of active component.Monolayer VOx and MoOx are the main form on the catalyst surface,which is beneficial to the 2-NA selectivity.However,the corresponding weak interactions between Mordenite and active components may lead to the production of oxide crystals and the separation of active components,thus reducing the 2-NA selectivity.Due to the high Na content,new crystal NaVMoO6 forms on the NaY surface,which is inactive in the reaction.For V-Mo/TiO2,V and Mo can be inserted into the TiO2 lattice,changing the electronic structures of active components and support and improving the activity of surface oxygen species.This investigation highlights an important consideration on supports properties when designing supported catalysts.

Investigation of liquid–liquid equilibrium of the ternary system(water +1,6-diaminohexane + 2-methyl-1-propanol or 3-methyl-1-butanol) at different temperatures

In this study, the LLE data of ternary system(water + 1,6-diaminohexane + 2-methyl-1-propanol) and(water +1,6-diaminohexane + 3-methyl-1-butanol) were measured at 293.15, 303.15 and 313.15 K under atmospheric pressure. Reliability of the experimental tie-line data was checked by empirical Hand, Othmer-Tobias and Bachman equations. Distribution coefficient(D) and selectivity(S) were calculated in order to investigate capability of the studied organic solvents for 1,6-diaminohexane extraction. The high values of separation factors demonstrated that 2-methyl-1-propanol and 3-methyl-1-butanol were applicable for this purpose. The experimental data were correlated by nonrandom two-liquid(NRTL) and universal quasi-chemical(UNIQUAC) models.The percent-root-mean-square deviation(RMSD) values for NRTL and UNIQUAC models were less than 0.15,which indicated that the experimental data have been sufficiently correlated.

Dynamic Characteristics Analysis of Ice-Adhesion Transmission Tower-Line System under Effect of Wind-Induced Ice Shedding

The tower line system will be in an unsafe status due to uniform or uneven fall of ice coating which is attached to the surface of tower and lines.The fall of ice could be caused by wind action or thermal force.In order to study the dynamic characteristics of the self-failure of the transmission line under the action of dynamicwind load,a finite elementmodel of the two-span transmission tower line system was established.The birth and death element methods are used to simulate the icing and shedding of the line.Tensile failure strength is the shedding criterion for ice coating.The fluctuating wind speed time history of the tower line systemis first simulated,and then the fluctuating wind and the average wind are superimposed to generate the instantaneous wind speed and converted into wind load.The dynamic response of the transmission tower line systemunder iced coupling with different wind speeds and different thicknesses of ice coating was studied.This is the first attempt that the coupling dynamic response of the icing shedding and wind load for the transmission tower-line system is discussed in this paper.In addition,the dynamic characteristics of wind are included.In particular,the limiting mechanical conditions are considered.According to the simulation results,it is found:because of the ice shedding,the stress of the conductor changes obviously in the first 20 seconds,and the ground wire changes sharply in the first two seconds;the icing of the conductor(ground)wire is gradually deicing under the action of wind vibration;the displacement of tower top increases with the increase of wind speed and icing thickness.