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Process simulation of dimethyl ether synthesis via methanol vapor phase dehydration

Bai Z., Ma H., Zhang H., Ying W., Fang D.

Polish Journal of Chemical Technology

2013

Vol. 15, nr 2

122–127

The production processes included catalytic dehydration of methanol in an adiabatic fixed-bed reactor and two columns product separations. In this study, the technological process for dimethyl ether (DME) synthesis is built on PRO/II platform based on the combined parameters of the reaction dynamic model for methanol dehydration reaction, the improved NRTL model of the liquid phase, the PR model of vapor phase. In order to validate the proposed model, the simulation results have been compared with the available data from a set of industrial production equipment with a production capacity of 200 000 tonnes per annum. A comparison between the calculated and measured results has proved that these results are satisfactory. The bed height and the volume of the catalytic bed are calculated aim at one million t/a DME yields and while taking account of high-purity DME production. After discussing the influence of feed stage location and reflux ratio for DME product purity, the suitable unit operation conditions are chosen. Accordingly, accurate process simulation results provide the basis and guidance for an improvement and development of the similar industrial device.

Experimental and Theoretical Study on4-Phenyl-3-[(1,2,4-triazol-1-yl)methyl]-triazole-5-thione

Jian F., Zhao P., Bai Z., Cai Z.

Polish Journal of Chemistry

2006

Vol. 80, nr 2

325-333

The title compound, 4-phenyl-3-[(1,2,4-triazol-1-yl)methyl]-triazole-5-thione, was synthesized and characterized by elemental analysis, IR and electronic spectra. Density functional theory calculations of the structure, natural bond orbital and thermodynamic functions of the title compound were performed at B3LYP/6-311G** level of theory. Vibrational frequencies were predicted, assigned, compared with the experimental values, and they are supported each other. Electronic absorption spectra were calculated by the time-dependent density functional theory (TD-DFT), which indicates that the two absorption bands aremainly derived from the contribution of bands pi--pi*. The calculation of the second order optical nonlinearity was carried out with PM3 semi-empirical method that resulted in the molecular hyperpolarizability equal to 4.397x10-30 esu.