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Hydrogenation of silicon tetrachloride(STC) in the presence ofsilicon was investigated both thermodynamically and experimentally.The thermodynamic results revealed that the reaction is thermodynamicallyconstrained and the STC equilibrium conversion is nearly temperature-independentbut increases with increasing pressure and H2/STC feedratio. Trichlorosilane (TCS) was calculated to be the dominant product,with trace amounts of dichlorosilane (DCS) and HCl as feasible byproducts.Experimental tests were conducted in a fixed-bed reactor loaded withsilicon. The results indicated that the reaction is kinetically restrictedin the absence of a catalyst. Adding CuCl to the silicon mass bedwas found to result in a dramatic increase in the STC conversion,and Cu3Si was determined to be the active species. In allof the tests runs, TCS was determined to be the dominant product,and the STC reaction rate was found to increase markedly as the temperatureand STC partial pressure increased but not to depend on the siliconparticle size. [ABSTRACT FROM AUTHOR]

Currently, the mechanical vapor recompression (MVR) system is extensively used for single salt separation, but the relevant research on mixed salt system treatment is still in initial stage. As a very common salt solution system, sodium chloride–potassium chloride–water system can be readily found in many processes. It is no doubt of great significance to separate their crystals from the mixed solution in an efficient and environmentally friendly way. Therefore, with the aid of Aspen Plus software, this study aims to design an MVR evaporation system capable of treating sodium chloride–potassium chloride–water system. Subsequently, the analysis about the start‐up schemes and some influencing factors in the steady‐state operation are carried out, so as to provide some guidance and reference for the future technical route to separate mixed salt system with low energy consumption. [ABSTRACT FROM AUTHOR]

Thispaper presents a reactive distillation column for the catalyticdisproportionation of trichlorosilane to silane which includes threeconsecutive reversible reactions with a thermodynamic conversion tosilane as low as 0.2% and is of no practical significance using theconventional reactors. This reaction system is however characterizedby a large distinction in the boiling points of the components, whichmakes the reactive distillation extremely favored. Nevertheless, thenormal reactive distillation column possesses the shortage of highrefrigeration requirement as the standard boiling point of the overheadproduct silane is −112 °C. A novel reactive distillationcolumn with intercondensers placed within has been simulated usingAspen Plus package for a feasible alternative to alleviate this drawback.The calculated results show that a reduction in the refrigerationload of more than 97% can be obtained when one intermediate condenseris inserted between the rectifying and reaction zones, and that anothernormal intermediate condenser equipped within the reaction sectioncan further decrease the condensation requirement of the first intermediatecondenser by 50%. Effects of the configuration parameters and operationalconditions have also been investigated for optimal design and operationof the proposed reactor. [ABSTRACT FROM AUTHOR]