Device and method for preparing high-purity silane through disproportionation reactive distillation of trichlorosilane

Abstract

The invention relates to a device and a method for preparing high-purity silane through disproportionation reactive distillation of trichlorosilane. The method comprises a disproportionation reactive distillation process (A), a silicon tetrachloride absorption process (B), a fixed bed absorption process (C) and a product filling process (D). The method comprises the steps that: two-step disproportionation reaction is adopted, and the distillation separation action of a reactive distillation column is utilized to finally obtain a mixed gas of silane and dichlorosilane on a column top to be used as non-condensable gas of a condenser to be extracted, and a silicon tetrachloride product is obtained at a column bottom after reaction formation; a gaseous product which is recovered through a disproportionation reactive distillation column enters into a silicon tetrachloride absorption column, wherein the main ingredient of an absorbed gas is silane, an absorption liquid is filled into a silicon tetrachloride desorption column, the desorbed dichlorosilane is recovered on the column top, and the desorption liquid of the column reflows back to the silicon tetrachloride absorption tower; the absorbed gas is filled into a fixed bed to absorb so as to obtain a high-purity silane product; and the silane product is filled into a buffer tank under the pressurization condition. Technological equipment is simple, and the obtained silane product has high purity.

Description

technical field [0001] The present invention relates to a device and method for preparing high-purity silane through disproportionation reaction distillation of trichlorosilane, in particular to a device and method for preparing high-purity silane through disproportionation reaction distillation using trichlorosilane as raw material and using reactive distillation technology devices and methods. Background technique [0002] Silane, English name: silane, molecular formula is SiH 4 . As an important silicon source material, silane is widely used in semiconductor microelectronic IC, photovoltaic solar cell PV, liquid crystal display LCD and other industries. [0003] At present, there are three main production methods of silane: sodium aluminum fluoride method, silicon-magnesium alloy method and chlorosilane disproportionation method. Among them, the sodium aluminum fluoride method uses sodium aluminum hydride and silicon tetrafluoride as raw materials to react and synthesi...

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Problems solved by technology

[0005] There are certain defects in the existing foreign chlorosilane disproportionation technology to prepare silane: firstly, the multi-step disproportionation process equipment using fixed bed matching rectification sequence is complex, and because the boiling point of silane at atmospheric pressure is extremely low, about -112°C, silane The operating pressure of the purification tower is relatively high, generally higher than 1.5Mpa, and the temperature at the top of the tower is relatively low, generally lower than -35°C. , but it also faces the problem of low-temperature condensation, and the process is more difficult to realize

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