Reactive distillation device for preparing trichlorosilane from mixed chlorosilane and method for device

Abstract

The invention relates to a reactive distillation device preparing trichlorosilane from mixed chlorosilane and a method for the reactive distillation device. The method comprises the following steps of: feeding mixed chlorosilane raw materials at a middle position of an upper reaction section C and a lower reaction section E, obtaining dichlorosilane on the top of a tower, and making partial dichlorosilane return to the lower part of the lower reaction section E under the gravity and serve as a feed to enter the tower; obtaining silicon tetrachloride at the bottom of the tower, and returning partial silicon tetrachloride serving as a feed to the tower through the upper part of the upper reaction section C by using a feed liquid circulating pump at the bottom of the tower; extracting a trichlorosilane product in the middle of the tower; pressurizing and heating the partial dichlorosilane extracted on the top of the tower through a compressor, performing heat exchange with the partial silicon tetrachloride extracted at the bottom of the tower, returning the heated silicon tetrachloride to the bottom of the tower for refluxing, and returning the cooled dichlorosilane to the top of the tower for refluxing through a throttling valve and the feed liquid circulating pump on the top of the tower. The traditional reactive distillation equipment and subsequent separation and purification equipment are integrated in a dividing-wall tower, the process flow is simplified, the equipment investment is saved, and energy consumption is reduced.

Description

technical field [0001] The invention belongs to the technical field of reactive distillation, and relates to a device and process for heat pump rectification and dividing wall tower reactive distillation, in particular to a reactive rectification device and method for preparing trichlorosilane by mixing chlorosilane. Background technique [0002] At present, polysilicon production enterprises mainly adopt the improved Siemens method. This process mainly produces the hydrogen reduction reaction of trichlorosilane, and some dichlorodihydrogen silicon and a large amount of silicon tetrachloride by-products are produced during the production process. Silicon tetrachloride is mainly converted into trichlorosilane by cold hydrogenation technology, but this technology has low efficiency and high energy consumption; there is no mature technology for dichlorodihydrogen silicon to effectively use it, and the leaching process is often used Exhaust gas treatment is carried out, and dich...

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Problems solved by technology

[0003] Conventional distillation towers take heat from the top condenser and supply heat to the bottom reboiler at the same time. Usually, the heat taken by the top condenser is about 90% of the heat added to the bottom reboiler. Energy utilization very unreasonable

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