Small Scale 700Nm3/H Polysilicon Tail Gas Recycle From CDI Workshop

Small Scale 700Nm3/H Polysilicon Tail Gas Recycle From CDI Workshop

Asia Silicon Industry 700Nm³/H Polysilicon Tail Gas Recycle

A number of front-stage distillation and back-stage hydrogen extraction patented technology is adopted, and the technology is coupled, and the HCL and chlorosilane are recovered from polycrystalline silicon exhaust for the whole units. The chlorosilane can be adopted as raw material and the gas purity of products can exceed 99.999%.

The hydrogen extraction project of polysilicon tail gas comes from CDI workshop tail gas, which has high hydrogen content, low impurity content and high product purity requirements. The design adopts temperature swing adsorption for treatment. That is to say, the feed gas is designed with appropriate space velocity, and harmful impurities (hydrogen chloride and chlorosilane) in the feed gas are removed through TSA unit, and then the solid suspended solids and dust impurities in the product gas are removed through precision filter to produce high-purity product hydrogen. Most of the hydrogen is transported to the pipe network as products, and a small part of the hydrogen is returned to TSA section for regeneration of adsorbent, and the desorbed gas is returned to the hydrogen compressor of the front section for recycling chlorosilane. The process route is mature and stable, which can effectively ensure the product quality. At the same time, the desorbed gas is returned to the absorption section for treatment, which improves the hydrogen recovery rate, and there is no waste gas emission in this section.

Technical indexes

Purity:＞99.999%

Capacity:700Nm³/H

Yield: ≥99%

Reference