I. TSA Method Chlorine/ Hydrogen chloride drying

1 I. Overview

In the polysilicon production process, high-purity trichlorosilane is obtained through chemical means, and its synthesis requires the use of high-purity chlorine gas, hydrogen gas, and hydrogen chloride gas (with a water content ≤10–20 ppm). ), therefore, both commercial chlorine gas (with a water content of 400–1,000 ppm) and synthesized hydrogen chloride (with a water content of 1,000–3,000 ppm) must undergo thorough drying. In the chlor-alkali industry, dried chlorine gas is required as a raw material for chemical production. Our company provides desiccants and drying processes that can reduce the water content of chlorine gas to below 2 ppm. Our equipment operates smoothly and reliably, and currently our market share for such units exceeds 90%.

2 1. Technical Specifications
Pressure: Atmospheric to 2.0 MPa
Temperature: Ambient (excluding regeneration)
Water content in chlorine/chlorine hydrogen: ≤2–20 ppm (adjustable)
Gas handling capacity: 50–10,000 Nm³/h ³/h

3. The temperature-variable adsorption method for drying electronic-grade high-purity chlorine/chlorine hydrogen has the following advantages:
(1) Purification before and after hydrogen chloride synthesis is entirely carried out by adsorption, with no limitations on production scale, a simple process, and high levels of automation. High degree of sophistication and simple operation.
(2) Significantly reduce power consumption and improve product quality.
(3 ) It requires lower investment than traditional methods, has a shorter construction period, and occupies a smaller footprint.
(4) The equipment used has a simple structure and does not require special materials.
(5) The drying unit features minimal chlorine/chlorine hydrogen loss, high recovery rate, and no environmental pollution.

II. TSA Method from SiHCl ₃ or the recovery of chlorides and hydrogen from polysilicon off-gas

1 I. Overview

During the production of trichlorosilane or polysilicon, large volumes of gas containing various chlorosilanes and hydrogen chloride must be vented. Due to the unique properties of chlorosilanes and hydrogen chloride, substantial capital investment is required for exhaust-gas treatment, which in turn leads to a reduction in the yield of trichlorosilane during the production process.

Our company has developed a chlorosilane-specific adsorbent that can recover nearly 100% of the chlorosilane, while also ensuring that the recovered hydrogen and chlorosilane contain, It contains no harmful impurities and fully meets the requirements for polysilicon production.

2 1. Technical Specifications

Technical Specifications for Chloride Recovery

Operating temperature:          0.5 ~5.0 MPa

Operating temperature: Room temperature (adsorption separation process)

Processing gas volume: 10–30,000 Nm³ ³/h

Chlorosilane recovery rate: ≥99.99%

Hydrogen purity: ≥99.999%

Recovery chlorosilane pressure: Atmospheric pressure

Hydrogen recovery pressure drop: ≤0.05 MPa

Carbon content of recovered hydrogen: ≤20 ppb (meets the quality requirements for hydrogen in polysilicon reduction furnaces).
 

3 1. Advantages of the TSA Chloride Recovery Unit
(1 ) A dedicated adsorbent is employed, exhibiting a very high separation factor for chlorides and other gases, enabling the removal of chlorides at low partial pressures. Effective adsorption separation;
(2) The recovered chloride and hydrogen are both free of other harmful substances and fully meet the production requirements of the polysilicon plant.
(3 ) It employs an adsorption-based approach, featuring a simple process, low energy consumption, a high degree of automation, and easy operation, while its production scale is unrestricted. to make;
(4) Low capital investment, short payback period, and small footprint.