Safe and Efficient Disposal of Hexachlorodisilane Liquid
Nguyen, Thanh-Trung
Huang, Yu-Wen
Yan, Pei-Xuan
Hu, Yu-Chun
Tsai, Hsiao-Yun
Chen, Jenq-Renn
Ngai, Eugene Y.

How to Cite

Nguyen T.-T., Huang Y.-W., Yan P.-X., Hu Y.-C., Tsai H.-Y., Chen J.-R., Ngai E.Y., 2022, Safe and Efficient Disposal of Hexachlorodisilane Liquid, Chemical Engineering Transactions, 90, 205-210.


This research project was to develop a safe and efficient method for disposal of HCDS liquid in large quantities. The proposed method is a two-stage process which includes direct hydrolysis of HCDS liquid in water, followed by alkaline cleavage of the hydrolyzed product in aqueous suspension by an aqueous potassium hydroxide (KOH) solution. In the first stage, HCDS liquid was directly hydrolyzed in water. The required ratio of HCDS to water was 1:25 by weight. During the hydrolysis, the reaction was mild and took place without significant fuming. There was a new peak at 915 cm-1 observed only in the IR spectrum of the liquid HCDS hydrolyzed deposit hydrolyzed in water that may be attributed to the existence of small silicon-oxide molecules in the cluster. It was determined that, unlike other hydrolyzed deposits formed in moist air, the liquid HCDS hydrolyzed deposit formed in water was readily reactive to alkaline solution at ambient conditions with a concurrent release of hydrogen gas. In the second stage, aqueous KOH solution (20 wt%) was then added to neutralize the suspended solution. The required weight ratio of KOH to HCDS was 2:1 to get a final pH of about 12.6. The residual deposit was completely dissolved in two hours.
Keywords: Hexachlorodisilane, HCDS, hydrolyzed deposit, shock sensitive, disposal.