title: Numerical investigation on three-dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere.
abstract: The world has experienced heavy thirst of energy as it has to face a dwindling supply of fossil fuel and polycrystalline silicon photovoltaic solar energy technology has been assigned great importance. Silicon tetrachloride is the main byproducts of polysilicon industry, and it's volatile and highly toxic. Once silicon tetrachloride releases, it rapidly forms a dense gas cloud and reacts violently with water vapor in the atmosphere to form a gas cloud consisting of the mixture of silicon tetrachloride, hydrochloric acid and silicic acid, which endangers environment and people. In this article, numerical investigation is endeavored to explore the three dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere. The k-ϵ model with buoyancy correction on k is applied for turbulence closure and modified EBU model is applied to describe the hydrolysis reaction of silicon tetrachloride. It is illustrated that the release of silicon tetrachloride forms a dense cloud, which sinks onto the ground driven by the gravity and wind and spreads both upwind and downwind. Complicated interaction occurs between the silicon tetrachloride cloud and the air mass. The main body of the dense cloud moves downwind and reacts with the water vapor on the interface between the dense cloud and the air mass to generate a toxic mixture of silicon tetrachloride, hydrogen chloride and silicic acid. A large coverage in space is formed by the toxic mixture and imposes chemical hazards to the environment. The exothermic hydrolysis reaction consumes water and releases reaction heat resulting in dehydration and temperature rise, which imposes further hazards to the ecosystem over the affected space.
authors: Lab of Fluid Flow and Heat Transfer and IGCIT, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: zhangjw@mail.buct.edu.cn.
authors: Zhang
authors: Z
authors: Jianwen
authors: Yantai Guo Bang Chemical Mechanical Technology Co., LTD, China.
authors: Yin
authors: Y
authors: Xinxin
authors: Lab of Fluid Flow and Heat Transfer and IGCIT, Beijing University of Chemical Technology, Beijing 100029, China.
authors: Xin
authors: X
authors: Yanan
authors: Lab of Fluid Flow and Heat Transfer and IGCIT, Beijing University of Chemical Technology, Beijing 100029, China.
authors: Zhang
authors: Z
authors: Jian
authors: Department of Automation, Tsinghua University, Beijing 100084, China.
authors: Zheng
authors: Z
authors: Xiaoping
authors: SINOPEC Institute of Safety Engineering, Qingdao 266071, China.
authors: Jiang
authors: J
authors: Chunming
mesh_terms: D000392:Air Movements; D000395:Air Pollutants, Occupational / Q000032:analysis*; D000465:Algorithms; D002712:Chlorides / Q000737:chemistry*; D003198:Computer Simulation; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D006868:Hydrolysis; D008962:Models, Theoretical; D017655:Silicon Compounds / Q000737:chemistry*
chemical_list: D000395:Air Pollutants, Occupational; D002712:Chlorides; D017655:Silicon Compounds; C039676:silicon tetrachloride
keywords: Dispersion and conversion; Hazardous effects; Numerical investigation; Release; Silicon tetrachloride