Modeling of Chemical Vapor Deposition of Silane for Silicon Production in a Spouted Bed via Discrete Element Method Coupled with Eulerian Model

Abstract

A CFD–DEM coupling model was applied to the silicon production by silane chemical vapor deposition in a spouted bed to investigate local phase movements, mass transfer, heat transfer, and the deposition rate of silicon. Silicon particle growth by heterogeneous deposition on the seed particle and fines formation in the gas phase were included. In addition, the scavenging effect was also considered in the particle growth mechanism. The spouted bed has advantages to promote heterogeneous deposition time due to a larger solid holdup and higher gas residence time in the annulus region. Furthermore, the effects of operating conditions, i.e., inlet gas temperature, silane composition, and gas velocity, on the reactor performance were investigated in detail, and some guidelines are provided for the choice of operating conditions. Verification of solid movement results with the experimental data and correlations show good agreement. In addition, the axial profile of bed voidage agrees well with correlation.

Numerical Studies on Particle Dynamics in a Spouted Bed

“…The main motivation was to reduce the operating pressure drop with improved particle recirculation rate. , Since its discovery, the spouted bed technology is found to be widely used in various industrial processes such as drying of wet products, combustion, pyrolysis, − gasification, and for the processing of fine particles . Very recently, this technique has gained momentum in the process of spray coating , and chemical vapor deposition (CVD)-based coating processes. , …”

Pilot-Plant Production of High-Performance Silicon Nanowires by Molten Salt Electrolysis of Silica

“…Silicon has been recognized as one of the most promising negative electrode material for the lithium-ion batteries (LIBs) of next generation because of its high specific capacity (10 times that of graphite). − The market share of silicon-based materials for LIBs has increased to 3–5% in the past three years because of the huge demand of electric vehicles. However, the large volume expansion of silicon (approximately 360%) during charge–discharge cycling leads to a rapid decline of the LIB capacity. − To solve this problem, one of the effective methods is preparing silicon of nanostructures, such as nanoparticles, nanotubes, and nanowires. − It is reported that the unique structure of silicon nanowires (SiNWs) can not only shorten radial Li-ion diffusion distance, but also enhance the structural robustness against volume variations, which makes SiNWs become a promising new negative electrode material for LIBs. − SiNWs can be prepared by various methods, such as chemical vapor deposition, , laser ablation, , thermal evaporation, and template method . In spite of their respective specific merits, all of these methods have their own shortcomings, such as the high cost because of the requirements of energy-consuming equipments, high-purity Si substrates, and noble metal catalysts.…”

“…7−10 It is reported that the unique structure of silicon nanowires (SiNWs) can not only shorten radial Li-ion diffusion distance, but also enhance the structural robustness against volume variations, which makes SiNWs become a promising new negative electrode material for LIBs. 11−13 SiNWs can be prepared by various methods, such as chemical vapor deposition, 14,15 laser ablation, 16,17 thermal evaporation, 18 and template method. 19 In spite of their respective specific merits, all of these methods have their own shortcomings, such as the high cost because of the requirements of energy-consuming equipments, high-purity Si substrates, and noble metal catalysts.…”

Computational Fluid Dynamics–Discrete Element Method Studies on Dynamics and Segregation in Spouted Bed with Polydispersed Particles

“…It is also being applied for coating 9,10 or surface modification of particles using the chemical vapor deposition (CVD) process. 11,12 Very recently, this technique has also been used for handling even fine particles. 13 A large number of studies on the prediction of minimum spouting velocity using the pressure−velocity characteristic curve for a binary mixture of solids with a difference in size and density are reported in the literature.…”