Sustainable Thermochemical Extraction of Amorphous Silica from Biowaste.

Autor: Banoth, Swapna, Babu, V. Suresh, Raghavendra, G., Rakesh, K., Ojha, S.
Zdroj: SILICON (1876990X); Jul2022, Vol. 14 Issue 10, p5289-5296, 8p
Abstrakt: The objective is to utilize zero wastage rice hull material which contains silica as a major component in amorphous form and is used as reinforcement material for various applications. Burning of rice hull (RH) under controlled condition after removal of metal ions leads to white silica of high purity. An inexpensive method for extraction of amorphous silica by thermochemical treatment (pyrolysis process) is performed. Pyrolyzed biomass at four different temperatures is observed for treated and untreated rice hull. Calcination of the rice hull at 600ºC in a muffle furnace turns it into white amorphous silica. In this research, HCl was used to retrieve silica from the rice hull. Extracted silica was characterized by X-ray diffraction analysis, which indicates that the silica is in amorphous form, and displayed a strong broad peak at 22.32º and 21.52˚ (2θ). The FTIR data revealed the existence of peaks at 4000 cm− 1& 400 cm− 1 showing the presence of siloxane and silanol groups. UV-Visible (absorption) band maxima was demonstrated at 367 nm, photoluminescent (emission) spectra displayed a short peak at 453 nm and a sharp intensity peak at 488 nm is comparable with amorphous nano-silica. Less amount of silica appeared at the inner surface of rice hull fiber revealed by SEM analysis. Other element traces were absent, high purity of amorphous silica is observed by EDS. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index