Hot water treatment effect in the elephant grass ashes calcinated at different temperatures
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Data
2018-01-01
Autores
Nakanishi, Erika Yukari
Santos, Valdemir dos
Cabral, Matheus Roberto
Santos, Sergio Francisco [UNESP]
Rodrigues, Michelle Santos
Frias, Moises
Savastano Junior, Holmer
Título da Revista
ISSN da Revista
Título de Volume
Editor
Univ Fed Rio De Janeiro, Lab Hidrogenio
Resumo
In recent years, agro-industrial residues have focused attention in the scientific community as a new source of pozzolans. In Brazil, for example, one of the wastes generated from agro-industrial activities comes from elephant grass that is cultivated as biomass for energy cogeneration. This study evaluated the effect of hot water treatment on the crystalline structure of elephant grass ashes calcinated in two different temperature (700 and 900 degrees C). To study the chemical structure and the composition of the ashes the X-ray fluorescence (XRF) and X-ray diffractions (XRD) analyses were carried out. The results achieved in the present work shown that, elephant grass ashes meet the ASTM C-618 standard, for the minimum sum content of the silica (SiO2), aluminum (Al2O3) and iron (Fe2O3) oxides, of 50% to be considered as a pozzolanic material. The presence of an amorphous phase has been detected in all XRD patterns. The ashes calcinated at 700 degrees C showed lower crystallinity and the treatment with hot water decreased crystallite size, i.e., the material became more amorphous. On the other hand, the ashes calcinated at 900 degrees C, less reactive, had a lower content of K2O. Therefore, the hot water treatment was effective to reduce the potassium content in the ashes. Additionally, it contributed to reduce the crystallite size of silica in the ash calcinated at 700 degrees C, while the effect is contrary to the ash calcinated at 900 degrees C.
Descrição
Palavras-chave
Mineral addition, biomass, amorphous formation, potassium leaching, crystallite size
Como citar
Materia-rio De Janeiro. Rio De Janeiro Rj: Univ Fed Rio De Janeiro, Lab Hidrogenio, v. 23, n. 3, 10 p., 2018.