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Upscaling of W zeolite direct synthesis from coal fly ash and its water adsorption capacity
Author(s) -
GameroVega Karen Y,
MedinaRamírez Adriana,
Khamkure Sasirot,
OrozcoNúñez Sylvia I,
AguileraGonzález Elsa N,
GameroMelo Prócoro
Publication year - 2019
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.5922
Subject(s) - zeolite , fly ash , hydrothermal circulation , adsorption , potassium hydroxide , crystallization , amorphous solid , chemical engineering , chemistry , molecular sieve , sodium hydroxide , mineralogy , materials science , nuclear chemistry , organic chemistry , catalysis , engineering
BACKGROUND Alkaline amorphization of fly ash (FA) and crystallization of the potassium W zeolite from the resultant amorphous materials was carried out at different scales by a straightforward hydrothermal method. The experimental factors and levels were evaluated during the FA amorphization study by variation of the metallic hydroxide, concentration, temperature and time for the hydrothermal reaction. RESULTS The alkaline FA hydrothermal activation study quantified a set of optimal conditions to obtain amorphous materials easy to be recrystallized into W zeolite. The activation process at laboratory scale involved the hydrothermal treatment of 3.6 g FA with 74.43 mEq KOH dissolved in 21 mL water at 125 °C for 4 h. A product with ≤94.7% of the amorphous phase was obtained. The direct zeolitization of FA was performed at 175 °C for 16 h with a KOH:FA weight ratio of 0.33 and molar ratios of 1.64, 17.08 and 3.90 for SiO 2 :KOH, H 2 O:SiO 2 and SiO 2 :Al 2 O 3 , respectively. An amount of dried zeolitic material c .25% higher than the weight of FA used was obtained. CONCLUSION Adsorbents formulated with the W zeolite showed higher water adsorption capacity than the commercial molecular sieves used by industry for drying wet natural gas. © 2019 Society of Chemical Industry