Indirect Carbonation of Coal Fly Ash for Carbon Dioxide Captured via Mechanochemical Reaction
Loading...
Date
2018-06
Authors
Nurul Athira Omar Saifuddin
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Many mineral wastes that produced in Malaysia have the potential
candidates for CO2 mineral sequestration. One of them is by using coal fly ash.
Therefore, to reduce CO2 from escaping towards the surroundings, carbonation
(namely indirect carbonation) process is used to capture CO2. Indirect carbonation
undergoes calcium extraction, followed by carbonation process using planetary
ball mill. In extraction process, the influence of milling time, milling rotational
speed and solid-liquid-ratio were explored. Increasing the milling time from 10 to
180 minutes and rotational speed from 100 to 400 rpm subtly increases the amount
of calcium extracted. In carbonation process, KHCO3 was used as a carbonating
agent in this study where the concentration was varied. At concentration from 2.5
to 5.5 mol/L, shows increasing of amount calcium being extracted. Addition to it,
CO2 capacity of coal fly ash also increased due to the activation extraction of
mineral particles especially calcium. The highest CO2 capacity and calcium
extracted achieved were at 0.2310 g CO2/g CFA and 0.210 g Ca2+/g CFA. Using
similar operating conditions, the carbonation was repeated using open vessel
microwave. Planetary ball mill demonstrates higher carbonation efficiency
compared to microwave. It gave positive impact shown by planetary ball mill
where the amount of calcium extracted and the ability to sequestrate CO2 is higher
as compared to microwave. Lastly, CFA were characterized using scanning
electron microscopy (SEM) and FTIR spectrometer.