Study on the Effect ofCoal Drying in Adsorbing CO2, CH4 and N2 at different Temperature and pH

Carbon Dioxide (C02) sequestration has become one of the attractive approaches to
mitigate the high concentration of Carbon Dioxide in the atmosphere. C02
sequestration is the process where C02 is injected onto selected geological storage
such as ocean, deep saline reservoirs, depleted oil and gas reservoir and sequestration
in coal seams. However, this research will be focused on the sequestration in coal
seams. The research has several objectives to be achieved. The objectives are to
study on the reliability of this process to be implemented and to determine the
suitable environment for the C02 adsorption to occur effectively. Then the research
continues to recognize on the potential for C02 sequestration to be implemented in
Malaysia. For this research, the scope has been narrowed to study on the effect of
C02 adsorption onto coal in different temperature, pH and particle size. Then the
scope moves to study on the coal adsorption preferential towards different types of
gas which are CH4 and C02. The coal used here is sub-bituminous. For the
temperature variation, the temperatures are chosen from 30°C, 40°C, 50°C and 60°C.
For pH variation, the pH is chosen between 2.4, 6.2 and 12 while for particle size
variation, the sizes are 250um and 1000pm. The experiment setup is done in low
constant pressure. The adsorption is monitored based on either two observations, one
is through the reduction of pressure in the closed coal sample cell and the other is to
compare on the peak area ratio yielded by the Gas Chromatograph. From the
experiments conducted, the following results are obtained. For temperature variation,
the adsorption is low in higher temperature where it shows that relatively can cause
the incomplete filled coal seams and time wasted for the coal to cool if the
surrounding temperature is too high. For vary in pH, acidic coal (low pH) is
preferable than neutral coal and base coal (high pH) for the adsorption to take place.
This can further study on considering co-sequestering of acid gasses which
technically can increase pore capacity. Between two different particle sizes, the
adsorption is higher in the smaller particle size. For vary in type of gas, it shows that
CO2 has the highest adsorption onto coal compared to CH4. This can be concluded
where it can help to reduce cost by having CH4 as the by product (sell or recycled
energy) in the condition where the coal do adsorp C02 and let released CH4 as the
byproductofthe process.