Study on the Effect of Coal Drying in AdsorbingC02 at Different Temperature and pH

C02 is the primary green house gas representing roughly 83% of the anthropogenic
effect. One of the options to mitigate the rising atmospheric concentration of CO2 is
through CO2 geologic sequestration in coal seams process. Part of understanding the
sequestration is to study what is the effect on the rate of CO2 adsorption at different
temperature and pH in a coal mine environment. The objectives of this study are to
investigate CO2 gas adsorption patterns on local coal sample at different temperature,pH
and particle sizes. It is also to determine the basic properties of the local coal sample and
determine how the characteristic of the coal sample affects the adsorption rate of CO2
gas. In the characterization ofthe coal sample process, there were a number ofparameters
which was studied and tested. They were the moisture content, the ash content, carbon
content and mineral content of the coal sample. For the study on the effect of varying
parameters on the CO2 adsorption on coal seams, the CO2 adsorption behavior was
investigated using a manometric apparatus. The experimental set-up will be used in the
investigation of the effects of temperature (24.6°C, 30°C, 40°C and 55°C) pH (acidic of
pH 0.51, near neutral of pH 5.97 and alkali of pH 12.40), and particle size (lOOOum and
2000um) of the CO2 adsorption rate on the local coal sample. The moisture content of the
coal sample was found to be 37.4%. The ash content analysis gave a percentage ash of
11.02%). The elemental composition analysis gave an elemental carbon content of 56% to
60%. The mineral matter in the coal sample was found to be 12.09%. The chemical
elements analysis indicated silica as having the highest amount in the coal sample. The
experiments conducted for the study of the CO2 adsorption in coal seams showed that
smaller particle size lOOOum had a higher adsorption rate per mass of coal sample as
compared to the 2000um sample. The effect of increasing the temperature is to decrease
the equilibrium adsorption capacity of the coal samples. It can be observed that the
untreated coal sample has the highest extent of adsorption capacity followed by the
acidic, alkali and neutral conditions. The coal samples were found to be of lignite type.
From literature review, coals of lignite type were found to exhibit the most sorption
tendency towards CO2 as compared to coals of other ranks.