CO2 emissions from Illinois Basin coals and influence of their petrographic composition

Abstract

Lithotypes from Pennsylvanian high-volatile bituminous coals from the Illinois Basin were isolated by hand and analyzed to investigate the influence of their chemical and petrographic composition on the amount of CO2 emissions during combustion. Heating values and ultimate carbon contents were used to calculate CO2 emissions from individual lithotypes as well as whole seam samples. The influence of maceral composition, vitrinite reflectance (Ro), and other selected coal properties on calculated CO2 emissions was investigated for the Danville, Springfield, and Lower Block Coal Members of the Dugger, Petersburg, and Brazil Formations, respectively.

In general, little difference in CO2 emissions has been documented for each of the four locations. Calculated mean values of CO2 emission from bulk seam samples vary from 86.04 to 88.38 (in kg of CO2 per gigajoule [GJ]). Emissions from selected lithotypes show more variations. In fusains, CO2 emissions vary from 78.93 to 95.58, with 89.58 being the average. Fusain is the lithotype that has the highest average emissions of all lithotypes studied. For vitrains, calculated emissions range from 86.18 to 89.01, having the average of 87.92. Clarain, the dominant lithotype of these coals has a range of emissions from 86.02 to 86.86 kg of CO2 per gigajoule. On a maceral scale, our study shows that an increase in inertinite content correlates with an increase of CO2 emissions, whereas increasing liptinite content is associated with decreasing CO2 emissions.