Modes of formation of carbon oxides (CO_x (x = 1,2)) from coals during atmospheric storage: Part i effect of coal rank

Emissions of carbon oxides, particularly carbon dioxide, from fossil fuels have an enormous environmental and economical impact on coal (under atmospheric storage) utilization as a fuel for utility plants. Therefore, a deeper understanding of the processes controlling their formation is crucial. This work investigates the effect of coal rank on the carbon oxides emissions. It offers a new perspective on the subject as it encompasses three classes of coals (bituminous, sub-bituminous, and lignite) and can shed light on the specific coal parameters that effect the formation of carbon oxides at low temperatures. It is suggested that the main product carbon dioxide is not only a direct product of the consumed oxygen but that its formation is also dependent on the pre-existing O content in the coal macromolecule. The effect of coal rank on the formation of carbon oxides during low temperatures at the coals surface is discussed in detail.