Effects of organic acid pretreatment on the structure and pyrolysis reactivity of coals

Pretreatment of coal by ionic liquids towards coal electrolysis liquefaction

“…In comparison with the original coal, the [Bmim]Cl-pretreated coal exhibits more loose stacking structures. It is probably due to the fact that interactions between coal particles are broken during the pretreatment, and the coal particles are dissociated and rearranged in the presence of [Bmim]Cl [33]. In addition, more small particles are distributed over the surface of the pretreated coal.…”

The influence of addition of coal tar pitch (CTP) and expired pharmaceuticals (EP) on properties and composition of pyrolysis products for lower and higher rank coals

“…It can be concluded from the works [17][18][19][20] that the processes of plasticization of organic coal material could have been also affected by the addition of organic and non-organic acids. These works interpret the interaction of acids with organic coal material in a different way.…”

Role of pH on CO2 sequestration in coal seams

“…A decrease in pH can dissolve and extract mineral matter associated with the coal [16,17]. A pH change can alter the surface charge of the coal [18] and disturb the intermolecular interactions including hydrogen bounding, van der Waals interaction, electrostatic forces, and ionic interactions responsible for the 3-dimentional (3-D) structure of the macromolecular network [19][20][21]. Because the aperture size of a pore in the coal is important for gases to access within the pores and because the maximum adsorbed amount is related to the pore volume [22], all of these may affect the storage capacity of the coal and the stability of the adsorbed CO 2 .…”

“…Goodman et al [33,34] have shown that CO 2 did not interact with the adsorbed water in coal evidenced by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). Nevertheless, studies of the effects of acidic and basic solutions on coal have frequently focused on the demineralization of the coals [17,19,21,31]. Most of these investigations have involved leaching the mineral matter in coal with concentrated acid and base solutions at elevated temperatures [21,31].…”