Water absorption by coals: effects of pore structure and surface oxygen

Capacity and mechanism of phenol adsorption on lignite

“…However, several works report a decrease in phenol adsorption from water with surface oxidation Mahajan et al, 1980;Leng, 1996;Franz et al, 2000;Terzyk, 2003Terzyk, , 2004Moreno-Castilla, 2004). Since lignites are rich in oxygen surface groups Küçükbayrak et al, 2000), they have a high affinity for water (Allardice and Evans, 1971;Schafer, 1972;Kaji et al, 1986;Müller and Gubbins, 1998;Lee and Reucroft, 1999). Therefore, the decrease in adsorption with oxidation is attributed to the preferential hydration of the surface oxygen groups over the hydrogen-bonding of the -OH of the phenol molecule.…”

Secondary atomization of single coal-water fuel droplets

“…Because agglomerates of all ranks remain intact after the water evaporates, the mechanism binding the agglomerate is independent of coal rank (26). Monolayers of water adsorbed by the coal could serve to hold the particles together (26,27).…”

Effects of particle size on the desorption kinetics of water from Beulah-Zap lignite coal: Differential scanning calorimetry results

“…Mraw and Silbernagel'suggested that the amount of water present in coal provides a measure of pore volume. On the other hand, Kaji et t 6 al. found no correlation between the water-holding capacity of 13 coals (of various ranks) and their pore volume.…”

“…2 as a function of moisture content. As can be seen from 6 From Equations ( 3 ) and (6) the fractional conversion a can be solved mathematically as a function of temperature. The appropriate non-isothermal expressions for F ( a ) , representing twelve different kinetic models, were solved and are listed in Table 1.…”

“…The appropriate non-isothermal expressions for F ( a ) , representing twelve different kinetic models, were solved and are listed in Table 1. To extract the activation energy from the experimental data, Equation (6) should be further simplified by taking logarithms, i.e. ,…”