The influence of potassium carbonate on surface area development and reactivity during gasification of activated carbon by carbon dioxide

Study of Activation of Coal Char

“…The rate is observed to significantly decline upon the acid washout of some of the mineral matter. Catalytic impurities has been reported to lead to greater meso-and macro-pore and less micro-pore formation [29][30][31][32].This part of the study will examine whether that is the case for both a high and low rank coal.…”

“…6 char in air, as a lead-in to the more detailed discussions that follow on various topics. greater meso-and macro-pore and less micro-pore formation [29][30][31][32]. The influence of catalytic matter on the porosity will be examined further below.…”

Study of Activation of Coal Char

“…The observation of similar reactivity is therefore interesting insofar as it suggests that these factors are not fundamentally altered or overridden by the processes that take place during the achievement of high burnout-the sample from the fly ash is similar to an ordinary lab char. These factors are not addressed here, though they can also influence porosity development (e.g., catalytic impurities can lead to greater meso-and macro-pore and less micro-pore formation [29][30][31][32]). …”

Insight into hydroxides-activated coals: Chemical or physical activation?

“…Marsh & Walker 1979 [6]) and there are numerous reports in the literature [7][8][9][10][11][12][13][14][15][16][17], nowadays, it is still unclear and, as consequence, continues being under study [18]. The porosity development is strongly influence by numerous experimental parameters such as coal/KOH weight ratio, maximum treatment temperature, time at the maximum temperature, nitrogen flow and, as consequence, several mechanisms have been proposed.…”

“…Some authors point out that the intercalation of metallic potassium [16,19,20] or potassium compounds [7,21,22] in the carbonaceous structure is the main cause of the porosity development. Other authors [9,10,23,24] suggest that the gasification reactions between KOH and carbon is the main activation process pathway. All these proposals can explain the experimental results, so, 1 all of them are acceptable.…”