Behavior of Chars from Bursa Mustafa Kemal Paşa Alpagut and Balıkesir Dursunbey Çakirca Lignite (Turkey) during Non-catalytic and Catalytic Gasification

Abstract

The reactivities of chars obtained by pyrolysis of Bursa Mustafa Kemal Paşa Alpagut lignite and Balıkesir Dursunbey Çakırca lignite (Turkey) at different temperatures were determined by CO 2 gasification and by combustion with O 2 . Catalytic effect of Na 2 CO 3 on the CO 2 and O 2 gasification reactivity of chars was investigated. Gasification tests were performed in the fixed bed reactors operating at ambient pressure. Reactivity of chars during the CO 2 gasification reactions was determined by calculating the reaction rate constants and reactivity of chars during the O 2 gasification was determined by using ignition temperatures of the samples. Activation energies and Arrhenius constants of the chars on the CO 2 gasification reactions were also calculated by the help of Arrhenius curves. The activation energy for CO 2 gasification was generally decreased with pyrolysis temperature, due to the different surface characteristics and different nature of carbon atoms gasified as the gasification reactions proceed. Generally, the increase in pyrolysis temperature leads to an increase in gasification reactivity with CO 2 . The reactivity of chars in catalytic gasification was higher than the corresponding non-catalytic reactivity of the same chars. Ignition temperature increased with increasing pyrolysis temperature.

Katalysatoren des Leuna Werkes 1945 – 1991: Von der Empirie zur Wissenschaft. Teil II: Reformier‐ und Isomerisierungskatalysatoren

“…Mineral matter content of coals is known to influence gasification reactivity because of the presence of catalytically active components. The potential of catalysis in high‐temperature CO 2 gasification was discussed elsewhere 11. 12 Walker et al 1.…”

An Empirical Correlation between Char Gasification Reactivity and Its Parent Coal

“…The potential of catalysis in high-temperature CO 2 gasification was discussed elsewhere. [11,12] Walker et al [1] showed that K and Na added to low-rank coals by ion exchange and high-rank coals by impregnation were excellent catalysts for char gasification in O 2 , CO 2 , and H 2 O. Fernµndez-Morales et al [12] showed that R CO 2 correlated well with the amount of Ca in chars prepared from several lignites. R CO 2 at 900-1200 8C was related to the amount of Fe 2 O 3 , CaO, MgO, Na 2 O, and K 2 O in the chars.…”