Naslov
Investigations of the gibbsite and boehmite dehydroxylation process by means of dynamic thermogravimetry

Autori
Perić, Jelena ; Krstulović, Ruža ; Ferić, Tereza ; Vučak, Marijan

Izvornik
Travaux de l`ICSOBA (0350-7548) 20-21 (1991), 23; 35-41

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
gibbsite ; boehmite ; dehydroxylation ; thermogravimetry

Sažetak
The process of dehydroxylation of g-Al(OH)_3 (gibbsite) and g-Al(OOH) (boehmite) has been examined by means of nonisothermal thermogravimetrical analysis. Examinations have shown that the overall degydroxylation reaction rate is determined by random formation of new phase centres, and that the mechanism can be best described by the function f(a)=(1-a)^n, where n reaches 1. A change of conversion degree in dependence of time and temperature indicates that the influence of temperature is greater than that of process duration, which is characteristic for reactions taking place in the kinetic stage, and which is confirmed by the values for the activation energy. The average value for the activation energy for the first stage of gibbsite dehydroxylation in the temperature range 504....640 K amounts to 124.4 kJ/mol ; for the boehmite dehydroxylation in the temperature range 653...984 K it amounts to 216.7 kJ/mol.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA