Study of adsorbents thermal stability
UDC: 661.183:66.074.31
DOI: 10.33285/0207-2351-2023-2(650)-52-57
Authors:
GAFAROVA ELIZA B.1,
MELNIKOV VYACHESLAV B.
1,
MAKAROVA NATALYA P.1
1 National University of Oil and Gas "Gubkin University", Moscow, Russia
Keywords: silica gel, zeolites, thermal activity, adsorption drying
Annotation:
When applying the method of differential scanning calorimetry and thermogravimetry, the dependences of changes in thermal gravimetry (TG) and derivative thermal gravimetry (DTG) were revealed, characteristic of both all the studied zeolite adsorbents and their distinctive features. It was found that the crystal structure of zeolite samples NaX (without binder), NaX (with binder), NaA (with binder), NaA (without binder), CaA is stable under heat treatment conditions up to 800 ºC, and at temperatures above 800 ºC, amorphization of their crystal lattice is observed. The most significant differences in the variation of the TG and DTG curves are observed for the zeolites NaX and NaA. The experimental data obtained made it possible to distinguish three areas of thermal effects and processes occurring during heating of silica gel adsorbents: in the range of about 100 ºC, this effect is caused by the water molecules release loosely bound to the silica gel structure; at 150…380 ºC it is associated with dehydroxylation due to the destruction of intermolecular hydrogen bonds of structural OH-groups in silica gel, at 380…800 ºC, dehydroxylation occurs due to the destruction of residual structural OH-groups and sintering of the silica gel structure along the micro-pores; the thermal effect at 890 ºC is caused by the pores sintering in the silica gel structure.
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