Contribution of transmission electron microscopy to the study of the coal carbonization processes

Abstract

With the help of 002 dark field images, Transmission Electron Microscopy is the best adapted tool to follow the microtextural evolution of a coal during pyrolysis. Randomly distributed in the coal, the polyaromatic structural units cluster in parallel in the coke to form Molecular Orientation (MO) domains. The size histogram of these MO domains is the fingerprint of the coke microtexture and permits us to precisely determine the solvolyzer role of the molecular component and the cross-linking effect of oxygen atoms during the plastic stage.