Properties of brown coals as raw materials for processing

The composition and chemical and physicochemical properties of different brown coals as raw materials for deep thermochemical processing were considered. The effect of the modifying treatments of coals on their properties was studied. Correlation relationships between the calcium content of coals and the structure characteristics and reactivity of the organic matter were established. It was found that coals with an increased calcium content were characterized by a dense rigid supramolecular structure and low activity on hydrogenation in hydrogen-donor solvents. In contrast to this, calcium compounds exerted a considerable catalytic effect on the reaction rate and the composition of the resulting gaseous products in high-temperature oxidative processing (oxidative destruction in air and steam gasification).