Integrated Activation Techniques for Enhanced Thermal Dissolution of Barzas Coal into Liquid Hydrocarbons

The study investigates the thermal dissolution of Barzas coal using mechanochemical activation, ozone treatment, and ultrasonic processing to enhance the yield and quality of liquid products. The experimental work comprised preparing coal samples by high-energy ball milling, followed by ozone oxidation and ultrasonic pretreatment, and thermal dissolution in tetralin at 375-425 °c. The results showed that the integrated activation approach significantly increased organic matter conversion, reaching up to 88.3% at 400 °C with ultrasonic treatment, compared with 64.9% without activation. The yield of liquid fractions was 57.9% of the dry coal mass, and the light fractions exhibited a high calorific value of up to 41.2 MJ/kg, with aromatic hydrocarbon content exceeding 65%. Lower heating rates and controlled temperature conditions were essential to maximise conversion and minimise heavy residue formation. The findings highlight the effectiveness of combining mechanical, oxidative, and ultrasonic activation to improve coal dissolution and produce liquid hydrocarbons suitable for fuel components and chemical feedstock applications.