Differential scanning calorimetry studies on coal. 2. Hydrogenation of coals

✍ Scribed by Om P. Mahajan; Akira Tomita; Jordan R. Nelson; Philip L. Walker Jr

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 906 KB
• Volume: 56
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(77)90038-2

✦ Synopsis

Results of exothermic heats involved during hydrogenation of twenty U.S. raw coals of varying rank at 5.6 MPa (gauge) and temperatures up to 570°C are reported. The heat evolved during hydrogenation up to 57O'C decreases with increase in coal rank. A part of the total heat released during hydrogenation of coals appears to be due to the exothermic reaction between Hz and surface carbon-oxygen complexes removed during the reaction. The transition temperature, that is the temperature corresponding to the onset of exotherms, is markedly dependent on coal rank. A sharp increase in the transition temperature occurs for coals having a carbon content, on a dry-ash-free basis, in the 75-80% range. Demineralization of coals lower in rank than HVA bituminous decreases the heat of hydrogenation; in the case of higher-rank coals, exothermic heats increase upon demineralization. The presence of pyrite has a beneficial catalytic effect on coal hydrogenation.