Low-temperature Pyrolysis Characteristics of Inner Mongolia Lignite

The utilization of high moisture, high volatile low rank coals such as lignite is gaining importance day by day to meet the growing demands of coal for the energy sectors. For the combustion of pulverized material it appears essential to dry lignite. Further, lowest possible ash and moisture as well as high heat content are desired for combustion. The present work gives the details of the preparation of a product of higher calorific value by thermal treatment of Inner Mongolia lignite. The low-temperature pyrolysis characteristics were carried out on the regularities of pyrolysis temperature and holding time on the product yield of dry distillation of lignite by using aluminium retort method. The result shows that the suitable pyrolysis condition of lignite is 450 similar to 510 degrees C, holding time for 30 min. The ratio of aliphatic and aromatic groups of 400 degrees C semi-coke obviously decrease 53.1% and 11.8% compared with raw coal. The degree of aromatization of semi-coke is gradually increased and aromatic nucleus condensation degree increases. The retort process of lignite is a dehydrogenation, deoxidization and carbon-rich process.