Study on isothermal drying process and kinetics of lignite

YANG Yali; WANG Zhichao; YANG Zhongcan; YAO Wei; FANG Lijun

doi:10.13226/j.issn.1006-6772.2017.01.004

Abstract：For the research of lignite drying process,using the water quality analyzer and differential thermogravimetric analysis method,isothermal drying experiments were carried out on lignite with different grain sizes at different drying temperatures.The curves of moisture content and drying time and the curve of drying rate and water content were obtained.The moisture content conversion of lignite with different particle sizes was made by the size distribution coefficient,and the experimental data were fitted with different drying models.The drying equation and the kinetic parameters of the three drying stages were obtained at the medium temperature of 140 ℃.The results showed that the drying rate characteristics constant k,which was obtained by introducing the particle size distribution coefficient,was similar to that of the drying rate characteristic constant k with different particle sizes.According to the drying rate and moisture content of lignite,the drying process was divided into three stages.The drying equation model was obtained by using linear drying model,Wang empirical model and Page model respectively.According to the empirical formula of Arrhenius,the relationship between Ink and 1/T was established,and the activation energy of Ea was 17.088 kJ/mol and the pre exponential factor A was 12.47 min-1.