Microwave drying of Liushuhe oil shale and its effect on pyrolysis characteristics

Drying pretreatment plays an important role in the use of oil shale. Microwave drying is a rapid, efficient and energy-saving method. A microwave drying experiment system was set up by remolding the household microwave oven, by which the microwave drying characters and the influence on the pyrolysis characteristic were investigated. The result shows that the time needed for microwave drying is about 20% of the one for traditional drying, and the rate of microwave drying is much higher than that of traditional drying. The Page model is suitable for describing the process of Liushuhe oil shale microwave drying. There is no difference in the changing curves of the pyrolysis activation energy with conversion for the microwave drying oil shale, hot-air drying oil shale and the original one. The trend of the curve first rises, then falls, and at x≈0.7 appears the maximum value. The activation energy changes between 80 kJ/mol and 200kJ/mol. At the same time, the activation energy of organic matter decomposition for the microwave drying oil shale pyrolysis is increased.