Energy consumption and product release characteristics evaluation of oil shale non-isothermal pyrolysis based on TG-DSC

Thermogravimetric-Differential Scanning Calorimetry Analysis (TG-DSC) was applied to study non-isothermal pyrolysis characteristics of oil shales, such as the starting point, stability, pyrolysis interval and product release using Fuyu and Huadian oil shale samples. Results show that with the increase of heating rate, oil shale pyrolysis moves to higher temperature zone. This trend is more noticeable at higher oil content. The pyrolysis stability of the oil shale is related to oil content and pyrolysis atmosphere. The higher the oil content, the more stable the pyrolysis of the oil shale. Under nitrogen atmosphere, the pyrolysis interval of oil shale is more concentrated, air prolongs the pyrolysis interval, and the pyrolysis stability index decreases. In addition, the increase of heating rate favours the release characteristic index of the product, which is not practically affected by oil content. The release characteristic indices of pyrolysis products from oil shale under nitrogen atmosphere are higher than those under air atmosphere. The optimum heating rate that produces the highest oil product yield for pyrolysis progress of Huadian oil shale is 20 °C/min, and Fuyu oil shale is 40 °C/min.