Co-hydrothermal carbonization of oil shale and rice husk: Combustion, pyrolysis characteristics, and synergistic effect

Countries all over the world are looking for fuel to replace fossil energy due to environmental concerns and a scarcity of fossil fuels. Oil shale (OS) and rice husk (RH) are both viable fuels, although they both have issues like high ash content and poor calorific value. OS and RH were used as feedstock for high-quality fuel in this study, which uses a hydrothermal technique to provide a novel way to utilize OS and rice. At different hydrothermal temperatures (150, 200 and 250 degrees C), including combustion and pyrolysis processes, the thermogravimetric analyzer (TGA) was used to analyse thermal transformation characteristics of co-hydrothermal carbonization (co-HTC) of OS and RH, as well as the synergistic effects. Results showed that the co-HTC pretreatment had a significant effect on the thermal transformation behaviour of OS and RH. On the one hand, the co-HTC has higher volatile content than its calculated value. On the other hand, a synergistic effect was found in combustion processes, and this effect was the most obvious when the hydrothermal temperature was around 200 degrees C, and the characteristic peak of functional groups vibration was strong. Therefore, the co-HTC was considered suitable for combustion. The combination of co-HTC modification with subsequent thermochemical processes has positive implications for the energy production and utilization of organic waste.

Automated summary

This study explores the utilization of oil shale and rice husk as high-quality fuel through hydrothermal carbonization, and analyzes their thermal transformation characteristics and synergistic effects at different temperatures. The results show that hydrothermal carbonization has a significant effect on the thermal behavior of oil shale and rice husk, and a synergistic effect is observed in the combustion process. This research has positive implications for energy production and utilization of organic waste.