Effect of hydrothermal on thermoelectric properties of rice husk char

In order to investigate the effect of hydrothermal pretreatment on the thermoelectric properties of rice husk char, the rice husk was modified by different hydrothermal temperatures, and its fuel characteristics, functional groups and pyrolysis characteristics were analyzed. The properties and microstructure of rice husk char were characterized by industrial analysis, elemental analysis, FTIR analysis and N2 adsorption. The specific surface area and total pore volume of rice husk char were increased after modification. The result demonstrated that after hydrothermal pretreatment, hemicellulose, alkali metal and alkaline earth metals were significantly reduced in the rice husk, the volatile content was increased, and more oxygen-containing functional groups were obtained. The rice husk char with a specific surface area of 335.1m2/g and the total pore volume of 0.173cm3/g could be acquired when the hydrothermal temperature was 150℃. By using the rice husk chars as electrode and NaCl solution as electrolyte, the output voltage of the modified chars was improved dramatically. At the temperature difference of 50K, the output voltage was 67.084mV and the specific energy was 106.7mJ/g, exhibiting the excellent thermoelectric conversion performance of modified rice husk char as a low-cost porous carbon. © 2020, Chemical Industry Press. All right reserved.