Pyrolysis of Rice Straw Using Radio-Frequency Plasma

In this study, a radio-frequency (RF) plasma thermolysis reactor was used for pyrolyzing the biomass waste of rice straw. The effects of some major system parameters on the performance of the pyrolysis of rice straw via RF plasma were studied and elucidated. Examining the characteristics of the RF plasma thermolysis reactor with the working gas nitrogen indicates that as the loading power (PWL) increases from 137 to 591 W, the plateau temperature (TP) of plasma increases from 607 to 954 K. The corresponding times of tH to reach TP (the corresponding tH is denoted as tHP) at 607 and 954 K are about 5 and 2 min, respectively. Thus, a higher PWL gives a higher TP with a shorter tHP. The times of tH with PWL of 308, 363, and 591 W to reach a setting temperature (TS) (the corresponding tH is denoted as tHS) at 783 K are about 5, 1.5, and 0.67 min, respectively. Again, a higher PWL needs a shorter tHS to reach the same TS. No tar product is formed via pyrolysis using RF plasma, while about 1.5 wt % of tar is produced using traditional electric–thermal heating. Thus, the gaseous products obtained via the former method would contain more hydrocarbons (HCs) of low molecular weight than those via the latter method. This indicates that the ability of cracking HCs via the former is better than the latter, supporting the idea that the former can provide syngas with better quality.