烟气中CO2/O2气氛对稻壳流化床热解制炭的影响规律

烟气常用作流化床热解的气体热载体，而烟气中低浓度的CO₂、O₂等成分对流化床热解制炭的影响少有报道。在自行搭建的小型流化床实验台上开展了不同气氛（不同N₂/O₂/CO₂体积比，简单模拟烟气氛围）下稻壳热解制备生物炭试验研究，获得了稻壳热解三相产物产率分布规律、稻壳生物炭工业分析特性基本特征，通过FTIR、BET手段分析了生物炭表面官能团及多孔结构变化情况，同时探究了不同O₂浓度下稻壳热解制炭能量转移特性。结果表明:提高O₂和CO₂浓度均有利于热解产物由固相向气相转移，会降低炭产率、降低生物炭中有机组分含量，但有利于生物炭表面形成多孔结构和提高表面官能团芳香化程度；稻壳在低O₂浓度下热解能达到80%上的能耗比以及70%以上的能量回收率。

PYROLYSIS AND CARBON PRODUCTION OF RICE HUSK IN FLUIDIZED BED UNDER FLUE GAS WITH DIFFERENT CO_2/O_2 ATMOSPHERES

Pyrolysis of rice husk in different atmospheres (by alternating the volume ratios of N₂, O₂, and CO₂) were carried out on a small-scale fluidized bed to obtain the distribution pattern of the three-phase product of rice husk pyrolysis and the characteristics of the rice husk biochar. The functional groups and porous structure on the surface of biochar were analyzed by means of FTIR and BET, and the energy transfer during the pyrolysis of rice husk under different O₂ concentrations were investigated. The results showed that increasing the concentration of O₂ and CO₂ were conducive to the transfer of pyrolysis products from the solid phase to the gas phase, which would reduce the biochar yield and the content of organic components in biochar, but it was conducive to the formation of porous structures and aromatic functional groups on the surface of biochar. Rice husk could achieve an energy consumption ratio of more than 80% and an energy recovery rate of more than 70%, under lower O₂ concentration.