毛竹水热炭燃烧特性及动力学研究

INVESTIGATION ON COMBUSTION CHARACTERISTICS AND KINETICS OF BAMBOO HYDROCHAR

该文先对毛竹进行水热处理制备水热炭，然后对毛竹原料及其水热炭进行燃烧实验，采用的升温速率为10、20、40K／min，基于无模式函数多重扫描速率法（FWO法、KAS法、FR法），研究毛竹及水热炭燃烧特性及动力学。结果表明：1）升温速率提高，样品挥发分燃烧和固定碳燃烧阶段均向高温区转移，着火性能下降，燃尽温度提高；水热炭较原料挥发分含量降低，固定碳含量升高；水热温度越高，热值越大，能量产率越低，水热温度为260℃时，能量产率最低，为35．97％，230℃水热炭的原子数比[O]／[C]、[H]／[C]已接近泥煤，燃料性能较优。2）采用FWO法、KAS法活化能结果相近，模型较优，以FWO法为例，原料、200、230、260℃水热炭活化能区间分别为89-126、89-216、86-118、80-90kJ／mol。

Hydrothermal carbonization is employed to pretreated moso bamboo for hydrochar preparation in this study. Thermal gravimetric curves are measured for the raw bamboo and hydrochars at different heating rates （10, 20, 40 K/min）. The combustion kinetics parameters are calculated by the model-free methods, of which Flynn- Wall-Ozawa and Kissinger-Akahira-Sunose are the most appropriate for the calculation of activated energy and result in the similar values. The activation energy increases first and then decreases with the increase of the mass conversion. Taking the FWO method as an example, the activation energy range of raw bamboo, hydrochar from temperature of 200, 230 and 260 ℃ （HC200, HC230, HC260） are 89-126,89-216,86-118,80-90 kJ/mol, respectively. Both the first and second peaks in DTG curves shift to the higher temperature and meanwhile the ignition performances of hydrochars decrease and the burnout temperatures increase when the heating rate increases. The higher the hydrothermal temperature, the greater the calorific value and the lower the energy yield are. The lowest energy yield of 35.97% is HC260 .The atomic O/C and H/C ratios of HC230 move towards to those of peat whose atomic O/C and H/C ratios are 0.64 and 1.36, respectively. The combustion property of HC260 is lower than that of the raw material, while the combustion performance of HC200 and HC230 are better than that of the raw material. Taking the calorific value, the energy yield and the comprehensive combustion characteristic index into considering, HC230 is suitable for use as fuel.