烘焙预处理对稻壳燃料品质及热解特性的调控机制研究  

Study on the regulation mechanism of torrefaction pretreatment on fuel quality and pyrolysis characteristics of rice husk

作　　者：王卓智 张雷 熊立夫 许连飞 杨建成 沈伯雄 WANG Zhuo-zhi;ZHANG Lei;XIONG Li-fu;XU Lian-fei;YANG Jian-cheng;SHEN Bo-xiong(School of Chemical Engineering and Technology,Hebei University of Technology,Tianjin 300401,China;School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]河北工业大学化工学院,天津300401 [2]哈尔滨工业大学能源科学与工程学院,黑龙江哈尔滨150001

出　　处：《燃料化学学报（中英文）》2023年第3期320-329,共10页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(52006052)资助。

摘　　要：研究493–573 K惰性烘焙和有氧烘焙对稻壳元素构成、组分分布、芳香结构、孔隙结构、热解特性和反应动力学的影响规律。结果表明,烘焙温度对生物质燃料品质影响最为明显,氧化剂的加入可以增加生物质燃料品质对温度变化的敏感性。烘焙温度的升高促使生物质中含氧结构逐渐解离,当烘焙条件为573 K的烟气气氛时,样品的H/C和O/C比明显降低(0.188和0.259)。多种氧化剂能够协同调控生物质的官能团结构、活性芳香结构和孔隙结构,温度的升高促使稻壳中羟基减少、活性芳香结构占比逐渐降低和轻质挥发分的解离,在573 K烟气烘焙后活性结构占比达到最小值1.79、比表面积达到最大值295.78 m^(2)/g。稻壳的热解动力学参数可以通过Coats-Redfern近似函数求解,烘焙可以有效提高生物质发生热解的温度和活化能(14.84→28.82 kJ/mol)。相较于惰性气氛和贫氧气氛,烟气气氛能够更加节能、高效地提高生物质的燃料品质和存储稳定性。Elemental distribution, compositional variation, microstructural feature, surface pore structure, pyrolysis characteristic and reactivity of samples derived from inert/oxidative torrefaction performed in 493 –573 K were investigated. The results illustrated that reaction temperature was the dominant factor affecting fuel quality of torrefied sample, and the addition of oxidizing agents would strengthen the variations in fuel properties after undergoing torrefaction. Increasing reaction temperature would promote the decomposition of oxygen containing functional groups from the particles, when torrefaction performed in raw flue gas atmosphere at 573 K, the H/C and O/C reached the minimum values(0.188 and 0.259). Additional oxidizing agents would synergistically modify the surface functionality distribution, microstructure and surface physical structure of rice husk particles, and the increase of temperature was beneficial to this phenomenon. The critical values were obtained from the sample torrefied in raw flue gas atmosphere at 573 K, the minimum I(Gr + VL + Vr)/ID value was 1.79 and the maximum specific surface area was 295.78 m^(2)/g. By means of the utilization of Coats-Redfern approximation function, the pyrolysis kinetics(14.84 → 28.82 kJ/mol) and characteristic parameters would be determined via the TGA data for each sample. Flue gas seemed to be more energy-saving and efficient for improving fuel quality and storage stability of biomass.

关 键 词：生物质 烘焙 燃料品质 热解 反应性 

分 类 号：TK019[动力工程及工程热物理]