不同液化条件下生物质残渣的燃烧特性研究

Combustion characteristics of residues from liquefaction of sawdust under different operation conditions

对锯屑在不同液化条件(溶剂、气氛、温度、催化剂)下所得液化残渣在热天平上进行了燃烧特性研究,通过比较液化残渣燃烧的三个特征温度,着火点ti、燃烧峰温tp和燃烬温度tb,分析了液化条件对残渣燃烧特性的影响。同时通过热重曲线所得数据探讨了液化残渣燃烧过程的动力学,并计算了活化能和频率因子。结果表明,不同溶剂下所得液化残渣的燃烧特性显著不同,以四氢萘为溶剂所得液化残渣具有较好的燃烧特性;不同气氛下所得残渣的燃烧特性没有明显的不同;350℃下所得液化残渣的燃烧特性要好于300℃下所得液化残渣的燃烧特性;由于催化剂的影响,加入1%M o后降低了所得液化残渣的燃烧特性;液化残渣的燃烧反应符合两段一级反应动力学。

Experiments to examine the combustion different operation conditions （ solvent, atmosphere, characteristics of residues from sawdust hquefaction under temperature and catalyst） were performed in a thermogravimetric analyzer （TGA92）. The effect of liquefaction conditions on the combustion property of the residues was examined through comparing their characteristic parameters such as ignition temperature （ti ）, peak temperature of maximum weight loss rate （tp） and burnout temperature （tb）. Based on the TG/DTG profiles, a residue combustion kinetics model was proposed and the kinetics parameters such as activation energy （E） and frequency factor （A） were obtained by Coats -Redfern method. The results show that liquefaction solvent could affect the combustion characteristics of residue obviously. The residue from biomass liquefaction with tetralin as solvent has the best combustion reactivity than both with toluene as solvent and without solvent, while the higher heating value of residue has the opposite trend. The residues from different liquefaction atmospheres almost have the same combustion characteristics. Other hquefaction conditions such as temperature and catalyst also could affect the combustion characteristics of residues. The kinetics of residue combustion could be described by a two - stage first order kinetic model.