利用热重分析仪研究了玉米芯及其酸水解残渣热解焦的气化反应性,重点考察了热解温度、升温速率、气化温度和气化介质(CO2、H2O)对残渣热解焦气化反应性的影响,并借助SEM观测了热解焦的表观形貌。结果表明,残渣热解焦的气化反应性较玉米芯热解焦有所下降;在热解温度550~850℃,残渣热解焦的气化反应性随热解温度提高而降低,在热解升温速率0.1K/s下制取的热解焦,其气化反应性低于15.0K/s下的热解焦;在气化温度850~950℃,提高气化反应温度和使用水蒸气作为气化介质能显著提高残渣热解焦的气化反应性;采用混合反应模型计算了残渣热解焦的气化反应动力学参数。
The gasification reactivities of chars generated from the pyrolysis of corncob and its acid hydrolysis residue (AHR) were investigated by using a thermal gravimetric analyzer (TGA). The effects of pyrolysis temperature, heating rate, gasification temperature and gasification agent (CO2 and H2O) on the gasification reactivities were examined, and the char morphology was characterized by means of scanning electron microscopy (SEM). The results show that the AHR char performs lower gasification reactivity than the corncob char does in both steam and carbon dioxide. The gasification reactivity of AHR char decreases with increasing the pyrolysis temperature from 550 to 850 ℃, but increases when the pyrolysis heating rate increases from 0.1 to 15.0 K/s. The gasification reactivity of AHR increases with increasing temperature, and the steam gasification reactivity of AHR char is higher than the CO2 gasification reactivity at gasification temperatures between 850 and 950 ℃. The gasification kinetic parameters based on a mixed reaction model were calculated.