烘焙对玉米秸秆碱金属释放动力学的影响

Effect of torrefying on corn straw alkali metal release kinetics

为研究烘焙对玉米秸秆碱金属释放动力学的影响,利用多点LIBS测量烘焙玉米秸秆燃烧过程中碱金属释放,并进行碱金属释放动力学模拟。结果表明,低温烘焙玉米秸秆燃烧时,在挥发分阶段释放至气相中的钾浓度高,在焦燃烧阶段钾释放浓度较低;高温烘焙玉米秸秆燃烧时,在挥发分阶段释放的钾浓度低,在焦燃烧阶段释放的钾浓度高。在挥发分阶段,碱金属释放动力学的活化能随烘焙温度升高,先升高后下降;在焦燃烧阶段,活化能随烘焙温度升高整体降低。

In order to study the effect of torrefying on the release kinetics of alkali metals from corn straw, multi-point LIBS was used to measure the release of alkali metals from corn straw during burning process and simulate the release kinetics of alkali metals. The results show that the concentration of potassium released into gas phase is high in the volatilization stage of low temperaturetorrefied corn straw, and low in char combustion stage. When corn straw is torrefied at high temperature, the concentrationof potassium released in volatilization stage is low, and the concentration of potassium released in char combustion stage is high. In volatilization stage, the activation energy of alkali metal release kinetics increases first and then decreases with the increase of torrefying temperature. In char combustion stage, with the increase of torrefying temperature, the activation energy decreases as torrefying temperature increases.