Effect of alkali metal on pyrolysis characteristics and pyrolysis gas products of Triarrhena lutarioriparia

This paper presents a comprehensive study that effect of acid washing conditions and alkali metal impregnation solution on the pyrolysis characteristics and gas products of Triarrhena lutarioriparia(TL) studied by the thermogravimetric-Fourier transform infrared spectrometry (TG-FTIR). The results showed that the HNO3washing significantly reduced the contents of K+and Na+in TL. The highest removal rates for K+and Na+were 98.46% and 98.32%, respectively. When the HNO3washing condition was 5%, 25 °C, and 2 h, the benefits of alkali metal removal and pyrolysis of Triarrhena lutarioripariawere the best. Immersion of TL with KCl and NaCl solutions decreased the pyrolysis temperature of TL. The order of char yield was KCl impregnation sample > NaCl impregnation sample > original sample > HNO3washing sample. The catalytic effect of alkali metals improved with increasing the concentration of K+and Na+in the impregnation solution. K+and Na+impregnation increased the peak absorbance and precipitation of CO2and CO and inhibited the generation of CH4, C = O and C–O–C.