Fast pyrolysis characteristics of miscanthus over M/ZSM-5 (M = La and Ca)

Catalytic fast pyrolysis analysis of miscanthus over HZSM-5, La/ZSM-5, and Ca/ZSM-5 was performed using pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). The characteristics of the catalysts used in this study were analyzed using XRD, SEM, Pyridine IR, ICP, and N 2 adsorption. The catalytic performance of the three catalysts was evaluated in terms of deoxygenation. Py–GC/MS results show that with increasing temperature, pyrolysis vapor yield first increased and then decreased. This may be due to secondary cracking at higher temperatures, which produced more gas products. Moreover, hydrocarbon content increased with rising temperature. The optimum temperature was found to be 600 °C, which resulted in the greatest liquid yield. All three catalysts increased pyrolysis vapor yield by about 30 %. Moreover, the hydrocarbon content of miscanthus increased from 6 to 39 %, 46, and 44 %, respectively, when HZSM-5, La/ZSM-5, and Ca/ZSM-5 were applied. In conclusion, the three catalysts were effective for deoxygenation of pyrolysis vapor yield. Considering both economic and catalytic upgrading effect, Ca/ZSM-5 may be the best catalyst.