Catalytic fast pyrolysis of rice husk over hierarchical micro-mesoporous composite molecular sieve: Analytical Py-GC/MS study

摘要

In order to promote efficient production of hydrocarbons, catalytic fast pyrolysis (CFP) of rice husk (RH) over catalysts is performed using Py-GC/MS. The catalyst is hierarchical micro-mesoporous composite molecular sieve prepared under different conditions including different concentrations (1.5 mol/L, 2.0 mol/L, 2.5 mol/L, 3.0 mol/L) of NaOH solution, different mass fraction of cetyltrimethylammonium bromide (CTAB) solution, different temperatures (90 degrees C, 100 degrees C, 110 degrees C, 120 degrees C) and durations (12 h, 24 h, 36 h). The fabricated hierarchical catalyst with HZSM-5 structure as the core and MCM-41 structure as the shell is characterized using N-2 adsorption-desorption measurement and transmission electron microscopy. As the experimental results suggest, the highest value of total peak area of all the chemical compounds is obtained at 600 degrees C. The fabricated hierarchical catalyst exhibit pronounced deoxygenation and excellent selectivity of aromatics. The maximum relative abundance of hydrocarbons (54%), maximum relative abundance of aromatics (39%) and value of selectivity of monocyclic aromatics (65%) are obtained by comparison with different hierarchical catalysts. Besides, the catalyzed transformation of large oxygenated compounds into hydrocarbons can be improved as a function of significant activation of hydrocarbon pool.