The effect of steam on the catalytic fast pyrolysis of cellulose

The effect of steam for the catalytic fast pyrolysis of cellulose with ZSM-5 was studied in a bubbling fluidized bed reactor. Irreversible and reversible changes due to steaming were identified. Steam caused dealumination, a loss of total acidity, an increase in the zeolite-crystal size, and agglomeration of particles. For runs both with and without steam co-feeding, these irreversible changes caused lower yields for aromatics and char/coke, and higher yields for methane and unidentified products. In addition to irreversible catalyst changes, steam co-feeding was also found to reversibly lower yields of aromatics, char/coke, and identifiable oxygenate species, increase yields of CO and methane, and not change the overall yields of CO2 and olefins.