Increasing Thermal Stability of Bio-Oil by Neutralization and Catalytic Cracking of Stabilized Products

This work investigates a method for stabilizing bio-oil by increasing its pH through treatment with sodium hydroxide and ammonia. It was shown, that alkaline treatment significantly improves the thermal stability of bio-oil and provide the possibility of its involvement in the process of catalytic cracking of vacuum gas oil was demonstrated. The stabilized samples were subjected to catalytic cracking in order to study the effect of the processing stage on the yield of the main products. An increase in the pH level of bio-oil contributes the intensification of the cracking process. Sodium hydroxide treatment leads to an increase in the conversion of vacuum gas oil from 78.6 to 82.2 % wt. and the yield of the gasoline fraction (IBP-200ºC) increased from 44.7 to 47.3 % wt. Ammonia treatment leads to an increase the yield of the gasoline fraction from 50 to 54.2 % wt. However, the cracking of bio-oil treated with sodium hydroxide led to irreversible catalyst deactivation due to the presence of sodium, whereas no such deactivation was observed for bio-oil treated with ammonia.