CATALYTIC UPGRADING OF FAST PYROLYSIS OIL OVER HZSM-5

The upgrading of bio-oil, obtained by fast pyrolysis of maple wood. was studied over HZSM-5 in a fixed bed microreactor operated at atmospheric pressure and in the temperature range 330-425-degrees-C. The objective of upgrading was to maximize the amount of organic distillate product with a high yield of aromatic hydrocarbons. A maximum organic distillate of 38 wt. % of bio-oil, which represented 28.6 wt. % of wood, was obtained at 370-degrees-C. The yield of aromatic hydrocarbons was 19.9 wt. % of wood. Above 400-degrees-C, nearly 50 wt. % of the bio-oil was converted to coke and char. The conversion of non-volatile components of the bio-oil (pitch) to volatiles was at a maximum of 68 wt. % at 370-degrees-C. However, when the bio-oil was co-processed with tetralin, the maximum conversion of non-volatiles increased to 86 wt. % at 410-degrees-C and the amounts of coke and char decreased. The yield of aromatic hydrocarbons also decreased to a maximum of 10.3 wt. % of wood. The role of tetralin was mainly as a diluent and not as a hydrogen donor solvent.