科研之友
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摘要
The hydrodeoxygenation (HDO) of bio-oil derived from white oak wood using non-sulfided catalysts was studied in a two zone continuous flow trickle bed reactor system. The major organic components of the pyrolysis oil were pyrolytic lignin (large phenolic polymers), xylose, levoglucosan, organic acids (primarily acetic acid), and hydroxyacetaldehyde. The first zone was a low temperature zone (130 degrees C) that contained a Ru/C catalyst. In this zone, carbonyl groups were hydrogenated, producing propylene glycol (from hydroxyacetone), ethylene glycol (from hydroxyacetaldehyde), and sorbitol (from levoglucosan). A more severe hydrotreatment was performed in a second zone containing a bifunctional Pt/ZrP catalyst at a temperature between 300 and 400 degrees C. In the two-stage HDO, an organic phase was produced that consisted of a distribution of hydrocarbons that were primarily cyclic alkanes (naphthenes) ranging from C-7 to C-24. The organic phase carbon yield decreased with increasing reaction temperature in the second zone. Catalyst deactivation and reactor plugging by coking occurred under all reaction conditions after 55-72 h time on stream (TOS). After approximate to 55 h TOS, more than 25% of the carbon in the original bio-oil was accumulated as coke, with increasing amounts for higher temperatures in the second zone. Hydrotreatment gave rise to > C-5 hydrocarbon (gasoline and distillate-range fuel) overall yields between approximate to 30 and 47 carbon% for all experiments compared to the 79.5% theoretical yield calculated for the bio-oil feedstock. Coke formation and undesired cracking to C-1-C-4 hydrocarbon gases were the main causes of lower fuel carbon yields.
- 出版日期2017-1
