| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1742127 | Algal Research | 2013 | 10 Pages |
Crude bio-oil produced from hydrothermal liquefaction of Nannochloropsis sp was reacted over HZSM-5 catalyst with high pressure H2. The effects of reaction temperature (400–500 °C), reaction time (0.5–4 h), and catalyst loading (5–50 wt.%) on the composition and yields of the oil and gas products were determined. Treatment greatly reduced the heteroatom (N, O, and S) content in the oil. S was reduced to below detection limits (< 0.1 wt.%) at all reaction conditions investigated. The lowest N/C ratio achieved is about 25% of the original N/C ratio in the crude bio-oil. The O/C ratio of the oil treated at 450 and 500 °C was an order of magnitude lower than that in the crude bio-oil. The carbon content of the oil increased at all reaction conditions investigated, but the H/C ratios of the oils treated at 450 and 500 °C fell below that of the crude bio-oil due to their high aromatic content and the migration of H atoms into the gaseous products. This study demonstrates the opportunities to engineer the composition of the products that emerge from this catalytic treatment of the crude bio-oil. Catalytic processing at 400 °C produced a paraffinic oil that was 95 wt.% C and H and retained 87% of the energy content of the crude bio-oil. This product would be useful as a feedstock for liquid transportation fuels. Catalytic processing at 500 °C, on the other hand, produced a freely flowing liquid mixture composed of aromatic hydrocarbons in 44 wt.% yield along with a hydrocarbon gas stream in 19 wt.% yield. These products, which could be useful as feedstocks for industrial chemicals, contained 70% of the carbon originally present in the crude bio-oil.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Catalytic upgrading of algal bio-oil on zeolite HZSM-5 can make feedstocks for fuels or chemicals. ► Process variables investigated were temperature, time, and catalyst loading. ► N and O were greatly reduced with HZSM-5. ► Reaction temperature had the largest effect on composition of the treated oil. ► Reaction temperature and time had the greatest influence on the gas yields.
