The photo is sourced from lesindustry.ru
Bio-oil is a mix of water and hydrocarbons, which may be received by recycling the wood processing industry waste (including shavings and chips) into a liquid. However, due to the high concentration of oxygen-containing compounds (up to 60%) bio-oil has very low calorific value, which makes it unfit for refining into motor fuel. This problem may be resolved by removing the oxygen-containing elements with the help of catalysts based on non-reactive metals, ruthenium in particular.
Such catalysts practically are not subject to coking under high temperatures and are tolerant to carbon deposition. However, when processing feedstock with high water content, such as bio-oil, with 30% concentration of H2O, ruthenium-based catalysts may lose their efficacy due to washing-out the active component particles from the surface of the carrier.
The scientists of the I.M. Gubkin Russian State Oil and Gas University and of the M.V. Lomonosov Moscow State University attempted to resolve this problem by using halloysite, a clay material with tubular structure, as the catalyst carrier. The halloysite aluminosilicate nanotubes feature low acidity, so catalysts based on such material have very low reactivity. That is why the researchers decided to treat the halloysite aluminosilicate nanotubes in the sulfuric acid for raising its acidity level and increasing its specific surface and the internal cavity size.
Then the scientists carried out the experiment using the acidised halloysite as the carrier for ruthenium-containing catalysts. The experiment showed that the de-aluminised halloysite allows to remove the guaiacol (the product of wood processing) from the bio-oil with many-fold higher efficiency vs the catalyst carried by an ordinary mineral.
“The results of our studies may be widely used when creating catalysts for large-tonnage processes, in particular, for receiving motor fuels components and valuable petrochemical semi-products from the recycled feedstock. We will continue our work of creating new catalysts for converting alternative types of hydrocarbons-containing feedstock into value-added products”, the Russian Science Foundation is citing Alexander Glotov, the head of the project and the lead researcher of the I.M. Gubkin Russian State Oil and Gas University.