| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 41292 | Applied Catalysis A: General | 2011 | 11 Pages |
Fast pyrolysis oil (PO), the liquid product of fast pyrolysis of lignocellulosic biomass, requires upgrading to extent its application range and for instance to allow for co-feeding in an existing oil-refinery. Catalytic hydrotreatment reactions (350 °C, 20 MPa total pressure, and 4 h reaction time) with mono- and bi-metallic metal catalysts based on Rh, Pt, Pd on a zirconia support were performed in a batch set-up. Pd/ZrO2 showed the highest activity, followed by Rh/ZrO2. Upgraded oils with the best product properties were obtained with Rh/ZrO2. For this catalyst, the TGA residue, which is a measure for coking tendency, was 13.4 wt% and the Mw of the upgraded oil (748 g/mol) was lowest. All noble metal catalysts showed higher activities per gram of metal than the benchmark catalyst CoMo/Al2O3. Hydrotreatment reactions at variable batch times were performed to gain insights in reaction pathways and showed the involvement of competitive hydrogenation/hydrocracking and polymerisation pathways. Temperature programmed oxidation (TPO) measurements of spent catalysts showed the presence of carbonaceous deposits on the catalyst (2–6 wt%). These deposits may be removed by oxidation at temperatures lower than 600 °C without changing the morphology of the catalyst.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (196 K)Download as PowerPoint slideHighlights► Noble metal catalysts on ZrO2 were tested for hydrotreatment of pyrolysis oil. ► The catalysts are more active on a metal basis than the benchmark CoMo/Al2O3. ► Rh/ZrO2 gave a product oil with the lowest tendency for coking (TG residue). ► A reaction network is proposed and involves repolymerisation and hydrogenation. ► Carbonaceous deposits on spent catalysts can be removed by an oxidation step.
