Hydrogen production from biomass-derived oil over monolithic Pt- and Rh-based catalysts using steam reforming and sequential cracking processes
✍ Scribed by Marcelo Eduardo Domine; Eduard Emil Iojoiu; Thomas Davidian; Nolven Guilhaume; Claude Mirodatos
- Book ID
- 104009910
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 770 KB
- Volume
- 133-135
- Category
- Article
- ISSN
- 0920-5861
No coin nor oath required. For personal study only.
✦ Synopsis
The conversion of biomass-derived crude oil towards H 2 production was investigated using continuous catalytic steam reforming and sequential cracking/reforming processes. The performances of Pt/Ce 0.5 Zr 0.5 O 2 and Rh/Ce 0.5 Zr 0.5 O 2 catalysts deposited on cordierite monoliths were comparatively studied. The Pt-based catalyst showed better catalytic activity than Rh for steam reforming in the whole range of steam-to-carbon molar ratios (S/C) studied, the amount of added water determining the H 2 yield for both noble metals. The best H 2 yield (70%, corresponding to $49 mmol of H 2 /g of bio-oil) was obtained with the Pt catalyst at S/C ratio of 10 at 780 8C, with CH 4 concentrations below 1%. In the case of sequential cracking, the process alternated cracking steps, during which the bio-oil is converted into H 2 , CO, CO 2 , CH 4 and carbon stored on the catalyst, with regeneration steps where the deposited coke was burnt under O 2 . Comparison with thermal bio-oil cracking showed that the catalyst plays a major role in enhancing the H 2 productivity up to 18 mmol of H 2 /g of bio-oil ($50% of H 2 in gaseous products stream) and lowering the CH 4 formation. The steam reforming offers high yields towards H 2 but is highly endothermic, whereas the sequential cracking, despite lower H 2 yields, offers a better control of coke formation and catalyst stability, and due to lower energy input can theoretically run auto-thermally.