Molybdenum Carbides, Active and In Situ Regenerable Catalysts in Hydroprocessing of Fast Pyrolysis Bio-Oil
We assessed molybdenum carbides as a potential catalyst for fast pyrolysis bio-oil hydroprocessing. Currently, high catalyst cost, short catalyst lifetime, and lack of effective regeneration methods are hampering the development of this otherwise attractive renewable hydrocarbon technology. A series of metal-doped bulk Mo carbides were synthesized, characterized and evaluated in sequential low-temperature stabilization and high-temperature deoxygenation of a pine-derived bio-oil. During a typical 60-h run, Mo carbides were capable of upgrading raw bio-oil to a level suitable for direct insertion into the current hydrocarbon infrastructure with residual oxygen content and total acid number of upgraded oils below 2 wt% and 0.01 mg KOH g-1, respectively. The performance was shown to be sensitive to the type of metal dopant, Ni-doped Mo carbides outperforming Co-, Cu-, or Ca-doped counterparts; a higher Ni loading led to a superior catalytic performance. No bulk oxidation or other significant structural changes were observed. Besides the structural robustness, another attractive property of Mo carbides was in situ regenerability. The effectiveness of regeneration was demonstrated by successfully carrying out four consecutive 60-h runs with a reductive decoking between two adjacent runs. These results strongly suggest that Mo carbides are promising catalytic materials which could lead to a significant cost reduction in hydroprocessing bio-oils. This paper highlights areas for future research which will be needed to further understand carbide structure-function relationships and help design practical bio-oil upgrading catalysts based on Mo carbides.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1324881
- Report Number(s):
- PNNL-SA-116507; BM0102060
- Journal Information:
- Energy and Fuels, Vol. 30, Issue 6; ISSN 0887-0624
- Publisher:
- American Chemical Society (ACS)
- Country of Publication:
- United States
- Language:
- English
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