Supported molybdenum oxides as effective catalysts for the catalytic fast pyrolysis of lignocellulosic biomass [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 543.2 Classical methods
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Energy Efficiency and Renewable Energy ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2016
• Mô tả vật lý: Size: p. 5548-5557 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 263437
• Chủ đề: 1. 09 biomass fuels; 2. 37 inorganic, organic, physical, and analytical chemistry; 3. Biomass; 4. Catalytic fast pyrolysis; 5. Hydrodeoxygenation

Tóm tắt

 The catalytic fast pyrolysis (CFP) of pine was investigated over 10 wt% MoO<
 sub>
 3<
 /sub>
 /TiO<
 sub>
 2<
 /sub>
  and MoO<
 sub>
 3<
 /sub>
 /ZrO<
 sub>
 2<
 /sub>
  at 500 �C and H<
 sub>
 2<
 /sub>
  pressures ? 0.75 bar. The product distributions were monitored in real time using a molecular beam mass spectrometer (MBMS). Both supported MoO<
 sub>
 3<
 /sub>
  catalysts show different levels of deoxygenation based on the cumulative biomass to MoO<
 sub>
 3<
 /sub>
  mass ratio exposed to the catalytic bed. For biomass to MoO<
 sub>
 3<
 /sub>
  mass ratios <
 1.5, predominantly olefinic and aromatic hydrocarbons are produced with no detectable oxygen-containing species. For ratios ? 1.5, partially deoxygenated species comprised of furans and phenols are observed, with a concomitant decrease of olefinic and aromatic hydrocarbons. For ratios ? 5, primary pyrolysis vapours break through the bed, indicating the onset of catalyst deactivation. Product quantification with a tandem micropyrolyzer-GCMS setup shows that fresh supported MoO<
 sub>
 3<
 /sub>
  catalysts convert ca. 27 mol% of the original carbon into hydrocarbons comprised predominantly of aromatics (7 C%), olefins (18 C%) and paraffins (2 C%), comparable to the total hydrocarbon yield obtained with HZSM-5 operated under similar reaction conditions. In conclusion, post-reaction XPS analysis on supported MoO<
 sub>
 3<
 /sub>
 /ZrO<
 sub>
 2<
 /sub>
  and MoO<
 sub>
 3<
 /sub>
 /TiO<
 sub>
 2<
 /sub>
  catalysts reveal that ca. 50% of Mo surface species exist in their partially reduced forms (i.e., Mo<
 sup>
 5+<
 /sup>
  and Mo<
 sup>
 3+<
 /sup>
 ), and that catalyst deactivation is likely associated to coking.