Qiangu Yan

Catalytic conversion wood syngas to synthetic aviation turbine fuels over a multifunctional catalyst.

A continuous process involving gasification, syngas cleaning, and Fischer-Tropsch (FT) synthesis was developed to efficiently produce synthetic aviation turbine fuels (SATFs). Oak-tree wood chips were first gasified to syngas over a commercial pilot plant downdraft gasifier. The raw wood syngas contains about 47% N(2), 21% CO, 18% H(2), 12% CO(2,) 2% CH(4) and trace amounts of impurities. A purification reaction system was designed to remove the impurities in the syngas such as moisture, oxygen, sulfur, ammonia, and tar. The purified syngas meets the requirements for catalytic conversion to liquid fuels. A multi-functional catalyst was developed and tested for the catalytic conversion of wood syngas to SATFs. It was demonstrated that liquid fuels similar to commercial aviation turbine fuels (Jet A) was successfully synthesized from bio-syngas.

Synthesis of tungsten carbide nanoparticles in biochar matrix as a catalyst for dry reforming of methane to syngas

Tungsten carbide (WC) nanoparticles were synthesized by carbothermal reduction (CR) of tungsten-promoted biochar. The tungsten carbide nanoparticles were characterized for physicochemical properties by multiple morphological and structural methods (e.g. SEM, TEM, and XRD). Characterization results revealed that the transformation of tungsten oxide (WO3) to tungsten carbide nanoparticles involved the following sequence steps: WO3 → WO2 → W → W2C → WC. The lower the reaction temperature, the lower the CH4 and CO2 conversions, as well as the lower CO yield, since dry reforming is an endothermic reaction. CH4 conversion was observed to decrease with an increase in CH4/CO2 ratio, whereas CO2 conversion increased with an increase in CH4/CO2 ratio. The higher the GHSV, the lower the CH4 and CO2 conversions as well as the lower the CO yield. Stability testing of the tungsten carbide nanoparticles in the biochar matrix showed no catalyst deactivation during the 500 hours test duration.

Catalytic removal of oxygen from biomass-derived syngas

Selective oxygen (O2) removal from wood-derived syngas was investigated over three types of ceria-modified alumina supported metal catalysts (i.e., Pt, Pd, and Cu). Complete O2 removal was observed with the Pt and Pd catalysts at a lower temperature than with the Cu catalyst. Gas hourly space velocity (GHSV) was another critical parameter affecting O2 removal, substantially reducing O2 conversion by all three catalysts at 4000 h(-1) or above. The Cu catalyst appeared to be most sensitive to GHSV. Among three catalysts, the Pd catalyst had the best performance on O2 removal. In addition to reaction conditions, CO2 and water vapor in the syngas also influenced O2 removal, both of which had adverse effects on O2 conversion. Stability tests indicated that both Pt and Pd catalysts were quite stable over a 300 h testing period while the Cu catalyst was deactivated after 50h and regenerated by elevating reaction temperature.

Catalytic Conversion of Biomass-derived Syngas to Gasoline Range Hydrocarbons

Catalytic conversion of biomass-derived syngas (bio-syngas) into gasoline range hydrocarbons has been regarded as one of potential routes to utilize biomass. In this route, biomass is firstly converted into bio-syngas through biomass gasification. Then bio-syngas is catalytically converted into transportation fuels or chemicals. In this paper, catalytic synthesis of gasoline range hydrocarbons by using model syngas similar to bio-syngas has been carried out over Mo/HZSM-5 catalysts. Different system temperatures were adopted in the experiments to figure out the effects of reaction parameters. The products were analyzed by GC and GC-MS. The catalysts were characterized by SEM-EDS and TEM. The results showed that Mo/HZSM-5 was active in model bio-syngas.