Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed to achieve fast pyrolysis of biomass and on-line analysis of the pyrolysis vapors. Four biomass materials (poplar wood, fir wood, cotton straw and...Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed to achieve fast pyrolysis of biomass and on-line analysis of the pyrolysis vapors. Four biomass materials (poplar wood, fir wood, cotton straw and rice husk) were pyrolyzed to reveal the difference among their products. Moreover, catalytic cracking of the pyrolysis vapors from cotton straw was performed by using five catalysts, including two microporous zeolites (HZSM-5 and HY) and three mesoporous catalysts (ZrO2&TiO2, SBA-15 and Al/SBA-15). The results showed that the distribution of the pyrolytic products from the four materials differed a little from each other, while catalytic cracking could significantly alter the pyrolytic products. Those important primary pyrolytic products such as levoglucosan, hydroxyacetaldehyde and 1-hydroxy-2-propanone were decreased greatly after catalysis. The two microporous zeolites were ef-fective to generate high yields of hydrocarbons, while the three mesoporous materials favored the formation of furan, furfural and other furan compounds, as well as acetic acid.展开更多
Bio-oil is a new liquid fuel but very acidic. In this study, bio-oil pyrolyzed from rice husk and two bio-oil/diesel emulsions with bio-oil concentrations of 10 wt% and 30 wt% were prepared. Tests were carried out to ...Bio-oil is a new liquid fuel but very acidic. In this study, bio-oil pyrolyzed from rice husk and two bio-oil/diesel emulsions with bio-oil concentrations of 10 wt% and 30 wt% were prepared. Tests were carried out to determine their corrosion properties to four metals of aluminum, brass, mild steel and stainless steel at different temperatures. Weight loss of the metals immersed in the oil samples was recorded. The chemical states of the elements on metal surface were analyzed by X-ray photoelectron spectroscopy (XPS). The results indicated that mild steel was the least resistant to corrosion, followed by aluminum, while brass exhibited slight weight loss. The weight loss rates would be greatly enhanced at elevated temperatures. Stainless steel was not affected under any conditions. After corrosion, increased organic deposits were formed on aluminum and brass, but not on stainless steel. Mild steel was covered with many loosely attached corrosion materials which were easy to be removed by washing and wiping. Significant metal loss was detected on surface of aluminum and mild steel. Zinc was etched away from brass surface, while metallic copper was oxidized to Cu2O. Increased Cr2O3 and NiO were presented on surface of stainless steel to form a compact passive protection film. The two emulsions were less corrosive than the bio-oil. This was due to the protection effect of diesel. Diesel was the continuous phase in the emulsions and thus could limit the contact area between bio-oil and metals.展开更多
基金Supported by the National Basic Research Program of China (Grant No. 2007CB210203)National Key Technologies R&D Program of China (Grant No. 2007BAD34B02)Knowledge Innovation Program of Chinese Academy of Sci-ences (Grant No. KGCX2-YW-330)
文摘Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed to achieve fast pyrolysis of biomass and on-line analysis of the pyrolysis vapors. Four biomass materials (poplar wood, fir wood, cotton straw and rice husk) were pyrolyzed to reveal the difference among their products. Moreover, catalytic cracking of the pyrolysis vapors from cotton straw was performed by using five catalysts, including two microporous zeolites (HZSM-5 and HY) and three mesoporous catalysts (ZrO2&TiO2, SBA-15 and Al/SBA-15). The results showed that the distribution of the pyrolytic products from the four materials differed a little from each other, while catalytic cracking could significantly alter the pyrolytic products. Those important primary pyrolytic products such as levoglucosan, hydroxyacetaldehyde and 1-hydroxy-2-propanone were decreased greatly after catalysis. The two microporous zeolites were ef-fective to generate high yields of hydrocarbons, while the three mesoporous materials favored the formation of furan, furfural and other furan compounds, as well as acetic acid.
基金National Natural Science Foundation of China (Grant No. 50576091)Knowledge Innovation Program of Chinese Academy of Science (Grant No. KGCX2-YW-306-4)National Basic Research Program of China (Grant No. 2007CB210203)
文摘Bio-oil is a new liquid fuel but very acidic. In this study, bio-oil pyrolyzed from rice husk and two bio-oil/diesel emulsions with bio-oil concentrations of 10 wt% and 30 wt% were prepared. Tests were carried out to determine their corrosion properties to four metals of aluminum, brass, mild steel and stainless steel at different temperatures. Weight loss of the metals immersed in the oil samples was recorded. The chemical states of the elements on metal surface were analyzed by X-ray photoelectron spectroscopy (XPS). The results indicated that mild steel was the least resistant to corrosion, followed by aluminum, while brass exhibited slight weight loss. The weight loss rates would be greatly enhanced at elevated temperatures. Stainless steel was not affected under any conditions. After corrosion, increased organic deposits were formed on aluminum and brass, but not on stainless steel. Mild steel was covered with many loosely attached corrosion materials which were easy to be removed by washing and wiping. Significant metal loss was detected on surface of aluminum and mild steel. Zinc was etched away from brass surface, while metallic copper was oxidized to Cu2O. Increased Cr2O3 and NiO were presented on surface of stainless steel to form a compact passive protection film. The two emulsions were less corrosive than the bio-oil. This was due to the protection effect of diesel. Diesel was the continuous phase in the emulsions and thus could limit the contact area between bio-oil and metals.
