Fast Pyrolysis Characteristics of Miscanthus

摘要

Biomass is widely considered to be an important renewable energy resource for the future because of low ash and sulfur content. Biomass can be converted to a variety of fuels and chemicals by fast pyrolysis, which is a promising technique for the conversion of the biomass to bio-oil. Miscanthus, a perennial grass, is a most promising renewable energy because of rapid growth and high yield. Thermogravimetric analyzer (TGA) and Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) were employed to study the pyrolysis and fast pyrolysis characteristics of miscanthus as well as on-line analysis of the pyrolysis vapors. TGA result shows that there were four stages of weight loss of miscanthus during pyrolysis, where cellulose and hemicellulose accounted for 73%. After demineralization, the temperature corresponding to the maximum weight loss rate shifted from 372 °C to 380°C, indicating de-mineralization delayed the reaction. Ion coupled plasma (ICP) result displays that potassium, sodium and magnesium content decreased after washed with water. This indicates that they promoted the pyrolysis process. Py-GC/MS result demonstrates that the main composition of the pyrolysis vapor was phenol, furfural, 2-methylbenzaldehyde, 2-methoxy-4-vinylphenol, 2-methoxyphenol, 2-methoxy-4-methylphenol, eugenol and vanillin, etc. Temperature has an obvious effect on the yield of pyrolysis vapor and the optimist temperature was 600°C. Compared with HY, HZSM-5 was an effect catalyst for improving the heat value of the pyrolysis vapor. The demineralization promoted the yield of pyrolysis vapor. However, the yield of hydrocarbons compounds were relatively lower than that of HZSM-5.