| Biomass fast pyrolysis liquefaction to obtain biological oil is a mixture of water and hundreds of organic compounds, can be used as liquid fuel or chemical raw materials used in different fields. However, the traditional biological oil as the use of liquid fuels, low grade, the manifestation of low calorific value, acid and corrosion resistance, thermal stability and chemical stability etc. In addition, existing in the traditional biological oil of all kinds of high value-added chemicals, including all kinds of hard materials, synthesis by conventional methods, but most of the material content is very low, which makes the extraction separation not only technical difficulties, and there is no good economic benefits. In order to increase the application value of the bio-oil, on the one hand, the biological oil can be refined, on the other hand can target specific biomass raw materials, selective control pyrolysis reaction process, thereby gaining specific high grade oil.1. Two-step fast pyrolysis of bagasse to produce 4-vinyl phenol and high-grade bio-oil.In this study, through rapid pyrolysis gas chromatography/mass spectrometry experiments, examines the bagasse level of fast pyrolysis product distribution characteristics and the pyrolytic temperature’s influence on the subsequent secondary pyrolysis product distribution. The experimental results show that the bagasse low temperature pyrolysis products rich in 4-VP, under 250℃relative peak area of the content as high as 48.11%, and attain to the maximum production rate under 300℃.Primary pyrolysis temperature on the subsequent secondary has important effects on the distribution of pyrolysis products, from fuel grade, primary pyrolysis of solid products for secondary pyrolysis under 300℃ for bio-oil has the high grade of fuel. Which can be set for bagasse two-stage pyrolysis process is:the first level of fast pyrolysis under the 300℃the preparation of 4-VP, then solid residue at 500℃ for the secondary pyrolysis to obtain the high grade oil.2. Study on the fast pyrolysis of corn stalk and its different partsAnalytical Py-GC/MS (pyrolysis-gas chromatography/mass spectrometry) experiments were performed to investigate the pyrolysis characteristics and product distribution of the whole corn stalk and its different parts (stalk bark, leaf, bract, core), as well as to determine the effects of pyrolysis temperature on the product distribution. The results indicated that the pyrolysis characteristics of the different corn stalk parts differed greatly from each other, and were influenced differently by the pyrolysis temperature. The low-temperature fast pyrolysis of core would obtain abundant 4-Vinyl phenol (4-VP), with the peak area% as high as 21.27% at 300℃, whereas the products from fast pyrolysis of stalk bark at 300℃ contained large amounts of both 4-VP (15.6%) and 5-Hydroxymethyl furfural (HMF) (6.61%). Moreover, the medium-temperature fast pyrolysis of leaf (500℃) produced a lot of light carbonyl products, while products from fast pyrolysis of bract at 500℃had the lowest acid content, suitable to be used as the liquid fuel.3. Fast pyrolysis product distribution of biopretreated corn stalk by methanogenAfter pretreated by methanogen for 5,15 and 25 days, corn stalk (CS) were pyrolyzed at 250,300,350,400, and 450℃by Py-GC/MS and product distribution in bio-oil was analyzed. Results indicated that methanogen pretreatment changed considerably the product distribution:the contents of sugar and phenols increased; the contents of linear carbonyls and furans decreased; the contents of linear ketones and linear acids changed slightly. Methanogen pretreatment improved significantly the pyrolysis selectivity of CS to phenols especially 4-VP. At 250℃, the 4-VP content increased from 28.6% to 60.9%. Increasing temperature was contributed to convert more lignin into 4-VP, but decreased its content in bio-oil due to more other chemicals formed. The effects of biopretreatment time on the chemicals contents were insignificant. |
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