| This research is a part of project subsidized by National 863 Project"Research on bio-oil production from biomass fast pyrolysis based on improving bio-oil qualities"(2008AA05Z404). Self-made fluidized-bed reactor was used to obtain bio-oil, and research of properties of bio-oil, chemical composition, aging properties as well as emulsification with diesel was conducted in this paper.This paper has concluded detailed the current status of biomass pyrolysis for liquid product in China and overseas, especially about analysis of bio-oil properties. From the point of view of continual development, the technology of biomass pyrolysis for producing bio-oil has a good prospect.The fluidized-bed reactor designed by our research center was mainly consisted of three parts, that is, the feeding system, the pyrolysis reactor and the collecting system for products. With biomass fed at the rate of 1～2 kg/h, and the vapor residence time at 0.8～1.2 s, three kinds of biomass materials were selected, that is, poplar sawdust, sweet sorghum stalk and dusk residues, for bio-oil production.Properties of three different bio-oils, including water content, heating value, kinetic viscosity, density, ash content, CCR and pH vale were analyzed. Results showed that with relatively low water content and high heat value of bio-oil, its density, ash content and CCR were higher than ordinary fuels. Simultaneously, the kinetic viscosity of bio-oil decreased significantly with the temperature increasing, proving its prominent viscosity-temperature characteristic. In addition, when compared with other bio-oils, bio-oil from poplar sawdust was better, due to its low water content (25.01%) and high heating value (20.6MJ/kg).Moreover, both of Fourier Transform Infrared Spectrum (FTIR) analysis and 1HNMR were used to detect chemical composition of bio-oil. According to chemical composition analysis, bio-oil is a highly complex mixture of organic compounds, and bio-oil from husk residues and sweet sorghum stalk were similar to each other. From 1HNMR spectrum, different types of hydrogen can be observed, with the larges account of Phenolic(OH) and olefinic proten more than 50%.For the purpose of analyzing its aging process, changes of properties of bio-oil during three months were measured. Results showed that, water content increased only 0.82%, while kinetic viscosity went up as much as 1.18mm2/s.For further enlarge application of bio-oil, different emulsification conditions were tried to get better emulsification results. When surface active agents account for about 5%, stable time was relatively longer than other conditions, though improvements on emulsification were required.In conclusion, these foundation researches of biomass fast pyrolysis for producing liquid fuel is significant for optimizing experiment parameter, forecasting the result of experiment and magnifying equipment etc. Besides, research of properties of bio-oil, its aging process and emulsification with diesel provides reliable date for deep study of bio-oil. |
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