Heat Transfer Model And Experimental Research On Biomass Fast Pyrolysis And Liquefaction

The exploit and utilization of biomass energy is an effective method for relieving the pressures of conventional energy resources shortage and environment pollution in China. Biomass pyrolysis technology which can convert low-quality biomass to higher quality liquid fuel or high add-value chemical material have been pay great attention. It can not only relieve the demand press of power fuel and improve the using efficiency of biomass energy in China rural area, but also can improve the structure of china energy. According to this purpose, a systemic experimental research on the biomass has been carried out.First of all, an introduction of current research state of biomass pyrolysis instrument, dynamics model,characteristic analysis of bio-oil, etc were introduced. Then ameliorated the device by improving feeding system and heating system, and achieved good results. In the heat transfer mechanism aspect, this paper has introduced particles impact heat transfer model for laboring the heat transfer characteristic of biomass particles in fluid bed, furthermore, calculated the time that the biomass particles with different size achieve the reaction temperature needed, and ascertain the optimal particle size for pyrolysis: sawdust 0.5～2.0mm, peanut shell 0.2～0.8mm, wheat bran and rice polishing 0.2～0.5mm,it provided the basis for experimental material selection. For the experiment, in order to find out the reactor temperature,particle size,settle time,etc influence on pyrolysis results, chose sawdust and peanut shell for particular research under the temperature of 400℃, 450℃, 500℃, 550℃, 600℃, fluidization gas amount of 4 m3/h, 6 m3/h. Through massive experiments with different conditions, found out the rule of reactor temperature,particle size,settle time influence on pyrolysis products rate, especially on bio-oil production rate. Reactor temperature is the most important influence factor and plays the decision role to the bio-oil production rate, the particle size and fluidization gas amount play the relative small role to it. At last, based on knowing the bio-oil characteristic, an introduction of bio-oil refine methods were given, the technologies provided informations for the application of bio-oil can be generalized. The conclusions of this paper provided the theory base and scientific experimental study method for continuous study.