Pyrolysis Mechanism Of Corn Straw Powder In The Fluidized Bed Reactor

Agriculture and forest residues can be converted to liquid bio-oil by fast pyrolysis technology.Nitrogen,sulfur and metallic composition is not contained in bio-oil which is a kind of green fuel.High content of oxygen makes bio-oil unsteady and limits its application,so bio-oil needs to be upgraded.The metal element and additives in biomass have great influences on pyrolysis and composition of the productions during the pyrolysis process.Using different bed materials at different temperatures to study the influence on composition of productions and bio-oil characteristics was proposed.In order to study the pyrolysis of biomass in detail,a pyrolysis fluidized bed reactor (100 mm in diameter and 1170 mm in height)with feeding rate of 5 kg/h was designed and established.After commissioning and installation,the improper parts were upgraded.Many experiments were done under the same conditions in order to examine the reliability of the experimental results.The similarity of the results makes out high reliability of the experimental results.Corn stalk powder was used for the pyrolysis experiments and quartz sand,aluminous soil and dolomite was respectively used as bed material in reactor,and the temperatures of 450℃,475℃,500℃和525℃were chosen.Within the experimental range,the results show as follows:1.When quartz sand,aluminous soil and dolomite was respectively used as bed material in reactor,the gather rate of bio-oil are firstly becoming bigger with the increase of temperature.But when temperature got some value,the gather rate of bio-oil starts to decrease with the increase of temperature.The gather rate of bio-oil is the biggest using dolomite as bed material in reactor,and that of quartz sand is bigger,and that of aluminous soil is the smallest.The biggest gather rate of bio-oil will be gained at the temperature of 500℃.The gather rate of char decreases with the increase of temperature.The gather rate of char is similar when quartz sand or aluminous soil is used as bed material in reactor, while the gather rate of char is smaller when dolomite is used as bed material in reactor.2.The change of the weight ratio of layer bio-oil to gained bio-oil and the gather rate of bio-oil are similar with the increase of temperature,and they get the maximum value at the temperature of 500℃,then the former will decrease more greatly than the latter.The temperature and bed material in reactor all have great influence on productions of biomass pyrolysis.The optimal choice of bed material in reactor can upgrade the distribution of production and improve the gather rate of bio-oil.A suggestion was given that dolomite should be used as bed material in reactor and the temperature of 525℃should be chosen from the view of gainning more light bio-oil.In this paper,the characteristic of bio-oil was analyzed.In order to expend the range of feedstock of biomass pyrolysis,experiments of furfural residue,corncob residue and kelp have been done.