| This paper was studied the material gasifier gasification technology from the point of views of China is a big agricultural country and crop straw are rich, We homemade a biomass gasifier of suction type furnace of120cm height; The furnace diameter is32cm, The thickness of thermal insulation layer is2cm; Furnace gate is20cm height from the ground, At the same time, we set up5cm in diameter of the ash gate, gasifying agent accessing the stove from tornado grate under the stove. Meanwhile, the grate was been improved on the basis of former and designed the spiral、anti-jam grate, designed the "three general" tar、water condensing collection devices. Experimental materials are corn cob and corn stalk. The main experiments and analysis results are as follows:(1) Study the influence of the gas production quality on biomass gasifier of suction style by the three factors of air、material accumulation height, the particle of materials. Research shows that:Take the air into the gas as the research object, the corn cob and corn straw gas production has best quality when the air feed rate is1.6m3/h; Take the material accumulation height as the research object, the corn cob and corn straw gas production has best quality when the material accumulation height is70cm; Take the particle of materials as the research object, the corn cob and corn straw gas production has best quality when the particle size of materials is1.5cm.(2) Using the response surface method integrated research the three factors of air into the gas and material accumulation height, material of particle size affects the quality of gas production comprehensively on biomass gasifier suction type. Research shows that:The corn cob and corn straw gas production has best quality when the air feed rate is1.6m3/h、the material accumulation height is70cm、the particle size of materials is1.5cm. At this time, the CO, H2content can be up to33.43%and27.16%in corn cob production gas, the CO2content is22.16%; the CO, H2content can be up to31.09%and26.55%in corn straw production gas and the CO2content is23.35%; Corn cob and corn straw have basically the same physical and chemical properties, the trends of factors in the experiment is basically the same on the corn cob and corn straw.(3)Obtain and analysis the thermal gravimetric analysis figure in5℃/min,10℃/min,15℃/min,20℃/min,30℃/min heating rate conditions respectively heated to1000℃, another conditions is at200℃,250℃,300℃,350℃,400℃constant temperature for4hours. Research shows that:The trends of corn cob and corn straw weight loss curve are basically the same, for different heating rate, pyrolysis of materials are generally divided into three processes. with the pyrolysis temperature rises, the free water within the material began to lose slowly, within about100℃, free water evaporation trend started to slow down, When the temperature reaches250℃, the free water in the basic evaporative completely. With the further increase in material temperature, the volatile within the material begins to precipitate. Materials volatile precipitation rate is very fast in the range of250-330℃, With the further rise in temperature, the materials volatile precipitation rate started to slow down, Slow interval is in the range of330-530℃. When the temperature reaches530℃, volatile basic entirely precipitation, the rest is carbon.The heating rate of10℃/min of corn cob, the maximum weight loss rate of the material can reach97.94%, the heating rate of15℃/min of corn cob, the maximum weight loss rate of the material can reach98.74%. In the later actual production, In the conditional of control heating rate, for different materials we can control different heating rate, which can make the material of weightlessness rate is the largest, the volatile Precipitation most, the gas production of gas best quality, The gas has the best quality of gas production. (4) Through the derivation, we can be drawn gasification kinetics model of the corn cob and corn straw lnf[F(a)/T2=lnAR/βE-E/RT,it satisfies the linear equation of Y=kX+b, we can obtain pyrolysis reaction activation energy E and frequency factor A by multi-point graphic and k=-E/R、b=lnAR/βEThrough the graphic and calculation:In the heating rate for5℃/min, in the corn cob gasification process, when the temperature stage is250—330℃, the gasification reaction are two reaction, fitting a straight line equation of y=-2332.3x-7.9534, R2=0.9978; when the temperature stage is330—530℃, the gasification reaction are one reaction, fitting a straight line equation of y=-1960.5x-9.7076, R2=0.9134.In the heating rate for10℃/min, in the corn straw gasification process, when the temperature stage is250—330℃, the gasification reaction are one reaction, fitting a straight line equation of y=-3799.7x-6.4494, R2=0.9978; when the temperature stage is330—530℃the gasification reaction are also one reaction, fitting a straight line equation of y=-2572.1x-8.8102, R2=0.692. |
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