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Research Of Critical Components Of Biomass Continual Pyrolysis Reactor

Posted on:2014-02-12Degree:MasterType:Thesis
Country:ChinaCandidate:X L SuFull Text:PDF
GTID:2233330398453661Subject:Agricultural mechanization project
Abstract/Summary:PDF Full Text Request
Biomass is an unique energy, which not only can store solar energy, but also is a kind of renewablecarbon source, among various kinds of renewable energy. It can be transformed into new energy products,which is high quality, high effective, commercialized, transported easily and integrated utilization, throughvarious biomass conversion technologies. Slow pyrolysis is one of the main methods of energy conversionand utilization. The biomass continuous pyrolysis reaction device was developed and investigatedexperimentally with theoretical consideration in this article. The main contents are as follows:1) Experimental research on pyrolysis kinetics of rice husk were done on the NETZSCH STA449Cthermogravimetric analyzer. Dynamical model of pyrolysis was established, according to the laws of thepyrolysis. The pyrolysis reaction process was forecasted under different heating rates, combined with theactual reaction conditions. And theoretical basis for the design of pyrolysis reactor was provided. Dynamicsanalysis for movements of rice husk in the spiral conveyor, were carried out, which offered theoreticalreferences for designing and optimizing of vital parameters of the special screw conveyer.2) To design and optimize the special continual pyrolysis screw conveyor, relevant tests and researchfor factors impacting conveying capacity are performed,such as depth of screw groove,surface quality ofscrew and cylinder wall,material size,variability of pitch, etc. Test results showed that surface quality levelof screw and cylinder wall and grain size takes certain impact on conveying capacity,while the bigger thevariability of pitch, the greater the change of filling coefficient, and the lower the conveying capacity.Using variable pitch model, such as30-40-50-50, could form a relatively loose cylindrical, formingdynamic material sealing. Because of that, not only the pressure near the feed end of the conveyor wasincreased, which could achieve the purpose of sealing, but also the filling coefficient of material in thesubsequent thermal decomposition period was kept around0.25ensuring the sufficient pyrolysis.Meanwhile, numerous experiments showed that pyrolysis volatiles can be more smoothly to end by way ofcombining the variable pitch with pros and cons screw.3) For general biomass, the productivity of the device was about5~20kg/h, and stay time was2~10min, under the given experimental conditions, which can meet the needs of pyrolysis reaction stablyand continuously.
Keywords/Search Tags:Biomass, Continual pyrolysis reactor, Screw conveying, Experimental research
PDF Full Text Request
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