Research On The Pyrolysis And Gasification Of Crop Straw

This paper selects two common crop straws?rape straw and corn straw?from Southern Region as the object of study.Firstl y,we arraged the basic analysis on the samples.Secondly,by using the thermogravimetric analysis we studied the effects of heating rates,particle sizes and catalysts on the crop straw pyrolysis and gasification under the certain conditions.And then,by using the technology of thermogravimetric analysis coupled with near infrared measurement,we studied the different effects on the gaseous productsdivision of straw.The experimental results showed that: with the final pyrolysistemperature and sample size determined as the premise,with the heating rate increasing,the straw pyrolysis temperature increased as follow.The results of the effect of particle size on the pyrolysis characteristics showed that,in the particle size of 1mm,the smaller the sample size was,the more conducive to the pyrolysis reaction.In the thermogravimetric experiments,by adding catalysts to the straw,CoCl₂ could lower pyrolysis temperature of straw.By using TG-FTIR to analyse pyrolysis gaseous products of rape straw division,we could found that: the gasous pyrolysis compositions of two types of sample was relatively complex,but most of them were compositions with C-H,C-O groups matter,they also contained a lot of combustible gases with low molecular,they were H2,CO and CH4.By using the scanning electron microscopy to observe epidermis and inner core of rape straw before and after pyrolysis,we could found that the segments of rape straw had produced a lot of granular material.By using a fixed bed reac tor under anaerobic conditions to study the effects of heating rate,the catalyst for pyrolysis products of crop straw,we could found that: with the increasing of reaction heating rate,regardless of whether adding or not adding catalysts,the productivity of pyrolysis products would increase.And the higher the heating rate was,the better the influence of Cr₂O₃ and CoCl₂ would be,while the catalytic performance of Co₂O₃ is relatively stable.Study on the application of GC/MS to analyse the pyrolysis oil of crops straw on the condition of different heating rates,catalyst compositions showed that: with the differ ent heating rates and catalysts,the main substances produced by pyrolysis was alcohol,benzene,phenol and esters,they also contained a small amount of alkenes and alkanes.To be used as catalyst,Cr₂O₃ mainly promoted the increasing of product species,while Co₂O₃,CoCl₂ mainly promoted the increasing of carbonyl compounds.