摘要
对棉秆和玉米秆在200~390℃范围内的低温脱氧过程进行研究。分析其产物特性并对脱氧过程进行动力学分析,为进一步探索生物质低温脱氧的反应机理提供理论依据。结果发现与原样相比,390℃低温脱氧棉秆O/C和H/C分别降低78.5%和60.9%,390℃低温脱氧玉米秆O/C和玉米秆的热值分别提高36.4%和31.9%;棉秆与玉米秆在290~390℃时的失重比其在200~290℃时分别提高28.22%和52.28%;棉秆和玉米秆的热解可运用分级反应模型求其动力学参数,低温脱氧过程中棉秆和玉米秆的活化能分别为120.91、109.27 kJ/mol;生物质三组分可运用一级反应模型求其动力学参数,低温脱氧过程中半纤维素、纤维素、木质素的反应活化能分别为77.19、238.99、28.42 kJ/mol。
The low temperature deoxidation processes of cotton stalk and corn stalk ranged from 200 ℃ to 390 ℃ were studied. The product characteristics and the kinetics of the deoxidation processes were analyzed to provide a theoretical basis for further exploration of the reaction mechanism of low temperature deoxidation of biomass. The results showed that compared with the raw biomass,after 390 ℃ low temperature deoxidation reaction,the O/C and H/C of cotton stalk dropped 78.5% and 60.9%,the O/C and H/C of corn stalk dropped 71.8% and 59.7%,the effect on deoxidation is obvious,and the calorific value of cotton stalk and corn stalk increased 36.4% and 31.9%. The weightlessness of cotton stalk and corn stalk during 290-390 ℃ were increased by 28.22% and 52.28% over the weightlessness during 200 and290 ℃. The pyrolysis process of both cotton stalk and corn stalk can be described by hierarchical reaction model,the activation energy of cotton stalk and corn stalk during low temperature deoxidation are 120.91,109.27 kJ/mol. The pyrolysis process of biomass three components can be described by first order model,the activation energy of hemicellulose,cellulose,lignin during low temperature deoxidationare 77.19,238.99,28.42 kJ/mol.
引文
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