The pyrolysis behavior of three typical agricultural residues including rice husk, rice straw and wheat straw, was studied at different heating rates(15℃/min, 40℃/min and 100℃/min) in a dynamic nitrogen flow ...The pyrolysis behavior of three typical agricultural residues including rice husk, rice straw and wheat straw, was studied at different heating rates(15℃/min, 40℃/min and 100℃/min) in a dynamic nitrogen flow of 80mL/min by TG analysis coupled with Fourier Transform Infrared Spectroscopy (FT-IR). The various gaseous products released during biomass pyrolysis were examined. The kinetic parameters under different heating rates were acquired by kinetics analysis. The correlation coefficients are above 0.99. The results show that as heating rate increases the TG curve shifts to low temperature zone and the peak of DTG curve goes to low temperature area accordingly, but the total weight loss and activation energy of pyrolysis fluctuate little. The releasing behavior of gaseous products during pyrolysis of the three samples is similar. CO, CO2, H2O, CH4 and organics are the main gaseous products during biomass pyrolysis. When the heating rate increases, the yield of gaseous products released increases, so does the releasing rate.展开更多
UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion （HBPUA-PUDA/SiO2） was prepared with isophorone diisocyanate （IPDI）, hyperbranched polyester Boltorn H20 （H20）, hydroxy-ethyl...UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion （HBPUA-PUDA/SiO2） was prepared with isophorone diisocyanate （IPDI）, hyperbranched polyester Boltorn H20 （H20）, hydroxy-ethyl acrylate （HEA）, polyethyleneglycol （PEG-200）and nano-SiO2. The UV curing kinetics of the films was investigated by FTIR. The results show that the curing speed of the films increases with the adding of nano-SiO2 and decreases with the adding of PUDA due to the slower chain movement. The thermal stability of the HBPUA-PUDA/SiO2 films was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy （TGA/FTIR）. The results show that all films exhibit two degradation stages located at about 320 and 440℃ corresponding to the degradation for hard segments of urethane-acrylate and the degradation for soft segment and polyester core. In addition, the results from the analysis of TGA/FTIR also indicate that the decomposition temperature of HBPUA-PUDA/SiO2 film is 15℃ higher than that obtained for pure polymer. The degradation mechanism was proposed according to TGA/FTIR results.展开更多
微藻是一种新型的可再生生物质资源,采用快速热解技术,可得到高品质的先进液体燃料和高附加值化学品。该文采用热重-红外联用仪、快速热解-气质联用仪和分布式活化能动力学模型(distribution activation energy model,DAEM)对莱茵衣藻(C...微藻是一种新型的可再生生物质资源,采用快速热解技术,可得到高品质的先进液体燃料和高附加值化学品。该文采用热重-红外联用仪、快速热解-气质联用仪和分布式活化能动力学模型(distribution activation energy model,DAEM)对莱茵衣藻(Chlamydomonas reinhardtii,CDR)、小球藻(Chlorella vulgaris,CRV)和铜绿微囊藻(Microcystis aeruginosa,MCA)的热解行为开展了研究,系统地对比了3种微藻在化学组成、热解失重规律、动力学、热解产物等方面的差异,并对微藻的热解机理进行了探讨。结果表明:1)3种微藻的热解过程可分为3个阶段,分别为干燥段、快速热解段和炭化阶段,其中铜绿微囊藻失重率最大,达到17.34%/min,且随着升温速率的增加,TG/DTG(thermogravimetry/differential thermogravimetry)曲线往高温一侧移动;2)红外光谱分析结果表明微藻热解主要产物为CH4、CO2、含C=O键的脂肪酸、含N-H键和C-N键的酰胺类化合物,其中莱茵衣藻热解产生的CH4质量分数最高,铜绿微囊藻热解产生的含C=O键化合物质量分数最高;3)铜绿微囊藻的活化能数值最高,随着转化率增加,活化能从100增加到680 k J/mol;4)Py-GC/MS分析表明小球藻热解产生的含氧化合物质量分数最高,达到30.89%,铜绿微囊藻热解产生的酚类化合物、芳香族碳氢化合物、胺和酰胺类和其他含氮化合物的质量分数最高,分别达到10.41%,13.46%,13.87%和14.27%。本文可为微藻的能源化利用提供科学和基础数据。展开更多
文摘The pyrolysis behavior of three typical agricultural residues including rice husk, rice straw and wheat straw, was studied at different heating rates(15℃/min, 40℃/min and 100℃/min) in a dynamic nitrogen flow of 80mL/min by TG analysis coupled with Fourier Transform Infrared Spectroscopy (FT-IR). The various gaseous products released during biomass pyrolysis were examined. The kinetic parameters under different heating rates were acquired by kinetics analysis. The correlation coefficients are above 0.99. The results show that as heating rate increases the TG curve shifts to low temperature zone and the peak of DTG curve goes to low temperature area accordingly, but the total weight loss and activation energy of pyrolysis fluctuate little. The releasing behavior of gaseous products during pyrolysis of the three samples is similar. CO, CO2, H2O, CH4 and organics are the main gaseous products during biomass pyrolysis. When the heating rate increases, the yield of gaseous products released increases, so does the releasing rate.
文摘UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion （HBPUA-PUDA/SiO2） was prepared with isophorone diisocyanate （IPDI）, hyperbranched polyester Boltorn H20 （H20）, hydroxy-ethyl acrylate （HEA）, polyethyleneglycol （PEG-200）and nano-SiO2. The UV curing kinetics of the films was investigated by FTIR. The results show that the curing speed of the films increases with the adding of nano-SiO2 and decreases with the adding of PUDA due to the slower chain movement. The thermal stability of the HBPUA-PUDA/SiO2 films was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy （TGA/FTIR）. The results show that all films exhibit two degradation stages located at about 320 and 440℃ corresponding to the degradation for hard segments of urethane-acrylate and the degradation for soft segment and polyester core. In addition, the results from the analysis of TGA/FTIR also indicate that the decomposition temperature of HBPUA-PUDA/SiO2 film is 15℃ higher than that obtained for pure polymer. The degradation mechanism was proposed according to TGA/FTIR results.
文摘微藻是一种新型的可再生生物质资源,采用快速热解技术,可得到高品质的先进液体燃料和高附加值化学品。该文采用热重-红外联用仪、快速热解-气质联用仪和分布式活化能动力学模型(distribution activation energy model,DAEM)对莱茵衣藻(Chlamydomonas reinhardtii,CDR)、小球藻(Chlorella vulgaris,CRV)和铜绿微囊藻(Microcystis aeruginosa,MCA)的热解行为开展了研究,系统地对比了3种微藻在化学组成、热解失重规律、动力学、热解产物等方面的差异,并对微藻的热解机理进行了探讨。结果表明:1)3种微藻的热解过程可分为3个阶段,分别为干燥段、快速热解段和炭化阶段,其中铜绿微囊藻失重率最大,达到17.34%/min,且随着升温速率的增加,TG/DTG(thermogravimetry/differential thermogravimetry)曲线往高温一侧移动;2)红外光谱分析结果表明微藻热解主要产物为CH4、CO2、含C=O键的脂肪酸、含N-H键和C-N键的酰胺类化合物,其中莱茵衣藻热解产生的CH4质量分数最高,铜绿微囊藻热解产生的含C=O键化合物质量分数最高;3)铜绿微囊藻的活化能数值最高,随着转化率增加,活化能从100增加到680 k J/mol;4)Py-GC/MS分析表明小球藻热解产生的含氧化合物质量分数最高,达到30.89%,铜绿微囊藻热解产生的酚类化合物、芳香族碳氢化合物、胺和酰胺类和其他含氮化合物的质量分数最高,分别达到10.41%,13.46%,13.87%和14.27%。本文可为微藻的能源化利用提供科学和基础数据。
