农业工程学报
農業工程學報
농업공정학보
2015年
10期
249-253
,共5页
热解%温度%动力学%乌拉草%汉麻%挥发性有机物
熱解%溫度%動力學%烏拉草%漢痳%揮髮性有機物
열해%온도%동역학%오랍초%한마%휘발성유궤물
pyrolysis%temperature%kinetics%curaua%hemp%volatile organic compounds
为探究乌拉草纤维的热解性能及其在热解过程中挥发性有机物释放情况，基于傅里叶红外光谱仪及同步热分析质谱联用系统对乌拉草纤维及汉麻纤维的主要化学成分进行分析，探究其热分解过程，采用Coats-Redfern法进行热动力学计算，并对其热分解过程中挥发性有机物释放进行检测。研究结果发现，乌拉草纤维与汉麻纤维主要成分相似，以纤维素、半纤维素、木质素为主。其热分解过程可依次分为水分挥发失重、半纤维素热解、纤维素及木质素热解3个主要阶段，并可用半纤维素热解、纤维素热解、木质素热解3个独立的一级反应描述，纤维素与木质素热解阶段反应活化能较高，热解过程与汉麻纤维热分解过程相似。在乌拉草纤维热解过程中，除 H2O、CO2气体释放以外，同时释放少量甲醛等挥发性有机物。研究结果为乌拉草纤维实际应用中阻燃及环保问题的考虑提供参考。
為探究烏拉草纖維的熱解性能及其在熱解過程中揮髮性有機物釋放情況，基于傅裏葉紅外光譜儀及同步熱分析質譜聯用繫統對烏拉草纖維及漢痳纖維的主要化學成分進行分析，探究其熱分解過程，採用Coats-Redfern法進行熱動力學計算，併對其熱分解過程中揮髮性有機物釋放進行檢測。研究結果髮現，烏拉草纖維與漢痳纖維主要成分相似，以纖維素、半纖維素、木質素為主。其熱分解過程可依次分為水分揮髮失重、半纖維素熱解、纖維素及木質素熱解3箇主要階段，併可用半纖維素熱解、纖維素熱解、木質素熱解3箇獨立的一級反應描述，纖維素與木質素熱解階段反應活化能較高，熱解過程與漢痳纖維熱分解過程相似。在烏拉草纖維熱解過程中，除 H2O、CO2氣體釋放以外，同時釋放少量甲醛等揮髮性有機物。研究結果為烏拉草纖維實際應用中阻燃及環保問題的攷慮提供參攷。
위탐구오랍초섬유적열해성능급기재열해과정중휘발성유궤물석방정황，기우부리협홍외광보의급동보열분석질보련용계통대오랍초섬유급한마섬유적주요화학성분진행분석，탐구기열분해과정，채용Coats-Redfern법진행열동역학계산，병대기열분해과정중휘발성유궤물석방진행검측。연구결과발현，오랍초섬유여한마섬유주요성분상사，이섬유소、반섬유소、목질소위주。기열분해과정가의차분위수분휘발실중、반섬유소열해、섬유소급목질소열해3개주요계단，병가용반섬유소열해、섬유소열해、목질소열해3개독립적일급반응묘술，섬유소여목질소열해계단반응활화능교고，열해과정여한마섬유열분해과정상사。재오랍초섬유열해과정중，제 H2O、CO2기체석방이외，동시석방소량갑철등휘발성유궤물。연구결과위오랍초섬유실제응용중조연급배보문제적고필제공삼고。
In this paper, the pyrolysis behaviors and the release of volatile organic compounds (VOCs) of the curaua fiber and hemp fiber were investigated. Fourier transform infrared spectrometer (FTIR) was employed to analyze the main chemical composition of the curaua fiber and hemp fiber. The chemical composition mass fraction was tested by chemical method. The pyrolysis behaviors and the release of VOCs of the curaua fiber and hemp fiber could be investigated by thermogravimetry-mass spectroscopy (TG-MS). The activation energy of each stage during the fiber pyrolysis was calculated by the Coats-Redfern method. The results revealed that the main chemical components of the curaua fiber were the same to the hemp fiber, which were cellulose, hemicelluloses, lignin, pectin, wax and hydrotrope. The cellulose mass fraction of the curaua fiber (56.35%) was lower than that of the hemp fiber (71.37%), but the lignin mass fraction of the curaua fiber (19.70%) was higher than that of the hemp fiber (2.86%). The pyrolysis process of the curaua fiber and hemp fiber could be divided into 3 stages. In the first stage (50-250℃), the residual water and free water in the amorphous region evaporated. The next 2 stages were mainly the hemicelluloses pyrolysis (250-350℃) and the pyrolysis process of cellulose and lignin (350-700℃), respectively. The 3 independent first-order reaction models were constructed to describe the main pyrolysis process of the curaua fiber and hemp fiber. The first first-order reaction of the curaua fiber was mainly the hemicelluloses pyrolysis stage (265-356℃), the second first-order reaction of the curaua fiber was mainly the cellulose pyrolysis stage (356-426℃), and the third first-order reaction was mainly the lignin pyrolysis stage (426-463℃). The activation energies of the second and third first-order reaction stages (205.41, 497.56 kJ/mol) were higher than that of the first first-order reaction stage (125.06 kJ/mol). The activation energy in each stage was closely linked to the chemical composition and the mass fraction of each composition. Through the combination of the thermal analysis instrument and the mass spectrometer, it was detected that small amounts of formaldehyde, acrolein, and other VOC gas such as n-butane, benzene substance were released during the curaua fiber pyrolysis. The investigated result can be useful to the application of the curaua fiber, which can be developed as a kind of functional fiber, but the retardant problem and the environmental issues should be given attention to during the curaua fiber application.
