CAJ | 학술논문

采用一种新的原位漫反射红外技术研究了干燥脱灰褐煤中氢键的分解动力学,同时介绍并应用了一种防止高温下挥发分冷凝的原位漫反射红外实验方法.基于两条假设,当煤加热至560℃时,单一反应模型可以用于除OH-π键以外氢键分解动力学参数的求解.结果表明,煤中羧酸二聚体、OH-N和SH-N三种氢键的分解动力学遵循二级反应;OH-OR2,紧密结合的羟基四聚体和自缔合的羟基多聚体则遵循一级反应.计算所得的几种氢键分解活化能与文献中采用其他方法所得结果基本一致.在所考察的六种氢键中,羧酸二聚体、OH-N、SH-N和紧密结合的羟基四聚体的分解可以分为两个阶段(230℃～380℃和380℃～500℃),而OH-OR2和自缔合的羟基多聚体的分解可以按照一段来处理.另外,通过比较自缔合的羟基多聚体的分解活化能和文献中的氢键键能,获得了其分解机理.
채용일충신적원위만반사홍외기술연구료간조탈회갈매중경건적분해동역학,동시개소병응용료일충방지고온하휘발분냉응적원위만반사홍외실험방법.기우량조가설,당매가열지560℃시,단일반응모형가이용우제OH-π건이외경건분해동역학삼수적구해.결과표명,매중최산이취체、OH-N화SH-N삼충경건적분해동역학준순이급반응;OH-OR2,긴밀결합적간기사취체화자체합적간기다취체칙준순일급반응.계산소득적궤충경건분해활화능여문헌중채용기타방법소득결과기본일치.재소고찰적륙충경건중,최산이취체、OH-N、SH-N화긴밀결합적간기사취체적분해가이분위량개계단(230℃～380℃화380℃～500℃),이OH-OR2화자체합적간기다취체적분해가이안조일단래처리.령외,통과비교자체합적간기다취체적분해활화능화문헌중적경건건능,획득료기분해궤리.
The kinetics of decomposition of hydrogen bonds in a Chinese lignite was studied using a new method of in-situ diffuse reflectance FT-IR (DRIFT) with pulverized coal samples directly. In addition, a new experimental technique in DRIFT measurement to avoid the condensation of volatile matter at high temperatures was introduced and used in this work. Based on two hypotheses, the single reaction model is used to caculate kinetic parameters for decomposition of hydrogen bonds ( except OH-π) in coal heated up to 560 ℃. The results show that the decomposition of carboxylic acid dimers, OH-N and SH-N follows the second order reaction, while the decomposition of OH-OR2, tightly bound hydroxyl tetramers and self-associated hydroxyls follows the first order reaction. The calculated activation energies of some hydrogen bonds agree well with those obtained with other methods in references. Among the six types of hydrogen bonds studied, the decomposition of carboxylic acid dimers, OH-N, SH-N and tightly bound hydroxyl tetramers can be divided into two stages (230 ℃～ 380 ℃ and 380 ℃～ 500 ℃ ), while that of OH-OR2 and self-associated hydroxyl groups can be treated as only one stage. Moreover, the mechanism of the decomposition of tightly bound hydrogen bond was suggested based on the comparison of decomposition activation energy of self-associated OH with its bond strength in references.