利用衝擊波管研究二碘甲烷在高溫下熱解反應動力學

Abstract

利用活塞型衝擊波管-原子共振吸收光譜(ARAS)技術來研究溫度範圍在1483 K至1908 K之間的二碘甲烷熱解反應動力學。 我們利用數學式適解由實驗測得之碘原子濃度隨時間的變化圖，進而得到在該溫度壓力下二碘甲烷第二步驟熱解(CH2I+M→3CH2+I+M)速率常數。另外也藉由電腦模擬適解由實驗測得之氫原子濃度隨時間的變化圖，進而佐證k4-7的值。所得到的k (T) = 2.1 × 10-8 exp[-(29700)/T] cm3molecule-1s-1，與本實驗室之前發表的數值也相當吻合。

A diaphramless shock tube coupled with atomic resonance absorption spectrophotometry (ARAS) was employed to study the kinetics of the CH2I2 thermal decomposition reaction between 1483 and 1908 K. Numerical computation and ChemKin kinetic software were used to fit the trmporal profiles of I atom and H atom to obtain the rate constant for the thermal decomposition reaction of CH2I, ln(k4-7 / cm3molecule-1s-1 ) = -17.7(± 1.5) - 29.7(± 2.6) ×(1000/T). Present experimental results are found to be consistent with the experiment result from our previous work.