【摘要】 理论与实验研究了丙酮和甲苯气体在活性炭中的吸附性能与温度变化,根据吸附规律,建立了丙酮和甲苯的线性推动力模型(linear driving force,LDF)等温数学模型,并应用有限差分方法求解模型。讨论了传热与传质系数对吸附床层温度和流出浓度曲线的影响,并与实验进行了对比分析。结果发现吸附相传质系数ki变小,轴向导热系数KL、内换热系数hi和轴向质扩散系数DLi变大时,丙酮和甲苯的吸附饱和时间延长,床层温度波动变小,有利于吸附净化丙酮和甲苯的混合气体;反之,结果相反,但有利于变压吸附分离甲苯和丙酮。同时通过模拟计算得到与实际情况相符的各组分传质传热参数:KL=0.00319W/(m·K)-1,hi=0.01542W/(m2·K)-1,丙酮DL1=0.05692m2/s,k1=0.0605s-1,甲苯DL2=0.6556m2/s,k2=0.00756_s-1。更多还原

【Abstract】 The adsorption properties and temperature changes of acetone and toluene gas on activated carbon were studied theoretically and experimentally. Based on the rule of adsorption, a linear driving force isothermal model was developed and calculated by finite differences method. The effects of heat and mass transfer coefficients on the temperature of adsorb bed and effluent concentration were analyzed comparing by experiment. The result is that it is good for purifying the mixed gas made up of acetone and toluene when adsorption saturation time of acetone and toluene becomes longer caused by smaller mass transfer coefficients of adsorbed phase ki, bigger axial thermal conductivity coefficient KL, internal heat transfer coefficient hi and axial mass diffusion coefficient DLi; and on the contrary, it is good for separating acetone and toluene. The simulated heat and mass transfer coefficients in accordance with actual situation are as follows: KL=0.003 19 W/(m?K)?1, hi=0.015 42 W/(m2?K)?1, DL1=0.056 92 m2/s, k1=0.060 5 s?1 (acetone), DL2=0.655 6 m2/s, k2=0.007 56 s?1(toluene).更多还原