【摘要】 利用同步热跟踪原理,提供一种测定微量气液反应热的研究方法.通过程序控制容器外壳温度与内部溶液同步升温,减小温度梯度,形成"热屏障",阻止溶液以热传导、对流、辐射的形式与外界环境进行热交换,获得动态绝热环境,提高微量气液反应热直接测量的精度,减少样品用量,无需热补偿.采用MEA(乙醇胺)与MDEA(N-甲基二乙醇胺)两类弱碱吸收液,容积为15 m L,分别在10%、20%、30%、40%和50%质量分数下,测定吸收CO2的反应热.实验表明:同步热跟踪法测量更为准确;随溶液浓度的增加,MEA反应热先降低后升高,MDEA反应热逐渐降低;在质量分数为20%～40%时,MEA、MDEA质量分数对反应热的影响不显著;反应放热形成的升温曲线出现"下凹"现象.更多还原

【Abstract】 In the process of CO2 capture by chemical absorption,regeneration energy consumption accounts for 70%-80% of the total energy consumption. Currently,the most critical issue is how to reduce the energy consumption of regeneration. Equipment such as micro-reaction calorimeter( Thermal Hazard Technology provides),differential reaction calorimeter and Setaram C80 thermal differential calorimeter is used to compare the reference and sample solutions,which are simultaneously heated to compensate for heat loss of the sample solution during the measurement,but the heat of reaction cannot be directly measured. In this study,the reaction heats of MEA( ethanolamine) and MDEA( N-methyldiethanolamine) with CO2 at 10%,20%,30%,40%,and 50% mass fraction were measured by synchronous thermal tracing technique. By synchronously controlling the temperature of the shell of the container and the internal solution,the temperature gradient was reduced to form a "thermal barrier"to prevent the solution from exchanging heat with the external environment in the form of conduction,convection,or radiation. A dynamic adiabatic environment was obtained without thermal compensation. The accuracy of direct measurement of the trace gas-liquid reaction heat was improved to save the sample amount. The experimental results show that the simultaneous thermal tracking method is more accurate. With the increase of solution concentration,the reaction heat of MEA first decreases and then increases,and the reaction heat of MDEA decreases gradually. When the mass concentration of MEA and MDEA is between 20% and 40%,the mass concentration has no significant effect on the reaction heat. The curve of temperature rise formed by exothermic reaction appears to be concave.更多还原