不凝气体循环活气法蒸馏松脂的热力学特性及传递机理

Gas solubility and volumetric mass transfer coefficient of non condensable gas such as CO2, N2, H2, He, or their binary, ternary, and quaternary mixture in pine gum and will be measured in a equipment containing pressure autoclave, precision pressure transducer, programmable logic controller(PLC) with computeraided data collection online. The vapor-liquid equilibrium data for the pine gum system will be determined in a still with vapor-liquid atternative circulation. Thus, the desorption mechanism of different components from pine gum during the distillation process by circulating gas method with non condensable gas can be discussed. The pressure(P)-volume(V)-temperature(T)of non condensable gas mixture will be measured using a system composed of piston screw, hydraulic transmission and glass capillary to establish the thermodynamic properties model for rxpanding of the non condensable gas. The bubble distribution and relation between heat transfer quantity in a unit of time and the amount of distillate volatile components will be determined online as well with the technology of gas distributor combined with a laser monitoring observation and computer data online acquisition system. Since, the coefficient model of heat transfer and gas-liquid mass transfer for the distillation of pine gum by circulating gas method with non condensable gas will be obtained. Being analyzed the the distillate composition changing with the time, kinetic model for the distillation can be proposed. And the transfer mechanism will also be investigate, which can provide basic data of engineering design and solid theoretical foundation for the distillation of pine gum by circulating gas method with non condensable gas.

采用压力釜-精密压力变送器-可编程序控制器(PLC)-计算机在线数据采集实验装置，分别测定不凝气体CO2、N2、H2、He及其二、三、四元组分混合气在松脂中的溶解度与体积传质系数；采用具有液相对流和汽相冷凝双循环汽液平衡釜，测定松脂体系汽液平衡数据，探讨不凝气体循环活气法蒸馏松脂对不同组分的解吸机理；采用活塞螺杆-液压传动-玻璃毛细管实验装置测定不凝气体混合气压力(P)-体积(V)-温度(T)的数据，建立不凝气体节流膨胀的热力学模型；采用气体分布器-激光监视-计算机跟踪采集数据技术，在线测定松脂蒸馏器内的气泡分布及其单位时间传热量与挥发性组分蒸出量的关系，建立不凝气体循环活气法蒸馏松脂的给热系数模型和气液传质系数模型；在线采样分析蒸出产物组成与时间的关系，建立不凝气体循环活气法蒸馏松脂过程动力学模型，探讨其传递机理，为不凝气体循环活气法蒸馏松脂的工业化实施夯实理论基础和提供工程设计数据。

采用压力釜—精密压力变送器—可编程序控制器(PLC)—计算机在线数据采集实验装置，测定353~443K下不凝气体CO2、N2、H2、He在松脂、松香和松节油中的溶解度与体积传质系数，获得了溶解度系数与温度之间的关联式和溶解热、体积传质系数与温度、压力的关联式。不凝气体CO2、N2、H2、He在松脂、松香和松节油中平衡溶解度和体积传质系数均随温度和压力升高而增加，溶解度～压力曲线为通过原点的直线，这说明Henry 定律是适用的。采用改进的Ellis平衡釜和气相色谱分析方法，测定了常压、温度428.15K~488.15K下松香含量为0~70%的松脂体系汽液平衡数据。结果表明，松香浓度越高，气相单萜组分α-蒎烯含量越低，相平衡温度也随着松香浓度增加而升高，但松香作为不挥发组分对松节油馏出组分的汽液平衡组成含量影响不大。测定松脂体系α-蒎烯-蒎烷、α-蒎烯-长叶烯、蒎烷-长叶烯三个二元体系及α-蒎烯-蒎烷-长叶烯三元体系的常压汽液平衡数据，获得了每个二元体系中各组分的活度系数，再关联得到相应的过量Gibbs自由能与超额焓实验值，根据Wilson方程对三个二元体系的过量Gibbs自由能和超额焓进行了计算，关联值与实验值吻合。利用C80型Calvet微量量热仪测定了松脂主要成分对伞花烃+β-石竹烯,3-蒈烯+β-石竹烯和3-蒈烯+对伞花烃三个二元体系在298.15 K下的超额焓。三个二元体系的超额焓数据在全浓度范围内均为正值，在相同温度下，3-蒈烯+对伞花烃体系的超额焓值均大于含重质松节油组分的对伞花烃+β-石竹烯和3-蒈烯+β-石竹烯体系。自主设计了一套具有恒压、恒温控制的稳定鼓泡发生装置，考察CO2循环活气流量对松脂蒸馏器中气泡分布和气液相际传热传质行为的影响，采用高速摄影技术对静止松脂溶液中单个CO2气泡运动形态进行分析，考察了气泡尺度对松脂溶液中单个气泡形变特点和规律的影响。为不凝气体循环活气法蒸馏松脂的工业化实施夯实理论基础和提供工程设计数据。