正戊烯的Helmholtz状态方程研究

Helmholtz equation of state for n-pentene

正戊烯是重要的精细化工产品中间体和原材料,同时也是燃料添加剂,具有广泛的工业应用。正戊烯的生产和应用过程中常常涉及萃取、精馏、汽提等化工过程,而这些化工流程的设计、模拟、优化等都依赖于准确可靠的热物性数据。通过文献调研发现,目前还没有正戊烯的专用状态方程发表,因此利用文献中公开发表的实验数据开发了正戊烯的专用状态方程。该方程以Helmholtz自由能为显式、以密度和温度为自变量,适用范围为:温度从三相点到500 K,压力最高达到100 MPa,密度不超过15 mol?dm^(-3)。方程计算液相区密度的不确定度为0.2%,计算临界区及气相密度的不确定度为0.5%;计算饱和蒸气压的不确定度为0.3%,计算饱和液相密度的不确定度为0.2%,计算与能量相关的物性(例如C_(sat)、比热容、音速、焓等)的不确定度为1%以内。所开发的正戊烯专用状态方程不仅能够准确地复现实验数据,而且具有良好的外推性。

To popularize the application of n-pentene in industry,such as chemical simulation,process optimization,and properties research,the equation of state for n-pentene was developed based on a body of experimental data that has been critically assessed for internal consistency and for agreement with theory in this work.The Helmholtz energy as the fundamental property with independent variables of density and temperature was used for the equation of state.The equation of state is valid from the triple-point temperature to 500 K,with pressures up to 100 MPa and densities up to 15 mol?dm-3.Overall,the uncertainties in density range of the equation of state are 0.2%in the liquid region and 0.5%in the critical and vapor region.The uncertainty is 0.3%for the vapor pressure and 0.2%for the saturated liquid density.The uncertainties in the properties related to energy(such as heat capacity,sound speed,enthalpy and so on)are estimated to be 1%.The behavior of the equation of state is reasonable within the region of validity and at higher and lower temperatures and pressures.