煤液化过程中,反应单元和分离单元是整个液化体系的核心部分,反应器和分离器中各组分在气、液相中的平衡组成确定不仅决定设备的尺寸设计,而且对液化过程中供氢溶剂的选择和反应条件的优化起到关键作用。但由于煤液化油在高温高压下的气、液平衡数据不足,使得反应器内的组成分布无法预测,相关的反应器设计过程仅能凭经验进行。为得到反应条件下的气液平衡数据,研究引入流程模拟软件Aspen Plus,将煤液化油蒸馏得到的窄馏分段与各种气体组分(如H2、C2H6等)共同建立了煤液化油闪蒸过程,得到了高温高压下煤液化油气液平衡体系。利用闪蒸体系计算得到在给定温度、压力情况下,各组分在高温、低温分离器内的气、液两相分布情况,通过改变高温分离器的温度和压力,分析了高温分离器内相平衡常数随温度(623.15K-723.15K)、压力(10MPa-21MPa)变化的规律。为进一步归纳适用于煤液化油的气液平衡方程,以高温分离器数据为基础,对推导建立的高压下烃类相平衡方程中的参数进行回归,得到高温高压下,适用于神华煤液化油并具有物理意义的二元(T,P)气液相平衡常数方程。
In order to get the vapor-liquid equilibrium constants under the real liquefaction conditions, the data from the fractions of coal liquefied distillation oil and different gas, such as H2 and C2H6 , were combined together to establish the coal liquefied oil flash distillation system through the process simulation software Aspen Plus. By using the flash-distillation system, the vapor-liquid equilibrium composition and distribution were calculated at reaction temperature and pressure. Also the rules of equilibrium constant vary with the temperature (623.15K-723.15K) and pressure (10MPa -21 MPa) were explored. Furthermore, the parameters of deducing hydrocarbon equilibrium equation at high pressure were regressed. And the two variable vapor-liquid equilibrium equation specified for the Shenhua coal liquefied oil was established.