摘要
在温度353.2～453.2K、压力0.75～5.25MPa的条件下,采用平衡取样的方法,测定了氢气在不同组成(xi为摩尔分数)的四种液体乙酰丙酸、乙酰丙酸(x1=0.37)+水(x2=0.63)、γ-戊内酯、乙酰丙酸(x1=0.33)+水(x2=0.33)+γ-戊内酯(x3=0.34)中的溶解度.根据亨利定律对实验数据进行关联,得出不同温度下氢气在液体中的亨利系数,通过亨利系数和温度的关系,计算出氢气在液体中的摩尔溶解焓和摩尔溶解熵.结果表明:在实验温度、压力范围内,提高温度、增加压力,氢气在四种不同液体中的溶解度皆增大;在温度和压力相同时,氢气在四种液体乙酰丙酸(x1=0.37)+水(x2=0.63)、乙酰丙酸、乙酰丙酸(x1=0.33)+水(x2=0.33)+γ-戊内酯(x3=0.34)和γ-戊内酯中的溶解度依次增大;氢气在四种液体中的亨利系数均随着温度的升高而减小;氢气在四种液体中的摩尔溶解焓为正值,摩尔溶解熵为负值.
The solubility of hydrogen in the liquid phase of hydrogenation of levulinic acid to γ-valerolactone is an important parameter that influences the rate of the hydrogenation reaction in three-phase catalytic hydrogenation.The solubility of hydrogen in the liquid mixtures of levulinic acid ＋ water ＋ γ-valerolactone has been measured at pressures from 0.75 to 5.25 MPa and temperatures from 353.2 to 453.2 K based on analytical method using a high-pressure variable volume view cell.The result shows that the solubility of hydrogen increases with the elevation of pressure and temperature.The solubility of hydrogen in different liquids increases in the following order：levulinic acid （x1=0.37） ＋ water （x2=0.63） levulinic acid levulinic acid （x1=0.33） ＋ water （x2=0.33） ＋ γ-valerolactone （x3= 0.34） γ-valerolactone.The solubility of hydrogen in the liquid of this three-phase catalytic hydrogenation reaction increases with the process of the chemical reaction.An extension of Henry＇s law was employed to correlate the hydrogen solubility data.The Henry＇s law constants were obtained,and they decrease with the increase of temperature.The molar enthalpy of hydrogen solution is positive from 4.78 to 8.41 kJ mol-1 and the molar entropy of hydrogen solution is negative from-42.70 to-24.89 J mol-1 K-1.
出处
《中国科学：化学》
CSCD
北大核心
2010年第9期1387-1394,共8页
SCIENTIA SINICA Chimica
基金
北京市自然科学基金(2082017)
教育部新世纪优秀人才支持计划(NCET-08-0710)资助
关键词
氢气
溶解度
乙酰丙酸
γ-戊内酯
水
hydrogen
solubility
levulinic acid
γ-valerolactone
water
enthalpy of solution
作者简介
通讯作者，E—mail：wzwu@mail．buct．edu．cn
