Distillation Efficiency for Removal of Solved Minute Water in a Light Hydrocarbon

去除轻质烃中溶解微量水的蒸馏效率

• 批准号: 03650776
• 负责人: MUNAKATA Tsuyoshi
• 金额: $ 1.15万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03650776/
• 关键词: DEHYDRATING DISTILLATION; DISTILLATION EFFICIENCY; VAPOR-LIQUID EQUILIBRIUM RELATION; HYDROCARBON-WATER SYSTEM; TRAY COLUMN; 炭化水素ー水系; DEHYDRATING DISTILLATION; DISTILLATION EFFICIENCY; VAPOR-LIQUID EQUILIBRIUM RELATION; HYDROCARBON-WATER SYSTEM; TRAY COLUMN; 炭化水素ー水系

The purpose of this work is to clarify the reason why it is said that the efficiency of dehydrating distillation in hydrocarbon-water system is extremely low. The research results obtained so far are summarized as follows. 1.Distillation experiment with a single-tray column In dehydrating distillation experiments for three systems of benzene-water,toluene-water,and hexane-water,it was shown that in a range of relatively high water concentration the tray efficiency reached as high as those for heptane-toluene system(about 70%),but in a low water concentration range the efficiency became low as the water concentration decreases. 2.Distillation experiment with a five-tray column In this experiment,we examined a concentration profile in a five-tray column by measuring the water concentration on each stage. The results showed that the water concentration below the third or fourth stage from the top of the column does not change and hence the limit of the dehydration exists.The tray efficien … More cy in item 1 above is the calculated result based on the vapor-liquid equilibrium (VLE) relation obtained in a range of relatively high water concentration,where the VLE ratio was assumed to be constant. Taking into account also the above results,it was considered that the reason of the efficiency drop may be largely due to the VLE relation in a range of low water concentration, which have not been yet measured. Therefore we conducted careful measurement of the VLE relation mainly in that range. 3.Measurement of the VLE relation in a range of low water concentration Using the liquid on the bottom stage of the five-tray column and molecular sieves as a dehydrating agent,we could measure the VLE relation up to about 2wt-ppm in water content. For benzene-water and hexane-water systems it was found that in a range above 100wt-ppm in water content the VLE ratio is almost constant,but in a range of the lower concentration it decreases gradually with decrease of the water concentration and tends to approach unity abruptly below 5wt-ppm. The calculated values of the tray efficiency based on this VLE data became higher than those obtained in item 1, but still gave its low value in a low water concentration range. Consequently,we could not reduce the reason of the efficiency drop to the VLE relation only. So we intend to clarify this questionable point in future. Less

这项工作的目的是阐明说为什么碳氢化合物水系统脱水蒸馏的效率极低的原因。到目前为止获得的研究结果总结如下。 1.对三种苯水，甲苯 - 水和己烷 - 水的脱水蒸馏实验进行单件柱柱的缩减实验，结果表明，在一系列相对较高的水浓度中，托盘效率达到的托盘效率高于乙二烷 - 苯甲苯系统（约70％），但在低水平水中的水平均与低水平的水平降低。 2.在本实验中使用五垫柱进行缩减实验，我们通过测量每个阶段的水浓度来检查五垫柱中的浓度曲线。结果表明，从色谱柱顶部的第三或第四阶段的水浓度没有变化，因此存在脱水的限制。托盘有效……上面项目1中的更多CY是基于蒸气 - 液体等效的（Vle）关系的计算结果，在相对较高的水中浓度范围内获得了VLE浓度不变的范围。同时还考虑到上述结果，据认为，效率下降的原因可能主要是由于尚未测量的一系列低水位浓度的VLE关系。因此，我们主要在该范围内仔细测量了VLE关系。 3. VLE关系在一系列低水位浓度中使用五丝柱的底段和分子筛作为脱水剂的液体，我们可以测量水含量中的VLE关系最高约为2WT-PPM。对于苯水和己烷 - 水系统，发现在水含量高于100WT-PPM的范围内，VLE比几乎是恒定的，但是在较低浓度的范围内，它会随着水浓度的降低而逐渐减少，并且倾向于突然接近5WT-PPM以下的Unity。基于此VLE数据的托盘效率的计算值高于项目1中获得的值，但仍然在低水位浓度范围内给出了其低值。因此，我们不能仅将效率下降的原因仅限于VLE关系。因此，我们打算在将来澄清这个可疑的观点。较少的