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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

基本信息

批准号：
01550745
负责人：
MUNAKATA Tsuyoshi
金额：
$ 1.47万
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：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

The purpose of this investigation is to make clear the reason why it is said that the efficiency of dehydrating distillation in light hydrocarbon-water system is extremely low. The research results obtained so far are as follows.1. Investigation to past works The head investigator examined relevant literatures and reanalyzed the experimental data in them under taking into account uncertainty of vapor-liquid equilibrium (VLE) relation as well as heat balance, then pointed out the distillation efficiency depends largely upon the estimated value of the VLE relation.2. Measuremen of the VLF relation and examination to the result We examined into experimental apparatus to obtain the VLF data where the condensate of vapor forms two liquid phases, and using a means of providing a liquid decanter within a return pipe of the condensate, measured the VLE relation for three systems of benzene-water, hexane-water, and toluene-water over a wide range in concentration. The values of VLE ratio came u … More p to 2-5 times the data of Lino et. al. Which had been obtained in a range of low water concentration, but agreed fairly well with the values estimated by means of a modified UNIFAC equation.3. Distillation experiment with a packed column and examination to the result Using the Sulzer packing known as a "high efficiency" packing, we conducted a distillation experiment for the three kinds of systems described above. The HETP values obtained were, in contrast to 2-4cm for the heptane-toluene system. 30-40cm for the three hydrocarbon-water systems. This means a remarkable drop in distillation efficiency. Thus we suspected existence of some additional resistance for mass transfer in the change-of-state process between gas and liquid phases and schemed the next experiment with the intention of making use of active agents which can be expected to present catalytic action.4. Distillation experiment with a single stage column and examination to the result At first we conducted a distillation experiment without setting any active agent. Then, in a range of relatively high water concentration, the values of tray efficiency reached as high as those for heptane-toluene system (about 70%) but in a low water concentration range the efficiency became extremely low. This is the calculated result based on the VLE data obtained in item 2 above, and if the VLE ratios in a range of low water concentration diminish abruptly, it can not be said that this efficiency drop is to occur. Hence we consider that, in order to clarify this questionable respect prior to the aforementioned supposition of additional mass transfer resistance, it is necessary to conduct careful measurement of the VLE relations in a range of low water concentration. Less

本文的目的是弄清为什么轻烃-水体系的脱水蒸馏效率极低。目前取得的研究成果如下：1.对以往工作的考察本课题负责人查阅了相关文献，并对文献中的实验数据进行了重新分析，同时考虑了汽液平衡关系的不确定性和热平衡，指出精馏效率在很大程度上取决于汽液平衡关系的估算值. VLF关系式的测定及结果检验我们在实验装置上获得了蒸气冷凝物形成两液相时的VLF数据，并采用在冷凝物回流管中设置液体滗析器的方法，测定了苯-水、己烷-水和甲苯-水三个体系在较宽浓度范围内的VLF关系式。采用汽液平衡法测定了各组分的汽液平衡值， ...更多信息 p ~ 2-5倍于Lino et.这是在低水浓度范围内得到的，但与用修正的CNOAC方程估算的值相当吻合.填料塔的精馏实验及结果检验使用被称为“高效”填料的苏尔寿填料，对上述三种体系进行了精馏实验。与庚烷-甲苯体系的2-4cm相比，所获得的HETP值为2-4cm。三个烃水体系的平均厚度为30- 40 cm。这意味着蒸馏效率显著下降。因此，我们怀疑在气液相之间的状态变化过程中存在一些额外的传质阻力，并计划下一个实验，目的是利用可以预期呈现催化作用的活性剂.单级精馏实验及结果检验首先进行了不加任何活性剂的精馏实验。在较高的水浓度范围内，塔板效率可达庚烷-甲苯体系的塔板效率（70%左右），而在较低的水浓度范围内，塔板效率变得很低。这是基于上述第2项中获得的VLE数据计算的结果，如果在低水浓度范围内VLE比突然减小，则不能说会发生这种效率下降。因此，我们认为，为了澄清这一可疑的方面之前，上述假设的额外的传质阻力，有必要进行仔细测量的VLE关系在一个范围内的低水浓度。少