Gas absorption in an agitated gas-liquid-liquid system
Gas absorption in an agitated gas-liquid-liquid system
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DOI：
10.1016/s0009-2509(00)00324-9
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发表时间：
2001-02
影响因子：
4.7
通讯作者：
A. Cents;D. Brilman;G. Versteeg
中科院分区：
文献类型：
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作者：
A. Cents;D. Brilman;G. Versteeg
气液液系统在过去十年中引起了人们的兴趣，并在几个重要的工业应用中遇到了。在这些系统中，不混相的液相会显著影响气体吸收率。然而，这一现象尚未被完全理解，其潜在机制需要进一步研究。在这项工作中，使用著名的Danckwerts-plot技术同时确定了这类系统的液侧传质系数和气液界面面积a。以次氯酸钠为催化剂，在0.5 M K2CO30.5 M khco3缓冲溶液中吸附co2。甲苯、正十二烷、正庚烷和正辛醇为分散液相。danckwerts图可以很好地用于气液液系统，从结果来看，存在两种类型的系统；增强传质的系统和不增强传质的系统。低分散相含率的影响被观察到非常强，因此很重要，但在进一步分析分散相含率对传质的影响时没有考虑到这一点。在向缓冲溶液中加入十二烷和庚烷的体系中，没有观察到传质增强。然而，甲苯和1-辛醇的加入引起了传质的增强，这可以用一个均匀的穿梭机制模型来很好地描述。
Gas–liquid–liquid systems have gained interest in the past decade and are encountered in several important industrial applications. In these systems an immiscible liquid phase may affect the gas absorption rate significantly. This phenomenon, however, is not completely understood and underlying mechanisms need further study. In this work the well-known Danckwerts-plot technique is used to determine the liquid side mass transfer coefficient kLand the gas–liquid interfacial area a simultaneously in this type of systems. As absorption/reaction system CO2absorption in a 0.5 M K2CO30.5 M KHCO3buffer solution catalysed by sodium hypochlorite was chosen. Toluene, n-dodecane, n-heptane and 1-octanol were applied as dispersed liquid phases. The Danckwerts-plot could be well used in gas–liquid–liquid systems and from the results it appeared that two types of systems exist; systems that enhance mass transfer and systems that do not enhance mass transfer. Effects at low dispersed phase hold-up were observed to be very strong and are thus important, but were not taken into account in further analysis of the effect of dispersed phase hold-up on mass transfer. In systems where dodecane and heptane were added to the buffer solutions no enhancement of mass transfer was observed. However, the addition of toluene and 1-octanol caused an enhancement of mass transfer that could be well described using a homogeneous model of the shuttle mechanism.