Comparative study of flow schemes for a simulated countercurrent adsorption separation process
Comparative study of flow schemes for a simulated countercurrent adsorption separation process
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模拟逆流吸附分离工艺流程对比研究
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
M. S. Uddin
中科院分区：
文献类型：
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作者：
C. Ching;K. Chu;K. Hidajat;M. S. Uddin
连续分离三种碳水化合物混合物[果糖-葡聚糖（M。W. 9，400）、棉子糖-葡聚糖（M. W. 6，000），和果糖-棉子糖]已经使用模拟逆流过程用硅胶作为吸附剂和去离子水作为洗脱剂进行。实验进行了使用商业四段安排和修改后的三段流程，不回收部分洗脱液重复使用的计划。四段流程图的数据反映出萃余液中的产品浓度比三段流程图高得多，而新鲜洗脱液的消耗速率比三段流程图低得多。结果表明，当萃取液和萃余液都需要时，对于分离因子较小的混合物，通常需要大量的洗脱剂才能达到有效的分离，应采用四段流程。模拟的逆流过程的行为是理论上模拟的过程中表示的等效的真实逆流系统。在四段模式下，实验数据得到了较好的拟合。然而，相同的理论方法未能在一个方面提供三段方案的行为的良好表示：萃余液产物的预测浓度比实验值高约两倍。这种差异可能是由于三段模拟逆流装置在运行过程中流体进出口点的周期性切换造成的。
Continuous separation of three carbohydrate mixtures [fructose-dextran (M. W. ≈ 9,400), raffinose-dextran (M. W. ≈ 6,000), and fructose-raffinose] has been carried out using a simulated countercurrent process with silica gel as the sorbent and deionized water as the eluent. Experiments were conducted using the commercial four-section arrangement and a modified three-section flow scheme which does not recycle part of the eluent for reuse. Data for the four-section flow scheme reflect a much higher product concentration in the raffinate and a substantially lower rate of fresh eluent consumption than for the three-section scheme. It is concluded that when both the extract and raffinate products are desired, the four-section scheme should be used for the separation of a mixture with a small separation factor which usually requires a large quantity of eluent to achieve an efficient separation. The behavior of the simulated countercurrent process was simulated theoretically by representing the process in terms of an equivalent true countercurrent system. A good fit to the experimental data was obtained when the process was configured in the four-section mode. However, the same theoretical approach failed to provide a good representation of the behavior of the three-section scheme in one respect: predicted concentrations of the raffinate product were about two times higher than experimental values. The discrepancy may be attributed to the periodic switching of fluid inlet and outlet points in the operation of the three-section simulated countercurrent unit.