非平衡双柱交替循环色谱分离过程模型

摘要

Cycling chromatography separation is a new separation technology.It uses alternate cycling separations of short chromatographic columns to simulate a conventional single-cycle chromatography, which can make the sufficiently separated fractions of the sample be collected in each cycle and shorten the periods time of the separation, both of these improve the separation efficiency of the chromatography. In this work, a non-equilibrium model of double-column cycling chromatography is established. The experiments of the separation of sugar and reducing sugar using the process of the alternate cycling separation of the double chromatographic columns are conducted. The results of the experiments and computer simulation show that the elution curves calculated by the proposed model are in good agreement with experimental elution curves of chromatography. The production rate of the cycling chromatography is higher than that of the conventional chromatography even if there exists solid/liquid interface mass transfer resistance and is increased with the increase of cycle times. When axial dispersion is somewhat serious, apparent selectivity coefficients of adsorbents are small, or lumped mass transfer coefficients are small, the use of the cycling chromatography technique will improve the production rate remarkably.%循环色谱是一种新颖的分离技术，它以短柱多次循环分离模拟传统的长柱单循环色谱分离，并在分离的过程中不断把已被分离的组分切割抽出，缩短了操作周期时间，提高分离产率。本文建立了非平衡双柱交替循环色谱分离过程数学模型，并进行了双柱交替循环色谱分离蔗糖和还原糖实验和计算机模拟分析。研究结果表明，使用本文提出的非平衡双柱交替循环色谱模型计算得到的流出曲线与实验得到的流出曲线吻合很好。双柱循环色谱分离操作能比采用传统的色谱操作获得更高的分离产率，产率随着循环次数的增加而增大。当体系中轴向扩散较严重、液固两相间的传质阻力较大或表观选择性系数较小时，与采用传统的单长柱色谱操作方式比较，采用双柱交替循环色谱分离方式将能更明显地改善和提高分离产率。