Complete isolation of target solute from multicomponent similar mixture using continuous rotating annular chromatograph with double-stage partial recycling of effluent

A double-stage partial recycling continuous rotating annular chromatograph was proposed in order to isolate a target solute from multisolutes with similar retention strengths. The impurities with a higher retention strength are removed from the mixture by the first stage partial recycling where the effluent of incomplete separation is recycled to the inlet adjacent to that of the raw feed mixture. The effluent containing the target solute and the impurities with a lower retention strength is sent to the second stage and the target solute is isolated and collected. The optimum arrangement of the recycling channels and their corresponding nozzles was determined using a numerical calculation based on a mass transport model. The quadruple saccharides of kestose, sucrose, glucose and fructose were used as model solutes for experimental verification. The distribution coefficients needed for the numerical calculation were obtained from adsorption experiments. The effectiveness of the proposed technique was first verified using a two-apparatu system. On the basis of the two-apparatus method, the guide to designing a suitable single apparatus was discussed regarding the capital cost savings. The model target solute, sucrose, was isolated using a single apparatus by special recycling of a part of the effluents containing sucrose and kestose with a lower retention strength to the inlet of the first stage. An experimental concentration profiles of the respective saccharides were in reasonable agreement with the calculated ones.