Development of the Simulated Moving-Bed Reactor Equipped with Membrane-Type Enzyme Reactors

本研究的目的是开发一种将酶反应器和模拟移动床吸附器相结合的新工艺，以实现乳糖(4^G-β-D-半乳糖基蔗糖)的高产生产。通过利用该酶溶液进行间歇反应实验，发现果糖转移遵循有序双机理，蔗糖和乳糖的水解同时进行。根据得到的反应机理计算了反应速率。用树脂颗粒固定化酶和中空纤维超滤膜固定化酶进行了反应实验。通过将酶固定在树脂上，降低了乳糖的选择性，在后续的纤维膜反应器中，混合条件达到完全混合，使乳糖的选择性略有降低。通过单柱穿透实验测定了各糖的吸附等温线和体积传质系数。当酶液温度为50℃时，乳糖的选择性和得率分别为71%和51%。C.当固定化酶在50℃时，乳糖选择性为60%。C.模拟移动床反应器的数值模拟结果表明，将模拟移动床技术应用于该反应体系，成功地抑制了果糖转移反应的逆反应。在装有固定化酶柱的模拟移动床反应器中，为了获得高产量的乳糖，必须降低每个反应柱中的蔗糖转化率，增加反应柱的数量。

The objective of this study is to develop a new process by combining the enzyme reactors and simulated moving-bed adsorber and to achieve the high-yield production of lactosucrose (4^G-beta-D-galactosyl sucrose).By carrying out the batch reaction experiments using the enzyme solution, it was found that the transfructosylation followed the ordered bi bi mechanism and the hydrolyses of sucrose and lactosucrose took place simultaneously. The reaction rates were formulated from the obtained reaction mechanism. The reaction experiments using the enzyme immobilized on resin particles as well as the enzyme trapped in the hollow-fiber ultrafiltration membrane were also carried out. By immobilizing the enzyme on the resin, the lactosucrose selectivity was reduced, In the follow-fiber membrane reactor, the mixing conditions reached complete mixing, which slightly reduced the lactosucrose selectivity.The adsorption isotherms and volumetric mass transfer coefficients of each saccharide were determined in single-column breakthrough experiments.Simultaneous reaction and separation experiments were carried out by using the simulated moving-bed reactor with enzyme solution as well as with immobilized enzyme. The selectivity and yield of lactosucrose were 71% and 51% respectively when the enzyme solution was used at 50。C.The lactosucrose selectivity was 60% when the immobilized enzyme was used at 50。C.The results of the numerical simulation of the simulated moving-bed reactor demonstrated that the reverse reaction of the transfructosylation is successfully suppressed by applying the simulated moving-bed technology to this reaction system. It was also found that the sucrose conversion in each reaction column has to be reduced and the number of the reaction columns has to be increased in order to obtain a high yield of lactosucrose in the simulated moving-bed reactor equipped with the immobilized enzyme columns.