The main objectives of this work are to model the separation of lactic acid from an aqueous mixture by adsorption on a polyvinylpyridine resin (Reillex® 425), and to model the desorption of adsorbed lactic acid with methanol. The adsorption equilibrium isotherm of lactic acid in aqueous mixtures in Reillex® 425 has been measured. A theoretical model describing the column adsorption dynamics of lactic acid from an aqueous solution and its desorption with methanol has been developed and validated with experimental data. The model has been employed to design and optimize a simulated moving bed (SMB) process for recovering lactic acid from a lactic acid/water mixture containing 5% w/w of lactic acid, using the triangle theory and the separation volume method. The simulation results show that it is possible to obtain concentrated lactic acid (80% in water) with high recovery (95%) from lactic acid/water mixtures by SMB. The feasibility of recovering methanol from the extract and raffinate streams of the designed SMB process by distillation has also been analysed.

这项工作的主要目的是模拟通过在聚乙烯基吡啶树脂（425）上的吸附来从含水混合物中分离乳酸，并模拟吸附的乳酸在甲醇中的解吸。已在425中测量了乳酸在水性混合物中的吸附平衡等温线。建立了描述乳酸在水溶液中的柱吸附动力学及其在甲醇中解吸的理论模型，并通过实验数据进行了验证。该模型已被用于设计和优化模拟移动床（SMB）工艺，以利用三角理论和分离体积法从含5％w / w乳酸的乳酸/水混合物中回收乳酸。模拟结果表明，通过SMB可以从乳酸/水混合物中以高回收率（95％）获得浓乳酸（在水中为80％）。还分析了通过蒸馏从设计的SMB工艺的提取液和提余液中回收甲醇的可行性。