Separation of d-lactic acid from aqueous solutions based on the adsorption technology

A novel polar macroporous adsorption resin (AX-1) has been applied for separation of d-lactic acid (DLA) from aqueous solutions in a fixed-bed chromatographic column. The adsorption equilibrium and kinetics were investigated experimentally. A column model was subsequently established and validated by comparison of the simulation results to the experimental data obtained at different operating conditions in terms of feed flow rates and initial concentrations as well as bed heights. At the end of this work, the recycling studies were carried out. It was found that the saturated resin could be washed out DLA completely and repeated use by 353 K hot water. The results show that the AX-1 resin has a high adsorption capacity to DLA while no retention to sulfate ion. Based on this kind of resin, a green-production refining process could be established since only water is added in the entire separation process.

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► A novel polar macroporous resin was offered with good properties.
► A green refining process was proposed since only water was added.
► A model was established to design the d-lactic acid adsorption process.