Experimental Study. Ion Exchange Separation Of Levulinic Acid

Levulinic acid (LA) can be prepared from biomass with large scale. Low cost LA can be used as a platform chemical for the production of a wide range of value-added products.This paper deals with an economical, effective ion exchange method to recover levulinic acid from the hydrolyzed cellulose, provides process parameters for mass production.In this paper, D301 alkalescence anion exchange resin was selected as a suitable adsorptive material based on the study of ion exchange capacities. The kinetics and thermodynamics behaviors of ion exchanging were studied by static method.Firstly, the adsorption of LA by D301 alkalescence anion exchange resin was studied with the static method and the dynamic method. And the thermodynamics and kinetics behaviors of ion exchanging were studied by static method.In the thermodynamics, the adsorption behavior of resin under different temperature was discussed. The results show that the ion exchange is a favorable and spontaneous adsorption process, and the adsorption isotherm data can be satisfactorily fitted with the Redliclr-Peterson equation. Heat adsorption (ΔH) of resin D301 was also gained.In the kinetics, under optional reaction system, the influence on the ion exchange process including the granularities of resin, concentration of LA, speeds of stirring and temperature were investigated by batch ion-exchange method. Moving Boundary Model was applied to describe the kinetics of exchange process. The results show that the dominant procedure is ion diffusion through particles. The influence of stirring speed and temperature on the adsorption is little, the adsorption rate increases with the raise of primary concentration of LA. The rate constant of exchange (k₀), reaction order (n), the apparent activation energy reaction (Ea) and the total kinetics equation were obtained finally.The adsorptive process in ion exchange column was studied by dynamic method. We researched the dynamic absorbing and eluting process of pure LA solution with resin D301, and the influence of different factors such as LA concentration, flow rate and resin bed height on absorption were determined. Moreover, the HCl was used as eluting solution in dynamic eluting process, and the influence of HCl concentration and the flow rate on elution were also investigated.Secondly, levulinic acid (LA) can be prepared from the hydrolyzed cellulose with large scale. The adsorbing and eluting process were also studied by dynamic method. Under the condition of H:D 15.5, flow rate 1BV/h, the utilized rate of resin in absorbing process is 84.6%. Furthermore, LA with the purity 92.3% can be obtained by using 0.5M HCl as eluting solution with 1BV/h, and the yield of LA can reach to 77.9%.Generally, the process for LA recovery is simple. The demands for equipment and the cost of production are low, and it is suitable for the industrialization with large scale.