Liu Baojian, Yang Yiwen, Ren Qilong
National Laboratory of Secondary Resources Chemical Engineering, Zhejiang University, Hangzhou 310027, China.
J Chromatogr A. 2006 Nov 3;1132(1-2):190-200. doi: 10.1016/j.chroma.2006.07.080. Epub 2006 Aug 17.
The equilibrium and kinetics of levulinic acid (LA) adsorption on two basic polymeric adsorbents, 335 (highly porous gel) and D315 (macroreticular), were investigated. Experimental adsorption rates in batch stirred vessels under a variety of operating conditions were described successfully by the parallel pore and surface diffusion model taking into account external mass transfer and nonlinear Toth isotherm. The film-pore diffusion model was matched with the rate data and the resulting apparent pore diffusivities were strongly concentration-dependent and approached to a constant value for 335 adsorbent. Thus, the constant value was taken as the accurate pore diffusivity, while the pore diffusivity in D315 was estimated from the particle porosity. The surface diffusivities decreased with increasing initial bulk concentration for both adsorbents. The inverse concentration dependence was correlated reasonably well to the change of isosteric heat of adsorption as amount adsorbed.
研究了乙酰丙酸（LA）在两种碱性聚合物吸附剂335（高孔隙率凝胶）和D315（大孔网状）上的吸附平衡和动力学。考虑到外部传质和非线性托特等温线，采用平行孔和表面扩散模型成功描述了在各种操作条件下间歇搅拌容器中的实验吸附速率。膜-孔扩散模型与速率数据相匹配，335吸附剂的表观孔扩散率强烈依赖于浓度，并趋于恒定值。因此，将该恒定值作为准确的孔扩散率，而D315中的孔扩散率则根据颗粒孔隙率估算。两种吸附剂的表面扩散率均随初始本体浓度的增加而降低。浓度倒数依赖性与吸附等量热随吸附量的变化具有较好的相关性。
