香叶基丙酮在4种吸附材料上扩散系数和扩散机理  

DIFFUSION COEFFICIENTS AND DIFFUSION MECHANISMS OF GERANYLACETONE IN FOUR ADSORBENTS

作　　者：王明锋 何嘉杰[2] 李源栋 卢真保 李忠[2] 廖头根 WANG Mingfeng;HE Jiajie;LI Yuandong;LU Zhenbao;LI Zhong;LIAO Tougen(Technology Center of Yunnan Tobacco Industry Limited Liability Company Kunming 650202,China;School of Chemistry and Chemical Engineering,South China University of Technology Guangzhou 510640,China;Guangzhou HuaFang Tobacco Flavor Company,Guangzhou 510385,China)

机构地区：[1]云南中烟工业有限责任公司技术中心,昆明650202 [2]华南理工大学化学与化工学院,广州510640 [3]广州华芳烟用香精有限公司,广州510385

出　　处：《离子交换与吸附》2018年第4期374-384,共11页Ion Exchange and Adsorption

基　　金：烟草行业卷烟调香技术重点实验室开放课题基金(TX2014007)

摘　　要：本文主要研究4种吸附材料孔隙结构对香叶基丙酮脱附扩散机制的影响。主要基于线性吸附推动力模型,建立扩散系数De估算模型,对4种吸附材料进行孔隙结构表征,然后应用重量法测定香叶基丙酮在不同吸附剂上的脱附动力学曲线,计算得到香叶基丙酮在4种吸附剂上De～qt的关系曲线;讨论吸附剂的孔隙结构对香叶基丙酮在4种吸附材料扩散机理的影响。结果表明,香叶基丙酮在4种吸附剂上的脱附速率与吸附剂的孔隙结构有关,吸附剂孔径越大,相应的香叶基丙酮传质扩散系数越高;香叶基丙酮的扩散系数随着吸附剂表面吸附量的减少逐渐下降。香叶基丙酮在Hβ分子筛上的扩散,主要以克努森扩散(Knudsen diffusion)为主,并且在表面吸附覆盖率范围内,其扩散系数几乎为一个常数,这是由于Hβ分子筛的孔径分布比较均匀,主要集中在0.6nm,此外,其脱附率也较高。香叶基丙酮在活性炭上的扩散主要以表面扩散为主,因其含有大量小于0.5nm的微孔。因此,选择合适孔径尺寸且具有较均匀孔径分布的吸附剂,将是一种调控香叶基丙酮分子缓释性能的手段。这一研究结果对于应用多孔材料进行香料缓释以及调控吸附剂的缓释性能具有一定的指导意义。This work is mainly concerned with study of the effects of textural structures of four adsorbents on diffusion mechanisms of geranylacetone. The model for estimating diffusion coefficient of geranylacetone was established based on the LDF model. The desorption kinetic curves of geranylacetone from adsorbents were measured by thermo-gravimetric technique and then the diffusion coefficients De of geranylacetone desorption were estimated. Results showed that the textural structure of adsorbents had significantly influence on the diffusion of geranylacetone within the four adsorbents. The bigger the pore size of an adsorbent was, the higher the diffusion coefficient of geranylacetone within the adsorbent became. The diffusion coefficient of geranylacetone decreased with a decrease of amounts adsorbed. The diffusion of geranylacetone desorption from Hβ-zeolite was dominated by, Knudsen diffusion mechanism, and its Knudsen diffusion coefficient was nearly constant due to its even pore size of 0.6nm. The diffusion of geranylacetone desorption from activated carbon was dominated by surface diffusion mechnism since the activated carbon contained lots of micropores with pore sizes below 0.5nm.

关 键 词：香叶基丙酮 多孔材料 吸附 脱附 扩散系数 扩散机理 

分 类 号：TQ021.4[化学工程]