Experimental conditions of differential reactor method for resin–phenolic compound system

Abstract

For the design of a fixed-bed reactor, intraparticle diffusivity of adsorbents is one of the most important parameters. However, determining this diffusivity is difficult as measuring the effects of fluid film resistance of adsorbents. Shallow-bed (differential reactor) technique is commonly used to determine intraparticle diffusivity. The conventional shallow-bed technique is based on the assumption that fluid film resistance is negligible because of high fluid velocity; hence, the fluid film mass transfer is not calculated. For an activated carbon–phenolic compound system, both intraparticle diffusivity and fluid film mass transfer coefficient were determined using a shallow-bed reactor. However, no one has confirmed the accuracy of the conventional assumption for a synthetic resin adsorbent–phenolic compound system. In general, synthetic resin adsorbents have a larger fluid film resistance than activated carbon. Therefore, this study focused on the effect of fluid film resistance based on the conventional assumption. The conventional analysis method (intraparticle diffusion controlling model) and the new analysis method (both intraparticle diffusion and fluid film mass transfer controlling model) were compared, and the results indicated that the conventional assumption, which neglects the elimination of fluid film resistance, had no effect on intraparticle diffusivity. Therefore, the conventional analysis method is useful for determining intraparticle diffusivity for a resin adsorbent–phenolic compound system.