Effect of agitation on removal of acetic acid from pretreated hydrolysate by activated carbon.

Abstract

The effect of agitation on the adsorption of acetic acid by activated carbon was tested utilizing an external mass transfer-diffusion model. Simulated pretreated biomass was contacted with activated carbon under prescribed conditions of temperature and agitation. Adsorption isotherm studies are presented as well as batch kinetic rate studies. Use of these data enabled the determination of isotherm constants, an external mass transfer coefficient, and an effective diffusivity for each agitation rate studied. The external film coefficient results ranged from 33.62 microm/s to a complete absence of external mass transfer resistance, and the diffusivity results ranged from 0.8625 to 10.70 microm(2)/s. The optimum combination of no external film resistance, and highest diffusivity, 10.70 microm(2)/s, occurred at 250 rpm and 25 degrees C. The results of these models and the experimental parameters suggested an efficacious method and conditions for the removal of this undesirable chemical.