Utilization of beer lees waste for the production of activated carbons: The influence of protein fractions on the activation reaction and surface properties

Abstract

Activated carbons (ACs) were produced by carbonizing and activating beer lees waste, and the influence of protein fractions on the activation reaction order and surface properties of the resultant ACs was investigated. In the untreated control sample, the activation reaction could be regarded as first order. Conversely, the reaction system changed to zero order when the protein fractions were reduced by treatment with an alkali. In addition, the AC produced from the beer lees with reduced protein fractions showed a BET surface area of 1390 m2/g, which was approximately 1.4 times greater than that of AC from the untreated control beer lees. The tar fractions obtained from proteins in beer lees through dry-distillation at 280 °C or below were transformed into charcoals with somewhat densely packed carbon layers. This appeared to make the charcoal less reactive to CO2 and limited the adsorption capacity of the resultant AC.