Removal of sugar colorants by granular activated carbons made from binders and agricultural by-products

Twenty-four granular activated carbons (GACs) made from mixtures of four binders (coal tar, sugarcane molasses, sugar beet molasses, corn syrup) and three agricultural by-products (rice hulls, rice straw, sugarcane bagasse) were evaluated for their ability to remove sugar colorants (molasses color removal, sugar decolorization). These properties were compared to the same properties of two commercial reference carbons. GACs made from sugarcane bagasse, in general, possessed the best ability to remove sugar colorants and were closest to the reference carbons in this regard. In fact, the four highest ranked GACs all used bagasse as a feedstock along with four different binders. Therefore, the ability to remove sugar colorants appears to be by-product dependent with the binder playing a minor role.