Activated Carbon from Leathe Shaving Waste, Part II. Effect pf cjar Demineralization and Activation Time on Surface Area and Pore Size Distribution

Abstract

Leather shaving wastes generated by the leather industry can beused for microporous activated carbon production. In this work,chrome leather shaving wastes were pyrolyzed in a semicontinuouspilot screw reactor at 450oC. The char obtained wasactivated using carbon dioxide in a tubular reactor at 900oC. Theeffect of using nitrogen or carbon dioxide in the heating step ofthe activation process on the pore size distribution andcumulative pore volume was evaluated. Carbon dioxide reducedthe pore volume in the mesopore region. Changing time in thecarbon activation (4 and 6 h) was not significant on the surfacearea, increasing it from 757.9 m2g-1 to 927.4 m2g-1. However, thedemineralization had a significant effect on the surface area,increasing it from 427.7 m2g-1 to 927.4 m2g-1 for 6 h of activation.The pore size distribution of non-demineralized activatedcarbon was very similar to the one of demineralized activatedcarbon, showing a cumulative pore volume mainly in the regionof micropores.