Activated Carbon Lab Report

Abstract:
The chemical and physical conditions used in the preparation of activated carbon, an adsorbent used in water filtration influence the specific surface area and the porosity. In this study, coconut shell was used as the raw material and activation reagents such as Hydrochloric acid, Zinc Chloride and Phosphoric Acid were used. A single burn and double burn process was carried out for each method. The activated carbon obtained was compared in terms of absorption capacity, bulk density, BET specific surface area and pore volume. The best results were yielded for activated carbon prepared using phosphoric acid with the single burn technique.

Keywords: Activated carbon, Adsorption, Hydrochloric acid, Phosphoric acid, Zinc chloride

I. Introduction
Adsorption on activated carbon appears to be a reliable technique because of its simplicity of operation, and easy handling without any hazardous conditions.
The most common precursors used for the preparation of activated carbons are organic materials that are rich in carbon. These include a variety of agricultural wastes such as Palm oil shells, Apple waste, Banana peels, Bagasse, Coconut shells and Sawdust and also non-agricultural matter such as bituminous coal and by destructive distillation of bones.
In this study, coconut shell were chosen as a precursor for the production of activated carbon and the various methods of activation were studied to find the best activating reagent, since coconut shells are a waste material available at cheap rates in India and are abundant in nature.
Production of activated carbon can either be through physical or chemical activation. Physical activation involves carbonization in a furnace followed by steam or carbon dioxide activation whereas chemical activation involves carbonization in a furnace followed by use of chemical activating agents such as H3PO4, ZnCl2 and
Different activation agents were used to impregnate the shells, which include Hydrochloric acid, Zinc chloride and Phosphoric acid, all of them at 25% concentration. The crucibles were allowed to stand in a cool, dry and dark place for a period of 24 hours to facilitate impregnation of the chemicals into the crushed shells. The chemical agents are thus, dehydrating agents that penetrated deep into the structure of the carbon rich shells causing pores to develop within them. Pores in turn affect the specific surface area as more number of smaller pores will result in a larger specific surface area.
Activation Duration:
The duration of activation of the coconut shell has a significant effect on the development of pores and thus development of maximum specific surface area. The duration should be enough to allow for the elimination of all moisture and volatile components in the raw