Production and characterisation of low-tech activated carbon from coconut shell

Abstract

In this paper, prospect of employing a low-tech preparation of coconut shell as activated carbon was investigated. Activated carbon was prepared from locally available coconut shell with simple, inexpensive and low-tech production process. The influence of carbonisation temperatures (i.e. 500, 600, 700 and 800°C) and residence times (i.e. 1.5 and 2 hours) of the prepared activated carbon on the percentage of yield, adsorption capacity and the development of pores were examined. The charcoal was ground to particles size ranges of 0.6-1.0, 1.0-2.36 and 2.36-4.75 mm, respectively and was activated by saturated NaCl solution for 24 hours. Results show that the carbon yield reduces with both increasing temperature and residence time, but the adsorption capacity increases up to an optimum temperature of 700°C. The pore diameter was progressively increased from the carbonisation temperatures 500 to 700°C and stabilised even at higher temperature. Increasing residence time to two hours obviously increased the pore diameter but the structural pore walls started to collapse at 700°C. It is further found that 1.0-2.36 mm particle sized activated carbon has the best adsorption capacity of 58% compared with the other particle size range. The optimum condition obtained is at carbonisation temperature of 700°C and 1.5 hours residence time. The results of the study demonstrate that the low tech process of self-prepared coconut-shell activated carbon is feasible and may be utilised for water treatment.

Paper JHER0307.