Production of activated carbon from low grade coal and its role as effective adsorbent to control pollution

Abstract

The objective of the present study is to investigate the adsorption behaviour of acetic acid onto activated carbon prepared from low grade coal. In the project work it is mainly emphasised on preparation of activated carbon from homogeneous mixture of coal-limestone composites whereas adsorption process is taken just as a evaluation technique of the prepared carbon. To prepare activated carbon, after carbonization, the coals were homogeneously mixed with limestone by the ratio of 1: 7 and heated at 950°C in muffle furnace for different time. Experimental data shows, after oxidation by CO2 obtained from calcined limestone, the percentage removal of carbon increases linearly with heating time. After making very fine particles, activated carbons were immersed in water and being finer the ash suspended under the turbulence nature of water and finally the water mixed with ashes are removed. The process was repeated again and again. The initial concentration of acetic acid was varied between 0.025 and 0.4 mol/dm3. From the experimental data, Freundlich adsorption isotherm and Freundlich adsorption isotherm were calculated for all the six samples and compared. From adsorption test, it is seen that the experimental data follows the Freundlich Adsorption Isotherm. The solute acetic acids are loosely bonded on the carbon and after removing the acid can be easily separated from carbon. By this process powdered activated carbons with size below 45 μm were produced.