Chemical Activation of Lignite by using a Combination of H3PO4-NaHCO3

Abstract

Coal is divided into four classes: lignite, sub-bituminous, bituminous, and anthracite. Lignite is a low rank coal. About 30% of Indonesia's coal reserves are included in the low rank category. The use of lowrank coal is still limited for briquettes and as fuel for electricity generation. Improving the economic and usage values of low-rank coal, processing low-rank coal into activated carbon should be done because coal has a high carbon content. The purpose of this study is to determine the effect of activation time on the characteristics of the activated carbon produced by chemical activation process of lignite use a combination of activator H3PO4 NaHCO3. Lignite has been prepared -100 +120 mesh is carbonized at 6000C for 3 h, then after cold it was activated using 2.5 M concentration of H3PO4-NaHCO3 for 2, 4, 6, 8 and 12 h. Furthermore, proximate and iodine adsorption number analysis were used to investigate the characteristics of activated carbon produced refers to Indonesian National Standard (SNI 06-3730-1995) including moisture content, ash content, volatile matter, fixed carbon and iodine absorption number. The best results were obtained at 6 h of activation with the characteristics of activated carbon such as moisture content, ash content, volatile matter, fixed carbon and iodine absorption number respectively as follows 3.5%, 14.91%, 9.81%, 71.78% and 505.1 mg/g. Activated carbon is a well known material that is used extensively in industrial purification and chemical recovery operations. It offers an attractive and inexpensive option for removal of several solutes from aqueous solutions.