Activated Carbon from Date Palm Seed: Process Optimization Using Response Surface Methodology

Abstract

Date palm being one of the major biomass sources, largely being cultivated in UAE, is assessed for its potential to be an appropriate precursor for preparation of porous carbon. Porous carbon is prepared using the date palm pits in a tubular furnace with CO2 as the activating agent assessing the effect of process variables activation temperature, activation time and CO2 flow rate. Process optimization is performed to identify the process conditions that maximize the yield and BET surface area of the porous carbon using surface response methodology (RSM) based on central composite design (CCD). The influence of process parameters on the properties of porous carbon is investigated using analysis of variance (ANOVA) to identify the significant parameters. The optimum conditions for the preparation of porous carbon has been identified to be an activation temperature of 971°C, activation time of 56 min and CO2 flow rate of 5.1 cc/min based on the maximizing the yield and BET surface area. The optimum yield and BET surface area has been predicted to be 14.8% and 666 m2/g using the process optimization software. The textural characteristic of the optimized sample using nitrogen adsorption isotherm show the carbon to be predominantly microporous with the mean pore diameter estimated to be 1.76 nm using NLDFT method.