Effect of one step activation KOH modified carbon in dimethyl carbonate transesterification reactions

Abstract

In this work one step activation was introduced to potassium hydroxide (KOH) modified palm kernel shells. Various concentration of potassium hydroxide was used to activate and impregnate palm kernel shell before calcined at 600 °C for 2 hours. All the prepared samples were characterized using Fourier Transform Infrared spectroscopy (FTIR), Nitrogen Adsorption Analysis and Field Emission Scanning Electron Microscope (FESEM), respectively. The basicity and basic strength of the prepared samples were determined using back titration methods. Following the preparation, the samples were used as base heterogeneous catalyst in palm oil transesterification reaction using dimethyl carbonate (DMC). Analysis of the products were performed using Gas Chromatography-Flame Ionization Detector (GC-FID) while to check the possibility of leaching, that is the presence of potassium in the biodiesel X-ray Fluorescence (XRF) spectroscopy was used. FTIR analysis of the raw palm kernel shell showed the presence of various functional groups. However, after the activation most of the functional groups were eliminated. A high BET surface area of 1054 m2/g was obtained from 10% AC/K, while the BET surface area for 15%, 20% and 25% AC/K decreases. This study shows, as the percentage of one step activation potassium doped carbon increases, the basic strength increases and followed by the increase in biodiesel production with leaching free reaction. The percentage conversion of biodiesel for 10% AC/KOH, 15% AC/KOH, 20% AC/KOH and 25% AC/KOH calculated were 35%, 45%, 63% and 67%, respectively.