An Exploration of Modified Microwave-assisted Rapid Hydrothermal Liquefaction Process for Conversion of Palm Kernel Shells to Bio-oil

Abstract

Bio-oil is one of the potential resources to address the sustainable energy development and environmental issues. Microwave-assisted Rapid Hydrothermal Liquefaction Process is one of the popular techniques that is used to extract bio-oil from biomass. In this paper, the bio-oil has been extracted from Palm Kernel Shells by using microwave-assisted and conventional heating pyrolysis processes. A modified heating mantle apparatus are used to conduct the experiment for extracting the bio-oil. The experiments are conducted by varying the hydrothermal temperature and time for both techniques to achieve the conversion of the bio-oil from the raw material. It is found that the yield of bio-oil for microwave-assisted Rapid Hydrothermal Liquefaction Process at 350°C and 400°C are from 10.70 wt% to 25.60 wt% within hydrothermal time 6, 9 and 12 minutes. The pH value of the bio-oil is acidic with the range from 3 to 4. The calorific value of the bio-oil is varied from 24 to 26 MJ/kg for both conversion methods. Fourier Transform Infrared Spectroscopy (FTIR) result reveals that multiple functional groups (alcohol, aldehydes, carboxylic acid and ketones) are present in the PKS bio-oil.