Production of Bio-fuels by microwave-assisted Rapid Hydrothermal Liquefaction of Palm Kernel Shells Biomass

Abstract

Hydrothermal Liquefaction (HTL) process is an alternative way for converting biomass to bio-fuels product. The aim of this study was to determine the effect of sample’s mass and heating time on the product yield (wt%) from palm kernel shells (PKS) and to characterize the bio-oil as produced. PKS which is one kind of biomass efficiently converted to bio-oil, bi-char and bio-gas by HTL associated with modified microwave oven. A modified household microwave oven with 800W was employed in this process. The product yield was increased proportionally with the sample mass from 31.16 wt% to 41.92 wt% for bio-oil at constant time of 15 minutes. However, a vice versa trend was observed for bio char. Furthermore, it was exhibited that the highest value of 66.51 wt% and then it reduced to 42.17 wt%. The last product, bio gas shows an increasing trend from 2.32wt% to 15.90wt%. For the second parameter, the production of bio oil decreases with the increasing of heating time while bio char and bio gas increases with the increases of time. For the highest product yield, the calorific value is 37.68 MJ/kg for 15g sample and 22.32 MJ/kg for 35g sample at 15 minutes heating time. Fourier Transform Infrared Spectroscopy (FTIR) result reveals that multiple functional groups i.e. alcohol, aldehydes, carboxylic acid and ketones is present in the PKS bio oil. Additionally, the pH value of the bio oil was in the range of 2-3.

Optimization Study on Microwave-Assisted Hydrothermal Liquefaction of Malaysian Macroalgae Chaetomorpha sp. for Phenolic-Rich Bio-Oil Production

“…Microwaves are the electromagnetic waves that are formed by coupling of electrical and magnetic fields perpendicularly, with a frequency range between 0.3 to 300 GHz. Most of the reported microwave chemistry experiments are carried out at 2.45 GHz [21][22][23][24]. Microwave heating has been considered as a promising technique for providing the energy required for the thermochemical process due to its volumetric and selective heating mechanism [25,26].…”