Effects of temperature, time and pressure on the hemicelluloses yield extracted using subcritical water extraction

摘要

Oil palm (Elaeis guineensis Jacq.) is one of the most important commercial crops for the production of palm oil, which generates 10.88 tons of oil palm fronds per hectare of plantation as by-product. Oil palm fronds contain about 30.4 % hemicelluloses, which can be extracted using chemical or heat treatment for useful applications. Subcritical water extraction is an extraction and fractionation technique that uses water as an attractant between 100 to 374 °C under pressure for maintaining liquid state and it is environmentally friendly because it does not use organic solvents. The objective of this research was to maximize the hemicelluloses yields extracted using subcritical water extraction. Hemicelluloses were extracted from oil palm fronds using subcritical water extraction with different pressures, temperatures and reaction times. The effects of temperature from 170°C to 200 °C, reaction time from 5 to 20 min, and pressure from 500 psi to 800 psi on the hemicellulose yields were examined. It was shown that the highest yield of hemicellulose (69.60%) was obtained at 10 min reaction time with the pressure and temperature of 600 psi and 190°C, respectively. This result indicate that subcritical water extraction can be performed in order to maximize the hemicellulose yield.