Thermal decomposition of oil palm fruit press fiber (FPF) with sub/supercritical methanol, ethanol, acetone, and 1,4-dioxane treatments were investigated using a high-pressure autoclave reactor. When FPF was decomposed with methanol, ethanol, and acetone from 483 to 603 K, the highest degree of conversion obtained were 81.5%, 77.8%, and 67.9% while the highest liquid product yield (LP) obtained were 38.0%, 36.9%, and 38.5%, respectively. For the case of 1,4-dioxane, the conversion of FPF increased from 18.30% to 80.00%, while LP yield increased dramatically from 13.30% to 50.90% (consisting of 42.3% bio-oil compounds) when the reaction temperature was increased from 483 to 563 K. However, the conversion of FPF and LP yield decreased to 69.60% and 24.10%, respectively, when the temperature was further increased to 603 K. Comparison between all the solvents, subcritical 1,4-dioxane treatment was found very effective in the degradation of FPF to produce bio-oil component.
Thermal decomposition of oil palm fruit press fiber (FPF) into a liquid product (LP) was achieved using subcritical water treatment in the presence of sodium hydroxide in a high pressure batch reactor. This study uses experimental design and process optimisation tools to maximise the LP yield using response surface methodology (RSM) with central composite rotatable design (CCRD). The independent variables were temperature, residence time, particle size, specimen loading, and additive loading. The mathematical model that was developed fit the experimental results well for all of the response variables that were studied. The optimal conditions were found to be a temperature of 551 K, a residence time of 40 min, a particle size of 710-1000 microm, a specimen loading of 5 g, and a additive loading of 9 wt.% to achieve a LP yield of 76.16%.
Decomposition of oil palm fruit press fiber (FPF) to various liquid products in subcritical water was investigated using a high-pressure autoclave reactor with and without the presence of catalyst. When the reaction was carried in the absence of catalyst, the conversion of solid to liquid products increased from 54.9% at 483 K to 75.8% at 603 K. Simultaneously, the liquid yield increased from 28.8% to 39.1%. The liquid products were sub-categorized to bio-oil (benzene soluble, diethylether soluble, acetone soluble) and water soluble. When 10% ZnCl(2) was added, the conversion increased slightly but gaseous products increased significantly. However, when 10% Na(2)CO(3) and 10% NaOH were added independently, the solid conversion increased to almost 90%. In the presence of catalyst, the liquid products were mainly bio-oil compounds. Although solid conversion increased at higher reaction temperature, but the liquid yield did not increase at higher temperature.