Investigation of palm fibre pyrolysis over acidic catalyst for bio-fuel production

Abstract

This research aimed to evaluate the pyrolysis reaction for bio-fuel production from palm fibre. A preliminary step to investigate the effect of different type of heterogeneous catalyst revealed three different catalysts: zeolite type (H-Beta), tungsten–zirconia (WO3/ZrO2) and modified alumina (KOH/Al3O2). An increase in temperature was found to have a positive impact on the production of bio-fuel. Bio-fuel synthesis performed in a stainless steel tubular reactor was found to optimized at 650 °C using WO3/ZrO2 as a catalyst resulting in 40.5% bio-fuel, 7.1% bio-char and 14.3% gas. Formation of gas product is due to the presence of strong acid sites on the surface of WO3/ZrO2 promoting cracking reactions. H-Beta catalyst produced the largest about of bio-char which is also due to strong acid sites and narrow catalytic pore structure which caused rapid deposit of coke and then formation of bio-char. Pyrolysis of palm fibre over KOH/Al2O3 catalyst produced the least amount of bio-fuel, but contain the largest composition of phenolic compounds. These compounds are the transformed from lignin content in palm fibre on alkaline sites of the KOH/Al2O3 catalyst. A larger scale production facility was designed to produce larger amount of bio-fuel for the engine performance test. The biofuel blended gasoline (10% biofuel) was tested in an eight-cylinder spark–ignition engine. Engine performance testing revealed that the brake power and torque generated from combustion of bio-fuel blended oil was lower than conventional gasoline. The brake specific fuel consumption of bio-fuel blended was slightly higher than conventional gasoline.

Keywords

• Engine performance testing
• Heterogeneous catalyst
• Pyrolysis reaction
• Phenolic compounds