Biomass gasification is widely used for converting solid biomass into synthesis gas for energy applications. Raw biomass is commonly used as feedstock for the gasification process but it usually contains high moisture content and low energy value which lowering synthesis gas production. Thus, torrefaction as a pre-treatment process is necessary in order to upgrade the properties of feedstock for producing more synthesis gas production and improving gasification performance. The objective of this work is to study the effect of gasification temperature on the synthesis gas production and gasification performance using raw and torrefied palm mesocarp fibre (PMF). The gasification process is conducted using bubbling fluidized bed using steam as gasifying agent. Based on experimental work, by increasing gasification temperature from 650 – 900 °C, the compositions of hydrogen and carbon monoxide gases were enhanced greatly while carbon dioxide and methane gases were decreased for both raw and torrefied PMF. In terms of gasification performance, synthesis gas yield for raw and torrefied PMF is increased from 0.91 to 1.23 Nm3/kg and 1.10 to 1.35 Nm3/kg respectively. Besides, lower heating value (LHV) of torrefied PMF is 0.04 MJ/Nm3 higher than raw PMF at 900 °C. The result showed that the percentage of cold gas efficiency (CGE) reached maximum of 67% for raw PMF while carbon conversion (CC) at 85.6% for torrefied PMF at a gasification temperature of 900 °C. The higher CC obtained by torrefied PMF is because of the increment of carbon content from 45.2% to 53.7% as a result of torrefaction. Gasification temperature of 800 °C showed the best performance of the PMF gasification since the maximum performances of LHV is achieved and started to decrease once the gasification temperature is operated beyond 800 °C.

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An experimental work of empty fruit bunch gasification was conducted by using the bubbling fluidized bed to study the effect of the gasification temperature and steam biomass ratio (SBR) on the synthesis gas yield, Lower Heating Value (LHV) and Cold Gas Efficiency (CGE). Response Surface Methodology (RSM) was used to design the gasification experiment from the temperature range of 800 – 1000°C and SBR range of 0.5 – 1.5. Thirteen number of runs were generated based on Central Composite Design (CCD) with five replicated center points. Three regression models for predicting synthesis gas yield, LHV and CGE were developed and Analysis of Variance (ANOVA) was performed in this study. From ANOVA, the most influencing factor was gasification temperature which obtained higher F-value compared to SBR. The numerical optimization was also conducted in order to obtain the optimum condition to maximize the synthesis gas yield, LHV and CGE. From numerical optimization, gasification temperature of 800 °C and SBR of 1.14 were determined as the optimum condition which contributes to the maximum synthesis gas yield, LHV and CGE which are 1.25 Nm3/kg, 10.49 MJ/Nm3 and 90.72% respectively. The percentage error between the predicted and actual value of response variables was calculated and the error obtained lesser than 1%. Thus, it confirmed that the models obtained can be used to optimize the gasification of the empty fruit bunch.

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An experimental study of bubbling fluidized bed gasification process using empty fruit bunch (EFB) as a feedstock has been performed in order to study the effect of gasification temperature on gasification performance. Two types of EFB have been used, which are raw EFB and torrefied EFB at 300 °C. The composition of the synthesis gas, gas yield, low heating value (LHV), cold gas efficiency (CGE), and carbon conversion (CC) was determined and analyzed. In terms of synthesis gas, the composition of hydrogen and carbon monoxide gases were increased while methane and carbon monoxide gases were decreased for raw and torrefied EFB when the temperature is increased from 650 to 900 °C. Meanwhile, the synthesis gas yield was significantly enhanced and reached the maximum value of 1.21 and 1.45 MJ/Nm3 for raw and torrefied EFB respectively, which indicates that the torrefaction process improves the synthesis gas yield. Besides, the LHV for the torrefied EFB at highest gasification temperature is 11.08 MJ/Nm3 which is higher than raw EFB (10.81 MJ/Nm3). However, the value of CGE and CC of torrefied EFB are lower than raw EFB with the different about 3% and 5% respectively.