Empty Fruit Bunch Pellets Research Articles

Design of an automatic electric torrefaction reactor for oil palm empty fruit bunch pellets

Abstract One of the technologies for utilizing waste into high-quality fuel is torrefaction. Torefaction of empty palm fruit bunches is a thermochemical process without the presence of oxygen by heating the biomass slowly and holding it for a certain time. Torrefaction degrades the hemicellulose content to optimize mass and energy yields. The purpose of this study was to design a temperature control system using a electrical heater on a rotary torrefaction reactor for Oil Palm Empty Fruit Bunch (OPEFB) pellets. The validation temperature sensor has shown a coefficient of determination (R2) 0.9999 using the model coefficient y = 1.0029x + 0.4017. The performance results of the electric reactor control system for torrefaction show a temperature control accuracy of 85.77% at various setting points. The response of the temperature control system within 10 minutes can reach a temperature of 213°C and in the 13th minute it reaches 301.6°C. The stability of the tool produces good performance. The electric power consumption for 6 kg OPEFB pellets was 2.98 kWh at a cost of USD 0.33. The water content in the torrefaction pellets is 1-2%. The results of the hydrophobicity test showed that the torrefactive samples at temperatures above 200 °C did not change their physical form after immersion in water for 24 hours. These results indicate that the electric torrefaction reactor automatic has succeeded in increasing the caloric ratio of the material, resistance to water such as charcoal, but still has the characteristics and properties of biomass.

A Life Cycle Assessment of Cofiring in a Coal Power Plant to Estimate Purchasing Cost of Empty Fruit Bunch Pellets

A Life Cycle Assessment of Cofiring in a Coal Power Plant to Estimate Purchasing Cost of Empty Fruit Bunch Pellets

Oil Palm Empty Fruit Bunch (OPEFB) Pellets as a Biosorbent for Ni (II) and Cr (VI) removal in an aqueous solution

This study was carried out to examine the ability of adsorbent oil palm empty fruit bunch (OPEFB) pellet to remove Ni (II) and Cr (VI) in an aqueous solution. Raw OPEFB pellet and acid-treated OPEFB pellet were utilised as adsorbents. The constitution of OPEFB pellets that consisted of functional hydroxyl groups was proven by FT-IR results confirming its ability to adsorb Ni (II) and Cr (VI) ions. For the removal of Ni (II), the percent removal of Ni (II) was found to be better by using raw OPEFB pellets but the removal of Cr (VI) was found to be better by using acid-treated OPEFB pellets. The optimum conditions for Ni (II) removal were at pH 5, 10 mg/L of initial concentration, 2.0 g of pellets had removed 76% of Ni(II) within 90 min. The optimum conditions for Cr (VI) removal were at pH 7, 10 mg/L of initial concentration, 3.0 g of pellets had removed 63% of Cr (VI) within 120 min. Hence it was proved that oil palm empty fruit bunch pellet could successfully adsorb Ni (II) and Cr (VI) in an aqueous solution.

Microwave torrefaction of empty fruit bunch pellet: Simulation and validation of electric field and temperature distribution

Microwave simulation is significant in identifying a reactor design allowing the biomass to be heated and processed evenly. This study integrated the radio frequency and transient heat transfer modules to simulate the microwave distribution and investigated the performance of microwave heating in the cavity. The simulation results were compared with the experimental findings using the finite element analysis software of COMSOL MULTIPHYSICS to predict the temperature profile and electric field of microwave in the biomass (empty fruit bunch pellets). The higher temperature distribution was observed at the bottom and centre section of the empty fruit bunch pellet bed in the reactor, showing the uniqueness of microwave heating. According to the simulation results, the temperature profile obtained through the specific cavity geometry and dielectric properties agreed with the experimental temperature profile. The simulated temperature profile demonstrated a logarithmic increase of 120 °C/min at the first 50 s followed by 50 °C/min until 350 s. The experimental temperature profile showed three different heating rates before reaching 300 °C, including 78.3 °C/min (50–120 °C), 30.6 °C/min (121–250 °C), and 105 °C/min (250–300 °C). The results of this study might contribute to the improvement of microwave heating in biomass torrefaction.

An integrated life-cycle greenhouse gas protocol accounting on oil palm trunk and empty fruit bunch biofuel production

Improper discard of oil palm trunk and empty fruit bunch renders massive greenhouse gases. Turning these palm wastes into solid biofuels could aid in carbon reduction. The embodied environmental impacts of the solid biofuel densification process are neglected in carbon emission quantification studies applying Greenhouse Gas Protocol while the significance of classifying the system's direct and indirect carbon emissions were overlooked in those utilising life cycle assessment. Despite the prospect of both methodologies to complement their limitations for carbon emissions quantification, no study integrates both methodologies to investigate direct and indirect emissions systematically from a life cycle perspective. An integrated framework of life cycle assessment and Greenhouse Gas Protocol is developed to quantify the direct and indirect carbon emissions of oil palm trunk and empty fruit bunch densification from cradle-to-gate for three pellet plants in Indonesia and Malaysia. The emissions are categorised into three emission scopes: Scope 1, Scope 2, and Scope 3 according to the Greenhouse Gas Protocol, integrated with avoided emissions which are quantified via life cycle assessment. The pellet plants generate 534.7–732.3 kg CO2-eq/tonnepellet per hour, in which Scope 1 (i.e., direct emissions) is the major emission scope due to high emissions from wastewater production and drying fuel combustion. Washing equipment (169.2–439.0 kg CO2-eq/tonnepellet per hour) and burners (87.1–214.5 kg CO2-eq/tonnepellet per hour) are the hotspots found in the pellet plants. Producing empty fruit bunch pellets could reduce 62.0–74.1 % of emissions than landfilling the empty fruit bunch. Empty fruit bunch pellet and oil palm trunk pellet are recommended to co-fire with coal to phase down coal usage in achieving COP26 pledge. This study provides data-driven insights for quantifying carbon emissions through the integrated framework and could be a reference in future life cycle carbon footprint studies of the biomass densification process.

Integration of microwave co-torrefaction with helical lift for pellet fuel production

Abstract The heating performance of empty fruit bunch pellets (EFBPs) has been limited by its low energy density, high moisture, and ash content. Hence, microwave co-torrefaction (MCT) was performed with microwave heating unto waste oil mixed EFBP to produce high-energy biofuel. However, the non-homogeneous electromagnetic fields distribution in the microwave cavity results in an uneven heating behavior, producing the hot and cold spots. Hence, MCT coupled with helical lift was examined for its potential to improve heat distribution. The effect of temperature and types of waste oil on the proximate analysis and surface properties were studied. In comparison to the conventional torrefaction using a furnace (>30 min), MCT provided rapid heating (50–80°C·min−1) and a shorter process time (10 min). The use of helical lift with 2-dimensional movement – rotational (24 rpm·min−1) and vertical motion (5 cm·min−1) simultaneously, distributed microwave radiation uniformly for rapid heating. The proximate analysis demonstrated that the ash content was reduced from 8 to 3 wt%, and the highest fuel ratio of 2.0 was achieved. Additionally, the highly porous structure of EFBP biochar can act as an activated carbon precursor. MCT coupled with helical lift represents a promising approach to prevent hot spots during microwave heating.

A comparative assessment of biofuel products from rice husk and oil palm empty fruit bunch obtained from conventional and microwave pyrolysis

• This work is significance as sustainable alternative energy from biomass waste. • MP produced bio-oil with high monoaromatic and phenolic compound and low PAH. • High reaction temperature favour the production of biogas due to intensified secondary reactions. • A remarkable increase in syngas formation when reacted using MP in contrast to CP. Pyrolysis is an alternative heating method developed to produce bio-oil, biogas, and biochar from biomass, including oil palm empty fruit bunch (EFB) and rice husk (RH) pellets. This work focused on the comparison of the products obtained from microwave pyrolysis (MP) and conventional pyrolysis (CP). The experimental work was carried out using MP and CP at 500 °C and 800 °C. The properties of biochars produced from these reactions were characterized. The biofuels were characterized using FTIR and GC-MS, while the biogas was measured using GC-TCD. The composition of the H 2 gas or syngas was also analyzed. MP improved the yield of bio-oil and biochar, but the percentage of biogas yield decreased. The yield of bio-oil produced from the MP of RH and EFB pellets reacted at 800 °C increased significantly from 12.2 to 20.6 wt.% and 15.5 to 20.2 wt.%, respectively. The bio-oil derived from MP has a high content of monoaromatics and phenolic compounds compared to the oil produced from CP. Meanwhile, the bio-oil derived from CP contained a significant amount of polycyclic aromatic hydrocarbons. Although the yield of biogas produced via MP was slightly lower than CP, the total syngas produced from MP was significantly high for both EFB (78 vol.%) and RH (70 vol.%). For CP, only 62 vol.% and 68 vol.% of syngas was produced using EFB and RH, respectively. The findings highlight the potential of MP technology to synthesize environmentally-friendly bio-oil and biogas with a high percentage of syngas. Graphical Abstract .

Economic analysis on the potential of palm oil empty fruit bunch pellets as alternative fuel to reduce the cost of the government’s 3 kg LPG subsidy and its role in achieving sustainable development goals

Government subsidies related to 3 kg LPG per year are significant in the last three years if averaged up to IDR 50 trillion per year. Even though the number of users continue to increase, unfortunately, there are still many shortages of 3 kg LPG in areas outside Java; even in Java, there is still a scarcity. The Minister of Energy and Mineral Resources has issued Ministerial Decree No. 128 K / 70 / MEM / 2020 concerning the Task Force on Energy Security and Energy Utilization. In the second statement point, d stipulates the LPG Import Reduction Working Group. The purpose of this study is to calculate the economic value of the empty fruit bunch (EFB) pellet business as a recommendation to the government and the private sector. The method used is the calculation of NPV, MIRR, PBP, and ROI. In addition, ethical business and distribution models are used to deliver products to the end-user (customer) and guaranteed availability. Therefore, a breakthrough is needed to process empty fruit bunches (EFB) into industrial-scale solid fuel (pellets) that can replace 3 kg LPG, especially for poor people.

Production of biochar from microwave pyrolysis of empty fruit bunch in an alumina susceptor

Biomass-derived biochar emerges as a potential green bio-coal candidate for power generation. Microwave-assisted pyrolysis has been proven to be an efficient and economical technique for biomass conversion into biochar. The process can be further improved by utilising susceptor. This research focuses on producing biochar from microwave pyrolysis of empty fruit bunch (EFB) in an alumina susceptor. EFB pellet (PEFB) and EFB short fibre (FEFB) were pyrolysed in a 14 L bench scale microwave pyrolyser at temperatures between 200 and 400 °C. The pyrolyser performance (biochar yield, energy efficiency) and biochar properties (proximate analyses, ultimate analyses, calorific value and ash content) were analysed. The results showed that temperature of 300 °C demonstrated the optimised conditions for biochar production. FEFB produced 5.2% higher biochar yield and exhibited better biochar properties compared to PEFB. FEFB-derived biochar (FEFBC) overall characteristics were better than PEFB-derived biochar (PEFBC), with higher heating value (25.19 MJ/kg), fixed carbon (64.52%), volatile matter (13.38%) and carbon content (59.83%). However, FEFBC has high tendency of forming slagging and fouling in the combustor as the ash indexes were > 0.34 kg/GJ and RB/A > 1.75.

Torrefaction of oil palm empty fruit bunch pellets: product yield, distribution and fuel characterisation for enhanced energy recovery

In this study, the non-oxidative torrefaction of oil palm empty fruit bunch (OPEFB) pellets was investigated from 250 to 300 °C for 30 min in a horizontal fixed bed tubular reactor. The effects of the selected conditions on the yields, distributions and fuel characteristics of the torrefaction products were examined. The mass or solid yield (MY) decreased from 68.1 to 36.2%, whereas the liquid yield (LY) and gas yield (GY) increased from 19.4–40.1% and 12.5–23.7%, respectively, due to drying, devolatilization and depolymerisation during torrefaction. Physicochemical and calorific analyses showed that the torrefied OPEFB pellets have high carbon but low oxygen contents, which accounts for the high heating values (HHV = 22.83–25.81 MJ/kg). The torrefied OPEFB pellets also exhibit lower moisture (2–4%) and volatile matter (34.38–65.31 wt.%) but high ash (4–20 wt.%) and fixed carbon (28.69–41.62 wt.%) compared to the raw pellets. The OPEFB pellet fuel properties, namely pH that ranged from 6.65 to 7.74, hydrophobicity from 100 to 23.04% and grindability from 53.66 to 108, were markedly enhanced after torrefaction at 300 °C. The LY consisted of organics (67.64–62.62%) and water (32.36–37.38%) fractions characterised by high acidity (pH = 2.89–3.22) and dark hues formed by holocellulose and lignin thermal degradation at higher torrefaction temperatures. Based on the findings, the torrefied OPEFB pellets is a highly grindable, hydrophobic, thermally stable and promising solid biofuel for firing, co-firing or substituting coal in power plants provided the existing challenges that affect global biomass supply chains are addressed in detail.

Carbon dioxide torrefaction of oil palm empty fruit bunches pellets: characterisation and optimisation by response surface methodology

The carbon dioxide (CO2) torrefaction of oil palm empty fruit bunch (OPEFB) pellets was investigated at various temperatures from 250 to 300 °C and residence times from 15 to 60 minutes. The objective was to investigate the effects of CO2 torrefaction on the yield and characteristics of the torrefied products. The optimal conditions for maximum mass yield (MY) of CO2 torrefaction were also examined by response surface methodology (RSM) using full factorial design. Results revealed that temperature and time significantly influenced the mass (MY), liquid (LY) and gas (GY) yields. The MY and energy yield (EY) decreased with increasing severity of torrefaction, whereas the LY, GY, energy density (DE) and higher heating value (HHV) increased during the process. Characterisation revealed substantial improvements in the microstructure, pH, hydrophobicity and grindability of the torrefied pellets compared with the raw pellets. The thermal ignition and degradation characteristics of the OPEFB pellets were also significantly transformed after torrefaction. The liquid torrefaction products contained an acidic, turbid and pungent mixture of water and organic compounds. RSM optimisation revealed the optimal conditions: temperature of 275 °C and residence time of 35 minutes with the predicted MY of 50.54%, mass loss of ML = 49.46% and HHV = 24.47 MJ/kg. The findings revealed that CO2 torrefaction is a practical approach to clean energy recovery.

Potential of stepwise pyrolysis for on-site treatment of agro-residues and enrichment of value-added chemicals

This paper compares the yield and composition of bio-oil derived through stepwise and continuous pyrolysis of agro-residues. The temperature steps were selected using thermogravimetric analysis. Groundnut shell, empty fruit bunch pellets, and rice straw were pyrolyzed at 305 °C in the first step and 600 °C in the second step and pinewood chips were pyrolyzed at 340 °C and 600 °C. The cumulated yields of bio-oil were lower in both continuous and stepwise pyrolysis for agro-residues in comparison with woody biomass, with a corresponding increase in biochar and pyrolysis gas yields. Approximately 50% of the pinewood and 31–40% of the agro-residues were converted to bio-oil through both methods. This trend is explained by the differing biochemical composition of biomasses, and concentrations of inorganic components. Bio-oil fractions were separated into water-soluble and water-insoluble compounds before characterization. Bio-oil obtained in the first step was richer in organic acids, anhydrosugars, and carbonyl compounds, while the later fraction of bio-oil was richer in unbranched phenolic compounds. Thus, compounds known to promote bio-oil aging were separated into different fractions. Further, stepwise pyrolysis proved to be most effective for groundnut shells in isolating chemicals with a minimum loss of yield compared to continuous pyrolysis. A preliminary economic assessment of bio-oil showed that the value of bio-oil for crop residues was improved by 2–2.5 times during stepwise heating while for pinewood it reduced by half. This study provides a good starting point for further research in optimizing the temperature steps for pyrolysis and separation of chemicals from bio-oil.

Energy, economic, and environmental analysis of 10-MW biomass gasification based power generation in Malaysia

Biomass gasification based power plants can play an important role in power sector in Malaysia with her abundant agricultural and forest resources. In this research energy and economic feasibility, and environmental impact of biomass gasification power plant has been analyzed and assessed for sustainable power generation in Malaysia, the plant being a clean development mechanism supported project. Gasification based power generation with a dual fuel internal combustion engine is found more biomass combustion power plant. But, the annual fuel cost is significantly higher with gasification plant claiming MYR 10 million/y for a generation of 67,500 MWh. The net present value, internal rate of return, and PBP for a 10-MW gasification based dual fuel internal combustion engine power plant without loan financing using empty fruit bunch pellet as biomass; with CER issued at USD16/tCO2; and without loan financing provides net present value, internal rate of return, and PBP of MYR 19.68 million, 11.90%, and 6.05 y, respectively. With a loan financing at 3% per year with CER still be effective the net present value, internal rate of return, and PBP is estimated to be MYR 7.03 million, 3.97%, and 11.78 y, respectively. However, if a 60:40 debt equity is applied then the project net present value, internal rate of return, and payback period seen to improve slightly. The net present value attains a positive value of MYR 3.6 million. Internal rate of return and PBP values are found to be 7.08% and 8.27 y, respectively. The emission reduction achieved with the plant is 17,863 t CO2/y, 206 t SO2/y, 90 t NOx/y, and 10.37 t CO/y, respectively. Energy efficiency and tariff policy have been found to have highest impact on economic profitability of gasification based power generation units.

Production of high quality empty fruit bunch pellet by water washing and torrefaction

EFB pellet is the high potential biomass for combustion process due to the relatively high heating value and the high availability in the Southern of Thailand. However, the containing of high unwanted minerals, especially K and Cl is the main drawback of EFB pellet which causing the ash fouling or/and slagging during the combustion. In this study, the high quality EFB pellets (low K, low Cl, high heating value) were produced by applying the water washing and torrefaction methods. For water washing treatment, the effect of water and acetic acid solution on the mineral content of EFB pellet was studied. In addition, the effect of torrefaction temperature (250, 280 and 300 °C) on the quality of EFB pellet was investigated. Results revealed that the ash content of the washed EFB decreased from 5.3 % to 3.0 % and 0.7 % by washing with tap water and acetic acid solution, respectively. Comparing with the raw EFB pellet, K and Cl in ash were significantly reduced by washing about 60 % and 88 %, respectively. Heating value of the EFB and washed EFB pellet were increased after torrefaction with the higher temperature. The water washed EFB pellet and torrefied at 300 °C gave the highest heating value about 24.3 MJ/kg. It was 33% increased HHV when comparing with raw EFB pellet.

Non-oxidative thermal decomposition of oil palm empty fruit bunch pellets: fuel characterisation, thermogravimetric, kinetic, and thermodynamic analyses

The pre-treatment and pelletisation of oil palm empty fruit bunches (OPEFB) can potentially improve its biofuel properties for efficient thermal energy recovery. Therefore, this paper examines the physicochemical, thermal, kinetic, and thermodynamic properties of OPEFB pellets as a potential feedstock for pyrolysis. Physicochemical analysis revealed high proportions of carbon, volatiles, and fixed carbon compared to nitrogen and sulphur. Morphological analysis showed that the pellet microstructure is comprised of a dense network of polymeric fibres, whereas its ash has consistently shaped agglomerated particles with fine-textured surfaces. Thermogravimetric analysis (TGA) revealed the OPEFB pellets experienced significant mass loss (ML = 72.8–80.4%) and residual mass (RM = 19.6–27.2%) during thermal decomposition from 30 to 800 °C. The DTG plots revealed thermal decomposition occurred in three stages: I (30–150 °C), II (150–600 °C), and III (600–800 °C) due to drying, devolatilization, and char degradation, respectively. Kinetic analysis showed the activation energy, Ea, ranged from 76.87 to 195.78 kJ/mol, while frequency factor, A, was from 4.77 × 1001 to 1.22 × 1018 min−1 for the Flynn-Wall Ozawa and Kissinger-Akahira Sunose models. The highest kinetic parameters were observed at α = 0.40, indicating the rate-determining step for OPEFB pellets decomposition under pyrolysis condition occurs at 40% conversion. Thermodynamic analysis showed that thermal decomposition of OPEFB pellets was characterised by the formation of an activated complex, high reactive multiphase first-order reactions, and short reaction times. In conclusion, the results indicate that OPEFB pellets is a potentially suitable feedstock for pyrolysis owing to its excellent fuel properties and environmentally friendly nature.

Particle temperature and flue gas emission of a burning single pellet in air and oxy-fuel combustion

Pelletization of biomass increases the bulk energy density and the uniformity in size and shape with minimized mechanical degradation from transport, storage, and handling. A pellet can be burned in industrial circulating fluidized-bed or fixed-bed furnaces. This experimental study examines the combustion behavior of single pine wood and empty fruit bunch pellets in a laboratory-scale entrained-flow reactor. Individual biomass pellets were oxidized under both N2/O2 (79%/21%) and CO2/O2 (79%/21%) to investigate the burning characteristics during oxy-fuel combustion. The gas temperature was set at 860 K, 970 K, and 1090 K to examine its effect on combustion behavior. The burning pellets were directly observed in a visualization window in the reactor throughout the sequential combustion process. Direct observation, optical pyrometry, and flue gas analysis are synchronized for each pellet to interpret the relation between phenomenological events, particle temperature, and flue gas emission. The experimental results shows an increased homogenous ignition delay and a conical, less sooty flame in the presence of CO2. The particle temperature under CO2/O2 atmosphere is slightly lower than that under N2/O2, especially for the volatile combustion. The CO emission under CO2/O2 is significantly higher and produced from incomplete combustion. These combustion characteristics are attributed to low oxygen diffusion and the high volumetric heat capacity of CO2. The pine wood displayed a fast, homogeneous ignition and a sooty flame with high NO and SO2 emissions compared to the empty fruit bunches.

Effects of hydrothermal treatment and pelletizing temperature on the mechanical properties of empty fruit bunch pellets

Empty fruit bunch (EFB) has a high potential to be utilized as energy source. This study investigated the effects of the hydrothermal treatment and pelletizing temperature on the physical properties of the EFB pellets. EFB was hydrothermally treated using 10 m3 batch-type reactor and water washed using a centrifugal machine. Single pellet making device was used for pelletization of both treated and untreated EFB. The pellets were densified at a pressure of 60 MPa and a temperature of 100, 150 and 200 °C by using a single pelletizer.The pellet density, the compressive strength, the hydrophobicity and the durability of the produced pellets were evaluated. In addition, scanning electron microscope (SEM) was also utilized to examine the binding mechanism and its quality. The results showed that combination of hydrothermal treatment and water washing significantly improved the physical properties of EFB pellets especially, at the pelletizing temperature of 100 °C. At the pelletizing temperature of 100 °C, the pellet durability index (PDI) and compressive strength of untreated EFB pellet increased from 78.1% and 5.6 MPa to 98.72% and 15.6 MPa, respectively when compared to the treated pellet. Notable increase in pellet properties of untreated EFB were also observed as pelletizing temperature increase. At pelleting temperature of 200 °C, PDI and maximum load to 92.83% and 14.2 MPa respectively. However, only slight improvement in characteristics of the washed hydrochar pellets were observed as the pelletizing temperature increased. Finally, the energy balance in the process of EFB-to-Pellet was roughly calculated for the commercialized system, and the output energy in pellet products could reach 89.90%.

Effects of hydrothermal treatment and pelletizing temperature on physical properties of empty fruit bunch pellets

Abstract Palm empty fruit bunch (EFB) has a high potential to be utilized as energy source in Indonesia. However, due to some of its properties such as low bulk density, low hydrophobicity, high moisture content, high chlorine and alkaline content, pretreatment of EFB is required before it can be utilized as fuel. This study examined the effects of hydrothermal treatment and pelleting temperature on physical characteristics of EFB pellets. EFB was hydrothermally treated using 10m3 batch type reactor and water leached using centrifugal machine. Single pellet making device was used for densification of both treated and untreated EFB. Pellets were compacted at a pressure of 60 MPa and temperature of 100, 150 and 200 °C. Pellet density, compressive strength and durability of each pellets were evaluated. Results indicated that combination of hydrothermal treatment and water leaching significantly improved pelletization performance of EFB especially when it was pelletized at 100 °C. At pelleting temperature of 100 °C, pellet durability index (PDI) and compressive strength of EFB increased from 78.1% and 2.85 MPa to 98.72% and 7.80 MPa respectively when it was hydrothermally treated. Notable increase in pellet properties of untreated EFB were also observed as pelletizing temperature increase. At pelleting temperature of 200 °C, PDI and compressive strength increased to 92.83% and 7.09 MPa respectively. However, only slight improvement in characteristics of the washed hydrochar pellets were observed as the pelletizing temperature increased.

Preliminary torrefaction of oil palm empty fruit bunch pellets

Torrefaction of pelletised oil palm empty fruit bunches (OPEFBs) is a promising pretreatment technique for improving its solid biofuel properties and energy recovery potential. Therefore, this paper investigates the torrefaction of OPEFB pellets to examine the effects of temperature and purge gas flow rate on mass yield (MY), energy yield (EY), and mass loss (ML). The results revealed that MY and EY decreased due to significant ML during torrefaction. Furthermore, significant improvements in the higher heating value (HHV) and energy density (DE) were observed. The torrefaction temperature increased liquid (tar) and gas yields mainly above 300 °C at the expense of solid products. However, the effect of purge gas flow rate on the torrefaction products was found to be negligible. Consequently, the torrefaction of OPEFB pellets were limited to 250-300 °C, 30 min, and nitrogen (N2) gas flow rate of 200 ml min-1.

Design and Development of Downdraft Gasifier to Generate Producer Gas

The drive towards renewable energy become intense nowadays due to the increasing price of fossil fuels and depletion of their sources. Among promising resource of renewable energy is the biomass. In Malaysia, oil palm biomass are available in large quantity and suitable for conversion into value added bio-fuels. In this study, an-innovative small-scale downdraft gasifier was designed, development and tested for biomass gasification. The gasifier operates at flowrate less than 0.1 m/s 3 with a capacity of 5 KW. During testing and commissioning of the gasifier, the maximum efficiency of the gasifier was found to be about 71% when firing empty fruit bunch pellets. This gasifier has potentials to be up scaled for actual use either for domestic or industrial use.