Nor Afzanizam Samiran

The increase in the production of municipal solid waste (MSW) and oil palm biomass in Malaysia needs to be managed using more advanced thermochemical solutions to overcome the shortcomings of existing conventional gasification technologies such as high tar production, low conversion efficiency, and unstable syngas quality. This study was conducted to evaluate the performance of a thermal arc plasma co-gasification process using a combination of oil palm empty bunches (EFB) and plastic waste, specifically low-density polyethylene (LDPE) and polyethylene terephthalate (PET) as feedstock. The experiments were conducted in triplicates to ensure data reliability, using a 9 kW plasma integrated downdraft reactor operating at atmospheric pressure with a reaction time of 10–12 minutes at 90/10, 80/20, and 70/30 blend ratios. Gas chromatography analysis revealed that increasing the plastic fraction significantly enhanced hydrogen production (H2), with the EFB-LDPE blend reaching a maximum concentration of 8.83% at the 70/30 ratio, indicating an improvement in syngas quality. The optimum energy yield was obtained at the 80/20 blend ratio, producing a peak high calorific value (HHV) of 3.72 MJ/kg for the LDPE blend and 2.91 MJ/kg for the PET blend, demonstrating favourable energy recovery potential. Scanning Electron Microscopy (SEM) analysis using ImageJ software showed that the incorporation of LDPE increased the porous area to 18.05% with an average pore size of 55.29 µm², suggesting enhanced gas-solid interaction and improved char reactivity during the gasification process. In addition, Fourier Transform Infrared Spectroscopy (FTIR) analysis provided evidence at the molecular level regarding the ability of plasma to decompose complex polymer structures. For the EFB-PET char product, the appearance of peaks at 1014.93 cm⁻¹ and 1378.04 cm⁻¹ indicated the formation of ester bonds and partial decomposition of the polymer chain. For the EFB-LDPE sample, the detection of C=N stretching vibrations at 2332.52 cm⁻¹ and C-O-C ester vibrations at 1012.98 cm⁻¹ confirmed the existence of a structural recombination process and strong interactions between the biomass fraction and the polymer. Overall, these findings prove that plasma co-gasification can not only optimize syngas quality, but also assist in the complete transformation of waste into more stable char residue with the presence of distinctive functional groups.

The transition towards oxy–methane combustion is mainly driven by the need to improve CO₂ separation for carbon capture and storage (CCS) applications. However, operating with pure oxygen without any form of dilution often results in excessively high flame temperatures, which can significantly promote thermal NOₓ formation. In this study, the issue is examined through CFD simulations, focusing on both emission characteristics and thermal behaviour. The modelling framework combines the k–ω SST turbulence model with a mixture fraction PDF approach to compare three combustion environments, namely air combustion, pure oxygen, and a 50% O2– 50% CO2 oxy-fuel mixture. The numerical model was first validated against reference data, with temperature deviations remaining below 10%, indicating reasonable agreement. The results show that the pure oxygen case produces the highest peak temperature, reaching approximately 1900 K, which is accompanied by a significant increase in NO emissions due to the temperature-sensitive Zeldovich mechanism. When CO2 is introduced as a diluent, the combustion behaviour changes noticeably. The peak temperature decreases to around 1600 K, while NO formation is reduced. This can be linked to the higher heat capacity of CO2 as well as its contribution to radiative heat transfer, both of which help to moderate the combustion process. Further analysis of the velocity field and species distribution (CO, O2, CO2, and N2) suggests that the 50% O2– 50% CO2 configuration provides a more balanced condition. It maintains flame stability while keeping pollutant emissions at a lower level and, at the same time, produces a CO₂-rich exhaust stream that is more suitable for CCS applications. Overall, the findings suggest that CO2 dilution plays a key role in achieving a practical balance between combustion performance, emission control, and sustainability. This highlights its importance in the design of future low-carbon combustion systems.

Rigid spray polyurethane (RSPU) was commercially used as an injection in crack walls or soil surfaces to enhance material performance, increase lifetime, and save operating costs. The limitation of the RSPU nozzle was reported as easily clogging when sprayed out to the insulation and crack surface area and the finished product was less aesthetically pleasing. In this study, the RSPU nozzle of flat fan nozzle, 180° angle (Design A), Hollow cone nozzle, 60° angle (Design B), and Full cone nozzle, 90° angle (Design C) were prepared by using the SOLIDWORKS software. The effect of different pressures for RSPU nozzle design at the ranges of 4Mpa, 5MPa, and 6MPa was examined by ANSYS FLUENT software. The velocity of the outer spray nozzle shows a significant increase with increasing inlet pressure of the RSPU nozzle. The results reveal that the highest velocity of RSPU was obtained at the Hollow cone nozzle (Design B) as compared to (Flat fan nozzle) Design A and (Full cone nozzle) Design C at 394.249 m/s at 4MPa, 442.327 m/s at 5MPa and 485.37 m/s at 6MPa, respectively. The distribution droplet area shows the Design B spray formation had wider area coverage at 60° and exhibited that the injection nozzle spray was scatted and uniform at 6MPa. RSPU shows the velocity increased, distribution droplet increased, and output volume spray was decreased at the increasing of injection pressure. Hence, in this study was suggested that the size of RSPU nozzle design must be made at the ranges of 60° to 90° of outlet nozzle to obtain a good RSPU area. In conclusion, design B is the most effective for RSPU nozzle and is useful in injection cracking and insulation materials applications.

Performance for Horizontal Axial Wind Turbine (HAWT) is influenced by the difference in tip speed ratio (TSR) and mesh distribution. The objective of this article is to study the optimal performance of wind turbines when subjected to different mesh resolution, TSR and wind speed velocity.Therefore, it is important to study the effects of different mesh resolutions in terms of wind turbine performance. To achieve that, a 0.65m optimal twist and tapered (OPT) blade is used with various inlet velocities and TSR. This study uses the k-ꞷ shear-stress transport (SST) based Reynold-Average Navier Stokes (RANS) approach in commercial ANSYS Fluent CFD software. This simulation was performed using the Moving Ratio Frame (MRF) method. To find the optimum grid resolution, a Grid Independence Test (GIT) was conducted comparing the coefficient of power (Cp). From the RESULT, TSR 6 shows the best HAWT performance when Cp for inlet velocity 8 m/s is 0.2608.

Empty fruit bunch (EFB) contribute to a higher availability waste percentage compared to other types of residues in Malaysia’s Oil palm industries. Converting E Empty fruit bunch (EFB) contribute to a higher availability waste percentage compared to other types of residues in Malaysia’s Oil palm industries. Converting E

A poor management of solid residues from the oil palm industry is detrimental to health and the environment. One of the most produced wastes is the empty fruit A poor management of solid residues from the oil palm industry is detrimental to health and the environment. One of the most produced wastes is the empty fruit

Empty Fruit Bunch (EFB) is one of the promising wastes that can be converted into a valuable product such as activated carbon (AC) which is applicable for adsorption applications. The main objective of this work is to prepare and characterize the morphological surface properties of AC from EFB which is suitable for the adsorption of dye compounds and methylene blue application. AC was prepared by KOH impregnation with ultrasonic power and physical activation using a tube furnace. The influences of activation time using ultrasonic power (0, 45, 90 min) and activation time (300, 500, 700˚C) on the properties of the AC were analyzed. The surface morphology of activated carbon was analyzed using a scanning electron microscope (SEM). The samples were prepared using an ultrasonic method for 45 minutes during impregnation time. It is observed that the development of the pore increases as the chemical impregnation and ultrasonic time and activation temperature increase. EFB is identified as a suitable material for AC production as it is capable to develop the AC physical properties via specific processes and methods.

Combustion industries for many decades dealing with the issues in reducing the emissions without affecting the performance of combustion. The present study aims to investigate the performance of swirler mechanism which combining between both axial and radial types to reduce emissions and increase the mixing process via the non-premixed method. Each of axial and radial swirler consisted with 8 blades vane. Swirl angle for radial swirler is 35° and inclination angle for axial swirler is 15°. The swirler is designed using Solidworks software package and CFD analysis was then performed using ANSYS Fluent software package. The fuel used is liquefied petroleum gas (LPG) gas which contained 30% propane and 70% butane. The turbulence model standard k-epsilon was used in this study. The result found that the combined swirler was capable to reduce CO emission as the complete reaction into CO2 component was higher. This is due to the broader region of temperature and higher velocity magnitude produced by the combined swirler. However, the maximum temperature result for axial swirler was higher than the combined swirler. As a recommendation, the inclination blade angle in the axial swirler of the combined swirler should be increased to increase the temperature value

The present study investigated the performance of thermal arch plasma suction downdraft gasification which utilizing pelletized empty fruit bunch as a feedstock in producing syngas with high thermochemical conversion efficiency. Gasifying medium of air was used in this system. Syngas produced was evaluated and measured in terms of gas composition, carbon conversion efficiency, cold gas efficiency, syngas yield and calorific value. The effect of different equivalence ratio ranged from 0.18 to 0.46 was also evaluated. The results reported that syngas produced contained higher CO of 14.2 vol% at higher equivalent ratio, 0.42. In contrast to H₂ content, higher composition of 9.92 vol% was produced at lower equivalent ratio, 0.18. HHV and CGE value was higher at equivalent ratio of 0.36 which correspond to the balanced constituent of CO, H₂ and CH₄ at this condition. CCE and syngas yield was maximum at higher equivalent ratio of 0.46 due to higher production of CO from carbon elements. The results of the present study provided a useful data and guideline of equivalent ratio range for operational of plasma downdraft reactor.

The demand for a high-speed car is increasing in which vehicle stability and fuel economy are a primary concern. The vehicle’s aerodynamics play a crucial role as they influence the overall performance of the vehicles. The study of car aerodynamics involves the study of various forces that are acting on a car while it is moving on the road, i.e., drag force, lift force. The leading cause of aerodynamic drag for automotive vehicles is the flow separation at the rear end of the vehicles. By reducing the drag force, it is possible to improve the fuel economy. To study the delay of flow separation, rear-end spoiler application is tested at the end of a sedan car using a numerical model. This study is conducted by using Computational Fluids Dynamics (CFD) ANSYS software to analyze the flow pattern, drag coefficient Cd, lift coefficient Cₗ, streamline pattern, and pressure contour of a sedan car. The model was tested with seven conditions which are without rear end spoiler attached and with a rear-end spoiler of six different inclination angles (0°, -2°, 2°, 4°, 6° and 8°). The two-equation models utilized in this work are k with the Reynolds-averaged Navier Stokes (RANS) equations for the fluid flow behavior around the sedan automobile. The Reynolds number used is Re = 3.94 x 10⁶. Based on the results, the drag and lift coefficient of all models differs which affect the car fuel efficiency and stability. The velocity streamlines flow and vortex formation pattern differ according to the rear-end spoiler inclination angle.