Alina Rahayu Mohamed
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Preferred name
Alina Rahayu Mohamed
Official Name
Alina Rahayu, Mohamed
Alternative Name
Rahayu, M. Alina
Mohamed, Alina Rahayu
Rahayu Mohamed, Alina
Main Affiliation
Scopus Author ID
55349453800
Researcher ID
DHI-6721-2022

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  • Publication
    Durability properties of demineralized and torrefied Empty Fruit Bunch (EFB) pellets
    (IOP Publishing, 2020)
    Alina Rahayu Mohamed
    ;
    Ras Izzati Ismail
    ;
    Rashid, Mohammad Abdur
    ;
    Khairunissa Syairah Ahmad Sohaimi
    ;
    N N Kasim
    ;
    R Badlishah Ahmad
    The pelletization of raw and demineralized and torrefied empty fruit bunch (TDEFB) were conducted upon mixing with bio-oil that was obtained from EFB pyrolysis. The ratio of bio-oil addition to raw and TDEFB was varied from 0-20 wt%. Then it was pressed using the single pellet press machine. The effects of the ratio of bio-oil addition to raw and TDEFB and the thickness of pellets were evaluated towards its durability. It was identified that the ratio of bio-oil addition to raw and TDEFB pellet of 5 wt% had produced the optimum durability which was 69.27 and 74.46 % respectively. In terms of the thickness of the raw and torrefied pellets, it was determined that at thickness of 3 cm, the durability was the highest which were 70.12 and 71.12 % for both raw and TDEFB pellets respectively. The raw and TDEFB pellets were analysed using Fourier Transform Infra-Red (FTIR) spectroscopy in order to evaluate the presence of functional groups within the materials. The presence of O-H hydroxyl group, C=O from carbonyl or ester and C-H alkane groups are detected in both raw and torrefied pellets.
  • Publication
    Thermal characteristics of Malaysian Khaya Senegalensis wood fuel pellets: densification-induced changes at different feedstock moisture levels
    (Semarak Ilmu Publishing, 2025)
    Ras Izzati Ismail
    ;
    Alina Rahayu Mohamed
    This study investigates the thermal behaviour of Malaysian Khaya senegalensis wood energy pellets, examining the effects of densification at different feedstock moisture levels. Densified wood pellets are promising renewable energy sources, but the impact of densification on thermal characteristics, considering various moisture contents, is underexplored. The main objective is to quantify the thermal characteristics, which involved proximate analysis such as energy pellets’ ash content, fixed carbon, volatile matter, and calorific value. In this research, Malaysian Khaya senegalensis wood was converted into pellets through a densification process, spanning from of 4-20% feedstock moisture levels. The manufactured pellets were then subjected to various tests to characterize the thermal properties. Results reveal compelling insights on the relationships between densification, moisture content, and thermal properties. Densification significantly influenced thermal attributes, with effects tied to initial moisture content. Varying moisture levels led to distinct thermal responses, reflecting interactions between densification-induced changes in moisture and thermal responses. In this study, the best moisture content for ash content was found to be 16%, with 3.24% ash content, 16% moisture content with volatile matter of 85.24%, fixed carbon of 12% from 20% moisture content, and 16% moisture content with calorific value of 19.65 MJ/kg. These findings aid Khaya senegalensis wood pellet densification optimization for improved thermal performance. Understanding densification's impact on thermal behaviour under varying moisture conditions enhances pellet efficiency as sustainable energy sources. This research contributes to biomass pellet knowledge for renewable energy applications, advancing efficient and eco-friendly energy solutions.
  • Publication
    Cracking the code: process parameter effects on Khaya senegalensis energy pellet moisture content
    ( 2023-12)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    The production of energy pellets from biomass sources holds immense potential for sustainable renewable energy generation. This study investigates the influence of key process parameters on the moisture content of energy pellets derived from Khaya senegalensis, a promising biomass feedstock in Malaysia. With a focus on unlocking the relationship between process variables and pellet moisture, a systematic experimental approach was adopted. The objective of this study is to investigate the effects of raw material moisture, feedstock particle size, compression pressure, and pelletization temperature on the manufactured biomass energy pellet's moisture content. By employing a comprehensive design of experiments and statistical analysis, the nuanced effects of these parameters are revealed on the moisture content of Khaya senegalensis energy pellets. The results illuminate the complex interplay between these process variables and the final moisture characteristics of the pellets. Understanding how these parameters impact moisture content is crucial for optimizing pellet quality, combustion efficiency, and storage stability. The study found a quadratic relationship between particle size, compression pressure, and pelletization temperature, indicating that larger particle sizes correlate with higher moisture content. Excessive pressure led to elevated levels while increasing temperature showed a decreasing trend. This research contributes valuable insights that advance the knowledge frontier of biomass pelletization, paving the way for enhanced utilization of Khaya senegalensis as a renewable energy resource.
      1  34
  • Publication
    The effect of different khaya senegalensis raw feedstock particle sizes on solid fuel pellet quality
    ( 2020-07-09)
    Ras Izzati Ismail
    ;
    Usamah M.I.
    ;
    Abd Razak Shaari
    ;
    Yee K.C.
    ;
    Alina Rahayu Mohamed
    ;
    Mohd Riduan Jamalludin
    ;
    Norawanis Abdul Razak
    ;
    Leng L.Y.
    ;
    Nur Lailina Makhtar
    ;
    Rosli M.U.M.
    In recent years, the usage and demand for biomass pellet has been increasing due to the need of substitution for non-renewable energy source. Therefore, high quality solid fuel is in need to cater this demand. Pellet qualities such as durability, calorific value and density are different depending on the type of material, size of particle and the density of the feedstock. In this study, the durability, calorific value and unit density of Khaya Senegalensis pellet was investigated. This was done to identify the optimum particle size to obtain the best qualities of pellet possible. The ground biomass material was separated into 0.15 mm, 0.50 mm and 1.00 mm particle sizes, pelletized and ultimately the pellet durability, calorific value and unit density were tested in this study. It was found that 0.15 mm particle size resulted in the highest pellet durability, and density value. 1.00 mm particle size pellet has the highest calorific value. As a conclusion, different raw biomass feedstock particle size will affect the durability, density and calorific value of pellet.
      37  1
  • Publication
    Biomass fuel characteristics of Malaysian Khaya Senegalensis wood-derived energy pellets: effects of densification at varied processing temperatures
    ( 2024)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    This study addresses the effects of densification at varied pelletization temperatures on the novel Malaysian Khaya senegalensis wood-derived pellets biomass fuel characteristics. The lack of comprehensive understanding regarding the biomass fuel characteristics of this species prompted the research. By addressing this knowledge gap, this study explores the impact of temperature variations on key fuel properties, contributing to the optimization of sustainable biomass fuel production in manufacturing and materials processing. Khaya senegalensis wood, grown and harvested in Malaysia, was pelletized at different temperatures to analyze the calorific value, volatile matter content, ash content, fixed carbon, bulk density, and moisture contents of the pellets. The experimental data revealed a significant relationship between temperature and these fuel properties. Pelletizing at 75 °C produced the highest calorific value of 19.47 MJ/kg and the maximum fixed carbon content of 10.04%. A low ash level of 4.26% was achieved via pelletizing at 75 °C. According to the results, 75 °C produced the best thermophysical properties. These findings provide valuable understanding of how pelletization temperature influences fuel pellet thermophysical properties, a critical aspect in optimizing fuel pellet production, storage, advancing renewable energy resource utilization, and, finally, promoting a cleaner and more sustainable energy future.
      1  19
  • Publication
    The Effect of Different Waste Material Binders in Relation to Khaya Senegalensis Solid Fuel Pellet Quality
    ( 2023-11-01)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    ;
    Mustafa N.M.K.N.
    ;
    Lee Yit Leng
    ;
    Nur Lailina Makhtar
    ;
    Norawanis Abdul Razak
    Fuel pellets are an attractive renewable energy source derived from biomass sources thanks to their uniformity and ease of handling. However, raw biomass and waste material binders have several drawbacks, which include poor physical properties, particularly low density and compositional heterogeneity, which restrict their wider use as a general source of energy. Besides, due to the low energy density, low bulk density, and uneven shape and size of raw biomass, it is very difficult to store and transport biomass in its original form, which decreases transport efficiency. This study investigated the effect of waste material binders (rice husk, corn cob, and sugarcane bagasse) on the mechanical and thermal properties of Khaya Senagalensis pellets. The mechanical and thermal properties were determined according to ASTM standards. Waste material binders have affected pellet quality such as density, bulk density, moisture content, durability, compressive strength, shatter index, water resistance, ash content, volatile matter, fixed carbon, and calorific value. From the analysis, sugarcane bagasse as a binder shows the highest quality pellet in terms of mechanical properties. Sugarcane bagasse produces the highest density (0.967g/cm3), bulk density (0.4094), durability (99.71%), shatter index (98.85%), water resistance (98.35%), and thermal properties, which are the highest volatile matter (94.71%) and the lowest ash content (1.71%). In a nutshell, sugarcane bagasse is a good binder that gives a positive impact to the K.senegalensis pellets in terms of storage and transportation compared to corn cob and rice husk binder.
      37  1
  • Publication
    Optimization of fuel pellet parameter from oil palm fronds by using Response Surface Methodology (RSM)
    ( 2023-06)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    ;
    Nadiah Farzana Jamaludin
    ;
    Adli Azimi Abdul Rahman
    ;
    Mohd Riduan Jamalludin
    The oil palm tree, which had been producing a plentiful supply of oil palm fronds, had simply been left to rot on the ground. As biomass is a loose substance, pelletization was undertaken so that it could be transported and stored with ease. High-quality pellet production was studied to maximize oil palm frond use. Therefore, the primary goal of this study was to determine the impact of particle size and moisture content on fuel pellet quality. The response surface approach was utilized in this study to optimize the oil palm fronds pellet particle size and the moisture content on the durability, unit density, and calorific value. The particle sizes analyzed were 0.15 mm, 0.500 mm, and 1.00 mm, while the moisture content was 5%, 10.50%, and 16%. The pellets were manufactured using a hydraulic single pellet press, and their calorific value, unit density, and durability were evaluated using a bomb calorimeter, a density formula, and a sieve shaker, respectively. The optimization yielded the maximum desirability (0.5026) for particles with a 16% moisture content and a 0.500 mm particle size. The condition is ideal when the value of desirability is closest to 1.00. It may be concluded that the particle size and moisture content of oil palm fronds affect the durability, unit density, and calorific value of oil palm fronds pellet.
      1  65
  • Publication
    Pelletization Temperature and Pressure Effects on the Mechanical Properties of Khaya senegalensis Biomass Energy Pellets
    (MDPI, 2023)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    Biomass pellets are one of the most crucial feedstocks for bioenergy production on a global scale due to their numerous advantages over raw biomass resources. Pellets provide improved energy density, bulk density, moisture content, and homogeneity thereby reducing storage, handling, and transportation costs. To produce high-quality solid fuel, it is necessary to comprehend the properties of wood fuel. This study explored the potential of Khaya senegalensis (khaya) as a dedicated energy crop (DEC) for the production of green energy. It thrives in less-than-ideal conditions and grows rapidly. The low durability of energy pellets raises the risk of dust and fire during handling and storage. In addition, the potential for fines and dust formation is strongly correlated with the mechanical strength of materials. Due to this necessity, the current study examines the effects of pelletization factors, including temperature and pressure, on pellet properties, particularly on its mechanical properties. The durability and compressive strength of pellets were determined using a sieve shaker and a universal testing machine, respectively. The highest mechanical durability was observed at 3 tons of pressure and 75 degrees Celsius, each with a value of 99.6%. The maximum axial compressive strength was measured at 57.53 MPa under 5 tons of pressure. When pelletized at 125 °C, the axial compressive strength increased by 13.8037% to 66.06 MPa compared to the strength obtained at 5 tons of pressure. Pelletizing Khaya feedstocks at 4 tons of pressure, on the other hand, produced a slightly lower diametral compressive strength of 7.08 MPa compared to 7.59 MPa at 125 °C. The experimental results revealed that the aforementioned factors significantly affect the mechanical properties of pellets. The elucidation of wood biomass, solid fuel qualities and pelletization parameters of this potential energy crop may facilitate the production of high-quality pellets from Khaya senegalensis wood to meet the increasing local and worldwide energy demands.
      3  15
  • Publication
    Building Stronger Biomass : How Particle Size Affects the Physical and Mechanical Properties of Khaya senegalensis Fuel Pellets
    (Universiti Malaysia Perlis, 2025-06-10)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    Biomass has gained significant attention as a renewable energy source due to its potential to reduce dependency on fossil fuels and lower carbon emissions. Among various biomass-derived fuels, pelletized biomass offers enhanced energy density, improved combustion efficiency, and ease of handling and storage. Khaya senegalensis, a fast-growing tree that thrives in suboptimal conditions, requires regular pruning, leading to significant biomass waste. This study examines the influence of feedstock particle size on the mechanical properties of Khaya senegalensis fuel pellets. Biomass trimmings from Khaya tree branches were collected, processed into wood chips, and ground into five particle sizes (0.1, 0.3, 0.5, 1, and 2 mm) before pelletization. The pellets were produced under constant moisture content, pressure, temperature, and binder percentage. A one-factor-at-a-time (OFAT) approach was employed, with each process repeated three times to ensure consistency. The mechanical properties analyzed include unit density, durability, axial compressive strength, and diametral compressive strength. Experimental data are analyzed using analysis of variance (ANOVA) to examine correlations between feedstock particle sizes and mechanical properties. This study establishes that particle size plays a crucial role in determining the physical and mechanical properties of Khaya senegalensis wood pellets. The results indicate that finer particles (0.15 mm) contribute to higher unit density and durability, whereas coarser particles (1.00 mm) enhance compressive strength.
      17  1
  • Publication
    Cracking the Code : Process Parameter Effects on Khaya senegalensis Energy Pellet Moisture Content
    (Universiti Malaysia Perlis, 2023-12)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    The production of energy pellets from biomass sources holds immense potential for sustainable renewable energy generation. This study investigates the influence of key process parameters on the moisture content of energy pellets derived from Khaya senegalensis, a promising biomass feedstock in Malaysia. With a focus on unlocking the relationship between process variables and pellet moisture, a systematic experimental approach was adopted. The objective of this study is to investigate the effects of raw material moisture, feedstock particle size, compression pressure, and pelletization temperature on the manufactured biomass energy pellet's moisture content. By employing a comprehensive design of experiments and statistical analysis, the nuanced effects of these parameters are revealed on the moisture content of Khaya senegalensis energy pellets. The results illuminate the complex interplay between these process variables and the final moisture characteristics of the pellets. Understanding how these parameters impact moisture content is crucial for optimizing pellet quality, combustion efficiency, and storage stability. The study found a quadratic relationship between particle size, compression pressure, and pelletization temperature, indicating that larger particle sizes correlate with higher moisture content. Excessive pressure led to elevated levels while increasing temperature showed a decreasing trend. This research contributes valuable insights that advance the knowledge frontier of biomass pelletization, paving the way for enhanced utilization of Khaya senegalensis as a renewable energy resource.
      11  49