Lee Yit Leng
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Preferred name
Lee Yit Leng
Official Name
Yit Leng, Lee
Alternative Name
Leng, L. Y.
Leng, Lee Yit
Lee, Yit Leng
Main Affiliation
Scopus Author ID
36515068600
Researcher ID
AFJ-9629-2022

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  • Publication
    The effect of torrefaction reaction temperature on the Elaeis Guineensis Empty Fruit Bunch (EFB) pellet durability and calorific value
    ( 2020)
    Ras Izzati Ismail
    ;
    Lee Yit Leng
    ;
    Nur Lailina Makhtar
    ;
    A A A Rahman
    ;
    J A A Dali
    ;
    A R Shaari
    ;
    Khor Chu Yee
    ;
    A R Mohamed
    ;
    Mohd Riduan Jamalludin
    ;
    Norawanis Abdul Razak
    ;
    Wan Nur A'tiqah Wan Draman
    Empty Fruit Bunch (EFB) are not being fully utilized for energy production due to its high moisture content, low density, having bulky characteristics and low calorific value. In order to improve characteristic of Elaeis Guineensis empty fruit bunch as fuel, pre-treatment process is necessary to overcome these shortcomings. Therefore, the aim of this research is to examine the effect of torrefaction reaction temperature on the Elaeis Guineensis pellet energy characteristics. The observed pellet qualities include the pellet durability and calorific value of the pellet. The torrefaction of empty fruit bunch was conducted in a fixed-bed reactor at 200°C, 220°C, 240°C and 260°C. The torrefied sample was pelletized, analysed and tested to examine the characteristics of empty fruit bunch biomass as fuel. The pelletization process was carried out by using the cold single press pelletizer and using cassava starch as binder. At higher torrefaction temperature, the decomposition of cellulose and lignin become more prominent. At the torrefaction temperature 260°C, the gross calorific value is the highest due to the removal of moisture, release of volatile matter and the decomposition of biomass components such as hemicellulose, cellulose and lignin which resulted in energy densification. By comparing the torrefied empty fruit bunch at 260°C with the untorrefied empty fruit bunch, it was found that the torrefaction increased the energy densification and pellet qualities of empty fruit bunch that can be utilized as biomass energy sources in renewable energy.
      28  1
  • 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
    Antioxidant capacity and total phenolic content of fresh, oven-dried and stir-fried tamarind leaves
    ( 2017)
    Lee Yit Leng
    ;
    Mohd Nadzrin Mohammad Radzi
    ;
    Abd Razak Shaari
    ;
    Norawanis Abdul Razak
    ;
    Khor Chu Yee
    The aim of this study was to compare the antioxidant capacity and total phenolic content as well as the chemical groups of fresh, oven-dried and stir-fried tamarind (Tamarindus indica L.) leaves. Methanol was used for extraction of fresh, oven-dried and stir-fried tamarind leaves. The stir-fried leaves were prepared using medium heat for 10 minutes prior to extraction and chemical analysis while dried leaves were obtained by oven drying at 60°C for 3 hours. The stir-fried leaves had significantly highest total phenolic content (TPC) (139.87 mg/g) and percentage DPPH radical-scavenging inhibition (69.92%) while the fresh leaves had the lowest TPC (39.31 mg/g) and antioxidant capacity (16.46%). The FTIR spectral data suggest that the heat treatment increased the amine groups as well as the antioxidant capacity of the tamarind leaves. To increase the antioxidant capacity, the tamarind leaves should be prepared in a stir-frying process.
      1  20
  • Publication
    Mechanical and physical properties of khaya senegalensis solid fuel pellet with different binder percentages
    ( 2021-10-25)
    Ras Izzati Ismail
    ;
    Shaari A.R.
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    ;
    Rahim M.S.b.A.
    ;
    Lee Yit Leng
    ;
    Wan Nur A'tiqah Wan Draman
    ;
    Nur Lailina Makhtar
    ;
    Norawanis Abdul Razak
    ;
    Mohd Riduan Jamalludin
    The characteristics of the solid fuel pellets, such as its strength, durability and density can be used to assess its quality. During the transport and storage, pellets with low strength and durability produces dusts and ultimately resulting in equipment blockage, high pollution emissions, and an increased risk of fire and explosion. Therefore, pellet manufacturing process should be given priority to improve pellet quality. The use of binder in the production of pellets will aid in improving pellet quality. Therefore, this study investigates the influence of different binder percentages on the mechanical properties of K. senegelensis fuel pellets. Durability, unit density, bulk density and diametral compressive strength testing were carried out in compliance with international standards. It was discovered that pellets containing 4% cassava starch binder produces better results, particularly in terms of durability and compressive ldiametral strength.
      37  1
  • Publication
    Production of Solid Biofuels From Renewable Resources: A Review
    ( 2023-06-09)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Shaari A.R.
    ;
    Alina Rahayu Mohamed
    ;
    Abdul Halim M.H.B.
    ;
    Rahman A.A.A.
    ;
    Lee Yit Leng
    ;
    Nur Lailina Makhtar
    ;
    Norawanis Abdul Razak
    Increasing concerns over greenhouse gas emissions, volatile fossil fuel prices, and political instability have led to biomass as a renewable energy source. Close cooperation from the government supported by independent bodies also helps produce this effective and sustainable energy source. As a result, the current growth of solid biofuels has increased tremendously. Agricultural, municipal, forest, commercial waste and dedicated energy crops are the main sources of biomass. Due to this biomass's nature, the methods to produce them into solid biofuels are also different. The energy potential of these biomass sources is quite dependent on the use of technology and public awareness. Therefore, this paper review feedstock biomass, processing processes, product types and properties of solid biofuels in terms of mechanical and combustion. The paper also reviews the solid biofuel production situation in Malaysia.
      39  3