Khairuddin Md Isa
Thumbnail Image
Preferred name
Khairuddin Md Isa
Official Name
Md Isa, Khairuddin
Alternative Name
Isa, K. Md
Md Isa, Khairuddin
Md. Isa, Khairuddin
Isa, K. M.
Main Affiliation
Scopus Author ID
36188321600
Researcher ID
Y-7078-2019

Research Output

Filters

15
Reset filters

Settings
Now showing 1 - 10 of 15
  • Publication
    Sulfur dioxide removal by calcium-modified fibrous KCC-1 mesoporous silica: kinetics, thermodynamics, isotherm and mass transfer mechanism
    ( 2022-04-01)
    Hanif M.A.
    ;
    Naimah Ibrahim
    ;
    Khairuddin Md Isa
    ;
    Umi Fazara Md Ali
    ;
    Tuan Abdullah T.A.
    ;
    Jalil A.A.
    The removal of sulfur dioxide from industrial flue gas through dry flue gas desulfurization method commonly involves the use of adsorption process with porous sorbent. The efficiency of this process is highly dependent on the adsorption capacity and the adsorption rate of SO2 onto the sorbent materials. The use of KCC-1 mesoporous silica modified with calcium metal additives (Ca/KCC-1) in SO2 adsorption is examined in a fixed bed reactor system. The adsorption capacity of Ca/KCC-1 is found to be critically governed by the reaction temperature and inlet SO2 concentration where low values of both parameters are favorable to achieve the highest adsorption capacity of 3241.94 mg SO2/g sorbent. SO2 molecules are adsorbed on the surface of Ca/KCC-1 by both physisorption and chemisorption processes as assumed by the Avrami kinetic model. Thermodynamic study shows that the process is exothermic and spontaneous in nature, and changes from an ordered stage on the surface of KCC-1 towards an increasingly random stage. The process is well explained by Freundlich isotherm model indicating a slightly heterogeneous process and moderate adsorption capacity. The adsorption stage is limited by film diffusion at the initial stage and by intraparticle diffusion during the transfer of SO2 into the network of pores before adsorption takes place on the active sites.
  • Publication
    Optimization of hydrogen production from steam reforming of biomass tar over Ni/dolomite/La₂O₃ catalysts
    (Elsevier, 2020)
    Ru Shien Tan
    ;
    Tuan Amran Tuan Abdullah
    ;
    Aishah Abdul Jalil
    ;
    Khairuddin Md Isa
    Industrially, the endothermic process of steam reforming is carried out at the lowest temperature, steam to carbon (S/C) ratio, and gas hourly space velocity (GHSV) for maximum hydrogen (H2) production. In this study, a three-level three factorial Box-Behnken Design (BBD) of Response Surface Methodology (RSM) was applied to investigate the optimization of H2 production from steam reforming of gasified biomass tar over Ni/dolomite/La₂O₃ (NiDLa) catalysts. Consequently, reduced quadratic regression models were developed to fit the experimental data adequately. The effects of the independent variables (temperature, S/C ratio, and GHSV) on the responses (carbon conversion to gas and H2 yield) were examined. The results indicated that reaction temperature was the most significant factor affecting both responses. Ultimately, the optimum conditions predicted by RSM were 775 °C, S/C molar ratio of 1.02, and GHSV of 14,648 h−1, resulting in 99 mol% of carbon conversion to gas and 82 mol% of H2 yield.
  • Publication
    Tailoring the properties of calcium modified fibrous mesoporous silica KCC-1 for optimized sulfur dioxide removal
    ( 2022-01-01)
    Muhammad Adli Hanif
    ;
    Naimah Ibrahim
    ;
    Khairuddin Md Isa
    ;
    Fahmi Muhammad Ridwan
    ;
    Tuan Abdullah T.A.
    ;
    Jalil A.A.
    Dry regenerative flue gas desulfurization (FGD) is a promising method to tackle industrial issues regarding SO2 emission into the atmosphere due to its sorbent being highly accessible, the lack of water dependency and reduction in waste management. This study examined the feasibility of using fibrous mesoporous silica KCC-1 which has been reported to possess better properties than several other predecessor mesoporous silica as alternative sorbents for dry FGD. Calcium metal was introduced to overcome the lack of active sites available on KCC-1 while simultaneously providing sufficient basicity to counter the increase in acidity brought by SO2 adsorption. Three sorbent modification parameters were analyzed: metal loading (5–15 wt %), calcination temperature (823–973 K) and calcination time (5.5–7 h), and the prepared samples were characterized using BET surface area and pore analyzer, FESEM-EDX, XRD and H2-TPR. The breakthrough experiment was conducted using a lab scale fixed bed reactor system with 1500 ppm SO2/N2 at 200 mL/min. SO2 removal was optimized by sorbent prepared with calcium loading of 5 wt %, calcination temperature of 923 K and calcination time of 6.5 h with adsorption capacity of 3241.94 mg SO2/g KCC-1. The optimized sorbent demonstrated highest surface area, good pore development, high dispersion of calcium metal, appropriate impregnation of calcium oxide which caused only minor distortion to the silica framework of KCC-1. Subjecting the optimized sample to five consecutive regeneration cycles by heating at 773 K while simultaneously flowing N2 gas for an hour shows good regeneration performance with a total final reduction of only 25% from the initial adsorption capacity obtained from a fresh sample.
      1  42
  • Publication
    A single step transesterification process to produce biodiesel from the spent cooking oil
    ( 2021-05-24)
    Indah Thuraya Herman
    ;
    Khairuddin Md Isa
    ;
    Naimah Ibrahim
    ;
    Farizul Hafiz Kasim
    ;
    Abd Aziz M.A.
    A direct process of transesterification has been carried out to produce high yields of biodiesel. Conversion of waste cooking oil to methyl esters was performed using potassium hydroxide-glycerol (KOH-Gly) as a catalyst. KOH-Gly was produced by mixing KOH and glycerol at a mass ratio of 1:20 at a temperature of 80 oC for 120 minutes. The process of transesterification was performed at a reaction temperature of 60 oC, a molar ratio of oil to methanol of 1:6, 2% wt KOH-Gly catalytic loading for 30 minutes. This process resulted in a waste cooking oil conversion yield of about 97-98% to biodiesel using KOH-Gly as a catalyst. The two layers of the product were produced without the formation of soap, which facilitated the separation and purification process. Gas chromatography-mass spectrometry was used to analyse the chemical content of biodiesel.
      2  34
  • Publication
    Application of Mesoporous Silica as Catalyst Support in Sulfur Dioxide Removal: Metal and Amine Sorbent Modifications
    ( 2020-07-09)
    Adli Hanif M.
    ;
    Naimah Ibrahim
    ;
    Khairuddin Md Isa
    ;
    Abdul Jalil A.
    Emission of hazardous SO2 into the atmosphere due to the burning of fossil fuels in various industries is detrimental not only to the environment but also to human beings. Various mitigation techniques have been implemented to overcome this problem, with flue gas desulfurization (FGD) method being the most commonly used. Dry FGD does not typically perform as good as wet method and requires new type of sorbent to be tested. Mesoporous silica (MS), a sorbent with porosity in the range of 2-50 nm is considered as attractive alternative due to its high specific surface area, ordered pore structures and wide array of morphologies. Due to relatively weak interaction between MS and SO2 adsorbate during dry FGD process, additives are introduced to overcome this problem. These MS are modified with basic additives which are deemed more favorable for SO2 adsorption. Metal and amine-based additives are commonly employed where the latter are reported to obtain higher adsorption capacity. Increasing additive loading is beneficial up to an optimal value depending on the types of additives.
      10  33
  • Publication
    Comparative Study of Sulfur Dioxide Removal Using Mesoporous Silica KCC-1 and SBA-15
    ( 2022-01-01)
    Muhammad Adli Hanif
    ;
    Naimah Ibrahim
    ;
    Khairuddin Md Isa
    ;
    Masitah Hasan
    ;
    Tuan Abdullah T.A.
    ;
    Jalil A.A.
    Sulfur dioxide (SO2) emitted into the atmosphere by fossil fuel burning in the industries posed significant negative effects on humans and the environment. SO2 removal performance of two mesoporous silica: KCC-1 and SBA-15, are compared through breakthrough experiments on a lab-scale fixed bed reactor. The mesoporous silicas were characterized via nitrogen (N2) adsorption-desorption isotherm and field emission scanning electron microscopy (FESEM). KCC-1 demonstrates characteristics of capillary condensation and non-uniform slit-shaped pores while SBA-15 displays characteristic of a narrow range of mesopores with minimal network effects. Surface area, total pore volume and average pore diameter of KCC-1 are significantly greater than SBA-15 due to the presence of dendrimeric fibrous morphology. Under tested conditions, SO2 adsorption capacities of KCC-1 and SBA-15 are 614.01 mg/g and 274.64 mg/g, respectively. Superior performance by KCC-1 can be attributed to better accessibility of SO2 towards the active sites due to higher surface area provided by the dendrimer fibers.
      1  35
  • Publication
    Sulfur dioxide removal by calcium-modified fibrous KCC-1 mesoporous silica: kinetics, thermodynamics, isotherm and mass transfer mechanism
    ( 2022-04-01)
    Muhammad Adli Hanif
    ;
    Naimah Ibrahim
    ;
    Khairuddin Md Isa
    ;
    Umi Fazara Md Ali
    ;
    Tuan Abdullah T.A.
    ;
    Jalil A.A.
    The removal of sulfur dioxide from industrial flue gas through dry flue gas desulfurization method commonly involves the use of adsorption process with porous sorbent. The efficiency of this process is highly dependent on the adsorption capacity and the adsorption rate of SO2 onto the sorbent materials. The use of KCC-1 mesoporous silica modified with calcium metal additives (Ca/KCC-1) in SO2 adsorption is examined in a fixed bed reactor system. The adsorption capacity of Ca/KCC-1 is found to be critically governed by the reaction temperature and inlet SO2 concentration where low values of both parameters are favorable to achieve the highest adsorption capacity of 3241.94 mg SO2/g sorbent. SO2 molecules are adsorbed on the surface of Ca/KCC-1 by both physisorption and chemisorption processes as assumed by the Avrami kinetic model. Thermodynamic study shows that the process is exothermic and spontaneous in nature, and changes from an ordered stage on the surface of KCC-1 towards an increasingly random stage. The process is well explained by Freundlich isotherm model indicating a slightly heterogeneous process and moderate adsorption capacity. The adsorption stage is limited by film diffusion at the initial stage and by intraparticle diffusion during the transfer of SO2 into the network of pores before adsorption takes place on the active sites.
      2  26
  • Publication
    Innovative formulation and characterisation of grease made from waste engine oil
    (UPM Press, 2023)
    Muhammad Auni Hairunnaja
    ;
    Mohd Aizudin Abd Aziz
    ;
    Nurul Waheeda Abdu Rahman
    ;
    Mohd Azmir Arifin
    ;
    Khairuddin Md Isa
    ;
    Umi Fazara Md Ali
    Lubricating grease is usually produced from mineral oil, making the relationship between grease and mineral oil unavoidable. Formulation of grease from waste oil can reduce the dependency of the grease industry on mineral oil as well as help to reduce the waste generation of used oil. This study aims to produce fumed silica (FS) grease from waste engine oil (WEO) and analyse the properties of the formulated grease. The method started with treating WEO to remove any contaminants in the used oil. After that, the greases are produced using a weight percentage ratio before being examined for consistency, oil separation, oil bleeding, FTIR (Fourier transform infrared spectroscopy) analysis, and corrosiveness. In terms of uniformity, oil separation, and oil bleeding, WEO percentage content had a substantial impact on the findings. The FTIR demonstrated that synthetic greases had the same spectra when evaluated between 500 cm-1 and 4000 cm-1. The grease's corrosiveness is low, as determined by class 1 corrosiveness toward the copper strip. However, the grease properties differ when consistency, oil bleeding and oil separation test is done. Higher oil content in grease produced high oil bleeding and separation but low consistency. As a conclusion of the results, fumed silica grease with oil percentages of 83 and 82 have the most grease-like features, showing that the grease fits the traits' requirements. Based on the investigation's findings, it was established that WEO may be used as a base oil in grease formulation and that the grease's properties are satisfactory.
      2  10
  • Publication
    Chemically modified sugarcane bagasse as a potentially low-cost biosorbent for dye removal
    ( 2010)
    Saiful Azhar Saad
    ;
    Khairuddin Md Isa
    ;
    Rohazita Bahari
    The use of adsorbent prepared from sugarcane bagasse, an agro waste from sugar industries has been studied as an alternative substitute for activated carbon for the removal of dyes from wastewater. Adsorbents prepared from sugarcane bagasse were successfully used to remove the methyl red (MR) from an aqueous solution in a batch reactor. This study investigates the potential use of sugarcane bagasse, pretreated with phosphoric acid (SBC), for the removal of methyl red from simulated wastewater. Phosphoric acid treated sugarcane bagasse was used to adsorb methyl red at varying dye concentration, adsorbent dosage, pH and contact time. A similar experiment was conducted with commercially available powdered activated carbon (PAC) and untreated sugarcane bagasse (SB) in order to evaluate the performance of SBC. The adsorption efficiency of different adsorbents was in the order PAC > SBC > SB. The initial pH 3 to 6 favoured the adsorption of synthetic dyes by both SBC and SB. This prepared adsorbent was very efficient in decolorized diluted solution. It is proposed that SBC, in a batch or stirred tank reactors could be employed as a low-cost alternative in wastewater treatment for dyes removal.
      18  14
  • Publication
    Performance of Waste Cooking Oil Esterification for Biodiesel Production Using Various Catalysts
    ( 2024-03-01)
    Herman I.T.
    ;
    Khairuddin Md Isa
    ;
    Naimah Ibrahim
    ;
    Saiful Azhar Saad
    ;
    Abdullah T.A.T.
    ;
    Aziz M.A.A.
    ;
    Hairunnaja M.A.
    In this study, waste cooking oil (WCO) with high free fatty acid (FFA) content was esterified to produce biodiesel, and the catalysts’ performance was investigated. Two deep eutectic solvents (DESs) were employed as the liquid catalysts (K2CO3-Gly and KOH-Gly), while the solid heterogeneous catalysts used were spent bleaching earth (SBE), KCC-1, and Na/KCC-1. DESs were prepared by mixing at reaction temperature and time of 80°C and 120 min, respectively. The American Standard Testing Method (ASTM) D974 determined the acid value. The catalysts were first screened for their catalytic activity in WCO esterification. The parameters investigated in this study were oil-to-methanol molar ratio, catalyst loading, reaction time, and temperature. The highest conversion (94.7%) was obtained using Na/KCC-1. The performance of solid and liquid catalysts was evaluated using KOH-Gly and SBE for the reduction of FFA in WCO under different conditions of oil-to-methanol molar ratio (1:6–1:10), catalysts loading (0.2–2.0 g), reaction time (30–60 min), and temperature (40–100°C). The highest reduction of FFA in the esterification process for KOH-Gly and SBE as catalysts was 97.74% and 84.2%, respectively. Transesterification of the esterified oil shows a promising result (97%), and the process can potentially be scaled up. The GC-MS result shows that the produced oil has the highest percentage of hexadecanoic acid and methyl ester.
      2  43