Now showing 1 - 10 of 35
  • 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.
    ;
    ; ; ;
    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
    Adsorption of carbon dioxide (CO2) by activated carbon derived from waste coffee grounds
    ( 2021-05-24)
    Lim H.K.
    ;
    ; ;
    Aroua M.K.
    Currently, three are several agricultural bio-based materials have been successfully utilized as gas adsorbents. In this study, waste coffee grounds (WCGs) have been selected as a potential precursor of Carbon Dioxide (CO2) adsorbents. The preparation parameters for activated carbon derived from WCGs were optimized using Response Surface Methodology (RSM). The optimized preparation parameters were found to be 1:3.67 impregnation ratio of acid, 533oC of carbonization temperature and 1.13 hours of activation time, which resulted in 23.6 wt% of yield. The physical and chemical characteristics of WCGAC in terms of surface morphology, carbon content, ash content and yield were also investigated. The CO2 breakthrough time using WCGAC were carried out at the temperatures of 30, 40, and 60°C. It was found that WCGAC shows a longer CO2 breakthrough times (5 mins) and a higher adsorption capacity (4.33 mg CO2/g adsorbent) at 30oC.
  • Publication
    Oil palm waste-derived reduced graphene oxide (rGO) for dynamic adsorption of dye in a fixed-bed system
    ( 2024-01-01)
    Mohd Ali Jinnah S.N.H.
    ;
    ; ; ; ;
    Mohamed Zuki F.
    This study focuses on investigating the dynamic adsorption of Rhodamine B (RhB) from reduced graphene oxide (rGO) derived from oil palm waste. The synthesis of rGO from palm kernel shell (PKS) was achieved through double oxidation and carbonization method, resulting in a yield of 73.5 wt%. The reduction of oxygen-containing functionalities process using PKS was confirmed by FTIR spectroscopy, microscopic evaluation, and X-ray diffraction analyses. Laboratory-scale fixed-bed experiments were conducted with various process parameters. Both PKS and rGO were used as adsorbents, and a comparison was made based on breakthrough curve analysis, adsorption capacity and percentage removal of dye. The adsorption kinetics of RhB on PKS and rGO were best described by the non-linear Yoon-Nelson model, with a high adsorption capacity of 88.32 mg/g and 195.24 mg/g respectively. Using both PKS and rGO, the maximum adsorption capacity was observed when using 10 cm bed depth column, inlet dye concentration of 5 mg/L, flow rate of 12 mL/min and pH of 7. PKS exhibited good dye removal with an efficiency of 66.54%. Meanwhile, the exothermic behavior highlighted the potential of utilizing rGO for maximum dye removal, achieving an efficiency of 90.35%. This study justifies rGO as a cost-effective superior dye removal adsorbent, providing new prospect for large-scale dye removal.
  • Publication
    Enhancement of microplastics and nanoplastics removal via filtration method using surface-engineered palm kernel shell biochar
    (Elsevier B.V, 2025-07)
    Muhammad Adli Hanif
    ;
    ;
    Nur Adlyna Hayazi
    ;
    ;
    Aishah Abdul Jalil
    ;
    Achmad Syafiuddin
    ;
    Microplastics (MP) and nanoplastics (NP) are major aquatic contaminants, raising concerns due to their strong affinity for other toxic substances. Filtration is widely employed for MP and NP removal due to its simplicity, efficiency and variety of available filtration media. In this study, the removal efficiency of MP and NP was investigated using surface-engineered biochar of palm kernel shell (PKS) origin, modified with cetyltrimethylammonium bromide (CTAB). The modified biochar demonstrated performance superior to the unmodified biochar, achieving 95.71 % and 96.12 % polyethylene MP (2–4 μm) removal efficiency as measured by turbidity and gravimetric methods, respectively, at an optimal CTAB concentration of 1.5CMC. The optimized biochar (PKS-1.5CMC) also improved the removal efficiencies for a range of other MP and NP particles varying in size (159 nm–48 μm), shape (irregular, spherical, fibrous) and polymer type (polyethylene, polyamide). The modification with CTAB increased the biochar's surface positive charge and hydrophobicity, resulting in stronger electrostatic attraction and hydrophobic interactions with MP and NP particles, which are negatively charged and hydrophobic by nature. In terms of MP and NP properties, higher removal efficiencies were obtained for (i) larger MPs due to easier retention, (ii) NPs due to their tendency to agglomerate, resulting in larger particle size, (iii) irregularly shaped particles, because of their surface roughness, providing more attachment sites and (iv) polyethylene MPs and NPs, owing to their higher hydrophobicity and lower negative zeta potential. Significant formation of a cake layer observed on the upper surface of the filter media suggested that filtration, rather than adsorption, was the dominant mechanism for the removal of MP and NP by biochar.
  • Publication
    Sulfur dioxide removal using deep eutectic solvent–functionalized palm kernel shell–activated carbon
    (Springer, 2025-02)
    Wan Nur Amanna Wan Nuzi
    ;
    Muhammad Adli Hanif
    ;
    ; ; ; ;
    Raja Nazrul Hakim Raja Nazri
    ;
    The release of SOâ‚‚ into the atmosphere is concerning due to its role in acidification, which threatens living organisms and the environment. Adsorption processes using materials like chemically modified activated carbon (AC) have demonstrated strong potential for removing SOâ‚‚ before its release. This study evaluates the performance of AC derived from palm kernel shells, and AC functionalized with choline chloride-glycerol, a deep eutectic solvent (DES) (AC-DES), in removing SOâ‚‚ through breakthrough experiments conducted in a fixed bed reactor. AC and AC-DES achieved SOâ‚‚ adsorption capacities of 0.522 and 2.763 mg SOâ‚‚/g adsorbent, respectively. Characterization of the adsorbents indicated that DES functionalization significantly increased the number of active sites for SOâ‚‚ adsorption, leading to superior adsorption performance of AC-DES. The optimization of process parameters identified 40 Â°C and 1500 ppm inlet SOâ‚‚ concentration as the ideal conditions for optimal SOâ‚‚ adsorption. Experimental data fitted with three adsorption kinetic and isotherm models indicated that SOâ‚‚ adsorption onto AC-DES is best described by the Avrami kinetic model and the Sips isotherm model. Thermodynamics studies revealed that the process is exothermic, thermodynamically non-spontaneous, and goes from a random state to an ordered one. The findings suggest that SOâ‚‚ adsorption onto AC-DES follows a complex mixed mechanism involving both physisorption and chemisorption, with surface heterogeneity and adsorbate-adsorbent interactions playing a critical role in controlling the adsorption process.
  • 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
    ;
    ;
    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  12
  • Publication
    Microplastics in facial cleanser: extraction, identification, potential toxicity, and continuous-flow removal using agricultural waste–based biochar
    Microplastic (MP) is an emerging contaminant of concern due to its ubiquitous quantity in the environment, small size, and potential toxicity due to strong affinity towards other contaminants. In this work, MP particles (5–300 μm) were extracted from a commercial facial cleanser and determined to be irregular polyethylene (PE) microbeads based on characterization with field emission scanning electron microscopy (FESEM) and Raman spectroscopy. The potential of extracted MP acting as toxic pollutants’ vector was analyzed via adsorption of methylene blue and methyl orange dye where significant dye uptake was observed. Synthetic wastewater containing the extracted MP was subjected to a continuous-flow column study using palm kernel shell and coconut shell biochar as the filter/adsorbent media. The prepared biochar was characterized via proximate and ultimate analysis, FESEM, contact angle measurement, atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectroscopy to investigate the role of the biochar properties in MP removal. MP removal performance was determined by measuring the turbidity and weighing the dry mass of particles remaining in the effluent following treatment. Promising results were obtained from the study with highest removal of MP (96.65%) attained through palm kernel shell biochar with particle size of 0.6–1.18 mm and continuous-flow column size of 20 mm. Graphical abstract: [Figure not available: see fulltext.].
      7  38
  • Publication
    Surface alkali promotion of carbon dioxide hydrogenation for conservation of carbon sources: Cyclic voltammetry study
    ( 2020-01-01)
    Tan S.Y.
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    ; ; ;
    Aroua M.K.
    Conversion of CO2 captured from biogas upgrading process into useful chemicals or fuels e.g. methane is an attractive route towards conservation of carbon sources. Sustainable hydrogenation route could be achieved by combining the process with hydrogen generated from water electrolysis. In this work, cyclic voltammetry was used as preliminary technique to probe the electrochemical behaviour of Na-modified Pt/YSZ as model catalyst under CO2 hydrogenation. The reaction is irreversible and the voltammogram features are not easily distinguishable under reaction conditions. The increase in cathodic peak height and the decrease in peak potential with addition of sodium at low coverage (0.32%) indicated that the charge transfer reaction was enhanced and thus the methanation reaction could be electrochemically promoted given sufficient amount of H2 flow. However, increasing Na coverage was found to decrease the current hysteresis possibly due to formation of sodium compounds such as carbonates or oxides that populate the three-phase-boundary (tpb) active sites, thus deactivating the catalyst.
      1  24
  • Publication
    Comparative Performance of Catalytic and Non-Catalytic Pyrolysis of Sugarcane Bagasse in Catatest Reactor System
    ( 2020-04-30)
    Faraheen Kabir Ahmad S.
    ;
    ; ; ;
    Sataimurthi O.
    Catalytic pyrolysis is a favourable process used to enhance the quality of bio-oil. Based on reviews from previous research there are only scarce of studies on the comparison of catalytic and non-catalytic pyrolysis of biomass such as rice husk, olive husk and corncob. In this study, sugarcane bagasse was selected as it has not been explored much yet. The target of this research is to compare the impact of catalytic and non-catalytic pyrolysis of sugarcane bagasse in terms of the yield, properties, and also the compositions of bio-oil. Catalytic and non-catalytic pyrolysis was executed in catatest bed reactor at temperatures 400°C to 550°C with the aids of ZSM-5 zeolite catalyst. Bio-oil from catalytic and no-catalytic pyrolysis which gives the maximum yield was used to be studied further in terms of the properties and chemical compositions. The result shows that the maximum yield of bio-oil was accomplished from catalytic pyrolysis at temperature 500°C which was 21.4%. The properties and composition of bio-oil from catalytic pyrolysis shows better result compare to non-catalytic pyrolysis.
      2  13
  • 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
    ;
    ; ; ;
    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  31