Now showing 1 - 10 of 32
  • 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
    Production of fuel grade anhydrous ethanol: A review
    ( 2021-05-24)
    Lee Y.H.
    ;
    Chen C.H.
    ;
    ;
    Alcoholic fermentation of fermentable carbon sources like molasses and table sugar using yeast are typical route in producing alcohol particularly known as bioethanol (C2H5OH). The key challenge encountered in bioethanol production process is to eliminate the impurity presence within the bioethanol which mainly water. Distillation is an energy extensive process which commonly used to recover ethanol up to 95% purity due to the presence of azeotropic composition. The distillation will no longer appropriate for further purification once the azeotrope composition has reached. Nonetheless, to be able to use as a viable fuel for gasoline engine or for any other utilizations where the purity is a major concern, further dehydration steps are needed producing an absolute ethanol. Few studies have been investigated on various dehydration methods for producing anhydrous ethanol, including azeotropic distillation, extractive distillation, adsorption, membrane pervaporation, and solvent extraction process. This review offers an insight into currently used technology on the ethanol dehydration methods and the future prospect on the continuous improvement particularly on the process energy requirement and efficiency will be discussed.
      2
  • 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  10
  • Publication
    Surface alkali promotion of carbon dioxide hydrogenation for conservation of carbon sources: Cyclic voltammetry study
    ( 2020-01-01)
    Tan S.Y.
    ;
    ; ; ;
    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  21
  • 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  10
  • Publication
    Advancement in recycling waste tire activated carbon to potential adsorbents
    ( 2022-12-01) ;
    Hussin F.
    ;
    ;
    Aroua M.K.
    ;
    Khamidun M.H.
    ;
    Jusoh N.
    ;
    ;
    Ahmad S.F.K.
    Waste tires have been identified as one of the contributors to environmental problems and the issue of inadequate landfill spaces. The lack of consistent and systematic approaches such as specific regulations/laws or mechanisms of waste management to waste tires, limited application of technology for recycling waste tires and lack of awareness on the impacts of waste tires problem, make waste tires a source of environmental pollution. Various researches have been conducted on recycling waste tires into polymer bends, and materials to harden concretes, fuels and adsorbent. Researchers suggested that pyrolysis is the current trend of recycling waste tire to harvest the saleable pyrolysis oil and the recycled carbon black. Therefore, this review attempts to compile relevant knowledge about the potential of adsorbent derived from waste tires to be applied in the removal of various types of pollutants like heavy metals, organic pollutants, dye and air/gaseous pollutant. Studies were carried out on revealing the properties and the characteristics of activated carbon derived from waste tire as effective adsorbent which influence the application performance at liquid or gas phase. In addition, the challenges in the production of activated carbon derived from waste tire were discussed.
      1  31
  • Publication
    The Grease Formulation Using Waste Substances from Palm Oil Refinery and Other Industrial Wastes: A Review
    ( 2023-08-01)
    Hairunnaja M.A.
    ;
    Aziz M.A.A.
    ;
    Bashari N.A.F.
    ;
    Arifin M.A.
    ;
    Nedumaran N.
    ;
    ;
    Many applications use Spent Bleaching Earth (SBE) despite being considered hazardous waste from the palm oil refinery process. Its production increases yearly, similar to waste cooking oil (WCO). The SBE is known as a thickener in grease formulation. The same goes for red gypsum, waste motor oil, stearic acid, and lithium hydroxide monohydrate. They are all considered thickeners but have different durability in protecting base oil in grease. Then, previous studies revealed their performances with side effects detection against the environment and human bodies. Cooking oil is a heat transfer medium for serving foods with higher amounts of unsaturated fatty acids. The number of fatty acids might change after cooking oil consumption and become highly demanded due to the chemical properties of density, viscosity and fatty acids. Nowadays, people lack awareness of the importance of recycling palm oil waste. They intend to dispose of it instead of recycling it for sustainable energy resources. Therefore, this paper will discuss the grease formulation, contaminant available in WCO, its treatment, issues regarding different thickener consumption, treatment against Spent Bleaching Earth (SBE), and propose the safe thickener and additives for future intakes. This study found that adding Fume Silica (F.S.) as a thickener and Molybdenum Disulfide (MoS2) enhanced the grease stability. Further treatment against SBE (remove residue oil) and WCO (metal elements, undesired impurities and water content) is necessary for providing good quality formulated grease.
      3  29
  • 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  26