Pusat Pengajian Kejuruteraan Kimia - Tesis

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Agro-Based Catalyst Systems For Converting Palm Based Oils With High Fatty Acids And Water Contents Into Methyl Esters
(0008-12)
Ganesan, Shangeetha
Present work focuses on producing a dual catalyst system to esterify fatty acids and . transesterify triglycerides into methyl esters in the presence of methanol. Firstly, boiler ash sourced from waste empty fruit bunches of the palm oil industry was characterized and used as a pseudo-homogeneous base catalyst for transesterification of palm olein. Boiler ash successfully transesterified palm olein at mild reaction conditions (3 wt.% dried boiler ash, 15: 1 methanol : oil molar ratio, methanol refluxing temperature and reaction time of 0.5 b) to produce 90% methyl esters. Calcium oxide (calcined at 900 oe for 2 h) was added to boiler ash in order to increase the free fatty acids and water tolerance of boiler ash for transesterification of low quality oils. A mixture of boiler ash-calcium oxide was found to be able to tolerate 3 wt.% water and 4 wt.% free fatty acids.
Development Of A Catalytic Membrane Reactor For The Production Of Ethylene Using Oxidative Coupling Of Methane (Oem)
(2006-09)
Chua, Yen Thien
A catalytic membrane reactor resembles shell and tube heat exchanger integrated with a tubular ceramic membrane was developed for the application in oxidative coupling of methane (OCM) reaction. A 3-components catalyst system (Na-W-Mn/Si02) was used to study the OCM reaction in a packed bed catalytic reactor. The effects of various operating parameters were studied using design of experiments method. The interaction effects of each parameter were obtained and response surface methodology coupled with central composite design was applied in determining the optimum condition. The predicted optimum condition of temperature 850oe, gas hourly space velocity at 23,947cm3/g.hr, catalyst pretreatment period of 2 hrs, CH" to O2 ratio 7 and dilution ratio 0.2 gave 40.55% methane conversion, 79.51 % C2+ selectivity and 32.24% C2+ yield. The experimental value of with 43.05% methane conversion, 70.62% C2+ selectivity and 30.40% C2+ yield was obtained at an optimum condition.
Ultrasonically Aided Cross-Flow Membrane Filtration System For Latex Wastewater
(2012-08)
Che Lah, Nuur Fahanis
In this current study, an ultrasonically-aided membrane filtration system that offers cleaned membrane after being fouled by latex wastewater was developed. Characterizations of latex wastewater were investigated to decide the best and suitable membrane used for this filtration system under optimum condition. Some characterization steps were done such as the latex particle size analysis, by using Transmission Electron Microscopy (TEM) and Atomic Force Microscope (AFM), pH, total solid (TS), total suspended solid (TSS), Biological Oxygen Demand (BODs), Chemical Oxygen Demand (COD) and viscosity. In order to obtain high permeability of the membrane, cellulose acetate membrane was used as the filter after characterized the latex wastewater based on the hydrophilicity of the membrane. Based on the literature, an ultrasonic-aided membrane filtration system was set up. The result from surface contact angle analysis proves that the membrane was a good hydrophilic membrane which is one of the crucial characteristic of a membrane used in this study. Fourier Transform Infra Red (FTIR) analysis was done to investigate the cleaning effectiveness of ultrasound waves to the fouled-membrane surface. The model of the fouling process was determined from the permeate flux trends.
Preparation Of Activated Carbon From Pineapple Peel And Pomelo Peel For Dyes Removal: Equilibrium, Kinetic And Thermodynamic Studies
(2012-08)
Rosli, Nur Aisyah
The production of activated carbon from pineapple peel (PiPAC) and pomelo peel (PoPAC) through physiochemical activation consisting of potassium hydroxide (KOH) impregnation and carbon dioxide (C02) gasification has been successfully investigated. Activated carbon produced were used for removal of methylene blue (MB), methyl red (MR) and remazol brilliant violet 5R (RBV) dyes from aqueous solution. The experimental design results revealed that the activation temperature, activation time and KOH impregnation ratio (IR) were significant factors influencing adsorption performance for MB, MR and RBV. The optimum preparation conditions of PiPAC and PoPAC for MB removal were at activation temperature, activation time and IR of 732°C, 1.96 hour, 3.00, and 750°C, 2.19 hour, 2.12, respectively. Whereas optimum preparation conditions obtained for PiPAC and PoPAC for MR removal were at activation temperature, activation time and IR of 748°C, 2.13 hour, 3.00, and 800°C, 2.19 hour, 2.96, respectively.
Heterogeneous Photo-Fenton Decolorization Of Acid Green 25 Using Local Natural Clays And Dolomite Based Catalysts
(2012-09)
Mohammad Azmi, Nur Hidayah
In this research work, three different type of catalysts from natural mineral resources were developed as heterogeneous catalyst support for the decolorization of Acid Green 25 (AG25) dye using photo-Fenton process in a batch system. Fe-Ipoh clay (Fe-IC), Fe-Bandar Baru clay (Fe-BBC) and Fe-Dolomite (Fe-DOL) were successfully synthesized by immobilized iron ions derived from ferric nitrate nonahydrate (Fe(N03)3.9H20) on the catalyst support, Ipoh clay (IC), Bandar Baru clay (BBC) and Dolomite (DOL), respectively through impregnation process. Preliminary studies on effect of calcination temperature ancl duration of time by all catalysts on decolorization of AG25 were investigated.
Development Of Model Based Decoupler For Multi Input Multi Output Distillation Column
(2013-01)
Lee, Qiao Hui
Distillation column is a complex multivariable system and exhibits nonlinear dynamic behaviour due to the complex processing configurations and high product purities. The strong coupling among control loops often invalidates conventional loop controllers. Coupling is a very common phenomenon in multiple input multiple output (MIMO) systems. During processes, multiple control loops are designed for a process plant to control and guarantee the product quality. However, the control loops interact with other significantly. Due to the interaction between the loops, the stability and the product quality of the process may be compromised. Therefore, decoupling control was introduced to reduce the coupling problem in the nonlinear system.
Adsorptive Cathodic Stripping Voltammertries Of Lead In Water Samples Using 2, 2'-Bipyridyl; 1,10- Phenanthroline And Nitrite Ions
(2013-02)
Jawad, Masar Hadi
A new differential pulse adsorptive cathodic stripping voltammetric (DPAdCSV) method was developed for the determination of lead concentration in aqueous solution.. This was based on complexation of lead with combination of two complexing agents viz 2,21-hipyridyl and 1,1 O-phenanthroline with nitrite at hanging mercury drop electrode (HMDE). Variables affecting the response such as pH, supporting electrolyte, initial purge time, drop size, stirring speed, deposition potential, deposition and equilibration times, sweep rate, pulse amplitude and ligand concentration were investigated. Using the first reagent 2,2'-bipyridyl with nitrite[reagent (I)] and under optimized conditions the relationship between peak current and lead concentration was linear in the range of 10-500 ng mL-l. The limit of detection was found to be 0.48 ng mL-l. The relative standard deviation (RSD) for n= 9 determinations of standard 25 ng mL-I Pb2+ was to 1.74% with linear regression coefficient (R2) 0.9991.
Moving Bed Sequencing Batch Reactor: Optimization Of Operational Parameters For Nitrogen And 4-Chlorophenol Removal
(2013-03)
Lim, Jun Wei
Moving bed sequencing batch reactor (MBSBR) which incorporates both suspended-growth and attached-growth biomasses in a single reactor has been widely used in wastewater treatment plants. Nevertheless, information on the treatment of nitrogen containing wastewater via MBSBR is still scarce. Thus, more attention from researchers to explore the potential of using MBSBR in biological nitrogen removal is needed. This study aimed to optimize the use of polyurethane (PU) foam cubes as a support media and to apply the optimum aeration strategy during the REACT phase in the MBSBR for the enhancement of nitrogen removal in low COOIN ratio wastewater. In addition, the effect of 4-chlorophenol (4-CP) on the simultaneous 4- CP and nitrogen removal in the MBSBR was also investigated. The MBSBR was initially packed with PU foam cubes of various sizes to determine the effect of support media size on nitrogen removal. Subsequently, the aeration strategy during the REACT phase was converted from continuous to intermittent aeration and the performance of both aeration strategies in removing nitrogen was compared. The attached-growth biomass from the PU foam cubes was also dried and later added into the MBSBR to assess the feasibility to be utilized as an alternative solid carbon source in enhancing the nitrogen removal.
Bioregenera Tion Of Granular Activated Carbon Loaded With Phenol And Ocresol By Immobilized Biomass: Quantification And Kinetic Studies
(2013-11)
Toh, Run Hong
The objectives of this study were to (i) develop a novel approach to bioregenerate GAC loaded with phenol and a-cresol, respectively, using immobilized biomass as well as immobilized PAC-biomass, (ii) quantify and compare the bioregeneration efficiencies of GAC loaded with phenol and a-cresol, respectively using suspended and immobilized biomasses as well as immobilized PAC-biomass, and (iii) develop kinetic models to describe the bioregeneration process of GAC loaded with phenol and a-cresol, respectively, using the immobilized biomass.
Nonlinear Model Predictive Control For Bioethanol Fermentation Process
(2014-02)
Mohd, Noraini
The bioethanol fermentation process has a complex dynamics and is inherently nonlinear. The nonlinearity behavior of the process is caused by the variation in the biomass composition with the operating conditions while the constraints inherited by the process increase the process complexity. Due to these reasons, the modelling and the control of the bioethanol fermentation process is difficult and the application of model based control strategies often lead to a better performance. In this work, a Nonlinear Model Predictive Controller (NMPC), which is one of the well-known model control strategies, has been developed to control the product concentration and the fermenter temperature of the bioethanol fermentation process.
Synthesis, Characterization And Anticancer Studies Of Ne\V Silver(I)-Nheterocyclic Carbene Complexes Derived From Nitrile-Functionalized Imidazolium Salts
(2014-03)
Hafiz, Zetty Zuliklia
Five new nitrile-functionalized N-heterocyclic carbene (NHC) salts namely, 3-(2-cyanobenzyl)-I-methylimidazolium hexafluorophosphate (1.PF6), 3-(3- cyanobenzy1)-l-methylimidazolium hexafl uorophosphate 1,3-bis(2- cyanobenzyl)imidazolium bromide (3.Br), 1,3-bis(2-cyanobenzyl)imidazolium hexafluorophosphate (4.PF6) and 1,3-bis(3-cyanobenzyl)imidazolium hexafluorophosphate (5.PF6) have been successfully synthesized in excellent yield (76-91 %). These imidazolium salts then were treated with a basic metal source, silver oxide, via a simple complexation reaction to afford six novel silver complexes (C1-C6) in good yields (69-84%).
Modeling And Optimization Of Solvent-Free Isoamyl Acetate Production Via Enzymatic Esterification
(2014-04)
Yusoff Azudin, Nurhazwani
Isoamyl acetate is an organic compound listed under the esterfamily, and used as flavor additive especially in food industries. Studies on esterification processes begin with traditional extraction of ester from plants,followed by chemical synthesis route. Nowadays, the esterification process has shifted to biocatalytic flavor due to consumer's inclination towards natural compared to chemical resources. Thisstudy was carried out to examine the reaction synthesis between acetic anhydride and isoamyl alcohol in the presence of Candida antarctica Lipase-B (CALB) as a catalyst in solvent-free system (SFS). Results show that two reactions took place: (i) between acetic anhydride and isoamyl alcohol, and (ii) between acetic acid and isoamyl alcohol. Effect of different reaction parameters on the final yield of isoamyl acetate, and optimization of process parametersusing a statistical tool were also investigatedwithresponse surface methodology (RSM).
Dissolution Of Natural Fiber Using Ionic Liquid For Production Of Cellulose Nanoparticles
(2014-04)
Yahya, Nadzirah
Natural fiber (NF) exhibits desirable properties such as renewability, biodegradability, environment-friendly, lightweight, low density, high specific mechanical performance, good electrical and thermal conductivities, and low cost. Cellulose nanoparticles (CNPs) embedded in NF possess even greater properties caused by the high crystallinity of cellulose fiber. In this study, dissolution process was used in order to extract these CNPs from NF source; coconut fiber (CF). The process was done using an ionic liquid (IL) 'green solvent' that are best known for their capabilities in chemical reaction and extraction! separation processes. IL is known to be non-volatile, non-flammable, and recyclable, with low toxicity and vapor pressure. The properties of CNPs extracted was further determined using fourier transform infrared (FTIR) analysis, thermogravimetric analysis (TGA), scanning electron microscope (SEM) analysis, high resolution thermal electron microscope (HRTEM) analysis and dynamic light scattering (DLS) analysis. An optimization studies on the ultrafine CNPs extraction resulted in an optimum operating condition of 74.90min, 10S.06°C and O.OS wt% of CF:IL.
Copper-Tannate Complexes As Antifoulant In Antifouling Paint For Fish-Cage Nets
(2014-05)
Usol Ghafli, Nurul Azwin
Tannin extracted from mangrove bark, Rhizophora apiculata (R. apiculata) was used as a natural-origin source to be complexed with copper(U) salt. The copper-tannate (Cu-T) produced was used as an antifoulant in antifouling paint. Mangrove bark was extracted using 70% (v/v) aqueous acetone and gives 31.1 % extraction yield. The total phenolic content (TPC) of mangrove tannin extract (MT) was 186.0 mg gallic acid equivalent per gram sample, total flavonoid content (TFC) was 96.0 mg catechin equivalent per gram sample and condensed tannin content (CTC) was 95.5% weight content. The optimum condition of copper-tannate complexes (Cu-T) was studied using precipitation curve on varies parameters which were copper dosage, reaction temperature, reaction time and pH of Cu-T solution. The optimum conditions were taking into account of Cu-T percentage yield and IR spectrum analysis. Three derivatives ofCu-T at different pH, which were Cu-T pH 3.5, Cu-T pH 5.0 and Cu-T pH 8.0, were chosen for further analysis. The concentration of copper element in CuT and commercialized antifoulant, Cu-Oma was measured using AAS analysis and shown that Cu-T complexes had lower amount of copper content which are almost 50% lower than Cu-Oma.
Biotransformation Of Ferulic Acid Extracted From Biomass To Biovanillin By Amycolatopsis Sp. Atcc 39116
(2014-11)
Abu Sepian, Noor Raihana
This study focuses on the biotransformation of synthetic and extracted ferulic acid (FA) from lignocellulosic biomass using growing cells of Amyco/alopsis sp. ATCC 39116 as a biocatalyst. Preliminary alkaline hydrolysis showed that the hydrolyzate from oil palm empty fruit bunch (OPEFB) contained the highest amount of FA (199.4 mg/l) among the other three lignocellulosic wastes (i.e. oil palm frond, coconut fiber and sheIl). Optimization of extraction was carried out using Response Surface Methodology (RSM) via Central Composite Design (CCD) on the effect of three independent variables, i.e. concentration of NaOH (1.5-5 M), solid/liquid ratio (0.03-0.084 g/ml) and time (16-32 h). The optimum FA concentration of 2.04 mg/g OPEFB (365.19 mg/l) was obtained under the optimal conditions of 1.5 M ofNaOH concentration, 0.03 g/ml of solid/liquid ratio and 32 h of extraction time. The extracted FA was further purified using polyvinylpolypyrrolidone (PVPP) and activated carbon, and about 97.26% was successfully recovered from the extract using PVPP. The partially purified FA was converted into 38.47% molar yield of vanillin, showing the ability of Amyco/alopsis sp. ATCC 39116 to convert the extracted FA from lignocellulosic waste.
Photocatalytic Degradation Of Indigo Carmine And Phenol Using Agzs04-Deposited Zno Under Outdoor Light Irradiation
(2014-12)
Choo, Hui Sun
Silver sulfate (Ag2S04) was successfully deposited on ZnO via a simple impregnation method. The as-synthesized sample was characterized by XRD, SEM, TEM, EDX, FTIR, UV-vis DRS and BET surface characteristic. Then, the photocatalytic activities of pure ZnO and three Ag2S04-deposited ZnO with different Ag2S04 loading were being evaluated for the degradation of indigo carmine and phenol under outdoor light irradiation. Results showed that the photocatalytic activities of all theer Ag2S04-deposited ZnO were higher than pure ZnO and commercial Ti02 for both pollutants degradation, especially 0.03 Ag2S04/ZnO which exhibited superior photocatalytic performance compare to others. After that, calcination temperature at 300 oe was found to be the most suitable condition for the preparation of 0.03 Ag2S0
Establishment Of The Callus And Cell Suspension Cultures For The Growth Of Pogostemon Cablin
(2014-12)
Che Saad, Norlia
In this study, plant cell culture technique was used in order to investigate the production of patchouli alcohol in callus and cell suspension cultures. The callus cultures were induced from the intact Pogostemon cablin leaves called explants. Different types, concentration of plant growth regulators (PGRs) and different culture conditions (light, carbon source and inoculum size) were studied in order to produce a rapid-growing callus cultures and well-dispersed cell suspension cultures or P. cublin. The best condition for callus cultures growth was obtained in the Murashige and Skoog (MS) basal medium containing I mg/L picloram (MS I d) which was maintained in the dark for 21 days. Callus cultures were healthy with whitish and friable features. However, the cultured explants showed negative response to MS medium supplemented with 2, 4- D and all combination of picloram and 2, 4-0. The healthy, fast growing and friable callus cultures were then used to establish the cell suspension cultures. Under the influences of different concentrations and combinations of PGRs and light, rapid growth of cell suspension cultures were observed in the MDI medium.
Marcoscopic and microscopic motion of iron oxide magnetic nanoparticles stabilized pickering emulsion magnetophoresis at low field gradient
(2020-04-01)
Tham, Foo Kean
A magnetic responsive of magnetic Pickering emulsion (MPE) was synergistically stabilized by the iron oxide nanoparticles (IONPs) coated by poly(sodium 4-styrenesulfonate) (PSS) and cetrimonium bromide (CTAB) as well as the adjacent CTAB molecules. In this project, MPE, IONPs, IONPs-PSS and IONP-PSS-CTAB were synthesized with their chemical, physical and magnetism properties thoroughly characterized. The synthesized MPE was studied under two main scales: (1) macroscopic and (2) microscopic experiment for the motion of MPE. For macroscopic experiment, the changing of turbidity of the MPE suspension was recorded by a digital camera using intervalometer. Whereas, a bright field optical microscope was employed to study the microscopic behavior of the Pickering emulsion. All images analysis were performed by standard technique using Image J. At the macroscopic scale, the magnetic separation efficiency of MPE at 90 % was achieved within 30 minutes for all condition. However, the colloidal stability of MPE at pH 10 was the lowest as compared to pH 3 and deionized water conditions. MPE at pH 10 required the shortest time for achieving the highest separation efficiency. Hence, MPE at pH 10 experienced cooperative magnetophoresis as it could be irreversible flocculated during magnetophoresis. Besides that, the MPE didn’t deform and coalescence under the magnetic field, B of 0.26 T~0.66 T and magnetic field gradient (𝑑𝐵𝑑𝑧⁄), ∇𝐵 of 52.07 T/m~ 95.74 T/m during macroscopic study. At the microscopic scale, different diameters (2.5 μm~7.5 μm) of emulsion droplets of MPE were migrated under magnetic field gradient (𝑑𝐵𝑑𝑧⁄), ∇B of 98.38 T/m. The largest droplets (7.5 μm) required the shortest time to achieve the highest terminal velocity. Moreover, magnetophoresis analysis also concluded that monolayer of magnetic nanoparticles (IONPs-PSS-CTAB composites) was formed for the all sizes of emulsion droplets. Magnetophoresis analysis also showed that the surface coverage of IONPs composites on the emulsion droplets was coincided with the high positive zeta potential of MPE. This is because the CTAB molecules occupied the other large proportions of the surface of emulsion droplets in addition IONPs-PSS-CTAB. The successful of magnetophoresis of new synthesized MPE also contributed a great prospect for the oil recovery to prevent the loss of energy source.
Infuence of mass transfer towards pilot-scale semi-continuous cultivation of chlorella vulgaris
(2020-06-01)
Khoo, Choon Gek
Microalgae, well-known for their prominent photosynthetic efficiency and rapid growth rate emerge as a great feedstock for bio-energy production of third-generation biofuel. In this study, Chlorella vulgaris was chosen as the subject of investigation. The aim was to maximize the biomass production by investigating both the kinetic and mass transfer phenomena in a pilot-scale bubble column photobioreactor (BC-PBR) cultivation system. To account for the maximum microalgal biomass accumulation, the microalgae growth condition was optimized in the semi-continuous cultivation mode. Each cultivation cycle was carried out with 15 days of batch cultivation mode, followed by 3 cycles of 5 days each during semi-continuous cultivation mode. One-factor-at-a-time (OFAT) method was employed to investigate the effects of inoculum concentration of microalgae cells, photoperiod, and aeration rate towards microalgal growth performance, in the range of 0.1 – 0.35 g L-1, 12 and 24 h, and 0.12 – 0.19 vvm, respectively. The underlying mass transfer mechanism between gaseous CO2 and the culture medium were investigated under the optimized growth conditions. In addition, the reusability of the recycled water from the harvesting process was evaluated. To convert the microalgae into application biofuel, the harvested microalgal biomass was then converted into hydrochar via hydrothermal carbonization (HTC) reaction. The effects of hydrothermal temperature and retention time and the properties of hydrochar were studied at the range of 180 – 250 oC and 0.5 – 4 h, respectively. The research results showed that the optimum biomass accumulation was at 0.9819 g L-1, with cultivation conditions of: inoculum concentration of 0.3 g L-1, exposed under continuous (24 h) illumination with light intensity 60 – 70 μmol m-2 s-1, and supplied with compressed air at aeration rate of 0.16 vvm. The cultivation system underwent a bubble breakup mechanism during the transportation of gaseous CO2 into the culture medium with gas-liquid mass transfer coefficient, kLaL(CO2) of 0.45 s-1. Higher CO2 concentration environment did not affect the biomass accumulation due to the solubility limitation of CO2 in the microalgae culture. Based on optimized growth conditions for microalgae, a mathematical model for microalgae growth was developed. By incorporating the mass transfer parameter into the modified growth model, which was validated through an extended 120 days (21 cycles) of semi-continuous cultivation. In addition, the microalgae cells were proven to be able to grow in the recycled harvesting water. On the other hand, the highest energy yield of hydrochar was achieved at 76.59%, at the HTC under 210 oC for 0.5 h. Comparatively, higher heating value (HHV) of hydrochar produced was measured to be 24.51 kJ g-1, which is higher than that of raw biomass (12.58 kJ g-1). Moreover, the HTC process produced an aqueous phase that could be used as an alternative nutrient source for microalgae cultivation, yielding an average biomass accumulation of 0.8483 g L-1, demonstrating the feasibility of close loop cultivation. To conclude, mass transfer was a dominant factor affecting the kinetic growth of microalgae in pilot-scale semi-continuous BC-PBR cultivation system. It further affected the quality of produced biomass, and thus affected the downstream processing route chosen for optimal conversion of bioenergy.
Synthesis of bifunctional activated carbon from gasification residues for malachite green dye and atenolol adsorption
(2020-09-01)
Ahmad, Anis Atikah
The abundance of gasification char residues which contributed to solid waste management problem is one of the major concerns in biomass gasification industry. This study aims to synthesize activated carbon (AC) derived from gasification residues for malachite green (MG) dye and atenolol (ATN) adsorption via microwave- induced potassium hydroxide (KOH) and carbon dioxide (CO2) activation. Optimum preparation conditions for all ACs prepared were determined using response surface methodology (RSM). Gasified Glyricidia sepium woodchips-based AC (GGSWAC) showed the highest BET surface area and total pore volume of 633.30 m2/g and 0.34 cm3/g, respectively for MG removal; and 483.07 m2/g and 0.26 cm3/g , respectively for ATN adsorption. All adsorbents best fitted to the n-BET isotherm model, suggesting a multilayer adsorption for all systems. Gasified rubber tree root-based AC (GRTRAC) and GGSWAC showed higher maximum saturation capacity (Qe) of 259.49 and 120.57 mg/g, respectively for MG and ATN adsorption at 30ºC. The AC derived from gasified oil palm empty fruit bunches (GOPEFBAC) showed reasonably high removal of MG with Qe value of 219.39 mg/g. Kinetic studies showed that all system followed Avrami model with film diffusion was the rate-limiting step controlling MG removal, while film diffusion and chemisorption controlled the ATN adsorption. Thermodynamic study confirmed that all systems, except ATN-GRTRAC were endothermic in nature. For the column studies, the better correlation of breakthrough data shown by Thomas and Yoon-Nelson model. Results indicated that GGSWAC was the best adsorbent due to its high adsorption performance for both MG dye and ATN removal.

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