Pusat Pengajian Kejuruteraan Kimia - Tesis

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High-performance titaniumfunctionalised Sba-15 adsorbent for carbon dioxide adsorption
(2024-03)
Shalini a/p Mahendran
The adverse effects of global warming have attracted the attention of the world’s public and are becoming increasingly important today. This is a consequence of the greenhouse effect, in which greenhouse gases, especially CO2, trap heat near the Earth’s surface. Despite this, CO2 has several advantages, including the ability to generate electricity and fuel. Therefore, the use of one of the three primary methods of carbon capture is crucial to remove CO2 from the environment. CO2 adsorption when paired with a suitable adsorbent, presents itself as a promising technology for addressing the challenges posed by the rising CO2 levels and global climate change. In the sol-gel method, Santa Barbara Amorphous-15 (SBA-15) was produced using TEOS, a source of silica, and Pluronic P123, a non-ionic surfactant, with hydrochloric acid (HCl) serving as the catalyst. However, the synthesised adsorbent's potential has not yet been completely maximised, as a result, titanium isoproproxide modification was carried out, producing titanium modified SBA-15 (Ti-SBA-15). The synthesized and modified adsorbent was utilized in a fixed-bed column adsorption system to study the impacts of various factors including CO2 adsorption temperature, inlet concentration of feed, adsorbent mass, and feed flow rate. The synthesized SBA-15 was subjected to a number of physicochemical analyses, including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR), transmission electron microscopy (TEM), BET surface area analysis and Xray photoelectron spectroscopy (XPS). Based on experimental results, it can be concluded that the adsorbent’s ability to adsorb CO2 improved when it is modified with titanium isopropoxide. This is because titanium introduces new active sites called as the Lewis acid sites. These active sites interact with CO2 molecules through the Lewis acid-base interactions and therefore improving the CO2 adsorption capacity onto the adsorbent. Besides, the column’s ability to adsorb CO2 was enhanced when the CO2 content in the feed was raised while the adsorption temperature and feed flow rate were both lowered to 30oC. Pseudo- first-order and pseudo-second-order kinetics, as well as the Avrami model, were used to interpret the kinetics of the CO2 adsorption experiment. These three models help to understand and quantify the rate at which adsorption occurs over time and can provide insights into the adsorption mechanism and helps to optimize process conditions. This adsorbent’s ability to adsorb CO2 was improved as the CO2 feed concentration was raised, whereas it declined as feed flowrate, temperature, and adsorbent loading increased. This is due to the reduction in residence time when the flowrate is increased, the adsorption process being an exothermic process and the active sites being inaccessible to CO2 molecules. The kinetic model proposed by Avrami shows that it best fits the experimental data. Three fixed bed adsorption column models namely the Adam-Bohart model, Thomas model and Yoon-Nelson model were used to describe the behavior of an adsorption process occurring in the fixed bed. The Thomas and Yoon-Nelson models were successful in predicting how well SBA-15 adsorbs CO2 in a fixed-bed column while the Adam- Bohart model did not match the column data well, owing to the low R2 values of 0.6 and the weak correlation between experimental and model values.
Reduction Of Membrane Fouling Using Helical Baffles For Crossflow Microfiltration
(2003-04)
Mariadas, Anthony
The objectives of this research is investigate the use of helical baffles as a hydrodynamic for reducing membrane fouling and enhancing the flux. Experiments were conducted using ceramic, tubular membranes and using Ti02 suspensions and Bakers yeast solutions as the feed. The optimum configurations of helical baffles in respect to the geometry were explored. The effect of operating parameters such as different Transmembrane pressure, different feed concentrations, different shape of membrane inner surface, long hour experiments and the effect of different types of feed on flux were also conducted.
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.
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.

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