Prof. Ir. Dr. Nor Aishah Saidina Amin

Abstract:

1. Alireza Zarei, Nor Aishah Saidina Amin, Amin Talebian-Kiakalaieh and Nor Azimah Mohd Zain (2014). Immobilized lipase-catalyzed transesterification of Jatropha curcas oil_ Optimization and modeling Journal of the Taiwan Instiute of Chemical Engineering, 45, 444-451. Elsevier. (2012 IF = 2.084) DOI: https://doi.org/10.1016/j.jtice.2013.05.015

Abstract:

Fossil fuel depletion, global warming, climate change, and steep hikes in the price of fuels are driving scientists to investigate on commercial and environmentally friendly fuels. The process of CO₂ conversion to value-added products has been considered as a possible remedy to fulfill the requirements. The present review paper comprehensively discusses two different processes, namely hydrocarbon and methanol synthesis which are extensively used to convert CO₂ to value-added products. Reaction mechanisms as well as the effects of catalyst, reactor type and operating conditions on product efficiency enhancement of each process are reviewed. Furthermore a brief overview on the reactor types as the most effective component of the theoretical and experimental reported results on the process improvement is given. All the information is tabulated in order to make the gathered information easily conclusive. Finally, by taking the available information into account the best reactor configuration which is adjustable to reaction mechanism is proposed.

1. Samrand Saeidi, NorAishah Saidina Amin, MR Rahimpour-Hydrogenation of CO2 to value-added products—A review and potential future developments, 5,66-81, Journal of CO₂ Utilization, Elsevier DOI: https://doi.org/10.1016/j.jcou.2013.12.005

Abstract:

Levulinic acid (LA) is one of the versatile chemicals that can be produced from lignocellulosic biomass. In this study, response surface methodology (RSM) and artificial neural network (ANN) were applied to optimise LA yield from glucose, empty fruit bunch (EFB) and kenaf. The effect of process variables namely reaction temperature, reaction time and acid concentration on LA production was investigated. Application of ANN for modelling technique was more reliable since better data fitting and prediction capabilities were obtained. Next, both biomass were pre-treated with 1-ethyl-3-methylimidazolium chloride ionic liquid, [EMIM][Cl] to degrade the biomass and to observe its effect on the hydrolysis process. Thermal gravimetric analysis results revealed kenaf degraded to cellulose and hemicellulose more easily than EFB. Higher LA yield was obtained from both pre-treated samples, but the yield from kenaf (39.5 wt%) was more prevalent than EFB (31.6 wt%).

1. Nur Aainaa Syahirah Ramli, Nazlina Ya’aini and NorAishah Saidina Amin (2014) Comparison of Response Surface Methodology and Artificial Neural Network for Optimum Levulinic Acid Production from Glucose, Empty Fruit Bunch, Kenaf, Intl. J.Nano and Biomaterials Vol 5, No 1, 59-74. DOI: 10.1504/IJNBM.2014.061811

Abstract:

The esterification of oleic acid in the presence of magnetic ionic liquid, 1-butyl-3-methylimidazolium tetrachloroferrate ([BMIM][FeCl₄]) at reaction temperature of 65 °C has been investigated. Artificial neural network-genetic algorithm (ANN-GA) was used to simultaneously optimized methyl oleate yield and oleic acid conversion for the reaction. It was found that optimum responses for both yield and conversion were 83.4%, which can be achieved using molar ratio methanol–oleic acid of 22:1, catalyst loading of 0.003 mol and reaction time at 3.6 h. Esterification of oleic acid at optimum condition using recycled [BMIM][FeCl₄] registered not much loss in catalytic activity after six successive runs. Kinetic study indicated that the reaction followed a pseudo-first order reaction, with activation energy and pre-activation energy of 17.97 kJ/mol and 181.62 min⁻¹, respectively. These values were relatively low compared to homogeneous or heterogeneous catalysts for esterification of oleic acid. Thus, [BMIM][FeCl₄] is a promising new type of catalyst for conversion of high free fatty acid (FFA) feeds to biodiesel.

1. Ahmad Hafiidz Mohammad Fauzi and Nor Aishah Saidina Amin, Ramli Mat (2014). Esterification of oleic acid to biodiesel using magnetic ionic liquid_ Multi-objective optimization and kinetic study. Applied Energy, Volume: 114, 809-818. (2012 IF = 4.781) DOI: https://doi.org/10.1016/j.apenergy.2013.10.011

Abstract:

The kinetics of gas-phase glycerol dehydration in a packed-bed reactor over a highly active and stable supported silicotungstic acid catalyst with zirconium oxide and nanosized aluminum oxide (30HZ-20A) was investigated. The kinetic study is based on the optimal reaction conditions determined by response surface methodology. The reaction rate followed first-order kinetics with the activation energy and frequency factor, E = 27.5 kJ/mol and A = 5.35 × 10⁵ s^–1, respectively. Based on thermodynamic analysis, the values of ΔH° and ΔS° of the endothermic reaction were 14.70 and 0.09 kJ/(mol K), respectively, and ΔG° = −12.12 kJ/mol. The mass-transfer analysis revealed the pellet sizes of d_p < 1 μm proceeded under reaction-limiting conditions. Experimental results confirmed high efficacy of the tested catalyst due to unity effectiveness factor and very low Thiele modulus.

1. Amin Talebian-Kiakalaieh and Nor Aishah Saidina Amin (2015), Kinetic modeling, thermodynamic, and mass-transfer studies of gas-phase glycerol dehydration to acrolein over supported silicotungstic acid catalyst, Industrial and Engineering Chemistry Research, 54 (33), 8113-8121 DOI: 10.1021/acs.iecr.5b02172

Abstract:

Gold-nanoparticles (Au-NPs) incorporated TiO₂-nanowires (TiO₂-NWs) of controlled sizes prepared via hydrothermal and chemical reduction method have been investigated for CO₂ photoreduction with H₂ under visible light irradiations. The nanocatalysts have been characterized by XRD, FESEM, TEM, N₂ adsorption–desorption, XPS, UV–vis and PL spectroscopy. Highly crystalline TiO₂ nanowires of mesoporous structure were obtained in Au-deposited TiO₂ NWs. Au-NPs, uniformly distributed over TiO₂-NWs as Au-metal state, hindered charges recombination rate and increased TiO₂ activity under visible light through plasmon excitation. With the deposition of Au-NPs, the efficiency of CO₂ reduction to CO was greatly enhanced under lower energy visible light irradiations. The maximum CO and CH₃OH yield rate over 0.5 wt.% Au-NPs/TiO₂ NWs reached to 1237 and 12.65 μmole g catal.⁻¹ h⁻¹, respectively. High quantum yield was also observed over Au-NPs/TiO₂ NWs using H₂as reductant. The significantly improved photoactivity was evidently due to efficient electron–hole separation and surface plasmon response of Au-NPs. The reaction-pathway is proposed to provide insights over the mechanism of Au-plasmon-enhanced CO₂ conversion.

1. Muhammad Tahir, Beenish Tahir and Nor Aishah Saidina Amin (2015). Gold-nanoparticle-modified TiO2 nanowires for plasmon-enhanced photocatalytic CO2 reduction with H2 under visible light irradiation,. Applied Surface Science, 356, 1289-1299. DOI: https://doi.org/10.1016/j.apsusc.2015.08.231

Abstract:

Levulinic acid (LA) is a versatile platform chemical with numerous potential uses. Conversion of oil palm fronds (OPF) to LA over Fe/HY zeolite catalyst has been conducted in this study. The optimization process using Box-Behnken design gave 19.6% of LA yield at 181.7°C reaction temperature, 7.7 h reaction time, 1.13 g Fe/HY zeolite loading and 0.25 g OPF loading. The efficiency of OPF conversion at the optimum conditions was determined to be 61.1%. It was also demonstrated that Fe/HY zeolite gave sufficient performance for five successive cycles of OPF conversion to LA. The results suggested that Fe/HY zeolite is potential as catalyst for biomass conversion to LA.

1. Nur Aainaa Syahirah Ramli and Nor Aishah Saidina Amin (2015) Optimization of Oil Palm Fronds Conversion to Levulinic Acid using FeHY Zeolite Catalyst. Sains Malaysiana, 44, 6, 883–891.

Abstract:

The conversion of glucose to 5-hydroxymethyl furfural (5-HMF) and levulinic acid (LA) using ionic liquid is a promising method for producing liquid fuels from renewable resources. In this study, three types of acidic functionalized ionic liquids (FILs) were prepared and used as catalysts in the conversion of glucose to 5-HMF and LA. The prepared FILs were characterized using CHNS elemental analysis and ¹H and ¹³C NMR. The acidity of the FILs was examined using pyridine-FTIR, Hammett and acid-base titration methods. The FIL with high acidity and with both Brønsted and Lewis acid sites present seemed suitable for 5-HMF and LA production. Among the tested FILs, 1-sulfonic acid-3-methyl imidazolium tetrachloroferrate ([SMIM][FeCl₄]) demonstrated the highest catalytic performance. The yields of 5-HMF and LA reached as high as 18% and 68%, respectively after 4 h at 150 °C. The catalyst was reused five times without significant loss of activity. Furthermore, for the kinetic analysis performed for glucose conversion, the activation energy and pre-exponential factor for the reaction were 38 kJ mol⁻¹ and 925 min⁻¹, respectively. The experimental results demonstrated the potential of FIL as a catalyst for biomass transformation to platform chemicals under mild process condition.

1. Nur Aainaa Syahirah Ramli and Nor Aishah Saidina Amin (2015) A new functionalized ionic liquid for efficient glucose conversion to 5-hydroxymethyl furfural and levulinic acid Journal of Molecular Catalysis A: Chemical, 407, 113-121. DOI: https://doi.org/10.1016/j.molcata.2015.06.030

Abstract:

The performance of highly ordered nitrogen-doped titania (TiO₂) nanotube arrays, fabricated by anodization method, was tested for photocatalytic CO₂ conversion with CH₄. Nitrogen-doped titania nanotube arrays were characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and Ultraviolet–visible (UV–vis) spectra. The photoreduction products were identified using residual gas analyzer (RGA) and GC spectra. The effects of important parameters such as UV light power, initial ratios of CO₂:CH₄:N₂ in feed and distance between UV lamp and reactor on CO₂ and CH₄ conversions were analyzed using response surface methodology (RSM). FESEM images of titania nanotube arrays indicated highly ordered and vertically oriented morphology with inside diameter ranging from 3 to 50 nm. The optimal conditions for maximum CO₂conversion of 41.5% were determined as 250 W UV light power, 10% CO₂ initial ratio and 2 cm distance between UV lamp and reactor. H₂ and CO were the main products with selectivities being 80.5% and 18.9%, respectively. CO₂ and CH₄ molecules were competitively activated by the charge transfer excited complexes and the values of feed ratios influenced the selectivity for the formation of the desired products. The kinetic model based on Langmuir–Hinshelwood, incorporated photocatalytic adsorptive reduction and oxidation reactions over the catalyst surface fitted-well with the experimental data.

1. Saeed Delavari, Nor Aishah Saidina Amin and Mehrorang Ghaedi (2015 )Photocatalytic conversion and kinetic study of CO2 and CH4 over nitrogen-doped titania nanotube arrays Journal of Cleaner Production, In press. 10.1016/j.jclepro.2015.07.077 DOI : https://doi.org/10.1016/j.jclepro.2015.07.077