Prof. Ir. Dr. Nor Aishah Saidina Amin

Abstract:

Transesterification of waste cooking oil with heterogeneous (heteropoly acid) catalyst and methanol has been investigated. Response Surface Methodology (RSM) and Artificial Neural Network (ANN) were employed to study the relationship between process variables and free fatty acid conversion and for predicting the optimal parameters. The highest conversion was 88.6% at optimum condition being 14 h, 65 °C, 70:1 and 10 wt% for reaction time, reaction temperature, methanol to oil molar ratio and catalyst loading, respectively. The RSM and ANN could accurately predict the experimental results, with R² = 0.9987 and R² = 0.985, respectively. Kinetics studies were investigated to describe the system. The reaction followed first-order kinetics with the calculated activation energy, Ea = 53.99 kJ/mol while the pre-exponential factor, A = 2.9 × 10⁷ min⁻¹. These findings can help improve an environmentally friendly biodiesel process that conforms to ASTM D6751 standards.

1. Amin Talebian-Kiakalaieh, Nor Aishah Saidina Amin, Alireza Zarei and Iman Noshadi (2013).Transesterification of waste cooking oil by heteropoly acid (HPA) catalyst :Optimization and kinetic model. Applied Energy, 102, 283-292, Elsevier. (2012 I.F = 4.781)

Abstract:

The production of lignin from empty fruit bunch (EFB) has been carried out using liquefaction method with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid (IL), in presence of sulfuric acid (H₂SO₄) as a catalyst. Response surface methodology (RSM) based on a factorial Central Composite Design (CCD) was employed to identify the optimum condition for lignin yield. The result indicated that the second order model was adequate for all the independent variables on the response with R² = 0.8609. The optimum temperature, time, ionic liquid to EFB ratio, and catalyst concentration were 150.5 °C, 151 min, 3:1 wt/wt and 4.73 wt%, respectively for lignin yield = 26.6%. The presence of lignin liquefied product was confirmed by UV–Vis and FTIR analysis. It was also demonstrated lignin extraction from lignocellulosic using recycled IL gave sufficient performance.

1. Dilaeleyana Abu Bakar Sidik, Norzita Ngadi and Nor Aishah Saidina Amin (2013). Optimization of lignin production from empty fruit bunch via liquefaction with ionic liquid Bioresource Technology, 135, 690-696, Elsevier. (2012 I.F = 4.750)

Abstract:

Biomass is now regarded as a potential feedstock to produce renewable valuable chemicals that can be derived from sugar. In this study, it was demonstrated that Fe/HY catalyst was able to promote the hydrolysis in ionic liquid of oil palm biomass to reducing sugar without a prior pretreatment step. Initially, cellulose was utilized as a model compound and the effects of several variables including temperature, time, catalyst loading, cellulose loading, and 1-butyl-3-methylimidazolium bromide (BMIMBr) purity on the hydrolysis process were evaluated. A total reducing sugar (TRS) yield of 60.8% was obtained using Fe/HY catalyst in BMIMBr at 120 °C within 3 h. Next, the same catalyst was applied for direct hydrolysis of oil palm frond (OPF) and empty fruit bunch (EFB). The TRS yields obtained were 27.4% and 24.8%, respectively, while the efficiencies were 54.6% and 58.5% for OPF and EFB, respectively. The catalyst, tested for five runs, exhibited a minimal loss in the catalytic activity signifying its potential recyclability ability. Further conversion of the cellulosic hydrolysate led to promising levulinic acid yield and process efficiency. The experimental results confirmed that Fe/HY catalyst and BMIMBr have the potential to be used in a lignocellulosic biorefinery at mild process conditions for processing renewable feedstocks.

1. Nur Aainaa Syahirah Ramli and NorAishah Saidina Amin (2014) Catalytic hydrolysis of cellulose and oil palm biomass in ionic liquid to reducing sugar for levulinic acid production. Fuel Processing Technology, 128, 490-498. DOI: https://doi.org/10.1016/j.fuproc.2014.08.011

Abstract:

The pyrolysis of Imperata Cylindrica in a transported bed reactor has been carried out using sand as heat carrier. This study is to determine the significant effect of the pyrolysis process condition for heat carrier temperature and particle size on the liquid yield and bio oil properties. Physical and chemical properties of bio-oil such as the water content, pH, viscosity and density were determined. The results showed that the heat carrier’s temperature highly affected the liquid product, yielding 2.3 to 11.9 wt% in increasing the temperature from 450 to 600°C. The yield increased with larger particle size with 0.375 mm diameter gives maximum yield of 11.8 wt% but decreased gradually until 0.65mm diameter afterwards.

1. Mohd Fadhir Ahmad Kamaroddin, Tuan Amran Tuan Abdullah, Ramli Mat and Nor Aishah Saidina Amin (2014). Effect of heat carrier’s temperature and partial size on the pyrolysis of Imperata Cylindrica in transported bed reactor. Applied Mechanism and Materials. Vol 625, 612-615. DOI: 10.4028/www.scientific.net/AMM.625.612

Abstract:

The pretreatment of oil palm frond (OPF) has been carried out using 1-butyl-3-methylimidazolium bromide ([BMIM]Br) in the presence of aqueous sulphuric acid (H₂SO₄). The effects of reaction temperature, reaction time and [BMIM]Br loading on lignin degradation were investigated by applying Box Behnken Design of Response Surface Methodology (RSM). The optimized process condition for OPF pretreatment were 123°C, 175 min and 9.9 g of [BMIM]Br loading with an optimum lignin degradation of 88.2%. The experimental results fitted-well with the predicted value with less than 5% error. It was also demonstrated that lignin degradation using recycled [BMIM]Br gave sufficient performance for five successive runs. It was revealed from SEM and XRD analyses, that the pretreated OPF was porous and less crystalline after pretreatment. Consequently, the pretreated OPF renders 25.3% levulinic acid yield in acid hydrolysis compared to 18.2% yield for untreated OPF.

Nur Aainaa Syahirah Ramli and Nor Aishah Saidina Amin (2014) Catalytic Conversion of Oil Palm Fronds to Levulinic Acid in Ionic Liquid, Applied Mechanism and Materials. Vol 625 (2014), 361-365. DOI: 10.4028/www.scientific.net/AMM.625.361

Abstract:

The pretreatment of oil palm frond (OPF) has been carried out using 1-butyl-3-methylimidazolium bromide ([BMIM]Br) in the presence of aqueous sulphuric acid (H2SO4). The effects of reaction temperature, reaction time and [BMIM]Br loading on lignin degradation were investigated by applying Box Behnken Design of Response Surface Methodology (RSM). The optimized process condition for OPF pretreatment were 123°C, 175 min and 9.9 g of [BMIM]Br loading with an optimum lignin degradation of 88.2%. The experimental results fitted-well with the predicted value with less than 5% error. It was also demonstrated that lignin degradation using recycled [BMIM]Br gave sufficient performance for five successive runs. It was revealed from SEM and XRD analyses, that the pretreated OPF was porous and less crystalline after pretreatment. Consequently, the pretreated OPF renders 25.3% levulinic acid yield in acid hydrolysis compared to 18.2% yield for untreated OPF.

1. Nur Aainaa Syahirah Ramli and Nor Aishah Saidina Amin, Ismail Ware (2014) Optimization of Oil Palm Fronds Pretreatment Using Ionic Liquid for Levulinic Acid Production, Jurnal Teknologi, 71, 1, 33-41.

Abstract:

The significant surge in biodiesel production by transesterification of edible or non-edible oils have caused surplus of glycerol in the market. With its characteristics, unique structure, renewability, and bio-availability, glycerol has tremendous potential to be transformed to higher value-added chemicals. This article provides a comprehensive and critical review of glycerol dehydration to acrolein in both petroleum-and bio-based processes. Acrolein has enormous industrial applications as a significant chemical intermediate for acrylic acid, dl-Methionine and superabsorbent polymer production. The current development of several precursors on suitable support such as heteropoly acids, zeolites, mixed metal oxides, and pyrophosphates in creating superior catalytic properties for both liquid- and gas-phase processes has been discussed. The acidity and textural properties of various catalysts, as significant variables affecting acrolein yield and selectivity, are evaluated separately. Techno-economical evaluation on dehydration of petroleum- and bio-based glycerol to acrolein proved that the bio-based processes are more feasible compared to the conventional petroleum-based process. In addition, various proposed mechanisms for catalytic dehydration of glycerol to acrolein have been examined. Particularly, catalyst coking and few crude glycerol applications have been identified as the main drawbacks for immediate industrialization and commercialization of glycerol dehydration to acrolein.

1. Amin Talebian-Kiakalaieh Nor Aishah Saidina Amin Hadi Hevazageh (2014) Glycerol for renewable acrolein production by catalytic dehydration. Renewable and Sustainable Energy Reviews, 40, 28-59. DOI: https://doi.org/10.1016/j.rser.2014.07.168

Abstract:

Response surface methodology (RSM) and multi-objective genetic algorithm was employed to optimize the process parameters for catalytic conversion of glycerol, a byproduct from biodiesel production, to light olefins using Cu/ZSM-5 catalyst. The effects of operating temperature, weight hourly space velocity (WHSV) and glycerol concentration on light olefins selectivity and yield were observed. Experimental results revealed the data adequately fitted into a second-order polynomial model. The linear temperature and quadratic WHSV terms gave significant effect on both responses. Optimization of both the responses indicated that temperature favouring high light olefin formation lied beyond the experimental design range. The trend in the temperature profile concurred commensurately with the thermodynamic analysis. Multi-objective genetic algorithm was performed to attain a single set of processing parameters that could produce both the highest light olefin selectivity and yield. The turn-over-frequency (TOF) of the optimized responses demonstrated a slightly higher value than the one which was not optimized. Combination of RSM, multi-objective response and thermodynamic is useful to determine the process optimal operating conditions for industrial applications.

Zaki Yamani Zakaria, Nor Aishah Saidina Amin and Juhaa Linnekoski (2014).Optimization of catalytic glycerol steam reforming to light olefins using Cu_ZSM-5 catalyst Energy Conversion and Management, 86, 735-744. DOI: https://doi.org/10.1016/j.enconman.2014.06.040

Abstract:

Recently, in the research of photocatalytic conversion of CO2, there has been an increasing innovative interest to simultaneously reduce the level of CO2 emissions and produce valuable products. In this study, highly ordered nitrogen-doped titania (TiO2) nanotube arrays, fabricated by anodization method, were used for CO2 reduction in the presence of CH4. Response surface methodology (RSM) was employed to assess individual and interactive effects of UV light power, CO2:CH4:N-2 ratios in feed and distance between the UV lamp and the reactor on CO2 conversion. A face-centered central composite design (FCCCD) was utilized to optimize the photocatalytic process conditions. The optimal conditions for maximum CO2 conversion of 41.5 % were determined as 250 W UV light power, 10 % CO2 initial ratio and 2 cm distance between UV lamp and reactor.

1. Saeed Delavarai and NorAishah Saidina Amin (2014) Response Surface Methodology Analysis of CO2 Photocatalytic Conversion in Presence of CH₄ over Nitrogen-Doped Titania Nanotube Arrays Chemical Engineering Transaction, 39, 235-240.

Abstract:

Oxidative coupling of methane in the presence of corona discharge plasma has been studied for the production of higher hydrocarbons under the conditions of ambient temperature and atmospheric pressure. The corona discharge was created by applying 3 kV (DC) between a tip and a plate electrode, 1.5 and 2.5 mm apart, in a tubular reactor. The effects of variables such as methane to oxygen ratio, total flow rate, electric current and more importantly, electrode gap distance were investigated. The electrode gap distance affected the electric field strength and subsequent plasma reactions. Five electrodes shaped like needles in the tip plate were applied to create more discharge intensity. At CH₄/O₂ ratio = 4, total flow rate = 4 mL/min, electric current = 10 mA and electrode gap distance = 1.5 mm, 31.9, 58 and 55 % of C₂ yield, C₂selectivity and methane conversion, respectively were achieved. The main products were ethane, ethylene, acetylene, while CO and CO₂ were also observed. The corona discharge interaction with HY-zeolite catalyst has led to low temperature methane conversion. Thus, the effect of surface modified zeolite catalyst was also examined. At a CH₄/O₂ ratio of 4 and total flow rate of 4 mL/min, 59.4, 69.7 and 85.3 %, of C₂ yield, C₂ selectivity and methane conversion, respectively were achieved. Experimental results revealed that corona discharge techniques, in the presence of HY-zeolite catalyst, has potentials for improving methane conversion, C₂ selectivity and C₂ yield.

1. Saeed Delavarai, NorAishah Saidina Amin and Hoessin Mazaheri (2014). Oxidative coupling of methane in corona discharge plasma reactor using HY zeolite as catalyst.Reaction Kinetics, Mechanisms and Catalysis.DOI 10.1007/s11144-014-0741-z.