Anita Ramli

Gasifier selection, design and gasification of oil palm fronds with preheated and unheated gasifying air.

Oil palm frond biomass is abundantly available in Malaysia, but underutilized. In this study, gasifiers were evaluated based on the available literature data and downdraft gasifiers were found to be the best option for the study of oil palm fronds gasification. A downdraft gasifier was constructed with a novel height adjustment mechanism for changing the position of gasifying air and steam inlet. The oil palm fronds gasification results showed that preheating the gasifying air improved the volumetric percentage of H(2) from 8.47% to 10.53%, CO from 22.87% to 24.94%, CH(4) from 2.02% to 2.03%, and higher heating value from 4.66 to 5.31 MJ/Nm(3) of the syngas. In general, the results of the current study demonstrated that oil palm fronds can be used as an alternative energy source in the energy diversification plan of Malaysia through gasification, along with, the resulting syngas quality can be improved by preheating the gasifying air.

A Review of Bio-Oil Upgrading by Catalytic Hydrodeoxygenation

Fast pyrolysis is an attractive thermal conversion process to generate the alternative liquid fuel. However, the bio-oil obtained from biomass pyrolysis has polarity, instability and low energy density due to contained oxygenated compound. Hydrodeoxygenation (HDO) process is the most promising route for bio-oil upgrading through oxygen elimination. The products are suitable for co-feeding into the existing refineries. Metal catalyst and operating conditions play an important role in HDO efficiency. A summary of HDO process has been conducted with various metal catalysts, type of reactors, and reaction mechanisms. It also raises some challenges in improving catalyst efficiency, reducing hydrogen consumption, and effort to understand the HDO kinetics.

Modification of Epoxy Resin Using Liquid Natural Rubber

The cure process and the mechanical properties of liquid polymethylmethacrylate grafted natural rubber (LMG30) modified epoxy have been studied. Addition of LMG30 significantly increased the fracture toughness and the impact strength of the epoxy resin. The fracture toughness increased up to 22 fold (17.3 MNm-3/2) when modified with 5 phr LMG30. The glass transition temperature however, decreases as the rubber content increases. The SEM analysis shows uniform dispersion of rubber particles within the epoxy matrix with average particle size between 0.4 to 0.8 0m in diameter.

Effect of different metal oxides on the catalytic activity of γ-Al2O3–MgO supported bifunctional heterogeneous catalyst in biodiesel production from WCO

The catalytic activity of different γ-Al2O3–MgO supported bifunctional solid catalysts was successfully evaluated by carrying out simultaneous esterification–transesterification reactions in waste cooking oil. The physicochemical properties of the synthesized catalysts were studied using different characterization techniques to identify a catalyst of proper configuration for proper operation conditions to develop a sustainable and economical biodiesel production process. The results indicated that the Mo–Mn/γ-Al2O3-15 wt% MgO catalyst showed excellent performance in biodiesel production from selected waste cooking oil as compared with Mo–Zn/γ-Al2O3-15 wt% MgO or Mo–Sn/γ-Al2O3-15 wt% MgO catalysts and provided a biodiesel yield of 91.4% under optimal reaction conditions, i.e. methanol/oil molar ratio of 27 : 1, 5 wt% catalyst and a reaction temperature of 100 °C for 4 h. The good catalytic activity could be attributed to the existence of the optimal number of catalytically active sites on the surface of the catalyst. Moreover, the catalyst showed substantial reusability in biodiesel production from waste cooking oil.

Effect of Synthesis Duration on the Physicochemical Properties of Siliceous Mesoporous Molecular Sieve (Si-MMS)

Pure silica mesoporous molecular sieve (MMS) solid has been synthesized at 100°C by hydrothermal process. The effect of synthesis duration from 2 to 10 days has been investigated on the physicochemical properties of mesoporous molecular sieve. Samples were characterized by low angle XRD, N2 adsorption-desorption and HRTEM analysis. XRD patterns of the as-synthesized samples showed four well-defined diffraction peaks corresponding to 100, 110, 200 and 210 planes. These peaks are the fingerprint characteristics of MCM-41 mesoporous material. The high intensity diffraction peaks were observed in 8-days sample that define the high ordering of the pores and long range order. N2 adsorption-desorption results showed that all samples possessed a type IV isotherm having hysteresis loop of type H1 which is an identification of mesoporous material. Calcined samples exhibited high surface area i.e., 984-1036 m2 g-1, pore volume i.e., 1.00-1.13 cm3 g-1 and average pore diameter i.e., 3.04-3.30 nm. A hexagonal pore structure was found in the synthesized materials by HRTEM analysis, which confirms that the synthesized materials are MCM-41. HRTEM analysis showed the effect of synthesis duration on the materials and found that 8-days sample exhibited highly ordered hexagonal pore structure like honeycomb structure. All the samples were calcined at 550°C to remove the template and to study the changes in the mesoporous framework. The results showed that the mesoporous structure remained intact after calcination at 550°C, indicating that the mesoporous materials exhibit high thermal stability.

Temperature profile and producer gas composition of high temperature air gasification of oil palm fronds

Environmental pollution and scarcity of reliable energy source are the current pressing global problems which need a sustainable solution. Conversion of biomass to a producer gas through gasification process is one option to alleviate the aforementioned problems. In the current research the temperature profile and composition of the producer gas obtained from the gasification of oil palm fronds by using high temperature air were investigated and compared with unheated air. By preheating the gasifying air at 500?C the process temperature were improved and as a result the concentration of combustible gases and performance of the process were improved. The volumetric percentage of CO, CH4 and H2 were improved from 22.49, 1.98, and 9.67% to 24.98, to 2.48% and 13.58%, respectively. In addition, HHV, carbon conversion efficiency and cold gas efficiency were improver from 4.88 MJ/Nm3, 83.8% and 56.1% to 5.90 MJ/Nm3, 87.3% and 62.4%, respectively.

Effect of TEPA loading on the physicochemical properties of Si-MCM-41 by impregnation method

Si-MCM-41 with highly ordered hexagonal pore arrangement was synthesized hydrothermally at 100 °C. The calcined Si-MCM-41 was then modified with Tetraethylenepentamine (TEPA) using impregnation method. By impregnation method calcined Si-MCM-41 was modified with 10, 20, 30, 40 and 50% (w/w) of Tetraethylenpentamine (TEPA). The physicochemical properties were studied by characterizing these samples with FTIR, TGA, XRD, and CHNS analysis. Results showed that Si-MCM-41 successfully modified with TEPA by impregnation method. FTIR results showed that all the characteristic peaks of Si-MCM-41 i.e. 794, 1080 and 1230 cm−1 were existed after modification which means that mesoporous frame work remain intact. TGA analysis showed that TEPA impregnated Si-MCM-41 samples have thermal stability in the range of 140 - 500 δC. XRD results showed that intensity of the peaks reduced as the Si-MCM-41 modified with TEPA, this showed that TEPA molecules attached in the pores and on the surface. CHNS analysis confirmed the presence of carbon and nitrogen in the modified samples due to presence of Tetraethylenepentamine.Si-MCM-41 with highly ordered hexagonal pore arrangement was synthesized hydrothermally at 100 °C. The calcined Si-MCM-41 was then modified with Tetraethylenepentamine (TEPA) using impregnation method. By impregnation method calcined Si-MCM-41 was modified with 10, 20, 30, 40 and 50% (w/w) of Tetraethylenpentamine (TEPA). The physicochemical properties were studied by characterizing these samples with FTIR, TGA, XRD, and CHNS analysis. Results showed that Si-MCM-41 successfully modified with TEPA by impregnation method. FTIR results showed that all the characteristic peaks of Si-MCM-41 i.e. 794, 1080 and 1230 cm−1 were existed after modification which means that mesoporous frame work remain intact. TGA analysis showed that TEPA impregnated Si-MCM-41 samples have thermal stability in the range of 140 - 500 δC. XRD results showed that intensity of the peaks reduced as the Si-MCM-41 modified with TEPA, this showed that TEPA molecules attached in the pores and on the surface. CHNS analysis confirmed the prese...

Physicochemical Properties of Hydroxyapatite Extracted from Fish Scales

In this study, hydroxyapatite (HAp) was extracted from freshwater fish scales and saltwater fish scales using thermal decomposition method at various temperatures. The percentages of HAp in each species of raw fish scales were analysed using thermogravimetry analysis (TGA) whereas Fourier transform infrared (FTIR) was used to confirm the present of HA. The crystallinity of the HAp was studied using x-ray diffractometer (XRD). TGA and FTIR are found to be useful techniques to predict the composition of the HAp present in the fish scales. The results show that the composition of HAp in the fish scales was not significantly dependent on the species of the fish. The percentage of HAp in the fish scales ranged from 40 to 45 wt%. The heating temperature had an effect on the crystallinity and colour of the HAp produced. Results from FTIR and XRD confirmed that the HAp extracted from fish scales was similar to the HAp standard. However, the natural HAp produced from saltwater fish scales was more crystalline than that produced from freshwater fish scales. The HAp produced from this study is relatively cheap and more importantly they are HALAL for four billion Muslims population around the world.

Study on the physicochemical properties of Fe/CeO2 catalysts as an effect from different iron loading

The use of catalyst in the biomass gasification is effective to elevate hydrogen content and to reduce tar formation. This study presents the development of 2.5-10 wt% Fe/CeO2 catalysts for biomass gasification to hydrogen. The catalysts were prepared using incipient wetness impregnation method. Different characterization methods such as Powder XRay Diffraction (XRD), Temperature Programmed Reduction (TPR), N2 adsorption-desorption isotherm and Field Emission Scanning Electron Microscopy (FESEM) were used to characterize the prepared catalysts. BET analysis clearly indicates that Fe/CeO2 catalysts are mainly nonporous and the surface area of the catalysts increases with increasing of Fe loading. Characterization by XRD exhibited the formation of a solid solution of iron-cerium oxide, with the presence of cubic CeO2 structure which is in agreement with FESEM images. The TPR results show the emergence of two reduction peaks, corresponding to the surface and bulk reduction of CeO2 to Ce2O3. No distinct peak ...

Catalytic Hydrodeoxygenation of Rubber Seed Oil over Sonochemically Synthesized Ni-Mo/γ-Al2O3 Catalyst for Green Diesel Production

Hydrodeoxygenation is one of the promising technologies for the transformation of triglycerides into long-chain hydrocarbon fuel commonly known as green diesel. The hydrodeoxygenation (HDO) of rubber seed oil into diesel range (C15-C18) hydrocarbon over non-sulphided bimetallic (Ni-Mo/γ-Al2O3 solid catalysts were studied. The catalysts were synthesized via wet impregnation method as well as sonochemical method. The synthesized catalysts were subjected to characterization methods including FESEM coupled with EDX, XRD, BET, TEM, XPS, NH3-TPD, CO-chemisorption and H2-TPR in order to investigate the effects of ultrasound irradiations on physicochemical properties of the catalyst. All the catalysts were tested for HDO reaction at 350 °C, 35 bar, H2/oil 1000 N (cm3/cm3) and WHSV = 1 h-1 in fixed bed tubular reactor. The catalyst prepared via sonochemical method showed comparatively higher specific surface area, particles in nano-size and uniform distribution of particle on the external surface of the support, higher crystallinity and lower reduction temperature as well as higher concentration of Mo4+ deoxygenating metal species. These physicochemical properties improved the catalytic activity compared to conventionally synthesized catalyst for HDO of rubber seed oil. The catalytic performance of sonochemically synthesized Ni-Mo/γ-Al2O3 catalyst (80.87%) was higher than the catalyst prepared via wet impregnation method (63.3%). The sonochemically synthesized Ni-Mo/γ-Al2O3 catalyst is found to be active, produces 80.87 wt% of diesel range hydrocarbons, and it gives high selectivity for Pentadecane (18.7 wt%), Hexadecane (16.65 wt%), Heptadecane (24.45 wt%) and Octadecane (21.0 wt%). The product distribution revealed that the deoxygenation reaction pathway was preferred. Higher conversion and higher HDO yield in this study are associated mainly with the change in concentration ratio between oxidation states of molybdenum (Mo4+, Mo5+, and Mo6+) on the external surface of the catalyst due to ultrasound irradiation during the synthesis process. Consequently, the application of sonochemically synthesized non-sulphided catalysts favored mainly hydrodeoxygenation of diesel range hydrocarbon.