Asmadi Ali

Influence of Hydrophilic Polymer on Pure Water Permeation, Permeability Coefficient, and Porosity of Polysulfone Blend Membranes

It is well known that membrane with hydrophobic property is a fouling membrane. Polysulfone (PSf) membrane has hydrophobic characteristic was blended with a hydrophilic polymer, cellulose acetate phthalate (CAP) in order to increase hydrophilicity property of pure PSf membrane. In this study, membrane casting solutions containing 17 wt% of polymer was prepared via wet phase inversion process. The pure PSf membrane was coded as PC-0. PSf/CAP blend membranes with blend composition of 95/5, 90/10, 85/15 and 80/20 wt% of total polymer concentration in the membrane casting solutions were marked as PC-5, PC-10, PC-15 and PC-20 respectively. All of the membranes were characterized in terms of pure water flux and permeability coefficient in order to study their hydrophilicity properties. The investigated results shows that increased of CAP composition in PSf blend membranes has increased pure water flux, permeability coefficient and porosity of the blend membrane which in turn formed membrane with anti-fouling property.

A Linear Programing Approach for Landfill Gas Utilization for Renewable Energy Production

Landfill gas (LFG) is a mixture of gases mainly CH4 and CO2 which are the most problematic of the greenhouse gases (GHGs) due primarily to their highest rate of accumulation in the environment. These two main GHGs are emitted from most landfills in developing countries. As a mitigation measure, the gases can be collected and utilized as renewable energy source. This research therefore aimed at planning the utilization of LFG for renewable energy production using linear programing approach executed in general algebraic modeling system (GAMS) and applied to Seelong landfill in Johor, Malaysia as the case study. GAMS (the optimizer) selects the most profitable LFG utilization technology from a number of options such as: gas engine, gas turbine and steam turbine for electricity or combined heat and power production; steam boiler for steam production; direct LFG distribution to residences/industries as substitutes to natural gas. The results from the optimizer gave a maximum profit of USD2.54 million per year. This included revenues from product sale and carbon credit. The results also revealed that GHG reduction of about 9,000 tons CO2eq were accomplished, and thus this is environmentally and economically beneficial environmentally (in terms of carbon credit). Furthermore, the optimization results revealed that steam turbine running on low grade LFG is the most feasible option in terms of profitability and environmental consideration. This approach can be applied to any sanitary landfill as a means of simultaneously curbing GHG emission and generating revenue.

Dielectric relaxation process and microwave heating mechanism in ε- Caprolactone as a function of frequency and temperature

Dielectric properties of materials play a significant role in design of microwave assisted processing system. This paper is focused on the dielectric properties of ε-caprolactone (ε-cap) which is the monomer for the biodegradable polymer, Poly (ε-caprolactone) (PCL). The dielectric properties of ε-cap were measured across a wide range of frequencies (0.1 GHz5.0 GHz) and temperatures (20-150oC). Then the measured dielectric properties data was modelled using Debye model in order to relate quantitatively the dielectric properties to microwave heating mechanisms. The analysis carried out gives a clear picture of interaction of ε-cap with microwave energy and its heating mechanism in microwave assisted polymerisation process. This study concluded that microwave heating mechanism of the ε-cap in the measured range may be dominated by the dipole reorientation.

Design of a Bubbling Fluidized Bed Gasifier for the Thermochemical Conversion of Oil Palm Empty Fruit Bunch Briquette

This paper is focused on the design of a bubbling fluidized bed gasifier (BFBG) for EFB briquette gasification. The annual production of palm oil in Malaysia generates large quantities of lignocellulosic biomass which can be converted into clean, sustainable energy for the future. Hence, the prospect of valorising palm waste using biomass gasifiers presents a viable option for energy production. The fluidized bed gasifier (FBG) is considered the most suitable reactor for biomass gasification due excellent mixing, efficient heat temperature control and tolerance for fuels. Consequently, the proposed design of the bubbling fluidized bed gasifier for EFB briquette gasification will consist of three main parts; feeding zone, gasification zone and the effluent gas zone for syngas production. The results of feedstock physicochemical properties such as bulk density, particle size, the bed hydrodynamic and fluidization parameters for gasification used in the design of the gasifier are presented in this paper.

Effect of Shear Rate on Characteristics, Performance and Morphology of Polysulfone Blend Membranes

Rheological factor such as shear rate during membrane fabrication process has an effect on properties, structures and performance of membranes. Flat sheet asymmetric PSf/CAP blend membranes were prepared using an automatic casting machine at different shear rates in the range of 42.0 to 201.0 s-1. Results showed that increasing the shear rate from 42.0 to105 s-1 has increased the molecular orientation and thickness which then reduces the water content, porosity and pure water flux of PSf/CAP blend membranes. However, further increasing the shear rate beyond 105 s-1has resulted in an increase in the water content of PSf/CAP blend membranes.

Properties of Alpinia galanga Agro-Waste-HDPE Composites with Addition of MA-g-PE and Eco Degradant

Preparation of Alpinia galanga agro waste-high density polyethylene (HDPE) composites involved the addition of eco degradant and polyethylene-g-maleic anhydride (PE-g-MA). The Alpinia galanga agro waste fibers at 3, 6, 10 and 15 wt% were compounded in an internal mixer with the addition of 5 wt% MA-g-PE and eco degradant. The composite specimens were prepared using an injection molding machine. The results show that the maximum tensile strength of 33 MPa was obtained for sodium hydroxide (NaOH) & 3-aminopropyltriethoxysilane (3-APE) treated fiber composites with eco degradant and MA-g-PE at 15 wt% fiber loading compared to that of pristine HDPE (28 MPa). All the treated composites show an improvement in tensile strength. This indicates that the treatments using NaOH&3-APE and p-toluenesulfonic acid (PTSA) with addition of eco degradant and PE-g-MA improved adhesion between Alpinia galanga fiber and HDPE matrix. The Scanning Electron Microscopy (SEM) micrographs show the presence of a improved interaction between treated Alpinia galanga fibers and HDPE matrix with the addition of eco degradant and MA-g-PE. Thermal stability of composites was also improved for composites with treated fibers.

Effect of Cellulose Acetate Phthalate (CAP) on Characteristics and Morphology of Polysulfone/Cellulose Acetate Phthalate (PSf/CAP) Blend Membranes

Polysulfone (PSf) membrane is catogorized as hydrophobic membrane that easily fouled during membrane operation process. The presence of second hydrophilic polymer which added into membrane casting solutions plays a crucial role in adjusting the membrane properties. This hydrophilic polymer was employed in hydrophobic polymer membranes in order to improve hydrophilicity and performance as well as formed antifouling ultrafiltration (UF) membranes. In this study, a hydrophilic polymer, cellulose acetate phthalate (CAP) was added into polysulfone (PSf) membrane casting solutions by blending technique to produce PSf/CAP blend membranes. Flat sheet asymmetric PSf/CAP blend membranes were prepared by wet phase inversion method. The results revealed that an increase in CAP increased the hydrophilicity properties of PSf/CAP blend membranes compared to pure PSf membrane. The significant changes in size and numbers of microvoids and macrovoids in the morphological structures of PSf/CAP blend membranes were due to CAP promote the instantaneous liquid-liquid demixing during phase inversion process.

The Effects of Evaporation Time on Morphological Structure of Polysulfone/Cellulose Acetate Phthalate/Polyvinylpyrrolidone (PSf/CAP/PVP) Blend Membranes

Evaporation time is one of the important membrane fabrication parameter that can be manipulated in order to produce the desired membrane morphology in ultrafiltration (UF) separation process. The morphology of UF membrane has a significant effect on structural properties and performance of UF membrane. In this study, flat sheet asymmetric polysulfone/cellulose acetate phthalate/polyvinylpyrrolidone (PSf/CAP/PVP) blend membranes were prepared at different evaporation time in the range of 0 to 20 s to investigate its effect on the morphological structures of the blend membranes. The morphological structure of these blend membranes were characterized by using Scanning Electron Microscopy (SEM). The results showed that in the absence of evaporation time, the morphology of blend membrane consits of open finger-like structure and microvoids. Introduction of evaporation time period between 5 to 10 s, produced spongy blend membranes with less finger-like structure. Further increment of evaporation time between 15 to 20s, formed incomplete dense structure with small microvoids PSf/CAP/PVP blend membranes.

Trans-Esterification of Triglycerides with Methanol on Sulfated Zirconia Prepared with Different Concentration of Sulfuric Acid

Biodiesel derived from vegetable oils is renewable and environmentally friendly than those of petroleum diesel. Currently most of the biodiesel is produced using homogeneous catalysts which are corrosive and non-reusable, leading to an increased cost and causing environmental problems. Alternatively, heterogeneous catalysts are being considered over homogeneous catalysts. Trans-esterification of triacetin with methanol was studied over sulfated zirconia which was prepared with different concentrations of sulfuric acid. Liquid-phase reaction was performed at 60°C for 8 hours using a stirred batch reactor. IR-pyridine was used to characterize the acid sites concentration and strength of the solid catalyst. Conversion of triacetin was about 69% on sulfated zirconia modified with 2M sulfuric acid. The conversion of triacetin was improved due to an increased in the amount of acid sites. The acidity of the sulfated zirconia has significantly affected the catalytic activity in the trans-esterification of triacetin.

Additional Gas Resource for Coal Bed Methane by Applying Underground Coal Gasification and Enhanced Coal Bed Methane

Methane gas obtained from coal sources can be classified into two categories i.e Coal Bed Methane (CBM) and Underground Coal Gasification (UCG) gases. The Industry today often neglects the importance of capturing the UCG as important source of methane potential besides the surface gasification potential. This research will evaluate on the new resource estimation of methane as reserves with application of new technological advances in exploitation. As an analysis, the UCG energy return is significantly higher than that of CBM. Both CBM and UCG output gas can be liquefied, or used as a direct feedstock to local power stations. The CO2 generated from UCG process may be used for Enhanced Coal Bed Methane (ECBM) process because of more adsorption capacity than methane, may lead to additional methane potential. Deeper coal seams may be targeted for CBM, followed by UCG for additional resources in the form of coal gas. A depleted CBM area may be targeted for UCG with some modification on the well profile. Developing an integrated and centrally controlled approach to exploit the coal resources in which, the appropriate extraction methodology should be identified for each particular target coal-seam or groups of coal seam. It is important to strategize the sequencing of energy extraction methods to provide an optimal balance between the energy delivery for sustainable future and its true socio-economic value. As from this analysis, with 245.6 acres of coal, estimated gas can be produced is 3.25 TSCF which is 101 BSCF is coming from CBM, 3.14 TSCF from UCG and another 14.45 BSCF is from ECBM.