Greening Malaysian Industries

"An inaugural lecture delivered on 4 April 2016"

Investigation of convection and diffusion during biodiesel production in packed membrane reactor using 3D simulation

The 3D simulation of convection and diffusion phenomena within a ceramic membrane during transesterification reaction was the aim of this study. The ceramic membrane was a tubular micro porous TiO2/Al2O3 packed with the heterogeneous catalyst. The Navier–Stokes, Brinkman and Stephan–Maxwell equations were applied for investigation of fluid flow reaction and mass transfer within the system. The value of the convection was generally between 104 and 107 times higher than diffusion. It depends on concentration component, the diffusion coefficient and components velocity. A good agreement was found with the maximum deviation of 8% from experimental data

Synthesis of carbon-opacified-silica-aerogel using bamboo leaf

Opacification of silica aerogel to reduce its thermal conductivity had received much attention in recent years. In such context, aerogels are normally opacified with carbon black to mask out the radiative heat loss in the infrared region. The motivation of this work is to use bamboo leaf as a single source to synthesize water glass and activated carbon. Both of these prec~rsors ,:ere then used. to synthesize and opacify silica aerogel. Since bamboo leaf is an agriculture waste, this provides an alternatIve lost cost source to synthesize carbon-opacified-silica-aerogel.The properties of bambo.o leaf .aerogel that opacified activated carbon was compared then with other aerogels including those opacified With carbon black and also aerogel synthesized from TEaS alkoxide.Results show that aerogels opa~ified with activated carbon synthesized has bulk density of 0.069±0.0014 g.cm", porosity of 97.9%, .B.ET specific surface area ~f 3_~0.5±3.7m2.g-l, total pore volume of 1.38±0.07cm3.g -I and thermal conductivity of 0.0311±0.009W.m .K . TGA of aerogels also show that opacified aerogel is thermally stable up to 495°C and therefore suitable to be used in thermal insulation at high temperature

Optimization of reactive dyes degradation by Fenton oxidation using response surface method

The objective of this study is to determine the influence of various parameters on the degradation of dye (with high COD value) by using Fenton process. Design of experiment was applied for the optimization with respect to: initial concentration of Fe2+ and H2O2 to ascertain their respective effects on the treatment efficiency. The progress of dye degradation was analyzed by monitoring the Chemical Oxygen Demand (COD). The experimental results show that the initial concentration of H2O2, and Fe2+, had great influence on degradation of dye by Fenton process. Application of optimum operation conditions of: Fe2+/Dye = 10 and Fe2+/H2O2= 25 at constant pH=3, mineralization of 78% was achieved for the dye with initial COD value of 1228 mg/L. Based on the degradation effciency , the optimized initial concentration of Fe2+ and H2O2 has a proven influence in treatment of waste water with high COD value by Fenton process

Renewable energy harness to uplift the prosperity of Royal Belum Forest

Renewable energy resources exist over wide geographical areas and its technologies are also suited to rural and remote areas where energy is often crucial in human development. As of this preliminary study, a source of renewable energy is in focus to bring benefits to the stake holders of Royal Belum Forest; hydropower. In order to sustain the prosperity of Royal Belum Forest, micro-generation method will be introduced. Micro-generation is defined as a small-scale generation of electric power by individuals or small communities to meet their own needs, as alternatives or supplements to traditional centralized grid-connected power. As one of micro-generation methods, micro-hydro power has been chosen as its importance for its environmental conscious approach that aspire zero or low-carbon footprints. Micro-hydro power can make a large amount of energy out of a small water flow with minimal impact on the environment. Based on obtained preliminary data, an on-grid configuration micro-hydro power electric systems would be able to generate a reliable of electricity supply. Kampung Sungai Tiang has been chosen as it has the suitable rivers to facilitate this study. The presence of a high ground (514 meters above sea level) within Kampung Sungai Tiang vicinity creates a necessity for an observation tower. In addition to wildlife observation and forest fire prevention, this tower can be further exploited by the government or private companies for scientific and commercial activities. The construction and utilization of this tower would encourage the implementation of best practices in order to minimize impact on the environment

Dynamic modelling and simulation of eutectic freeze crystallization process for recovery of ammonium sulphate from aqueous solutions

The advancement of industrial sectors generates large amount of wastewater containing ammonium sulphate (AS) ions, yet the current AS recovery technologies are energy-extensive and produce excessive sludge. In this study, a dynamic model for a batch crystallizer was developed to investigate the eutectic freeze crystallization process of AS in aqueous solutions using the method of moment (MoM). The variables affecting the crystal size distribution of AS and ice were described in terms of zeroth moment (μ0), first moment (μ1), second moment (μ2) and third moment (μ3). The μ0 of ice crystals increased significantly until 2 s and slowed down thereafter while μ0 of AS crystal increased steadily and reached a constant value of 1/m3 s after 1 s. The μ1, μ2, and μ3 of the AS and ice crystals depicted a similar increasing trend. Through process optimization using a 3-D plot on the initial concentration of the system and initial temperature of cooling fluid which had been identified as the significant parameters via iterative plot using MATLAB software, the AS and ice reached maximum crystallization at 255 K which was close to the eutectic point of AS-water system at 254 K. The dynamic model which comprised of population, mass and energy balance equations established in this study demonstrated effectiveness in the prediction of crystallization of AS in aqueous solutions

The effects of different natural environment influences on health and psychological well-being of people: a case study in Selangor

Background: People benefit from the recreational services provided by an urban corridor, urban park, and urban forest. Due to ongoing land-use interest and urban development, however, these natural environments are coming under increasing pressure. Simultaneously, the world is becoming increasingly urbanised, and living in cities has been linked to mental health issues. On the other hand, different natural environments are known to create healthier environments, and the need for effective restorative environments has never been greater. The purpose of the study was to compare the impacts of walking in different natural environments. Methods: I) Kota Damansara Community Forest Reserve, II) Mutiara Damansara Recreational Park, and III) the Urban Green Corridor along Jalan PJU 7/2 were used as control study sites in this study. Each site was visited only once by the study participants (40 women and 40 men). Walking for 30 min was a part of the experiment. To identify the psychological effects of different natural environments, the Depression, Anxiety, and Stress Scale (DASS21), Profile of Mood States (POMS), Positive and Negative Affect Schedule (PANAS), and Restoration Outcome Scale (ROS) were utilised. Results: In all three natural environments, the restorative effects were found to increase significantly. Conclusion: The overall conclusion of the field experiment is that being in an urban green corridor can also provide a refreshing environment. In terms of stress reduction among working adults, the recreational park is sufficient, while urban-forested areas are more effective in improving mental health by minimising stress, anxiety, and depression

Compressive Behaviour and Energy Absorption of Copper Tube under Quasi Static and Ultrasonic Compression Test / Nur Amanina Damira Muhalim...[et al.]

The application of ultrasonic vibration in metal forming has significantly reduced the forming force. This force reduction can be explained by the softening effect of material and the reduction of friction between the interfaces. However, studies on metal forming focused on the deformation of bulk metal, but specific study focusing on the application of ultrasonic vibration on tube forming is very limited. Therefore, the present study aims to investigate the compressive behavior and energy absorption of a copper tube under quasi static and ultrasonic compression. This investigation was carried out for copper tube specimens on a simple compression test set up using a constant cross head speed of 30 mm/min on dry surface condition. For the quasi static compression test, specimens were statically compressed without ultrasonic vibration between an upper and lower rigid platen. For the ultrasonic compression test, specimens were compressed with ultrasonic vibration between upper rigid platen and ultrasonic horn. A specifically designed ultrasonic horn was fabricated prior to the test as a medium to transmit the ultrasonic vibration to the specimens. The horn was tuned to a longitudinal mode at 19.89 kHz frequency with a uniform nominal vibration peak amplitude of 6 μm on the horn surface. Load displacement distributions for quasi static and ultrasonic compression tests were analysed. A comparison of quasi static and ultrasonic compression test results has been made. It was found that the compressive stress was remarkably reduced with the onset of superimposed ultrasonic vibration during plastic deformation and has lowered the energy absorption of the specimens. In addition, better deformation profiles of end products were obtained by the increase of compressibility and formability of the specimens as compared to quasi static compression