Chief Guest Editor
Dr. Rozan Mohamad Yunus
Dr. Shahriah Basri, Dr. Sharifah Najiha Timmiati, Dr. Nabila A. Karim & Dr. Khuzaimah Arifin
The theme for this special issue of the Engineering Journal is Hydrogen and Cell Fuel Technology which includes hydrogen production research, hydrogen storage, fuel cell engineering, fuel cell education and materials. Full length papers, reviews and short communications are welcomed, on subjects such as experimentation (both techniques and data), new theoretical models, commentaries work and letters to the editor.
Table of Contents
|1.||Elektrolit Dwi Lapisan Bagi Sel Fuel Oksida Pepejal Bersuhu Sederhana-Rendah: Ulasan Kajian
Nurul Akidah Baharuddin, Andanastuti Muchtar & Dedikarni Panuh
Fuel cell is an energy converter device that generates electricity through electrochemical reaction between hydrogen and oxygen. An example of fuel cell is the solid oxide fuel cell (SOFC) which uses a ceramics based solid electrolyte. Due to the use of ceramics, SOFC normally operates at high temperatures up to 1000 °C. This high operating temperature makes SOFC known for its efficient energy conversion capability and excellent fuel flexibility. However, despite the advantages, the extreme temperatures limit the uses of SOFC. High operation temperature leads to long term operational issues in durability and cell degradation. Yttria stabilized zirconia, YSZ is a commonly used material for electrolyte in high temperature SOFCs. However, YSZ electrolyte is unable to perform well when the operating temperature is reduced to intermediate-low zones below 800 °C. Thus, development of new materials for SOFC components is needed whereby the production of electrolyte materials becomes one of the main scopes for research in intermediate-low temperature SOFCs. Apart from the synthesis of new materials, another approach in increasing the ionic conductivity of intermediate-low temperature SOFC is through the fabrication of a bilayered electrolyte. As such, this review article focuses on the potential of bilayered electrolyte for intermediate-low temperature SOFCs.
Keywords: Fuel cell, Solid oxide fuel cell; Electrolyte; Bilayered
|1 – 8|
|2.||A Short Overview Current Research of Catalyst for Methanol Oxidation Reaction in Direct Methanol Fuel Cell (DMFC) from Experimental and Theoretical Aspect
Nabila A. Karim & Norilhamiah Yahya Abstract
Direct Methanol Fuel Cell (DMFC) has shown a great development to replace fossil fuel as new alternative of power sources. However, there are still many issues need to overcome to achieve the dream of world use no more fossil fuel for power sources. One of the main issues is slow catalytic activity of methanol oxidation reaction in anode DMFC. There are several studies of catalysts for methanol oxidation reaction other than Platinum-Ruthenium (PtRu). Finding the catalyst that is cheaper and high reactivity towards methanol oxidation reaction is recommended. The catalyst synthesized should be tested on durability for a long period of time. The selection of catalyst support also affect in methanol oxidation reaction activity in DMFC. Catalyst support must have characteristics in high surface area, conductivity and strong interaction between support and catalyst to prevent leaching problem during long-term operation in DMFC. Several metal alloys and support catalyst has been review in this paper together with discussion about durability of the catalyst. In addition, the DFT study to find the most stable condition of methanol adsorption to occur is highly encouraged. The determination of mechanism reaction using DFT is important in which different pathways will give different activation energy during methanol oxidation reaction. This short overview presented the current research of new catalysts for methanol oxidation reaction.Keywords: Electrocatalyst; Methanol oxidation reaction; Direct Methanol Fuel CellDOI : dx.doi.org/10.17576/jkukm-2018-si1(2)-02
|9 – 17|
|3.||Kajian Fotomangkin Berasaskan Grafin Untuk Penurunan Karbon Dioksida
(Review on Graphene Based Photocatalyst for Carbon Dioxide Reduction)Rosmahani Mohd Shah, Rozan Mohamad Yunus, Abdul Amir H. Kadhum, Wong Wai Yin & Lorna Jeffery Minggu
Global warming and lack of energy are two important issues of this century. Heating caused by increased carbon dioxide is an important issue that can be addressed through the process of reducing carbon dioxide to produce certain sources of chemicals and fuels. At the same time, the production of carbon-based products through the reduction process can be generated to assist in the generation of useful energy. Reduced carbon dioxide by photocatalytic methods is increasingly gaining attention as this method can convert carbon dioxide into hydrocarbon fuels. Graphene, a two-dimensional material is now widely used in photocatalytic methods to enhance the ability of the reduction process. High electrical conductivity, wide surface area and high chemical stability make graphene-based photocalisers have their own advantages in reducing carbon dioxide. Fabrication of graphene-based materials has been known as one of the most feasible strategy to improve the carbon dioxide reduction performance of photocatalyst. Moreover, the combination of graphene with semiconductors provides a facile strategy to enhance their activities and stabilities.This study discusses the features and designs of graphene-based photocatalysts that aid the reduction process and the problems faced by graphene-based photocatalysts are also discussed for future applications. Through reviewing the significant advances on this topic, it may provide new opportunities for designing highly efficient graphene-based photocatalysts for carbon dioxide reduction application.Keywords : Graphene, photocatalytic, global warming, carbon dioxide reductionDOI : dx.doi.org/10.17576/jkukm-2018-si1(2)-03
|19 – 32|
|4.||Penyediaan Pelet Elektrolit Sr0.6Ba0.4Ce0.9Ga0.1O3-δ Melalui Kaedah Glisina Nitrat bagi Aplikasi Sel Fuel Oksida Pepejal Konduktor Proton
Nur Wardah Norman, Wan Nor Anasuhah Wan Yusoff, Abdullah Abdul Samat & Andanastuti Muchtar
The SrCeO3-based electrolyte pellet is one of the most commonly used materials in electrolyte research since the introduction of proton-conducting solid oxide fuel cell at intermediate temperatures. Electrolyte Sr0.6Ba0.4Ce0.9Ga0.1O3-δ (SBCG) has been produced by the glycine-nitrate method as it is found to produce fine powders in a short time and support in lowering sintering temperatures. A systematic characterization has been carried out on the electrolyte powders to determine properties such as thermal decomposition (thermogravimetric analysis, TGA), purity of the electrolyte powders (X-ray diffraction, XRD) and elemental analysis via X-ray energy distribution (EDX). Further, morphological characterization of the electrolyte pellets was conducted using scanning electron microscopy (SEM). TGA recorded the decomposition of the selective compounds was completed at a temperature of 1000°C. Based on the three calcination temperatures of 900°C, 1000°C and 1100°C, the powders calcined at 1000 °C were found to be eligible for the sintering process in the production of electrolyte pellet. This electrolyte pellet achieved a relative density of 99%. In addition, the pellet calcined at 1000 °C also displayed distinctive grain boundary despite having a wide range of grain sizes. Based on this study, Sr0.6Ba0.4Ce0.9Ga0.1O3-δ has been shown to have great potential to be used as an electrolyte for the application of proton-conducting solid oxide fuel cells at intermediate temperatures.
Keywords:Proton-conducting solid oxide cell fuel; electrolyte; glycine-nitrate method; morphology; density
|33 – 39|
|5.||Integrasi Sistem Penulenan Biohidrogen dan Aplikasi Sel Fuel
Muhammad Zhaahir Sidek, Mohd Shahbudin Masdar, Nik Muhammad Hafiz Nik Dir, Nur Fatihah Ainaa Amran, Simreth Kaur Dhalywal A/P Ajit Sing & Wong Woon Loong
Biohydrogen (bio-H2) has a large potential as an alternative and renewable energy in the future. However, there are a few constraints that need to be overcome such as CO2 removal as one of the fuel impurities. For instance, in fuel cell system, if bio-H2 is being used directly, it most likely will lead to low the performance and damage the fuel cell system. Thus, separation technologies are required to separate bio-H2 from the CO2 impurities, and hence produce H2 at high purity. In this study, the purification of bio-H2 system; adsorption technique; was integrated with hydrogen fuel cell system. Therefore, a commercial mixed gas H2/CO2 50 vol%/ 50 vol% as mimic bio-H2 gas is used as feed gas with flow rate of 0.2, 0.4, 0.6, 0.8, and 1.0 L min-1 to produce the purified H2 via adsorption technique. The purified H2 from adsorber column’s outlet then was flowed into polymer electrolyte membrane fuel cell (PEMFC) to obtain the power generation. Meanwhile, the breakthrough profile and adsorption capacity was plotted and measured to analyze the adsorption technique performances. As a comparison, a commercial pure H2 was used in order to compare the performance for both cases. From the results, the CO2 adsorption capacities decreased with the increasing of feed gas flowrate. Simultaneously, the performance of PEMFC would decrease significantly more than 50% when the impurities of CO2 exists in the adsorber column outlet. It was confirmed that the existence of CO2 in the H2 fuel with greatly decreased the PEMFC performance and results in unstable power generation. Therefore, an efficient purification system for bio-H2 is required as part of integration unit in bio-H2 application for power generation.
Keywords: Biohydrogen purification, CO2 removal, Adsorption, Activated carbon
|41 – 48|
|6.||Sifat Serbuk dan Sifat Elektrik Bahan Katod La0.6Sr0.4CoO3-δ yang Disediakan Melalui Kaedah Sol-Gel Terubahsuai Bagi Aplikasi Sel Fuel Oksida Pepejal
Abdullah Abdul Samat, Wan Nor Anasuhah Wan Yusoff, Nur Wardah Norman, Mahendra Rao Somalu & Nafisah Osman
The powder properties and electrical conductivity of lanthanum strontium cobalt oxide, La0.6Sr0.4CoO3-δ (LSC) material were systematically characterized with respect to application as cathode material for intermediate temperature solid oxide fuel cell (SOFC). The LSC was prepared via a modified sol-gel method assisted with a combination of ethylene glycol and activated carbon as a chemical additive. The decomposition of impurity compounds such carbon compounds and nitrates in the precursor powder was completed at 870 °C as revealed by thermogravimetry (TG) analysis. As the calcination temperature increased from 800 °C to 1000 °C, the purity and crystallite size of the the calcined precursor powder also increased as confirmed by X-ray diffrcation (XDR) analysis. The micrograph of scanning electron microscope (SEM) image showed that the particle of the calcined powders form agglomeration and this led to low relative density (80.18 %) of the sintered LSC pellet at 1200 °C. The direct current electrical conductivities (σdc) of the sintered LSC pellet measured using Van der Pauw technique in air were 1504 S cm-1 and 1069 S cm-1 at 400 °C and 800 °C, respectively. The relatively high σdc with low activation energy (Ea) of 0.021 eV indicates that the LSC prepared in this work has a great potential to be used as a cathode material for intermediate temperature SOFC application.
Keywords: Electrical conductivity; Perovskite Phase; Microstructure; Calcination Temperature
|49 – 57|
|7.||Nanocatalyst FeN4/C Molecular Orbital Behaviour for Oxygen Reduction Reaction (ORR) in Cathode Direct Methano Fuel Cell (DMFC)
Sahriah Basri & Siti Kartom KamarudinAbstract
Approaching commercialization phase of Direct methanol fuel cell (DMFC) technology, developing high kinetic rate active area with inexpensive non-precious metal catalyst (NPMC) for ORR catalyst materials to replace currently used Pt-based catalysts is a compulsory and crucial requirement in order to reduce the catalyst and overall system cost. Thus, the objective of this study is to describe the molecule orbital behavior of NPMC FeN4/C and discuss of recent works in the area of non-precious metal electrocatalys for ORR. Several important kinds of free energy study for carbon supported non-precious metal electrocatalys for ORR by using density functional theory (DFT) in CASTEP module analysis. The properties of FeN4/C nanocatalyst were studied, and their energy properties, band structure and density of state were evaluated accordingly. Besides, electronic properties of the nanostructure of FeN4/C also calculated. The results indicated that optimized geometry shows the oxygen in 3.699 Ao from the catalyst opposite with the Fe atom. Moreover, HOMO occurs in the orbitals 173 and LUMO occur in orbitals 174 and the band gap -0.82 proved that FeN4/C nanostructure catalyst is conductive and suitable to use as catalyst in fuel cell.
Keywords: Density Functional Theory; Non Precious Metal Catalyst; Direct Methanol Fuel Cell
|59 – 64|
|8.||Structural and Morphological Study of Sulfonated Graphene Oxide Prepared with Different Precursors
Yusra Nadzirah Yusoff, Shuaiba Samad, Kee Shyuan Loh*, Tian Khoon Lee
In this study, graphene oxide (GO) as nano sized filler to improve the properties of polymer electrolyte membrane was synthesized via the modified Hummers method. Hummers is the most common method used to synthesize GO. The GO is produced by exfoliation of graphite oxide under sonication method. Dispersion by sonication method shows mechanical disruption that breaks apart the graphite flakes which is then sterically stabilized in the base solution. The as-synthesized GO will be sulfonated using different precursors, namely (3-mercaptopropyl)trimethoxysilane (MPTMS), butane sultone (BS) and sulfanilic acid (SA). The structure and morphology of GO and sulfonated GO (SGO) were investigated in details by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). FTIR analysis confirmed the presence of several functional groups such as hydroxyl, epoxy, carbonyl, carboxyl and sulfonic acid group. The obtained SEM and TEM images indicated, that the morphology of GO dispersion is folded, multilayered and crumpled with some wrinkles. The morphology of SGO showed a folded, thicker and overlap surface compared with GO sheets. Based on TEM image, the addition of sulfonic acid group into the GO network reveals the black spot on the sheets surface. This SGO will act as a potential base material for the application of solid acid catalyst, water purification as well as a composite in membrane fabrication.
Keywords: Graphene oxide; Hummers method; Polymer electrolyte membrane; Sulfonated graphene oxide
|65 – 71|
|9.||Development of Road Maintenance Inventory in UKM by using Aerial
Fifi Susanti Sjafri, Khairul Nizam Abdul Maulud, Wan Shafrina Wan Mohd Jaafar, Faiz Arif, Abdul Aziz Ab Rahman,
Nowadays, all data and information management is conducted in integrated digital form. The same goes for inventory management of road maintenance to ensure the updated road information. Geographical Information System (GIS) is a powerful application and able to analyse and store all the geospatial data. The objective of this study is to identify the physical condition of the roads in UKM based on information from the unmanned aerial vehicle (UAV) technology, to produce spatial data storage of road distresses and to analyse the frequency of road distress in UKM. This study was carried out in the field and a desktop study. The results of the study proved that there is road damage occurring repeatedly in the same location yearly. The results from UAV found that in a period of one year, the types of distresses decrease from 11 types to 5 types, where patching is the highest occurring road distress. Lingkungan Ilmu indicates the highest number of road distress occurring along the period at 63 distresses in 2015 and 15 distresses in 2016. All the recorded information can be stored easily by using geospatial technology. This study shows that UAV and GIS are utilisable in maintaining road inventory management.
Keywords: Geospatial; Road distress; UAV technology; Road management; Inventory management.
|73 – 78|
|10.||Characterization of Waste Cooking Oil for Biodiesel Production
Nur Imamelisa Alias, Javendra Kumar A/L JayaKumar & Shahrom Md Zain
Waste cooking oil is one of the sources that can contributes to the water pollution. It originates from the preparation of food in the cafeterias and can be harmful to the environment. Therefore, production of biodiesel from waste cooking oil is the best alternative and further studies need to be done on the characterization of waste cooking oil. This study investigates the characteristics of waste cooking oil from cafeterias in Universiti Kebangsaan Malaysia (UKM) Bangi for biodiesel production. Parameters and characteristics of waste cooking oil are very important to determine the quality and suitability of biodiesel that will be produced. Characteristics that need to be observed are kinematic viscosity, saponification, flash point, moisture content and free fatty acid. Observations were done and being compared with the specification of biodiesel stated in the standard ASTM D6751. Methods that have been conducted are ASTM D7042, AOCS Cc 9b-55, AOCS Cd 3-25 and titration. Based on the results, waste cooking oil in UKM have kinematic viscosity of 39.74-56.04 (±4.904) mm2/s, saponification value of 198.0-205.5 (±2.853) mgKOH/g, flash point value of 198-290 (±44.321) ºC, moisture content of 0.02 to 0.51 (±0.0712) % and free fatty acid value of 0.52-4.74 (±0.047) %. From the comparison with ASTM D6751, samples show a very high values for each parameter and transesterification need to be done so that all the values can be reduce and biodiesel can be produced.
Keywords: Waste cooking oil; biodiesel; kinematic viscosity; flash point; saponification value; free fatty acid
|79 – 83|