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Aims and Scope
Editorial Board

1. Novel design of a compacted micro-structured air-breathing PEM fuel cell as a power source for mobile phones

Maher A.R. Sadiq Al-Baghdadi

Fuel Cell Research Center, International Energy & Environment Foundation, Al-Najaf, P.O.Box 39, Iraq.

Abstract: The presence of microelectromechanical system (MEMS) technology makes it possible to manufacture the miniaturized fuel cell systems for application in portable electronic devices. The majority of research on micro-scale fuel cells is aimed at micro-power applications. There are many new miniaturized applications which can only be realized if a higher energy density power source is available compared to button cells and other small batteries. In small-scale applications, the fuel cell should be exceptionally small and have highest energy density. One way to achieve these requirements is to reduce the thickness of the cell (compacted-design) for increasing the volumetric power density of a fuel cell power supply. A novel, simple to construct, air-breathing micro-structured PEM fuel cell which work in still or slowly moving air has been developed. The novel geometry enables optimum air access to the cathode without the need for pumps, fans or similar devices. In addition, the new design can achieve much higher active area to volume ratios, and hence higher volumetric power densities. Three-dimensional, multi-phase, non-isothermal CFD model of this novel design has been developed. This comprehensive model account for the major transport phenomena in an air-breathing micro-structured PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields. The model is shown to understand the many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. Fully three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented and analyzed with a focus on the physical insight and fundamental understanding. They can provide a solid basis for optimizing the geometry of the PEM micro fuel cell stack running with a passive mode.

Volume 1, Issue 4, 2010, pp.555-572.

2. Economic-environmental performance indexes for solar-powered absorption cooling system in Mediterranean area

N. Cardinale¹, G. Rospi¹, F. Ruggiero²

1 Faculty of Architecture, University  of  Basilicata, via Lazzazera, Matera, Italy.

2 Faculty of Architecture , Polytechnic of  Bari, Via Orabona 4, 70123, Bari, Italy.

Abstract: The most recent European (Directive 2006/32/CE of April 5/2006 relating to the efficiency of the final uses of the energy and the energetic services) and national (Decree 311/06) normatives impose the use of energetic systems more efficient that minimize the use of fossil fuels in comparison to the use of renewable energy. In this research a comparison was developed between the traditional electric equipments (which use vapour compression) and the absorption equipments (powered by solar thermal energy). This comparison was implemented considering the energetic, economic and environmental aspects. This research explores the technical - economic potentialities of solar HVAC systems, with particular reference to those based on the absorption cycles, verifying the possible applications in regions of the Mediterranean area (in particular Madrid, Palermo and Athens). In particular we define an economic index and an environmental-energetic index.

3. Numerical investigation into premixed hydrogen combustion within two-stage porous media burner of 1 kW solid oxide fuel cell system

Tzu-Hsiang Yen¹, Wen-Tang Hong², Yu-Ching Tsai², Hung-Yu Wang², Cheng-Nan Huang², Chien-Hsiung Lee², Bao-Dong Chen¹

1 Refining & Manufacturing Research Institute, CPC Corporation, Chia-Yi City 60036, Taiwan, ROC.

2 Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546, Taiwan, ROC.

Abstract: Numerical simulations are performed to analyze the combustion of the anode off-gas / cathode off-gas mixture within the two-stage porous media burner of a 1 kW solid oxide fuel cell (SOFC) system. In performing the simulations, the anode gas is assumed to be hydrogen and the combustion of the gas mixture is modeled using a turbulent flow model. The validity of the numerical model is confirmed by comparing the simulation results for the flame barrier temperature and the porous media temperature with the corresponding experimental results. Simulations are then performed to investigate the effects of the hydrogen content and the burner geometry on the temperature distribution within the burner and the corresponding operational range. It is shown that the maximum flame temperature increases with an increasing hydrogen content. In addition, it is found that the burner has an operational range of 1.2~6.5 kW when assigned its default geometry settings (i.e. a length and diameter of 0.17 m and 0.06 m, respectively), but increases to 2~9 kW and 2.6~11.5 kW when the length and diameter are increased by a factor of 1.5, respectively. Finally, the operational range increases to 3.5~16.5 kW when both the diameter and the length of the burner are increased by a factor of 1.5.

4. Methane cracking over commercial carbons for hydrogen production

J. Sarada Prasad¹, Vivek Dhand², V. Himabindu¹, Y. Anjaneyulu³

1 Centre for Environment, Institute of Science & Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500 085, India.

2 Centre for Nanoscience & Technology, Institute of Science & Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500 085, India.

3 TGLVRC, Jackson State University, JSU BOX 18739, Jackson, MS 39217 -0939, USA.

Abstract: A bench scale unit has been designed and developed indigenously for producing hydrogen from methane in the presence of a catalyst. Five number carbon samples (two carbon blacks and three activated carbons) of different origin procured from Indian market have been investigated in the bench scale unit with stainless steel continuous fixed bed reactor at a constant temperature of 850 0C and space velocity (VHSV) of 1.62 Lit/hr.g. Among all the five samples, activated carbon produced from coconut shells with BET surface area of 1185 m2/g showed promising activity with a sustainability factor (R1/R0) of 0.33 and initial activity (R0) of 0.623 mmol/min.g of catalyst. Accumulated carbon yield (over a period of four hours) of the above catalyst is 564 mg/g of catalyst.

5. Technology and market future prospects of photovoltaic systems

Andreas Poullikkas

Electricity Authority of Cyprus, P.O. Box 24506, 1399 Nicosia, Cyprus.

Abstract: During the past 20 years there has been a significant growth of the solar photovoltaic (PV) technology and today is considered by many countries as an important technology for the future. Many countries have already established or are in the process of establishing support programs to encourage the adoption of this new technology following in this way the examples of the major players of the PV market. In this work, an investigation of the technology and market future prospects of PV systems is carried out. In particular the PV key benefits are presented and the various PV solar cell technologies are described and compared. Emphasis has been given to the current and future PV solar systems market demand including their current and future economics. Solar PV has two big challenges that need to be resolved. Production costs need to go down before it becomes economically sustainable, while production capacity must continue to grow in order for PV to become a significant player in the global energy market.

6. Evaluation of Meteosat-8 measurements using daily global solar radiation for two stations in Iraq

Kais J. AL-Jumaily, Ali M. AL-Salihi, Osama T. Al-Tai

Department of Atmospheric Sciences, College of Science, AL-Mustansiriyah University, Baghdad, Iraq.

Abstract: The use of solar radiation measurements on various solar systems design needs knowledge on its spatial and temporal variations. Such knowledge can be acquired by employing interpolation ground measured solar radiation collected by ground radiometric stations. More reliable information could be obtained by analyzing satellite images. The aim of this work is to evaluate the measurements of daily global solar radiation extracted from Meteosat-8 images using Heliosat-2 method. Ground measurements from two Iraqi stations were used in the evaluation processes. The results indicated that the mean RMSE and MAE for Baghdad were 0.621 kWh/m² and 0.024 kWh/m² and for Mosul were 0.458 kWh/m² and 0.012 kWh/m² respectively. These results are very satisfactory for monitoring the temporal and spatial variation of solar radiation for places which suffer from shortage of ground solar radiation measurements.

7. Preparation and characterization of the PVDF-based composite membrane for direct methanol fuel cells

Qian Liu, Laizhou Song, Zhihui Zhang, Xiaowei Liu

Department of Environmental & Chemical Engineering, Yanshan University, Qinhuangdao 066004, China.

Abstract: The polyvinylidene fluoride-sulfonated polystyrene composite membrane with proton exchange performance, denoted as PVDF-SPS, was prepared using a thermally induced polymerization technique. The thermal stability of the PVDF-SPS composite membrane was investigated using thermogravimetric (TG) analysis. The complex formation of the composite membrane was ascertained by Fourier transform infrared spectroscopy (FTIR). The surface compositions of the PVDF-SPS membrane were analyzed using X-ray photoelectron spectroscopy (XPS). The morphology of the composite membrane was characterized by environmental scanning electron microscopy (ESEM). The proton conductivity of the PVDF-SPS membrane was measured using impedance spectroscopy in the hydrated condition. The PVDF-SPS membrane has a stronger hydrophilic character than the pristine PVDF membrane and the polyvinylidene fluoride-polystyrene composite membrane (PVDF-PS), which is caused by the incorporation of sulfonic acid groups. The proton conductivity and the methanol permeability of the PVDF-SPS membrane measured at 298 K are 29.3 mS.cm^-1 and 8.6×10^-8 cm².s^-1, respectively. Although PVDF-SPS composite membrane possesses the lower oxidative stability than Nafion-117 membrane, the composite membrane displays lower methanol permeability than the Nafion-117 membrane, and the selectivity (the ratio of proton conductivity and methanol permeability) of the composite membrane is almost 20 times than that of Nafion-117.

8. Thermo-acidophillic biohydrogen production from rice bran de-oiled wastewater by Selectively enriched mixed culture

D. Sivaramakrishna¹, D. Sreekanth¹, V. Himabindu¹, M. Lakshmi Narasu²

1 Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally Hyderabad-500 085, India.

2 Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally Hyderabad-500 085, India.

Abstract: The present study focuses on the biohydrogen production in an anaerobic batch reactor operated at thermophillic (570C) and acidophilic conditions (pH 6) with rice bran de-oiled wastewater (RBOW) as substrate. The hydrogen generating mixed microflora was enriched from slaughter house sludge (SHS) through acid treatment (pH 3-4, for 24h) coupled with heat treatment (1h at 1000C) to eliminate non-spore forming bacteria and to inhibit the growth of methanogenic bacteria (MB) prior to inoculation in the reactor. The hydrogen production rate was maximum at 570C (1861±14ml/L-WW/d) compared to 370C (651±30ml/L-ww/d). The Hydrogen yield increased with temperature from 1.1 to 2.2 molH₂/mol of substrate respectively. The optimum pH range for hydrogen production in this system was observed in between 5.5 to 6. Acid-forming pathway with butyric acid as a major metabolite dominated the metabolic flow during the hydrogen production.

9. Evaluation of wood residues from Crete as alternative fuels

D. Vamvuka¹, G. Bandelis²

1 Department of Mineral Resources Engineering, Technical University of Crete, Greece.

2 Professional School of Chania, EPAS Chania, Greece.

Abstract: Olive and citrus prunings, the main agricultural residues of Crete, are considered to be of premium importance for local energy production, substituting a large part of conventional fuels. The thermal behaviour of these fuels during combustion was studied by thermogravimetry, at non-isothermal heating conditions. Fly ashes were collected from tests in a lab-scale fluidized bed facility. The effect of the inorganic constituents of the fuels on slagging/fouling and agglomeration propensities, as well as environmental pollution was examined. Kinetic models were developed and reaction rates were determined. The agroresidues studied were characterized as good quality fuels, having high volatile and low ash and sulphur contents. Their ash was rich in Ca, Si, K and P minerals. However, fly ashes were poorer in alkali compounds, implying lower deposition and corrosion problems in boilers. The environmental impact of heavy metals is negligible. The thermochemical reactivity of the two fuels in air was very similar. A power low model fitted the experimental results accurately.

10. Optimization of factors affecting the production of biodiesel from crude palm kernel oil and ethanol

David K. Kuwornoo¹, Julius C. Ahiekpor²

1 Faculty of Chemical and Materials Engineering, Kwame Nkrumah University of Science and Technology (KNUST), Private Mail Bag, Kumasi, Ghana.

2 Chemical Engineering Department, Kumasi Polytechnic, P.O. Box 854, Kumasi, Ghana.

Abstract: Biodiesel, an alternative diesel fuel made from renewable sources such as vegetable oils and animal fats, has been identified by government to play a key role in the socio-economic development of Ghana. The utilization of biodiesel is expected to be about 10% of the total liquid fuel mix of the country by the year 2020. Despite this great potential and the numerous sources from which biodiesel could be developed in Ghana, studies on the sources of biodiesel and their properties as a substitute for fossil diesel have tended to be limited to Jatropha oil. This paper, however, reports the parameters that influences the production of biodiesel from palm kernel oil, one of the vegetable oils obtained from oil palm which is the highest vegetable oil source in Ghana. The parameters studied are; mass ratio of ethanol to oil, reaction temperature, catalyst concentration, and reaction time using completely randomized 24 factorial design. Results indicated that ethanol to oil mass ratio, catalyst concentration and reaction time were the most important factors affecting the ethyl ester yield. There was also an interaction effect between catalyst and time and ethanol- oil ratio and time on the yield. Accordingly, the optimal conditions for the production of ethyl esters from crude palm kernel oil were determined as; 1:5 mass ratio of ethanol to oil, 1% catalyst concentration by weight of oil, 90 minutes reaction time at a temperature of 30 ^oC.

11. Optimal thermo-hydraulic performance of solar air heater having chamfered rib-groove roughness on absorber plate

Apurba Layek

Department of Mechanical Engineering, National Institute of Technology, Durgapur 713 209, India.

Abstract: The use of an artificial roughness on a surface is an effective technique to enhance the rate of heat transfer to fluid flow in the duct of solar air heater. However, the increase in thermal energy gain is always accompanied by increase in pumping power. This paper is concerned with optimization of roughness parameters of solar air heater based on effective efficiency criterion. Effective efficiency of a solar air heater having repeated transverse chamfered rib–groove roughness on one broad wall has been computed using the correlations for heat transfer and friction factor developed within the investigated range of operating and system parameters. Roughness parameters viz. relative roughness pitch P/e, relative groove position g/P, chamfer angle , relative roughness height e/Dh and flow Reynolds number Re, have a combined effect on the heat transfer as well as fluid friction. The thermo-hydraulic performance of an air heater in terms of effective efficiency is determined on the basis of actual thermal energy gain subtracted by the primary energy required to generate power needed for pumping air through the roughened duct. Based on energy transfer mechanism to the absorber plate, a mathematical model is developed to compute effective efficiency. The selection of the optimal values of the roughness parameters involves the comparison of the enhancement of thermal performance and the increase of pumping losses as a result of using roughness in the collector system with that of the system without roughness. The effective efficiency criterion is maximized and reasonably optimized designs of roughness are found.

12. Recommended concentration limits of indoor air pollution indicators for requirement of acceptable indoor air quality

Wang J., Zhang X.

Institute of HVAC & GAS Engineering, College of Mechanical Engineering, Tongji University, Shanghai 200092, China.

Abstract: Object and goals of indoor air pollution control with ventilation may influence improvement of indoor air quality, building energy consumption and even carbon emissions. Indicators of indoor air pollution caused by occupants-related sources and building-related sources were chosen based on sources emitting characteristics, pollutants composition, indicator choosing principles and indoor air pollution situation in China. Then the recommended concentration limits of indicators were given for unadapted and adapted persons according to logarithmic index evaluation method, combined with percentage of dissatisfaction and joint effect of indoor air pollution caused by these two kinds of sources.

13. Towards energy sustainability in the world: the implications of energy subsidy for developing countries

Joseph Iwaro, Abraham Mwasha

University of West Indies, W. Department of Civil and Environmental Engineering, St.Augustine Campus, Trinidad and Tobago.

Abstract: Energy subsidies are widespread around the world but they vary greatly in importance and type of fuel and country. The fossil fuel consumption rate is growing every year and in about 50 years we will have depleted most of our fossil fuel reserves, so it is necessary to find alternative sources of energy before that happens. However, the only solution to this challenge is through investment on energy conservation programmes and renewable energy source. In line with this challenge and confusion on fund appropriate for energy. This paper is aimed at examining the effect of energy subsidy on energy conservation and renewable energy in developing countries. The study intends to quantify and analysis a case study of Trinidad and Tobago energy subsidy and its implications for developing countries and energy sustainability in the world. Findings show that huge amount investments and government intervention were being expended on energy subsidy in order to lower the price of energy products for consumers. The study further identified implication of this growing subsidy for developing countries and that the funds could be used for creating renewable energy technology and energy conservation programmes.

14. Emission reduction in SI engine using ethanol – gasoline blends on thermal barrier coated pistons

C.Ananda Srinivasan, C.G.Saravanan

Faculty of Engineering and Technology, Department of Mechanical Engineering, Annamalai University, Annamalai Nagar -608 002.Tamil Nadu, India.

Abstract: In this study, the effects of ethanol and unleaded gasoline with Isoheptanol blends on multi- cylinder SI engine were investigated. The test fuels were prepared using 99.9% pure ethanol and unleaded gasoline with Isoheptanol blend, in the ratio of E 60 + 2.0 Isoheptanol, E 50 + 1.0 Isoheptanol. In this work the performance, emission and combustion tests were conducted in multi-cylinder petrol engine. The experimental results reveal an increase in brake thermal efficiency on the use of test fuel. In the emission test, CO is found slightly decreased, while HC increased moderately and CO₂ and NOx are appreciably reduced, when compared to the sole fuel. The second part of the investigation is carried out in the same engine with Alumina Titania coated crown of the pistons, to gain more inside improvement of engine performance and in-cylinder pressure for coated pistons. The experiment is repeated along with fuel additives and ethanol blends in the same blended ratio to analyse the performance and combustion characteristics of the engine. The results show marginal increase in brake thermal efficiency and reduction in CO, NOx, HC and CO₂ emissions. In this study, combustion analyses are made with the help of AVL combustion analyzer, in which cylinder pressure, heat release rate and cumulative heat release are performed.

15. Analysis of the impact of the OHEW under full load and fault current

A. Hellany, M. Nassereddine, M. N. Nagrial

University of Western Sydney, School of Electrical Engineering, Sydney, NSW, Australia.

Abstract: Electrical Safety as a result of induced voltage is gaining more attention in the area of HV utilities. This paper discusses the Electrical safety in a pipeline running parallel to a HV transmission line, and the methods of calculating the mutual impedance between the HV and pipeline. In addition, it also introduces a method of calculating the induced voltage in the pipeline and its mitigation process.

16. Temperature base correlation for the estimation of global solar radiation on horizontal surface

C.K. Panday and A.K. Katiyar

Department of Applied Sciences, Institute of Engineering and Technology, Lucknow-21, India.

Abstract: In the present study, a correlation have been developed for the extraction of monthly mean daily global distribution of solar radiation from the ratio of monthly mean daily maximum to minimum ambient air temperature. The reason for this approach comes from the fact that, although the air temperature is a worldwide measured meteorological parameter, it rarely used in solar radiation techniques. Numerical calculations have been made using the new model corresponding to five Indian locations (viz. Jodhpur, Ahmedabad, Calcutta, Bombay and Pune) and the results are compared against the models available in literature and with the measured values. Statistical tests of root mean square error (RMSE), mean bias error (MBE) and t-test are also performed to compute the accuracy of present correlation. Based on overall results it was concluded that air temperature successfully substitutes the sunshine duration data in the estimation of the solar energy.