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Aims and Scope
Editorial Board

1. Performance optimization of a PEM hydrogen-oxygen fuel cell

Maher A.R. Sadiq Al-Baghdadi

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

Abstract: The objective was to develop a semi-empirical model that would simulate the performance of proton exchange membrane (PEM) fuel cells without extensive calculations. A fuel cell mathematical module has been designed and constructed to determine the performance of a PEM fuel cell. The influence of some operating parameters on the performance of PEM fuel cell has been investigated using pure hydrogen on the anode side and oxygen on the cathode side. The present model can be used to investigate the influence of process variables for design optimization of fuel cells, stacks, and complete fuel cell power system. The possible mechanisms of the parameter effects and their interrelationships are discussed. In order to assess the validity of the developed model a real PEM fuel cell system has been used to generate experimental data. The comparison shows good agreements between the modelling results and the experimental data. The model is shown a very useful for estimating the performance of PEM fuel cell stacks and optimization of fuel cell system integration and operation.

Volume 4, Issue 2, 2013, pp.175-184.

2. Harvesting, oil extraction, and conversion of local filamentous algae growing in wastewater into biodiesel

W. S. Grayburn¹, R. A. Tatara², K. A. Rosentrater³, G. P. Holbrook¹

1 Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA.

2 Department of Technology, Northern Illinois University, DeKalb, IL 60115, USA.

3 Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, USA.

Abstract: Algae are known to be a potential feedstock in the production of biodiesel fuel. Although much of the focus has been on microalgal species, macroalgae are also suitable  as  a source of lipids. In this study, a locally abundant (central Illinois) filamentous algae has been harvested from a water treatment plant; dried to about 10% of its initial weight; pulverized in a hammermill; and treated with methanol to extract the oil. The algae are a combination of several coexisting species including Cladophora sp. and Rhizoclonium. Oil yields ranged from 3% to 6%, by weight, of the dried mass. This oil was reacted by transesterification to yield fatty acid methyl esters (biodiesel fuel) with an overall mass conversion efficiency of 68%. A B5 blend of this algal biodiesel and petrodiesel was run in a 13.4-kW test engine. Measurements indicated similar performance compared to pure petrodiesel in terms of fuel efficiency and carbon dioxide and carbon monoxide exhaust emissions. Significantly, there was a 22% reduction in nitrogen oxides when using the B5 fuel. It has been demonstrated that filamentous macroalgae may be cultivated as biodiesel feedstock and have inherent advantages such as an ability to remove phosphorus and nitrogen compounds from wastewater, simplicity of harvesting, and natural resistance to local aquatic grazers and competing organisms.

3. An experimental study on the thermal valorization of municipal and animal wastes

Despina Vamvuka¹, Stelios Sfakiotakis¹, Kyriakos D. Panopoulos²

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

2 Centre for Research & Technology Hellas / Institute for Solid Fuels Technology & Applications (CERTH/ISFTA), 4^th klm. Nat. Rd. Ptolemais-Kozani-P.O. box 95 – GR 50200 Ptolemais, Greece.

Abstract: Poultry wastes and refused derived fuel disposal through thermochemical processes, such as combustion, has been proposed. These fuels have calorific values that in many cases exceed 20MJ kg-1. An extensive analysis has been performed of pyrolysis and combustion results obtained by thermal analysis measurements. The weight loss data were recorded continuously, under dynamic conditions, in the range 25-1300ºC. A first order parallel reactions model and a power low model fitted the experimental results accurately for pyrolysis and combustion, respectively. The pyrolysis of poultry waste was a complex process, occurring up to 1300°C with high activation energies.

4. Boosting biogas yield of anaerobic digesters by utilizing concentrated molasses from 2^nd  generation bioethanol plant

Shiplu Sarker¹, Henrik Bjarne Møller²

¹ Department of Renewable Energy, Faculty of Engineering and Science, University of Agder, Grimstad-4879, Norway.

² Department of Biosystems Engineering, Faculty of Science and Technology, Aarhus University, Research center Foulum, Blichers Allè, Post Box 50, Tjele-8830, Denmark.

Abstract: Concentrated molasses (C⁵ molasses) from 2^nd generation bioethanol plant has been investigated for enhancing productivity of manure based digesters. A batch study at mesophilic condition (35±1°C) showed the maximum methane yield from molasses as 286 LCH₄/kgVS which was approximately 63% of the calculated theoretical yield. In addition to the batch study, co-digestion of molasses with cattle manure in a semi-continuously stirred reactor at thermophilic temperature (50±1°C) was also performed with a stepwise increase in molasses concentration. The results from this experiment revealed the maximum average biogas yield of 1.89 L/L/day when 23% VS_molasses was co-digested with cattle manure. However, digesters fed with more than 32% VS_molasses and with short adaptation period resulted in VFA accumulation and reduced methane productivity indicating that when using molasses as biogas booster this level should not be exceeded.

5. Indoor tests to investigate the effect of brine depth on the performance of solar still

Marwah AW. Ali, Abdul Jabbar N. Khalifa

Nahrain University, College of Engineering, Jadiriya, P.O. Box 64040, Baghdad, Iraq.

Abstract: Many experimental and numerical studies have been done on different configurations of solar stills to optimize the design by examining the effect of climatic, operational and design parameters on its performance. One of the most important of the operational parameters that has received a considerable attention in the literature is the brine depth. This paper reports indoor experimental investigations on the effect of brine depth on the productivity and efficiency of the solar stills at four different brine depths of 1.5, 2, 4 and 5.5 cm. Indoor tests were used by simulating the solar input by proper electric heaters located at the bottom of the still for heating the water contained in the basin of the still. The present study validated the decreasing trend in productivity with the increase of brine depth and showed that the still productivity could be influenced by the brine depth by up to 24%.

6. Experimental testing method for solar light simulator with an attached evacuated solar collector

Mahmoud Shatat, Saffa Riffat, Francis Agyenim

Institute of Sustainable Energy Technology, University of Nottingham, Nottingham, NG7 2RD, UK.

Abstract: This paper describes a novel solar simulator of high solar irradiation. It consists of an array of 30 halogen lamps of 400W each, covering a gross area of 2.32 m². A standardized empirical method for solar simulator testing facility based on an experimental performance is presented. A uniform geometrical configuration design for a solar simulator was evaluated by its illuminance distribution to optimize the maximum source-to-target transfer efficiency of irradiative power. Experimental tests were carried out for various distances from the simulator surface. It was determined that the optimal distance between the light surface simulator and the solar collector is about 23 cm at different solar irradiance. The unevenness of solar radiation values were investigated at different points under the simulator facility and the maximum unevenness error percentage was found to be about 9.1%, which is well within the allowable limits of 15% set by British Standards for testing a solar simulator . The performance of an evacuated solar collector with an aperture area of 1.73 m² to simulate solar insolation during March in the Middle East region was investigated and it was proved that the efficiency of the solar collector was closely correlated with the efficiency data provided by the manufacturer. The design of such a solar light simulator associated with the development of a standardized test procedure can be utilized as a reliable and efficient experimental platform to investigate various solar collectors and materials.

7. Theoretical modeling of combustion characteristics and performance parameters of biodiesel in DI diesel engine with variable compression ratio

Mohamed F. Al-Dawody, S. K. Bhatti

Department of Mechanical Engineering, Andhra University, India.

Abstract: Increasing of costly and depleting fossil fuels are prompting researchers to use edible as well as non-edible vegetable oils as a promising alternative to petro-diesel fuels. A comprehensive computer code using ”Quick basic” language was developed for the diesel engine cycle to study the combustion and performance characteristics of a single cylinder, four stroke, direct injection diesel engine with variable compression ratio. The engine operates on diesel fuel and 20% (mass basis) of biodiesel (derived from soybean oil) blended with diesel. Combustion characteristics such as cylinder pressure, heat release fraction, heat transfer and performance characteristics such as brake power; and brake specific fuel consumption (BSFC) were analyzed. On the basis of the first law of thermodynamics the properties at each degree crank angle was calculated. Wiebe function is used to calculate the instantaneous heat release rate. The computed results are validated through the results obtained in the simulation Diesel-rk software.

8. Preparation of biodiesel from soybean oil by using heterogeneous catalyst

Kaniz Ferdous¹, M. Rakib Uddin¹, Maksudur R. Khan^1,2, M. A. Islam¹

1 Department of Chemical Engineering and Polymer Science Shah Jalal University of Science and Technology, Sylhet 3114, Bangladesh.

2 Faculty of Chemical and Natural Resources Engineering, University Malaysia Pahang, 26300 Gambang, Kuantan, Pahang, Malaysia.

Abstract: The predicted shortage of fossil fuels and related environmental concerns has recently attracted significant attention to search alternative fuel. Biodiesel is one of the alternatives to fossil fuel. Now-a-days, most biodiesel is produced by the transesterification of oils using methanol and a homogeneous base catalyst. The use of homogeneous catalysts is normally limited to batch mode processing followed by a catalyst separation step. The immiscible glycerol phase, which accumulates during the course of the reaction, solubilizes the homogeneous base catalyst and therefore, withdraws from the reaction medium. Moreover, other difficulties of using homogeneous base catalysts relate to their sensitivity to free fatty acid (FFA) and water and resulting saponification phenomenon. High energy consumption and costly separation of the catalyst from the reaction mixture have inspired the use of heterogeneous catalyst. The use of heterogeneous catalysts does not lead to the formation of soaps through neutralization of FFA and saponification of oil. In the present paper, biodiesel was prepared from crude (soybean) oil by transesterification reaction using heterogeneous base catalyst name calcium oxide (CaO). Various reaction parameters were optimized and the biodiesel properties were evaluated.

9. Numerical prediction of pressure loss of fluid in a T-junction

Mohammed Abdulwahhab¹, Niranjan Kumar Injeti¹, Sadoun Fahad Dakhil²

1 Department of Marin Engineering, Andhra University, AP, India.

2 Department of Fuel& Energy, Basrah Technical College, Iraq.

Abstract: This work presents a prediction of pressure loss of fluid with turbulent incompressible flow through a 90° tee junction was carried out and compared with analytical and experimental results. One turbulence model was used in the numerical simulations: k-ε model for two different values of area ratio between the main pipe and the branch pipe were 1.0 and 4.0, and flow rate ratios. The continuity, momentum and energy equations were discredited by means of a finite volume technique and the SIMPLE algorithm scheme was applied to link the pressure and velocity fields inside the domain. A three dimensional steady state flow was solving by using CFX 5 code ANSYS FLUENT13. The effect of the flow rate ratio q (ratio between the flow rate in the branch and outlet pipes) on pressure drop and velocity profile was predicted at different Reynolds numbers. The results show that increasing the flow rate ratio the pressure and total energy losses increase because the presence of recirculation and the strong streamline curvature.

10. Experimental study of DI diesel engine performance using biodiesel blends with kerosene

A. K. Azad, S. M. Ameer Uddin, M. M. Alam

Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh.

Abstract: The experimental investigation offers a comprehensive study of DI diesel engine performance using bio-diesel from mustard oil blends with kerosene. The vegetable oil without trans-esterification reaction have been blended with kerosene oil by volume in some percentage like 20%, 30%, 40% and 50% which have been named as M20 (20% mustard, 80% kerosene), M30 (30% mustard, 70% kerosene), M40 (40% mustard, 60% kerosene) and M50 (50% mustard, 50% kerosene). The properties of the bio-fuel blended with kerosene have been tested in the laboratories with maintaining different ASTM standards. Then a four stroke, single cylinder, direct injection diesel engine has been mounted on the dynamometer bed for testing the performance of the engine using the bio-diesel blends. Several engine parameters like bsfc, bhp, break mean effective pressure, exhaust gas temperature, lube oil temperature, sound level etc. have been determined. A comparison has been made for engine performance of different bio-diesel blends with kerosene with the engine performance of diesel fuel.

11. Investigation on utilization of biogas & Karanja oil biodiesel in dual fuel mode in a single cylinder DI diesel engine

Bhabani Prasanna Pattanaik¹, Chandrakanta Nayak¹, Basanta Kumar Nanda²

1 Department of Mechanical Eng., Gandhi Institute for Technological Advancement, Madanpur, Bhubaneswar - 752054, Odisha, India.

2 Department of Mechanical Eng., Maharaja Institute of Technology, Bhubaneswar, Odisha, India.

Abstract: In this work, experiments were performed on a single cylinder DI diesel engine by using bio-gas as a primary fuel and Karanja oil biodiesel and diesel oil as secondary fuels in dual fuel operation. The experiments were performed to measure performance parameters i.e. (brake specific fuel consumption, brake thermal efficiency and exhaust gas temperature) and emission parameters such as carbon monoxide, carbon dioxide, nitrogen oxide unburned hydro carbon and smoke etc. at different load conditions. For the dual-fuel system, the intake system of the test engine was modified to convert into biogas and biodiesel of a dual-fueled combustion engine. Biogas was injected during the intake process by gas injectors. The study showed that, the engine performance parameters like BP, BTE and EGT gradually increase with increase in engine load for all test conditions using both pilot fuels diesel and KOBD. However, the BSFC of the engine showed decreasing slope with increase in engine load for all test conditions. Above 40% engine load the BSFC values for all test fuels are very close to each other. The engine emission analysis showed that the CO₂, CO and NOx emissions increase with increase in engine load for both single and dual fuel mode operation using both pilot fuels. The NOx concentration of exhaust gases in dual fuel mode is superior than that of single mode.

12. Assessment of spatial and temporal drought in Iraq during the period 1980-2010

Yaseen K. AL-Timimi, Monim H. AL-Jiboori

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

Abstract: This study investigated the frequency of drought for the period 1980 to 2010 in Iraq, based on monthly rainfall data were collected from 39 meteorological stations distributed across the country and digitally encoded into a GIS database. The standardized precipitation index (SPI) is used to evaluated the spatial and temporal characteristics of meteorological drought. The result of SPI analysis reveal that the country faced during the past 30 years frequent non-uniform drought periods in an irregular repetitive manner. the paper suggest the presence of two drought types, local drought and national drought, Drought severity Classes; near normal drought, moderate drought, severe drought and extreme drought increased with time from normal to extreme levels especially at last decade. The result show the year 2008 was the worst dry year during the period, 30% of the area is under extreme drought, 36% under severe drought, 22% of the area is under moderate drought and 12% is near normal.

13. Integration and comparison of assessment and modeling of road traffic noise in Baripada town, India

Bijay Kumar Swain¹, Shreerup Goswami²

1 Department of Environmental Science, Utkal University, Bhubaneswar-751004, Odisha, India.

2 Department of Geology, Ravenshaw University, Cuttack-753003, Odisha, India.

Abstract: The road traffic is the predominant source of noise pollution in urban areas. Despite enactment of legislations and despite effort from Government level to abate vehicle noise, the noise exposure of people of India due to road traffic has hardly changed, but has increased day by day due to growth of vehicular population. Thus, an attempt had been made to assess the noise level in 12 different squares (major intersection points) of Baripada town during four different specified times (7-10 a.m., 11 a.m.-2 p.m., 3-6 p.m., 7-10 p.m.). The equivalent noise levels of all the 12 squares were found to be much beyond the permissible limit (70 dB during day time). Noise descriptors such as L₁₀, L₅₀, L₉₀, Leq, TNI (Traffic Noise Index), NPL (Noise Pollution Level) and NC (Noise climate) were assessed to reveal the extent of noise pollution due to heavy traffic in this town. It is pertinent to mention here that even the minimum Leq and NPL values were more than 70.9 dB and 88.4 dB, respectively. Chi-square (χ²) test was also computed for investigated squares at different times to infer the level of significance. The test depicts that the noise levels of different squares do not differ significantly at the peak hour. The prediction model was used in the present study to predict equivalent noise levels. Comparison of predicted equivalent noise level with that of the actual measured data demonstrated that the model used for the prediction has the ability to calibrate the multi-component traffic noise and yield reliable results close to that by direct measurement. Episodic and impulsive noise levels by the air-horn of motor vehicles in Baripada were also appraised and were more than the permissible limit. Though, the dimension of the traffic generated noise pollution in Baripada was not so alaraming like other towns of India, a preliminary public health survey has also been carried out.

14. Environmental monitoring of mercury in urban soils, air and plants of a Mediterranean area, Alexandria, Egypt

Mohamed Rashad¹, Kh. M. Darwish¹, Hassan E. Abdel Salam¹, Elsayed A. Shalaby²

1 Arid Lands Cultivation Research Institute, Land and Water Technologies Department, City of Scientific Research and Technological Applications (SRTACity), New Borg El-Arab, 21934 Alexandria, Egypt.

2 Environmental Studies Department, Institute of Graduate Studies and Research, Alexandria University, Egypt.

Abstract: This study was conducted in order to assess the levels of mercury (Hg) in air, soil, and plants in an area around chlor-alkali plant using mercury cells to produce chlorine gas. The output results indicated that the levels of Hg were decreased in the studied components with increasing the distance from the hot spot. Geographically, the highest levels of Hg were recorded to the prevailing wind direction i.e., Southeast direction, while the other directions West and East had the lowest levels. A wide variation in the amount of total Hg in the air samples collected at different distances around the hot spot was found. Also there was a pronounced difference in Hg concentration in soil samples depending on location and sampling time. The maximum concentrations of soil Hg were measured during February 2008 for all sampling directions. The levels of total Hg in plant samples during the period of 12 month-study were relatively narrow compared with the levels in air and soil which represented great differences in the total Hg among different directions and sites.

15. Processes assessment in binary mixture plant

N. Shankar Ganesh¹, T. Srinivas²

1 Department of Mechanical Engineering, Kingston Engineering College, Vellore 632 059, Tamil Nadu, India.

2 CO₂ Research and Green Technologies Centre, School of Mechanical and Building Sciences, Vellore Institute of Technology (VIT) University, Vellore 632 014, Tamil Nadu, India.

Abstract: Binary fluid system has an efficient system of heat recovery compared to a single fluid system due to a better temperature match between hot and cold fluids. There are many applications with binary fluid system i.e. Kalina power generation, vapor absorption refrigeration, combined power and cooling etc. Due to involvement of three properties (pressure, temperature and concentration) in the processes evaluation, the solution is complicated compared to a pure substance. The current work simplifies this complex nature of solution and analyzes the basic processes to understand the processes behavior in power generation as well as cooling plants. Kalina power plant consists of regenerator, heat recovery vapor generator, condenser, mixture, separator, turbine, pump and throttling device. In addition to some of these components, the cooling plant consists of absorber which is similar in operation of condenser. The amount of vapor at the separator decreases with an increase in its pressure and temperature.

16. Application of phytoremediation technique in the treatment of produced water using eichornea crassipes

Dune Kingdom K.¹, Ezeilo Fabian E.², Longjohn T.³

1 Department of Petroleum Engineering, Rivers State U. of Sc. & Tech., Port Harcourt, Nigeria.

2 Department of Civil Engineering, Rivers State U. of Sc. & Tech., Port Harcourt, Nigeria.

3 Department of Petroleum Engineering, Rivers State U. of Sc. & Tech., Port Harcourt, Nigeria.

Abstract: This paper reports on a study carried out to determine the effectiveness of using a hyper accumulating plant like Eichorneacrassipes (water hyacinth) to reduce toxicity of produced water gotten from an oil field of the Niger Delta region of Nigeria. Results from the phytoremediation experiment showed that the concentration of biological oxygen demand (BOD), chemical oxygen demand (COD), and oil/grease were reduced from initial concentrations of 10.6mg/l, 150 mg/l and 7.70 mg/l to 7.25mg/l, 106.25 mg/l and 8.35mg/l respectively. Heavy metals like iron (Fe), zinc (Zn), Magnesium (Mg), nickel (Ni), copper (Cu), and lead (Pb) were reduced from initial concentrations of 3.00 mg/l, 3.40 mg/l, 1.22 mg/l, 1.40 mg/l, 0.06 mg/l, and 0.030 mg/l to 2.18, 2.09, 0.82, 0.25, 0.015, and 0.009 mg/l, respectively. A comparison of the system’s effluent characteristics with effluent discharge limits in Nigeria, show that for inland, near-shore and offshore disposals, the effluent can be discharged into these environments with minimum public hazards. It is recommended that every company should carryout proper detoxification of produced water before disposal, while regulatory agencies such as DPR, FEPA, etc., must ensure proper monitoring and enforcement of effluent standards.

17. Prediction of environmental indices of Iran wheat production using artificial neural networks

B. Khoshnevisan, Sh. Rafiee, M. Omid, M. Yousefi

 Department of Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran.

Abstract: This study was carried out in the province of Esfahan in Iran in order to model field emissions of wheat production, using artificial neural networks (ANNs). Data were collected from 260 wheat farms in Fereydonshahr city with face to face questionnaire method. Life cycle assessment (LCA) methodology was developed to assess all the environmental impacts associated with wheat cultivation in the studied region. Global warming potential (GWP), eutrophication potential (EP), human toxicity potential (HTP), terrestrial ecotoxicity potential (TEP), oxidant formation potential (OFP) and acidification potential (AP) were chosen as target outputs. System boundary and functional unite were selected farm gate and one ton of wheat grain. All input energies and farm size were selected as inputs and six impact categories were chosen as outputs of the model. To find the best topology, several ANN models with different number of hidden layers and neurons in each layer were developed. Subsequently, we applied different activation functions in each hidden layer to assess the best performance with highest coefficient of determination (R2), lowest root mean square error (RMSE) and mean absolute error (MAE). Accordingly, ANN model with 12-6-6-6 structure showed the best performance. RMSE for GWP, HTP, EP, OFP, AP and TEP were 45.82, 6.22, 7.47, 0.96, 0.28 and 0.09, respectively. Also, MAEs for this model were 14.9, 0.77, 1.5, 0.02, 0.14 and 0.02 for GWP, HTP, EP, OFP, AP and TEP.

18. Bioreduction of chromate by immobilized cells of Halomonas sp

S. Murugavelh, Kaustubha Mohanty

Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781039, Assam, India.

Abstract: In this work, the bioreduction of Cr(VI) by immobilized cells of Halomonas sp was reported. Ca alginate, acryl amide and agar were tested as the matrices for immobilization. Ca alginate was found to be the suitable matrix among the different matrices studied. Of the various dosages of inoculum studied 2 g/L was found to be the optimum. Glucose at 1 g L^-1 was completely utilized by the immobilized Halomonas sp even in the presence of Cr(VI) at 40 mg L^-1. The optimum pH for the bioreduction of Cr(VI) by immobilized Halomonas sp was found to be pH 6. The mechanical strength of the beads plays an essential role in the bioreduction process. Halomonas sp entrapped in a alginate matrix reported a maximum of 98.9 % of reduction for an initial Cr(VI) concentration of 10 mg L^-1. The alginate beads can be reused for 3 times with slight drop in the percentage reduction. The presence of other metals decreased the bioreduction percentage.