volume-11-Issue 2 (2016)
Latest Articles
Development of Waste Heat Fired Activated Carbon Ammonia Adsorption Chiller
IJTEE, volume-11, Issue 2 (2016) , PP 131 - 135
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.02.008
by Mohammed Sadhikh, Jaice Joy Skaria from College of Engineering, King Khalid University, Abha, KSA Mechanical Engineer, Engineering Innovation Design & Consulting LLC, Oman
Abstract: Adsorption systems are promising alternatives to the existing refrigeration systems in the wake of alarming energy crises and potential danger due to the use of ozone-depleting refrigerants. Sorption systems use thermal energy as their power source and solid adsorbent beds to adsorb and desorb a refrigerant to obtain the desired cooling effect. Solar energy, engine exhaust, and low-grade waste heat could be used to drive the sorption compressors. The use of non-ozone-depleting refrigerants makes these systems environmentally benign. Adsorption refrigeration systems can meet the cooling requirement across a wide range of temperatures. These systems have minimal moving parts and hence they are free of noise, vibration, and related problems. This paper will present the description, operation, and simulated system characteristics for a 1000W adsorption chiller. The adsorption system performance factors such as coefficient of performance (COP), specific cooling power (SCP), and cycle time were predicted. Parameters such as the generation and adsorption temperature, condenser, and evaporator temperature were varied to analyze the influence of the varied operating conditions. A two bed 1000 W capacity adsorption water chiller to chill water from 12 to 7 C was considered for the simulation. COP of the simulated system ranged between 0.3 to 0.4 and SCP from 90 to 180 W/kg AC respectively. The maximum value of cycle time obtained was 25 minutes when the generation outlet temperature was 180 oC. read more... read less...
Keywords: Adsorption, Waste Heat, Chiller
Energy and Exergy Analysis of a Power Plant Based on a Three Reactor Chemical Looping Reforming System
IJTEE, volume-11, Issue 2 (2016) , PP 125 - 130
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.02.007
by Mohammed N. Khan, Tariq Shamim from Institute Center for Energy (iEnergy), Department of Mechanical and Materials Engineering, Masdar Institute of Science and Technology, Masdar City, Abu Dhabi, United Arab Emirates
Abstract: Chemical looping reforming (CLR) is an innovative way of simultaneously producing hydrogen (H2) and capturing carbon dioxide (CO2). In the CLR process, the fuel and the oxidizer do not meet and therefore, there is no energy penalty for separating CO2 as opposed to the conventional power plants. The only thing required to do to obtain pure H2 and CO2 is to condense the water vapor in both streams. The process is divided into three steps: oxidation of fuel in the fuel reactor (FR) to form CO2 and H2O, reduction of steam to form H2 in the steam reactor (SR), and the complete oxidation of the metal-oxygen carrier (OC) in the air reactor (AR). When the CLR system is integrated with a full power plant, there are energy losses in each of the components. It is necessary to know where the exergy is being destroyed and where it can be avoided. Therefore, an exergy analysis has been performed on the plant consisting of CLR system, steam cycle (SC) which incorporates triple pressure heat recovery steam generator (HRSG) and the compression system for compressing H2 and CO2 to high pressures ready for consumption or sequestration. This study employs an Aspen plus model to investigate the influences of various operating parameters such as the flow rates of fuel, air, steam, and OC on the electrical, H2 and exergetic efficiencies of the plant. The results show that the electrical and the H2 efficiencies are dependent on the reactor temperatures. The reactor temperatures can be easily controlled by varying the flow rates of the reactants. It is observed from the results that higher electrical efficiencies are obtained at lower fuel, steam, and airflow rates and higher OC flow rates. While the higher H2 efficiencies are obtained at lower flow rates of OC, air, and steam and higher flow rates of fuel. Since the energetic efficiency depends on the output of the plant which is H2, then a similar criterion is required to obtain high energy efficiency as that of H2 efficiency. read more... read less...
Keywords: Hydrogen Production, Chemical Looping Reforming, Exergy Analysis, Aspen Plus, Hydrogen Efficiency.
Optimization of Cable Layout Design in a Wind Farm: A Hybrid Approach
IJTEE, volume-11, Issue 2 (2016) , PP 117 - 123
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.02.006
by M. Tifroute and H. Bouzahir from Laboratory of Engineering Systems and Information Technologies, ENSA Ibn Zohr University, Agadir, Morocco
Abstract: In this paper, a hybrid algorithm based on modified Ants Colony Optimization (ACO) and Artificial Immune Algorithm (AIA) for solving the Steiner Minimal Tree Problem (SMTP) is introduced. Since the Steiner Tree Problem is NP-hard, we design an algorithm to construct high-quality Steiner trees in a short time which is suitable for real-time multicast routing in networks. After the breadth-first traversal of the minimal graph obtained by ACO, the terminal points are divided into different convex hull sets, and the full Steiner tree is structured from the convex hull sets partition. The Steiner points can be vaccinated by AIA to get an optimal graph. The average optimization effect of AIA is shorter than the minimal graph obtained using ACO, and the performance of the algorithm is shown. We give an example of an application in wind farm network design. read more... read less...
Keywords: Steiner Problem, Ant Colony Algorithm, Artificial Immune Algorithm
Optimization of Cable Layout Design in a Wind Farm: A Hybrid Approach
IJTEE, volume-11, Issue 2 (2016) , PP 111 - 115
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.02.005
by M. Tifroute and H. Bouzahir from Laboratory of Engineering Systems and Information Technologies, ENSA Ibn Zohr University, Agadir, Morocco
Abstract: In this paper, a hybrid algorithm based on modified Ants Colony Optimization (ACO) and Artificial Immune Algorithm (AIA) for solving the Steiner Minimal Tree Problem (SMTP) is introduced. Since the Steiner Tree Problem is NP-hard, we design an algorithm to construct high-quality Steiner trees in a short time which is suitable for real-time multicast routing in networks. After the breadth-first traversal of the minimal graph obtained by ACO, the terminal points are divided into different convex hull sets, and the full Steiner tree is structured from the convex hull sets partition. The Steiner points can be vaccinated by AIA to get an optimal graph. The average optimization effect of AIA is shorter than the minimal graph obtained using ACO, and the performance of the algorithm is shown. We give an example of an application in wind farm network design. read more... read less...
Keywords: Steiner Problem, Ant Colony Algorithm, Artificial Immune Algorithm
Regulating PPP Projects in the Energy Sector: An Exploratory Survey of Skills Required
IJTEE, volume-11, Issue 2 (2016) , PP 105 - 110
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.004
by Abdullahi A. Umara, Noor Amil W. A. Zawawi, Abdul Rashid Abdul Aziz, Taleb M. Al-Rousan from Alhosn University, Old Airport Road, Delma Street 13, Al-Musalla, Abu Dhabi, U.A.E `Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh Perak, Malaysia Universiti Sains Malaysia, Pulau Pinang, 11800 Penang, Malaysia
Abstract: The involvement of the private sector in the provision of public services through concessions has been growing over the years and the energy sector has seen its own fair share of such concessions. Because these services have monopoly characteristics, regulatory institutions were set up to protect society from monopoly exploitation, inefficiencies, and market failures. However, there has been a growing disenchantment with the state of service provision around the globe and consumers are blaming regulatory institutions' inability to protect them. The effectiveness of any regulatory institution is dependent on the expertise and competence of its staff. Therefore, this study seeks to determine the capacity requirement for effective regulatory governance and how best the present capacity gaps can be filled. This study reports the results of a survey of 101 energy industry stakeholders in public and private sectors across 35 countries. It was found that expertise in management, contract design, business analysis, project management, facilities management, risk management, ex-post negotiations, and sector-specific knowledge were crucial to the effective performance of regulatory institutions. Recruiting experts from the private sector were considered the most effective method of filling the capacity gaps in regulatory institutions. read more... read less...
Keywords: PFI/PPP; Infrastructure regulation; Skills
Hydropower and Future Environmental Policies
IJTEE, volume-11, Issue 2 (2016) , PP 99 - 103
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.02.003
by I. Yuksel, H. Arman, and I. H. Demirel from Department of Civil Engineering, Hydraulics Division, Faculty of Civil Engineering, Yildiz Technical University, 34220 Davutpasa-Istanbul, Turkey Geology Department, College of Science, United Arab Emirates University, P.O. 15551, Al-Ain, UAE
Abstract: Hydropower energy is a renewable, sustainable, and clean energy in the other alternative energy sources. Moreover, it does not deprive future generations in terms of raw materials or burdening them with pollutants or waste. Hydroelectric power plants utilize the basic national and renewable resources of the country. Although the initial investment cost of hydropower seems relatively high, the projects have the lowest production costs and do not depend on foreign capital and support, when considering environmental pollution and long-term economic evaluation. Hydropower is available in a broad range of project scales and types. Projects can be designed to suit particular needs and specific site conditions. As hydropower does not consume or pollute the water it uses to generate power, it leaves this vital resource available for other uses. read more... read less...
Keywords: Hydropower; Renewable Energy; Energy Utilization; environmental Policy, Turkey
Performance Improvement of Shallow Solar Pond using Nanoparticles
IJTEE, volume-11, Issue 2 (2016) , PP 93 - 98
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.02.002
by Mohammad A. Hamdan and Lana A. Al-Qudah from Dept. of Mechanical Engineering, Faculty of Engineering & Technology, The University of Jordan, Amman, Jordan
Abstract: Countries are going through a shortage of energy source; consequently, the futures are looking for an alternative source of energy. A very high potential Source of alternative source of energy is solar energy. A solar pond is one way to utilize solar energy and a shallow solar pond (SSP) is one type of solar pond. A shallow solar pond can be built easily and at a comparatively low cost over a large space, using and storing solar energy on a grand scale. They can’t pollute the air, and coupled with desalting units, they can be used to purify water. Shallow Solar ponds with nanoparticles give a great result. In this work, two shallow solar ponds were constructed and installed side by side to study the effect of adding aluminum oxide AL2O3 nanoparticles on the performance of the ponds (one with nanoparticles, while the other one without ). It was found that the performance of the shallow solar pond, in general, was improved by the addition of nanoparticles, with an increase in the temperature of the lower convective zone varies between 2.1oC to 11.3oC, with the maximum increase is obtained when 0.2% concentration of nanoparticles. read more... read less...
Keywords: Shallow Solar Pond, Nanoparticles, Energy Source
Polyethyleneimine Supported Mesoporous Silica for CO2 Capture: Adsorption Kinetics and Degradation Problems
IJTEE, volume-11, Issue 2 (2016) , PP 87 - 91
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.02.001
by Dang Viet Quang, Thosmas Nelson, and Mohammad R.M. Abu-Zahra from Masdar Institute of Science and Technology, P.O. Box 54224, Masdar city, Abu Dhabi, United Arab Emirates RTI International, Research Triangle Park, NC 27709-2194, USA
Abstract: Polyethyleneimine-supported mesoporous silica (PEI-MPS) has widely been investigated as solid sorbents for CO2 adsorption in the laboratory. However, the adsorption kinetics of CO2 on this sorbent is still a disputed problem and the sorbent degradation could be a cause that hinders the sorbent from industrial application. In this study, the PEI-MPS sorbent was prepared by impregnating PEI onto mesoporous silica, and then the adsorption kinetics was investigated using the pseudo-first-order model, pseudo-second-order model, and intraparticle diffusion model. Results indicated that the CO2 adsorption kinetics on the sorbent occurred in a 2 stage process. In the early stage, it is well fitted by the pseudo-first-order model, but in the later stage, it is well fitted by the intraparticle diffusion model. The pseudo-second-order model proved to be the most suitable one to describe the adsorption of CO2 on the sorbent for the whole adsorption period with less than 5% absolute deviation. The sorbent with a CO2 adsorption capacity of 144.9 mg/g was calculated based on the fitting of the pseudo-second-order model. The major degradation issues and their potential effects on the CO2 capture process were also discussed. The degradation significantly impacts the performance and efficiency of the CO2 capture process. The chemical degradation, however, can be considerably minimized by humidification read more... read less...
Keywords: CO2 adsorption; CO2 capture; Polyethyleneimine; Adsorption/regeneration; Kinetic.