MODELING AND SIMULATION OF THE PRODUCTION OF HYDROGEN USING HYDROELECTRICITY IN VENEZUELA

Author(s):  
A. Contrerasa ◽  
F. Possob ◽  
Т. N. Veziroglu

The purpose of this work is to develop and evaluate a mathematical model for the process of hydrogen production in Venezuela, via electrolysis and using hydroelectricity, with a view to using it as an energy vector in rural sectors of the country. Regression models were prepared to estimate the fluctuation of the main variables involved in the process: the production of hydrogen, the efficiency of energy conversion, the cost of hydroelectricity and the cost of the electrolyser. Finally, the proposed model was applied to various different time-horizons and populations, obtaining the cost of hydrogen production in each case. The results obtained are well below those mentioned in the references, owing largely to the low cost of the electricity used, which accounts for around 45% of the total cost of the system.

2016 ◽  
Vol 9 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Dionisio H. Malagón-Romero ◽  
Alexander Ladino ◽  
Nataly Ortiz ◽  
Liliana P. Green

Hydrogen is expected to play an important role as a clean, reliable and renewable energy source. A key challenge is the production of hydrogen in an economically and environmentally sustainable way on an industrial scale. One promising method of hydrogen production is via biological processes using agricultural resources, where the hydrogen is found to be mixed with other gases, such as carbon dioxide. Thus, to separate hydrogen from the mixture, it is challenging to implement and evaluate a simple, low cost, reliable and efficient separation process. So, the aim of this work was to develop a polymeric membrane for hydrogen separation. The developed membranes were made of polysulfone via phase inversion by a controlled evaporation method with 5 wt % and 10 wt % of polysulfone resulting in thicknesses of 132 and 239 micrometers, respectively. Membrane characterization was performed using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), atomic force microscopy (AFM), and ASTM D882 tensile test. Performance was characterized using a 23 factorial experiment using the time lag method, comparing the results with those from gas chromatography (GC). As a result, developed membranes exhibited dense microstructures, low values of RMS roughness, and glass transition temperatures of approximately 191.75 °C and 190.43 °C for the 5 wt % and 10 wt % membranes, respectively. Performance results for the given membranes showed a hydrogen selectivity of 8.20 for an evaluated gas mixture 54% hydrogen and 46% carbon dioxide. According to selectivity achieved, H2 separation from carbon dioxide is feasible with possibilities of scalability. These results are important for consolidating hydrogen production from biological processes.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shan Wang ◽  
Aolin Lu ◽  
Chuan-Jian Zhong

AbstractAs a promising substitute for fossil fuels, hydrogen has emerged as a clean and renewable energy. A key challenge is the efficient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efficient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active, stable, and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use, which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity, stability, and efficiency. This will be followed by outlining current knowledge on the two half-cell reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be discussed. New strategies and insights in exploring the synergistic structure, morphology, composition, and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally, future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efficient production of hydrogen from water splitting electrolysis will also be outlined.


2016 ◽  
Vol 10 (10) ◽  
pp. 133
Author(s):  
Mohammad Ali Nasiri Khalili ◽  
Mostafa Kafaei Razavi ◽  
Morteza Kafaee Razavi

Items supplies planning of a logistic system is one of the major issue in operations research. In this article the aim is to determine how much of each item per month from each supplier logistics system requirements must be provided. To do this, a novel multi objective mixed integer programming mathematical model is offered for the first time. Since in logistics system, delivery on time is very important, the first objective is minimization of time in delivery on time costs (including lack and maintenance costs) and the cost of purchasing logistics system. The second objective function is minimization of the transportation supplier costs. Solving the mathematical model shows how to use the Multiple Objective Decision Making (MODM) can provide the ensuring policy and transportation logistics needed items. This model is solved with CPLEX and computational results show the effectiveness of the proposed model.


Author(s):  
Hazael Phiri ◽  
Douglas Kunda ◽  
Jackson Phiri

<p class="Abstract"><span lang="EN-US">The coming of Internet of things (IoT) brings opportunities for the deploying of wireless sensor networks. One area of deployment is smart poultry farming to improve the quality and security of chicken varieties that include broilers. The quality of broilers produced is dependent on the environment in which the broilers are kept. In addition, the revenue of the farmer is guaranteed if theft of stock is prevented. The current methods farmers use are labour intensive and time consuming as they are manual. Leveraging the features of IoT and sensors can help to monitor the environment and ensure adverse conditions are reported for farmers to take action before they harm the livestock. Incorporating intruder detection when monitoring conditions in the environment can also prevent stock theft and that can increase the income obtained by farmers. For such a system to be widely adopted by low income farmers, the cost should be low compared commercially available climate control systems that are meant for commercial farmers. The system should also provide ease of use for less technically skilled farmers, reduce the time taken by farmers to take action in controlling theft and conditions in the environment and be accessible from any location other than the broiler house. In this paper, we propose a low-cost model that can be used to monitor conditions in the environment of a broiler house and send the values to the farmer in real-time. The proposed model is based on open source microcontrollers, ZigBee protocol, GSM network, mobile applications and cloud computing. </span></p>


2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Abdelhamid Mraoui ◽  
Abdallah Khellaf

Abstract In this work, the design of a hydrogen production system was optimized for Algiers in Algeria. The system produces hydrogen by electrolysis using a photovoltaic (PV) generator as a source of electricity. All the elements of the system have been modeled to take into account practical constraints. The cost of producing hydrogen has been minimized by varying the total power of the photovoltaic generator. An optimal ratio between the peak power of the PV array and the nominal power of the electrolyzer was determined. Photovoltaic module technology has been varied using a large database of electrical characteristics. It was noted that PV technology does not have a very significant impact on cost. The minimum cost is around 0.44$/N m3, and the power ratio in this case is 1.45. This results in a cost reduction of around 12% compared to a unit ratio. The power ratio and cost are linearly dependent. Only a small number of technologies give a relatively low cost of about 0.35$/N m3. These generators are interesting; however, we assumed an initial cost of $2.00/Wp for all technologies. In addition, it was noted that it is possible to increase hydrogen production by 10% by increasing the power of the photovoltaic generator, the extra cost in this case will only be 0.1%.


2021 ◽  
Author(s):  
Jabar Yousif

<p>This work is concerned with proposing mathematical models characterized by accuracy and ease in predicting the number of diabetics type 2 in the Sultanate of Oman. By analyzing the proposed mathematical models of the current work (1, 2, and 3), it was found that the proposed mathematical model in Equation 6 can accurately predict the number of diabetics in Oman up to 2050. In order to test the model's accuracy and validity, we revised it with actual data. The results prove the accuracy of the proposed model in predicting future data of 99%. Lastly, several recommendations were recorded that could help to reduce the prevalence of diabetes type 2 in Oman.</p>


Author(s):  
PANKAJ GUPTA ◽  
SHILPI VERMA ◽  
MUKESH KUMAR MEHLAWAT

The optimization techniques used in commercial-off-the-shelf (COTS) selection process faces challenges to deal with uncertainty in many important selection parameters, for example, cost, reliability and delivery time. In this paper, we propose a fuzzy optimization model for selecting the best COTS product among the available alternatives for each module in the development of modular software systems. The proposed model minimizes the total cost of the software system satisfying the constraints of minimum threshold on system reliability, maximum threshold on the delivery time of the software, and incompatibility among COTS products. In order to deal with uncertainty in real-world applications of COTS selection, the coefficients of the cost objective function, delivery time constraints and minimum threshold on reliability are considered fuzzy numbers. The fuzzy optimization model is converted into a pair of mathematical programming problems parameterized by possibility (feasibility) level α using Zadeh's extension principle. The solutions of the resultant problems at different α-cuts provide lower and upper bounds of the fuzzy minimum total cost which helps in constructing the membership function of the cost objective function. The solution approach provide fuzzy solutions instead of a single crisp solution thereby giving decision maker enough flexibility in maintaining cost-reliability trade-off of COTS selection besides meeting other important system requirements. A real-world case study is discussed to demonstrate the effectiveness of the proposed model in fuzzy environment.


2005 ◽  
Vol 128 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Stephan Möller ◽  
Dario Kaucic ◽  
Christian Sattler

Solar steam reforming of natural gas (NG) is a possibility to lower the cost for introducing renewable hydrogen production technologies to the market by a combination of fossil fuel and solar energy. It comprises the production of hydrogen from NG and steam that acts as a chemical storage for hydrogen and solar energy as the renewable energy source to heat up the system and set free the hydrogen. Using the solar reformer technology fuel savings of up to 40% compared to a conventional plant are expected. The CO2 emissions can be reduced accordingly. The cost study shows that hydrogen produced by solar reforming might cost between 4.5 and 4.7ct€∕kWh (LHV of H2) today. Therefore, it is only about 20% more expensive than conventionally produced hydrogen. Rising prices for NG will result in favorable conditions for the solar technology.


2014 ◽  
Vol 18 (3) ◽  
pp. 823-831 ◽  
Author(s):  
Jurij Avsec

Hydrogen is one of the most promising energy sources of the future enabling direct production of power and heat in fuel cells, hydrogen engines or furnaces with hydrogen burners. One of the last remainder problems in hydrogen technology is how to produce a sufficient amount of cheap hydrogen. One of the best options is large scale thermochemical production of hydrogen in combination with nuclear power plant. copper-chlorine (CuCl) cycle is the most promissible thermochemical cycle to produce cheap hydrogen.This paper focuses on a CuCl cycle, and the describes the models how to calculate thermodynamic properties. Unfortunately, for many components in CuCl cycle the thermochemical functions of state have never been measured. This is the reason that we have tried to calculate some very important thermophysical properties. This paper discusses the mathematical model for computing the thermodynamic properties for pure substances and their mixtures such as CuCl, HCl, Cu2OCl2 important in CuCl hydrogen production in their fluid and solid phase with an aid of statistical thermodynamics. For the solid phase, we have developed the mathematical model for the calculation of thermodynamic properties for polyatomic crystals. In this way, we have used Debye functions and Einstein function for acoustical modes and optical modes of vibrations to take into account vibration of atoms. The influence of intermolecular energy we have solved on the basis of Murnaghan equation of state and statistical thermodynamics.


2021 ◽  
Author(s):  
◽  
Keith Cassell

<p>Much of the cost of software development is maintenance. Well structured software tends to be cheaper to maintain than poorly structured software, because it is easier to analyze and modify. The research described in this thesis concentrates on determining how to improve the structure of object-oriented classes, the fundamental unit of organization for object-oriented programs. Some refactoring tools can mechanically restructure object-oriented classes, given the appropriate inputs regarding what attributes and methods belong in the revised classes. We address the research question of determining what belongs in those classes, i.e., determining which methods and attributes most belong together and how those methods and attributes can be organized into classes. Clustering techniques can be useful for grouping entities that belong together; however, doing so requires matching an appropriate algorithm to the domain task and choosing appropriate inputs. This thesis identifies clustering techniques suitable for determining the redistribution of existing attributes and methods among object-oriented classes, and discusses the strengths and weaknesses of these techniques. It then describes experiments using these techniques as the basis for refactoring open source Java classes and the changes in the class quality metrics that resulted. Based on these results and on others reported in the literature, it recommends particular clustering techniques for particular refactoring problems. These clustering techniques have been incorporated into an open source refactoring tool that provides low-cost assistance to programmers maintaining object-oriented classes. Such maintenance can reduce the total cost of software development.</p>


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