Maan Al-Zareer

Modeling and performance assessment of a new integrated gasification combined cycle with a water gas shift membrane reactor for hydrogen production

Abstract This paper investigates the effects of flow rate of gasification oxidant, gasification agent and coal type on the energy efficiency and hydrogen production rate of a proposed system. The present system consists of a pressurized entrained flow gasifier integrated with a cryogenic air separation unit, a water gas shift membrane reactor and a combined cycle. Aspen Plus software is used to develop and simulate the integrated system. Three different types of coal are fed to the gasifier. A Gibbs free energy based model of the gasification process is developed and validated. The Gibbs free energy based model is then used to assess the effect of gasification parameters since it is more straightforward regarding changing input flow rates. It is found that gasifying low grade coal is preferable in terms of energy efficiency to gasifying high grade coals, which are more advantageous for combustion regarding energy efficiency.

Heat transfer modeling of a novel battery thermal management system

ABSTRACT A battery cooling system is proposed for future carbon-free ammonia-based hybrid electric vehicles. In the proposed design, aluminum cold plates with tubes that are filled with liquid ammonia are placed between the batteries in the battery pack. The ammonia evaporates while cooling the plate, which then cools the batteries in the pack. The generated ammonia vapor passes to the vehicle electrical generator where it is used to produce electrical energy for driving the vehicle or charging the batteries. The proposed system was able to perform better than mini-channel liquid cooling systems, air cooling systems, and direct contact boiling systems.

3.11 Chemical Energy Production

This chapter explains in detail the process of assessing the performance of various chemical energy production systems using energy and exergy analyses, starting from a basic mixing chamber and extending to a multigeneration system. Detailed steps for analyzing multigeneration systems are provided to provide a clear and detailed procedure for analyzing chemical energy production systems. Case studies are provided to better illustrate some of these chemical energy generation systems and, more importantly, to provide and apply a procedure for analyzing and assessing the performance of such systems.

3.10 Electrochemical Energy Production

This chapter deals with electrochemical energy production from an engineering thermodynamics point of view by utilizing the first and the second laws of thermodynamics. The chapter starts with the basics of electrochemistry, including Nernst’s law and Faraday’s law. Then the chapter goes into the details of electrochemical energy production by focusing on common electrochemical energy producing devices, including fuel cells, electrolyzers, capacitors, and batteries. Each of the main categories of electrochemical devices is characterized and explained in depth and a thermodynamic model is developed to analyze and assess the performance of electrochemical energy production devices.

1.9 Exergoenvironmental Analysis

The environmental effects of energy producing and consuming processes and devices are of importance to the health and living standards of people. With continuous progress in improving living standards, more energy is generally required. If produced from nonrenewable sources like fossil fuels, this leads to increasing harm to the environment. Two most common measures of performance of energy systems are energy and exergy efficiencies. Exergy efficiency provides a measure that is relative to the ideal efficiency. With exergy analysis, a better understanding of thermodynamic losses can be achieved. In this chapter, exergoenvironmental analysis, a method for analyzing energy systems and their components from a combined point of view that considers both exergy and the environment, is described and discussed. The chapter starts by describing the theory behind exergy-based environmental impact assessment of energy systems, which considers the exergy analysis, the relevant time scale and environmental parameters. This is followed by examples describing exergoenvironmental analyses of components, cycles and systems and finally with an integrated system.

5.5 Exergy Management

In this chapter, we consider exergy management through four main aspects including the confluence of energy, environment, and sustainable development; application of exergy concepts and methods to industrial operations and problems; the integration of exergy analysis with industrial ecology; and finally exergy in policy development and education. The first part of the chapter focuses on exergy as the confluence of energy, environment, and sustainable development. The basis for this treatment is the interdisciplinary character of exergy and its relation to these disciplines. The relations between them also suggest that exergy is related to sustainable development. So, this chapter also presents a unified exergy-based structure that provides useful insights and direction to those involved in sustainable development. Following the discussion of exergy as the confluence of energy, environment, and sustainable development the application is described of exergy concepts and methods to industrial operations and their analysis, design, improvement, and optimization. Exergy methods are increasingly accepted by industry. For electrical generation, for instance, exergy methods can be used to design better stations, improve efficiency, and avoid performance deterioration, while for cogeneration exergy methods can help improve efficiency and resolve economic costing and pricing issues. The third part of the chapter concentrates on the integration of exergy analysis with industrial ecology, and its application. Industrial ecology is an approach to designing industrial systems that contributes to sustainable development by balancing industrial activity and environmental stewardship and thereby can. As exergy analysis pinpoints exergy losses, it can help make industrial technologies more ecologically benign and efficient when integrated with industrial ecology. Illustrations are discussed for combined cycle power generation, hydrogen production, and crude oil distillation. Finally, the chapter describes the role of exergy in policy development and education. Education and awareness of exergy are examined, focusing on the public and the media, as well as thermodynamicists and other technical experts. Also, it is demonstrated that exergy has a place in policy development, pointing out that the public is often confused when it discusses energy and needs to be better educated about exergy if energy issues are to be addressed appropriately, and that a basic level of “exergy literacy” is needed among engineers, scientists, and decision makers.

Multi-objective optimization of an integrated gasification combined cycle for hydrogen and electricity production

Abstract In this paper, an integrated coal gasification combined cycle system for the production of hydrogen and electricity is optimized in terms of energy and exergy efficiencies, and the amount and cost of the produced hydrogen and electricity. The integrated system is optimized by focusing on the conversion process of coal to syngas. A novel optimization process is developed which integrates an artificial neural network with a genetic algorithm. The gasification system is modeled and simulated with Aspen Plus for large ranges of operating conditions, where the artificial neural network method is used to represent the simulation results mathematically. The mathematical model is then optimized using a genetic algorithm method. The optimization demonstrates that the lower is the grade of coal of the three considered coals, the less expensive is the hydrogen and electricity that can be produced by the considered integrated gasification combined cycle (IGCC) system.