Solar Engineering Of Thermal Processes

A Roadmap to the Ammonia Economy

Numerous reviews on hydrogen storage have previously been published. However, most of these reviews deal either exclusively with storage materials or the global hydrogen economy. This paper presents a review of hydrogen storage systems that are relevant for mobility applications. The ideal storage medium should allow high volumetric and gravimetric energy densities, quick uptake and release of fuel, operation at room temperatures and atmospheric pressure, safe use, and balanced cost-effectiveness. All current hydrogen storage technologies have significant drawbacks, including complex thermal management systems, boil-off, poor efficiency, expensive catalysts, stability issues, slow response rates, high operating pressures, low energy densities, and risks of violent and uncontrolled spontaneous reactions. While not perfect, the current leading industry standard of compressed hydrogen offers a functional solution and demonstrates a storage option for mobility compared to other technologies.

Hydrogen Storage for Mobility: A Review

Ammonia, a molecule that is gaining more interest as a fueling vector, has been considered as a candidate to power transport, produce energy, and support heating applications for decades. However, the particular characteristics of the molecule always made it a chemical with low, if any, benefit once compared to conventional fossil fuels. Still, the current need to decarbonize our economy makes the search of new methods crucial to use chemicals, such as ammonia, that can be produced and employed without incurring in the emission of carbon oxides. Therefore, current efforts in this field are leading scientists, industries, and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis, this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector, moving through all of the steps in the production, distribution, utilization, safety, legal considerations, and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed, thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works, this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further, the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes, legal barriers that will be faced to achieve its deployment, safety and environmental considerations that impose a critical aspect for acceptance and wellbeing, and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein, this work sets the principles, research, practicalities, and future views of a transition toward a future where ammonia will be a major energy player.

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Review on ammonia as a potential fuel: from synthesis to economics

A review of ammonia as a compression ignition engine fuel

This review focuses on the use of renewable ammonia for power generation applications and discusses options to convert industrial-grade generators to run on ammonia fuel. The different methods to produce clean ammonia are also discussed in terms of possible advantages and challenges from socio-economic, energetic and environmental perspectives. The main aim of using clean fuel sources, such as ammonia and hydrogen, is to achieve higher sustainability and low carbon emissions compared to conventional fuels. In addition, the present review comparatively assesses and discusses methods for clean ammonia synthesis based on their technical, economic and environmental performance criteria. Numerous potential strategies to improve the clean ammonia production methods are also explored, namely, liquid-electrolyte based systems, composite-membrane based systems, solid-state electrolyte, ceramic/inorganic proton-conducting solid electrolyte based systems, polymer-membrane based systems, O2 conducting-membrane based systems, and molten salt based electrochemical systems. Furthermore, some potential methods to convert various types of commercially available generators to be able to ammonia are proposed and discussed based on the experimental work carried out in the field.

A review on clean ammonia as a potential fuel for power generators

Performance assesment of hydrogen and ammonia combustion with various fuels for power generators

Experimental investigation and evaluation of using ammonia and gasoline fuel blends for power generators

Thermodynamic analysis of cryogenic vacuum cooling of superconducting cables

This chapter concerns solar ponds, their historical developments, progresses made on solar pond methods, their classifications, their performance assessment, experimental and theoretical studies, and case studies on various types of those systems and applications. In this regard, it describes several concepts, where water is used as a thermal storage for collected energy and at the same time as a direct absorber of solar radiation available on all parts of the earth. The main advantages of solar ponds are combining the solar energy collection with a long-term storage for a variety of thermal applications with very low costs. Energy and exergy analyses are performed for solar ponds in this chapter combined with case studies and experimental analysis. Numerous case studies are presented to illustrate the concepts, systems, analysis, practices and efficiency evaluations, etc.

Arda Yapicioglu

Papers

A review on clean ammonia as a potential fuel for power generators

Performance assesment of hydrogen and ammonia combustion with various fuels for power generators

Experimental investigation and evaluation of using ammonia and gasoline fuel blends for power generators

Thermodynamic analysis of cryogenic vacuum cooling of superconducting cables

4.16 Solar Ponds