Cycles of reversible hydrogenation reactions are important for at least two different energy-related applications: reversible chemical hydrogen storage and thermally regenerative fuel cells. Hydrogen fuel is a green alternative to conventional hydrocarbon fuels for transportation applications. This is because the combustion product of hydrogen is simply water, which is non-toxic and ubiquitous. Hydrogen is also an attractive fuel because of its high energy content; however, because it is a gas it has poor volumetric energy density. In Chapter 2, ionic liquids consisting of both cations and anions that can undergo reversible dehydrogenative aromatization were used to chemically store hydrogen. Cations investigated included pyridinium ions, which were easily hydrogenated but could not be regenerated through the dehydrogenation of piperidinium ions; and carbazole containing ammonium (whose synthesis failed) and imidazolium (which failed to hydrogenate) cations. The anions studied were heterocyclic carboxylates and sulfonates, these ions were observed to undergo both hydrogenation and dehydrogenation to various degrees when reacted in solution. However, as components of ionic liquids, they fail to react at a significant rate. The viscosity of the fluids was suspected to be hindering the diffusion of either hydrogen or the ions to or from the catalyst surface. In addition to using hydrogen as the primary source of energy in a vehicle, reversible hydrogenation can form the basis of a thermally regenerative fuel cell: a device that converts low grade vehicle waste heat, from a conventional engine, into electricity for the vehicles auxiliary power units. In Chapter 3, secondary benzylic alcohols, in particular 1-phenyl-1-propanol, were determined to be able to undergo dehydrogenation to the corresponding ketone rapidly and with extremely high selectivity over a palladium on silica catalyst. The dehydrogenation gave an initial rate of hydrogen evolution of 4.6 l of hydrogen per gram of palladium per minute and the enthalpy and entropy of the dehydrogenation is +56 kJ mol-1 and +117 J mol-1 K-1. This adsorbed energy can then be released as electricity in a fuel cell and be used to power auxiliary units in a vehicle without decreasing fuel economy. / Thesis (Ph.D, Chemistry) -- Queen's University, 2011-08-29 16:19:06.012

Fossil fuel will eventually become exhausted. Also, fossil fuels produce large amounts of carbon dioxide, which cannot only bring environment pollution, but can also cause global warming. Therefore, clean and renewable energy sources should be investigated. In this project, renewable wind power was considered. Wind energy is free, clean and available in large quantities, although it is difficult to use due to its stochastic variability. Energy storage can reduce this variability allowing energy production to match energy demand. In this study, different kinds of energy storage approaches were introduced, compared, and simulated by using half hourly wind data from the Met Office, UK, and half hourly load data from the University of Bath, UK. Hydrogen has higher mass energy density than all other energy storage methods. It is seen as a versatile energy carrier of the future, complementary to electricity and with the potential to replace fossil fuels due to its zero carbon emissions and abundance in nature. On the other hand, because hydrogen is the lightest element under normal conditions; the same amount of hydrogen must occupy a huge volume compared to other elements. The mature technology for converting hydrogen into electricity has high cost and low efficiency. These are big issues that limit the usage of hydrogen energy storage methods. Using wind and load data, a new algorithm was developed and used for sizing the wind turbine, and energy storage requirements. The traditional way to supply energy is distributing electricity, but in this PhD research, there are some discussions about a new method, hydrogen transport-hydrogen pipeline. From the results of the comparison and algorithm, a practical hydrogen energy storage system for the University of Bath network was proposed and designed. In the proposed design the energy from a wind turbine was directed to the load and the remaining excess power was used to produce hydrogen by water electrolysis. The hydrogen was stored in a high pressure compressed tank, and finally a hydrogen fuelled combined cycle gas turbine was used to convert the hydrogen to electricity. In this thesis, the dynamics of the complete hydrogen cycle energy storage and recovery mechanism are discussed, identifying potential applications such as power smoothing, peak lopping and extending power system controller ranges. The results of calculations of the payback time and revenue verify the feasibility of the designed hydrogen energy storage system. The main objective of the PhD was to design a practical hydrogen energy storage system for micro-grid applications. During this research, hydrogen energy storage was investigated to show that it does solve the problems arising from renewable energy.

A problem that has become apparently growing in the deployment of renewable energy systems is the power grids inability to accept the forecasted growth in renewable energy generation integration. To support forecasted growth in renewable generation integration, it is now recognised that Energy Storage Technologies (EST) must be utilised. Recent advances in Hydrogen Energy Storage Technologies (HEST) have unlocked their potential for use with constrained renewable generation. HEST combines Hydrogen production, storage and end use technologies with renewable generation in either a directly connected configuration, or indirectly via existing power networks. A levelised cost (LC) model has been developed within this thesis to identify the financial competitiveness of the different HEST application scenarios when used with grid constrained renewable energy. Five HEST scenarios have been investigated to demonstrate the most financially competitive configuration and the benefit that the by-product oxygen from renewable electrolysis can have on financial competitiveness. Furthermore, to address the lack in commercial software tools available to size an energy system incorporating HEST with limited data, a deterministic modelling approach has been developed to enable the initial automatic sizing of a hybrid renewable hydrogen energy system (HRHES) for a specified consumer demand. Within this approach, a worst-case scenario from the financial competitiveness analysis has been used to demonstrate that initial sizing of a HRHES can be achieved with only two input data, namely – the available renewable resource and the load profile. The effect of the electrolyser thermal transients at start-up on the overall quantity of hydrogen produced (and accordingly the energy stored), when operated in conjunction with an intermittent renewable generation source, has also been modelled. Finally, a mass-transfer simulation model has been developed to investigate the suitability of constrained renewable generation in creating hydrogen for a hydrogen refuelling station.

Proton exchange membrane fuel cells are electrochemical devices which convert the chemical energy of hydrogen into electrical energy with a high efficiency. They are compact and produce a powerful electric current relative to their size. Different from the batteries they do not need to be recharged. They operate as long as the fuel is supplied. Fuel cells, therefore, are considered as one of the most promising options to replace the conventional power generating systems in the future. In this study five PEMFCs / namely EAE1, AOY001, AOY002, AOY003 and AOY004 were manufactured with different methods and in different structures. A test station was built to make the performance tests. Performances of the PEMFCs were compared by comparing the voltage-current (V-i) diagrams obtained during the initial tests at 25 &ordm / C of fuel cell and gas humidification temperatures. AOY001 showed the best performance among all PEMFCs with a current density of 77.5 mA/cm2 at 0.5 V and it was chosen for further parametric studies where the effect of different flow rates of H2 and O2 gases, gas humidification and fuel cell temperatures on the performance were investigated. It was found that increasing fuel cell and gas humidification temperatures increased the performance. Excess flow rate of reactant gases had an adverse effect on the performance. On the other hand increasing the ratio of flow rate of oxygen to hydrogen had a positive but limited effect. AOY001 delivered a maximum current density of 183 mA/cm2 at 0.5 V. The highest power obtained was 4.75 W

Metallic Glasses are multi-component alloys with disordered atomic structures and unique and attractive properties such as ultra-high strength, soft magnetism, and excellent corrosion/wear resistance. In addition, they may be thermoplastically processed in the supercooled liquid region to desired shapes across multiple length-scales. Recently developed metallic glasses based on noble metals (such as Pt and Pd) are highly active in catalytic reactions such as hydrogen oxidation, oxygen reduction, and degradation of organic chemicals for environmental remediation. However, there is a limited understanding of the underlying electrochemical mechanisms and surface characteristics of catalytically active metallic glasses. Here, we demonstrate the influence of alloy chemistry and the associated electronic structure on the activity of a systematic series of Pt42.5−xPdxCu27Ni9.5P21 bulk metallic glasses (BMGs) with x = 0 to 42.5 at%. The activity and electrochemically active surface area as a function of composition are in the form of volcano plots, with a peak around an equal proportion of Pt and Pd. These amorphous alloys showed more than two times the hydrogen oxidation reactivity compared to pure Pt. This high activity was attributed to their lower electron work function and higher binding energy of Pt core level that reduced charge-transfer resistance and improved electrocatalytic activity from weakened chemisorption of protons. To address the high cost associated with noble-metal-based amorphous catalysts, the performance of non-noble M100-xPx alloys was evaluated with a systematic variation in chemistry (M = Ni, Co; x = 0, 10, 15, 20, 30 at%). These alloys were synthesized by a scalable pulsed electrodeposition approach with glass formation seen in the range of 10 at% to 20 at% P. Enhanced corrosion resistance was observed with increasing phosphorus content as evidenced by the significant decrease in corrosion current density and ten-fold higher polarization resistance of M80P20 (M = Ni, Co) compared to its corresponding pure metal in representative electrolytes. Surface characterization showed enrichment of phosphorus in the passive layer, that likely promoted the restoration of the protective hypophosphite phase. The overpotential for hydrogen evolution reaction decreased by 35% and 45% in the case of Ni100−xPx and Co100−xPx, respectively, with increasing phosphorus content from 0 at% to 20 at%. Also, the M80P20 (M = Ni, Co) metallic glasses demonstrated excellent oxygen evolution reaction efficiency with a 10 mA/cm2 current density at 50% overpotential compared to pure Pt in alkaline media. The high activity and excellent durability of the non-noble amorphous alloys for hydrogen/oxygen evolution reactions (HER/OER) were attributed to the decreased binding energy of the P core level due to the synergy between the proton-acceptor (P centers) and hydride/hydroxide-acceptor (metal centers) sites.

With an ever-increasing need to find alternative fuels to curb the use of oil in the world, many sources have been identified as alternative fuels. One of these sources is hydrogen. Hydrogen can be produced through an electro-chemical process. The objective of this report is to model an electrochemical process and determine gains and or losses in efficiency of the process by increasing or decreasing the temperature of the feed water. In order to make the process environmentally conscience, electricity from a geothermal plant will be used to power the electrolyzer. Using the renewable energy makes the process of producing hydrogen carbon free. Water considerations and a model of a geothermal plant were incorporated to achieve the objectives. The data show that there are optimal operating characteristics for electrolyzers. There is a 17% increase in efficiency by increasing the temperature from 20ºC to 80ºC. The greater the temperature the higher the efficiencies, but there are trade-offs with the required currents.

Vienas iš didžiausių iššūkių su kuriais susiduria kompanijos norėdamos panaudoti vandenilio energetikos technologijas įvairiuose prietaisuose – vandenilio saugojimas. Dabartiniu metu egzistuoja trys technologijos, kurios naudojamos vandenilio saugojimui: suspaustas, kriogeninis vandenilis ir vandenilio saugojimas kompleksiniuose junginiuose. Suspaustas ir atšaldytas vandenilis jau pasiekė savo technologinius limitus. Daugiausiai vilčių dedama į vandenilio saugojimą kompleksinėse anglies nanostruktūrose ir metalų hidriduose. Šis darbas yra susijęs su bandymu sintetinti magnio hidridą, panaudojant magnetroninio garinimo sistemą, garinant magnį vandenilio ir argono reaktyvioje aplinkoje. Magnio hidridas yra vienas iš labiausiai tiriamų metalų hidridų vandenilio saugojimui. Deja, dabartiniu metu nėra sukurta technologiškai paprastų patikimų (greita vandenilio absorbcija ir desorbcija, minimalūs nuostoliai ir t.t) ir ekonomiškai efektyvių magnio hidrido sintezės metodų. Darbe gautos struktūros ištirtos panaudojant paviršiaus profilometrijos, SEM, EDS ir XRD metodus. Gauti rezultatai parodė, kad gautos struktūros yra tik dalinai magnio hidridas. / Hydrogen storage is one of the main challenges related with the use of hydrogen energy technologies in daily activities. Three main technologies for hydrogen storage available today: compressed, krio hydrogen and hydrogen storage in different compounds. Compressed and crio hydrogen almost reached its technological limits. A lot of expectations were related with hydrogen storage in carbon nanostructures and metal hydrides. This work is mainly related with magnesium hydride synthesis using magnetron sputtering in reactive hydrogen and argon atmosphere. Magnesium hydride is one of the most promising material. Unfortunately, there is no technologically simple and reliable methods (fast adsorbion/desorption kinetics, minimal losses and etc.) for magnesium hidride synthesis. The magnesium based structures which were received during the work were analyzed using SEM and EDS, surface profilometry and XRD methods. It is shown that received structure only partially transformed to magnesium hydride.

This research investigates the energy, financial and environmental performance of an innovative integrated gasification fuel cell combined cycle fuelled by municipal solid waste that includes hydrogen storage and electrolysis. The suitability for fuel cells to run on synthesis gas coming from the gasification of waste is determined by the sensitivity of the fuel cell to run on contaminated fuel. Out of the available fuel cell technologies solid oxide fuel cells (SOFCs), because of their ceramic construction and high operating temperatures, are best suited for syngas operation. Their high operating temperature ( > 650°C) and the presence of nickel at the anode means that it is possible to reform hydrocarbons to provide further hydrogen. A major contaminant to be considered in gasification systems is tar which can foul pipework and cause substantial performance losses to the plant. Experimental research on the effects of tar on a SOFC at varying concentrations and operating conditions show; that some carbon deposition serves to improve the performance of the fuel cell by reducing the ohmic resistance, and there is a tendency for the tar to reform which improves overall performance. These improvements are seen at moderate tar concentrations but at higher concentrations carbon deposition causes substantial performance degradation. Numerical simulations representing all aspects of the proposed system have been developed to understand the energy performance of the system as a whole as well as the financial and environmental benefits. Taking into account variations in the waste composition, and the wholesale electricity price the proposed system, scaled to process 100,000 tonnes of waste per year (40,000 removed for recycling), has a simple payback period of 7.2 years whilst providing CO2 savings of 13%. Over the year the proposed system will provide enough electricity to supply more than 23,000 homes and enough heat for more than 5,800 homes (supplying 25% of the electrically supplied homes).

With the increase in the world energy demand and environmental incentives, renewable energy sources (RES) need to determine their place as some of the primary power sources in future power systems. However, due to uncertain energy production, renewable energy sources cause unbalance in the power system due to the unsynchronized supply and electricity demand. The intermittent power production causes undesired power fluctuation, affecting the power quality and reliability of the power source. Energy storage is one solution that is debated to increase the reliability of renewable energy production. This thesis aims to model and simulate hybrid energy storage system (HESS), constructed of hydrogen and ultracapacitor energy storage, to investigate different operation strategies for everyday use and crises. The two different energy storage technologies complement each other, where hydrogen fuel cells can produce power for long periods of time while the ultracapacitor can quickly maintain the balance of production and consumption of electricity for a short instance. The HESS showed promising results for emergency power supply and supported service operation strategies. In case of a power shortage, the HESS could cover for the disconnected production. The ultracapacitor proved to be a suitable component due to its ability to support the shortcomings of a hydrogen energy storage system. Moreover, the HESS could meet the requirements to deliver support services. However, further studies have to be done to investigate how the HESS can deliver multiple support services to increase profit and help maintain the power system's balance and security.

Background: Green hydrogen energy systems can address environmental and societal concerns within the energy sector. Therefore, increased attentions from both public and private stakeholders has led to the general perception that hydrogen systems can serve as a disruptive innovation.  Given that disruption innovation theory has seen increased entrepreneurial involvement over recent years, the study focuses on assessing the role of green entrepreneurs within the implementation of hydrogen systems through cross-collaborative efforts and disruptive innovation drivers.    Purpose: The development of a theoretical matrix that interconnects disruptive innovation, entrepreneurial involvement, and cross-collaborative initiatives to establish entrepreneurial positioning roles within the energy market.    Method: The epistemology chosen was interpretivist, and its ontology subjectivism. The research followed an inductive approach. The research was qualitatively conducted and adopted a case study approach. The data was collected through semi-structured interviews, and followed a theoretical sampling approach.   Conclusion: The study proposes a theoretical matrix that extended disruptive innovation theory to green entrepreneurship and concluded that high levels of cross-collaboration, and a high innovation impact, serve as key drivers for green entrepreneurial implementations of disruptive energy. Results highlight the need for entrepreneurial involvement across all stages of market implementations.