Applications & Pathways

Hydrogen has received tremendous global attention as an energy carrier and an energy storage system. Hydrogen carrier introduces a power to hydrogen (P2H) and power to hydrogen to power (P2H2P) facility to store the excess energy in renewable energy storage systems with the facts of large-scale storage capacity transportability and multiple utilities. This work examines the techno-economic feasibility of hybrid solar photovoltaic (PV)/hydrogen/fuel cell-powered cellular base stations for developing green mobile communication to decrease environmental degradation and mitigate fossil-fuel crises. Extensive simulation is carried out using a hybrid optimization model for electric renewables (HOMER) optimization tool to evaluate the optimal size energy production total production cost per unit energy production cost and emission of carbon footprints subject to different relevant system parameters. In addition the throughput and energy efficiency performance of the wireless network is critically evaluated with the help of MATLAB-based Monte-Carlo simulations taking multipath fading system bandwidth transmission power and inter-cell interference (ICI) into consideration. Results show that a more stable and reliable green solution for the telecommunications sector will be the macro cellular basis stations driven by the recommended hybrid supply system. The hybrid supply system has around 17% surplus electricity and 48.1 h backup capacity that increases the system reliability by maintaining a better quality of service (QoS). To end the outcomes of the suggested system are compared with the other supply scheme and the previously published research work for justifying the validity of the proposed system.

In this paper the composition function and structure of the catalyst layer (CL) of a proton exchange membrane fuel cell (PEMFC) are summarized. The hydrogen reduction reaction (HOR) and oxygen reduction reaction (ORR) processes and their mechanisms and the main interfaces of CL (PEM|CL and CL|MPL) are described briefly. The process of mass transfer (hydrogen oxygen and water) proton and electron transfer in MEA are described in detail including their influencing factors. The failure mechanism of CL (Pt particles CL crack CL flooding etc.) and the degradation mechanism of the main components in CL are studied. On the basis of the existing problems a structure optimization strategy for a high‐performance CL is proposed. The commonly used preparation processes of CL are introduced. Based on the classical drying theory the drying process of a wet CL is explained. Finally the research direction and future challenges of CL are pointed out hoping to provide a new perspective for the design and selection of CL materials and preparation equipment.

The pursuit of future energy systems that can meet electricity demands while supporting the attainment of societal environment goals including mitigating climate change and reducing pollution in the air has led to questions regarding the viability of continued use of natural gas. Natural gas use particularly for electricity generation has increased in recent years due to enhanced resource availability from non-traditional reserves and pressure to reduce greenhouse gasses (GHG) from higher-emitting sources including coal generation. While lower than coal emissions current natural gas power generation strategies primarily utilize combustion with higher emissions of GHG and criteria pollutants than other low-carbon generation options including renewable resources. Furthermore emissions from life cycle stages of natural gas production and distribution can have additional detrimental GHG and air quality (AQ) impacts. On the other hand natural gas power generation can play an important role in supporting renewable resource integration by (1) providing essential load balancing services and (2) supporting the use of gaseous renewable fuels through the existing infrastructure of the natural gas system. Additionally advanced technologies and strategies including fuel cells and combined cooling heating and power (CCHP) systems can facilitate natural gas generation with low emissions and high efficiencies. Thus the role of natural gas generation in the context of GHG mitigation and AQ improvement is complex and multi-faceted requiring consideration of more than simple quantification of total or net emissions. If appropriately constructed and managed natural gas generation could support and advance sustainable and renewable energy. In this paper a review of the literature regarding emissions from natural gas with a focus on power generation is conducted and discussed in the context of GHG and AQ impacts. In addition a pathway forward is proposed for natural gas generation and infrastructure to maximize environmental benefits and support renewable resources in the attainment of emission reductions.

We demonstrate a new approach for producing highly dispersed supported metal phosphide powders with small particle size improved stability and increased electrocatalytic activity towards some useful reactions. The approach involves a one-step conversion of metal supported on high surface area carbon to the metal phosphide utilising a very simple and scalable synthetic process. We use this approach to produce PdP₂ and Pd₅P₂ particles dispersed on carbon with a particle size of 4.5–5.5 nm by converting a commercially available Pd/C powder. The metal phosphide catalysts were tested for the oxygen reduction hydrogen oxidation and evolution and formic acid oxidation reactions. Compared to the unconverted Pd/C material we find that alloying the P at different levels shifts oxide formation on the Pd to higher potentials leading to greater stability during cycling studies (20% more ECSA retained 5k cycles) and in thermal treatment under air. Hydrogen absorption within the PdP₂ and Pd₅P₂ particles is enhanced. The phosphides compare favourably to the most active catalysts reported to date for formic acid oxidation especially PdP₂ and there is a significant decrease in poisoning of the surface compared to Pd alone. The mechanistic changes in the reactions studied are rationalised in terms of increased water activation on the surface phosphorus atoms of the catalyst. One of the catalysts PdP₂/C is tested in a fuel cell as anode and cathode catalyst and shows good performance.

As a promising alternative to petroleum fossil energy polymer electrolyte membrane fuel cell has drawn considerable attention due to its low pollution emission high energy density portability and long operation times. Proton exchange membrane (PEM) like Nafion plays an essential role as the core of fuel cell. A good PEM must have satisfactory performance such as high proton conductivity excellent mechanical strength electrochemical stability and suitable for making membrane electrode assemblies (MEA). However performance degradation and high permeability remain the main shortcomings of Nafion. Therefore the development of a new PEM with better performance in some special conditions is greatly desired. In this review we aim to summarize the latest achievements in improving the Nafion performance that works well under elevated temperature or methanol-fueled systems. The methods described in this article can be divided into some categories utilizing hydrophilic inorganic material metal-organic frameworks nanocomposites and ionic liquids. In addition the mechanism of proton conduction in Nafion membranes is discussed. These composite membranes exhibit some desirable characteristics but the development is still at an early stage. In the future revolutionary approaches are needed to accelerate the application of fuel cells and promote the renewal of energy structure.

Through data mining and analysis of the word frequency and occurrence position of industrial policy keywords the main policy parameters affecting industrial development are determined and the functional relationship between industrial policy and industrial development is obtained through multi-parameter non-linear regression: Yit−1 (y1 y2 y3 y4 y5) = β1it X1 + β2it ln X2 + β3it ln X3 + β4it X1it ∗ ln X3 + εit . The time series function of the industrial development index: Y (t) = 0.174 ∗ e (0.256∗t) is established and the industrial development under the influence of next year’s policy is predicted. It is concluded from the mathematical expression of the statistical model that there is a certain coupling effect between different policies and that industrial development is influenced by the joint effect on the parent and sub-industries. This ultimately proves that there is a clear correlation between policy and industry development.

Maritime transport accounts for around 3% of global anthropogenic Greenhouse gas (GHG) emissions (Well-to-Wake) and these emissions must be reduced with at least 50% in absolute values by 2050 to contribute to the ambitions of the Paris agreement (2015). Zero carbon fuels made from renewable sources (hydro wind or solar) are by many seen as the most promising option to deliver the desired GHG reductions. For the maritime sector these fuels come in two forms: First as E-Hydrogen or E-Ammonia; Second as Hydrocarbon E-fuels in the form of E-Diesel E-LNG or E-Methanol. We evaluate emissions energy use and cost for E-fuels and find that the most robust path to these fuels is through dual-fuel engines and systems to ensure flexibility in fuel selection to prepare for growing supplies and lower risks. The GHG reduction potential of E-fuels depends entirely on abundant renewable electricity.

Hydrogen (H2) internal combustion engines may represent cost-effective and quick solution to the issue of the road transport decarbonization. A major factor limiting their competitiveness relative to fuel cells (FC) is the lower efficiency. The present work aims to demonstrate the feasibility of a H2 engine with FC-like 60%+ brake thermal efficiency (BTE) levels using a double compression-expansion engine (DCEE) concept combined with a high pressure direct injection (HPDI) nonpremixed H2 combustion. Experimentally validated 3D CFD simulations are combined with 1D GT-Power simulations to make the predictions. Several modifications to the system design and operating conditions are systematically implemented and their effects are investigated. Addition of a catalytic burner in the combustor exhaust insulation of the expander dehumidification of the EGR and removal of the intercooling yielded 1.5 1.3 0.8 and 0.5%-point BTE improvements respectively. Raising the peak pressure to 300 bar via a larger compressor further improved the BTE by 1.8%-points but should be accompanied with a higher injector-cylinder differential pressure. The λ of ~1.4 gave the optimum tradeoff between the mechanical and combustion efficiencies. A peak BTE of 60.3% is reported with H2DCEE which is ~5%-points higher than the best diesel-fueled DCEE alternative.

Heating and hot water within buildings account for almost a quarter of global energy consumption. Approximately 90% of this heat is derived directly from the combustion of fossil fuels primarily natural gas leading to the unabated emission of carbon dioxide. This paper assesses the environmental sustainability of a range of heating technologies and scenarios on a life cycle basis. The major technologies considered are natural gas boilers air source heat pumps hydrogen boilers and direct electric heaters. The scenarios use the UK as an example due to its status as a major economy with a legally-binding net-zero carbon target for 2050; they consider plausible future electricity and natural gas mixes including the potential growth of domestic shale gas. The environmental impacts are estimated using ReCiPe 2016. Current gas boilers have a climate change impact of 220 g CO₂ eq./kWh of heat which could fall to 64 g CO₂ eq./kWh for boilers fuelled by hydrogen derived from natural gas with carbon capture. Heat from electric air source heat pumps or hydrogen from electrolysis can achieve net zero with a decarbonised electricity mix but electrolysis has the highest energy demand of all options which leads to the highest impacts across 17 of the 19 categories. Despite their high carbon emissions gas boilers remain the lowest impact option across 12 categories as they avoid the impacts related to electricity generation including metal depletion toxicities and eutrophication. By 2050 the best performing scenario sees the climate change impact of the heating mix fall by 95%; this is achieved by prioritising electric air source heat pumps without hydrofluorocarbon refrigerants alongside demand reduction. The results show that if infrastructure and financial challenges can be overcome there are several viable decarbonisation strategies for heating with heat pumps offering the most environmentally sustainable option of those considered here. However increased renewable electricity demand may worsen some environmental impacts compared to natural gas boilers.

Geodesign is a participatory planning approach in which stakeholders use geographic information systems to develop and vet alternative design scenarios in a collaborative and iterative process. This study is based on a 2019 geodesign workshop in which 17 participants from industry government university and non-profit sectors worked together to design an initial network of hydrogen refueling stations in the Hartford Connecticut metropolitan area. The workshop involved identifying relevant location factors rapid prototyping of station network designs and developing consensus on a final design. The geodesign platform which was designed specifically for facility location problems enables breakout groups to add or delete stations with a simple point-and-click operation view and overlay different map layers compute performance metrics and compare their designs to those of other groups. By using these sources of information and their own expert local knowledge participants recommended six locations for hydrogen refueling stations over two distinct phases of station installation. We quantitatively and qualitatively compared workshop recommendations to solutions of three optimal station location models that have been used to recommend station locations which minimize travel times from stations to population and traffic or maximize trips that can be refueled on origin–destination routes. In a post-workshop survey participants rated the workshop highly for facilitating mutual understanding and information sharing among stakeholders. To our knowledge this workshop represents the first application of geodesign for hydrogen refueling station infrastructure planning.