Ammonia is heavily used in agriculture as a fertilizer and in industry as a raw material for the production of various organic nitrogen compounds. Its high hydrogen content and its established infrastructure for both storage and distribution makes ammonia a prominent candidate for storing fluctuating renewable energy. The Haber-Bosch heterogenous reaction of hydrogen and nitrogen on an iron-based catalyst is used today at large scale ammonia production sites. The current industrial hydrogen production is dominated by fossil energy sources. The traditional Haber-Bosch process can become green and carbon-free if renewable electricity is used for hydrogen generation. However, a continuous operation of power to ammonia can be challenging with a fluctuating renewable energy source. Techno-economic models show that electrolysis and the hydrogen supply chain is the main dominating cost factor of power to ammonia.
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Excess of renewable electricity from wind turbines or solar panels is used for electrolysis of water. To store this renewable energy as methane, the hydrogen is fed to an anaerobic digester to stimulate biological methanation by hydrogenotrophic methanogens. This workpackage focusses on the best ways for hydrogen delivery and the community changes in a biomethanation reactor as a result of hydrogen supply.
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Excess of renewable electricity from wind turbines or solar panels is used for electrolysis of water. To store this renewable energy as methane, the hydrogen is fed to an anaerobic digester to stimulate biological methanation by hydrogenotrophic methanogens. These work packages focus on the best ways for hydrogen delivery and the community changes in a biomethanation reactor as a result of hydrogen supply.
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Wind and solar power generation will continue to grow in the energy supply of the future, but its inherent variability (intermittency) requires appropriate energy systems for storing and using power. Storage of possibly temporary excess of power as methane from hydrogen gas and carbon dioxide is a promising option. With electrolysis hydrogen gas can be generated from (renewable) power. The combination of such hydrogen with carbon dioxide results in the energy carrier methane that can be handled well and may may serve as carbon feedstock of the future. Biogas from biomass delivers both methane and carbon dioxide. Anaerobic microorganisms can make additional methane from hydrogen and carbon dioxide in a biomethanation process that compares favourably with its chemical counterpart. Biomethanation for renewable power storage and use makes appropriate use of the existing infrastructure and knowledge base for natural gas. Addition of hydrogen to a dedicated biogas reactor after fermentation optimizes the biomethanation conditions and gives maximum flexibility. The low water solubility of hydrogen gas limits the methane production rate. The use of hollow fibers, nano-bubbles or better-tailored methane-forming microorganisms may overcome this bottleneck. Analyses of patent applications on biomethanation suggest a lot of freedom to operate. Assessment of biomethanation for economic feasibility and environmental value is extremely challenging and will require future data and experiences. Currently biomethanation is not yet economically feasible, but this may be different in the energy systems of the near future.
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Caribbean coral reefs are in decline and the deployment of artificial reefs, structures on the sea bottom that mimic one or more characteristics of a natural reef, is increasingly often considered to sustain ecosystem services. Independent of their specific purposes, it is essential that artificial reefs do not negatively affect the already stressed surrounding habitat. To evaluate the ecological effects of artificial reefs in the Caribbean, an analysis was performed on 212 artificial reefs that were deployed in the Greater Caribbean between 1960 and 2018, based on cases documented in grey (n = 158) and scientific (n = 54) literature. Depending on the availability of data, reef type and purpose were linked to ecological effects and fisheries management practices around the artificial reefs. The three most common purposes to deploy artificial reefs were to create new dive sites (41%), toperform research (22%) and to support ecosystem restoration (18%), mainly by stimulating diversity. Ship wrecks (44%), reef balls© (13%) and piles of concrete construction blocks (11%) were the most-often deployed artificial reef structures and metal and concrete were the most-used materials. The ecological development onartificial reefs in the Caribbean appeared to be severely understudied. Research and monitoring has mostly been done on small experimental reefs that had been specifically designed for science, whereas the most commonly deployed artificial reef types have hardly been evaluated. Studies that systematically compare the ecological functioning of different artificial reef types are virtually non-existent in the Caribbean and should be a research priority, including the efficacy of new designs and materials. Comparisons with natural reef ecosystems are scarce. Artificial reefs can harbor high fish densities and species richness, but both fish and benthos assemblages often remain distinct from natural ecosystems. Studies from other parts of the world show that artificial reefs can influence the surrounding ecosystem by introducing non-indigenous species and by leaking iron. As artificial reefs attract part of their marine organisms from surrounding habitats, intensive exploitation by fishers, without clear management, can adversely affect the fish stocks in the surrounding area and thus counteract any potential ecosystem benefits. This study shows that over 80% of artificial reefs in the Caribbean remain accessible tofishers and are a risk to the surrounding habitat. To ensure artificial reefs and their fisheries do not negatively affect the surrounding ecosystem, it is imperative to include artificial reefs, their fisheries and the surrounding ecosystem in monitoring programs and management plans and to create no-take zones around artificial reefs that are not monitored.
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The installation of facilities replicating the realworld condition is often required for carrying out meaningful tests on new devices and for collecting data with the aim to create realistic device model. However, these facilities require huge investments, as well as areas where they can be properly installed. In this paper, we present a test infrastructure exploiting the concept of Remote Power Hardware-In-the-Loop (RPHIL), applied for characterizing the performances of a 8kW Proton Exchange Membrane (PEM) electrolyser installed at the Hanze University of Applied Sciences in Groningen (The Netherlands). The electrolyser is subjected to different test conditions imposed both locally and remotely. The results show that this measurement procedure is effective and can open new perspectives in the way to share and exploit the existing research infrastructure in Europe
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Surface Active Agents, or surfactants, are chemicals which provide a surface (interface) activity when dispersed in liquids. They have different purposes, can be used as herbicides, anti-foaming agents, adhesives, cleaning agents and softeners. For cleaning purposes, their function is to alter (decrease) liquid surface tension. In this function they are ubiquitous in both industrial processes (cleaning of production equipment, storage vats, packaging lines, and cooking units either during the manufacturing process) and domestic applications. ProtoNeat proposes an alternative way to decrease water surface tension without adding chemicals (surfactants). This can be done by charging the water (producing protonically charged water) [2], i.e. positive and negative Bjerrum-defect like charges [3, 4]. This phenomenon was experimentally observed by Fuchs et al [5] in anolyte and catholyte when doing high voltage electrolysis of highly pure water during the so-called ‘floating water bridge’ experiment. The work done by the authors, when working with this “bridge”, showed that, in case of positive excess charge, the hydronium ions migrate to the surface [8] thereby significantly lowering the surface tension [9,10]. However, for how long this effect can be maintained and how effective it is to produce such water is still unknown. ProtoNeat wants to tackle these two questions and investigate whether a continuous production of protonically charged water as an environmentally friendly and sustainable cleaning agent is possible.
Hoe kunnen leeromgevingen in het beroepsonderwijs een rol vervullen bij het oplossen van complexe maatschappelijke problemen? Ilya Zitter, bijzonder lector Leeromgevingen in het Beroepsonderwijs bij Hogeschool Utrecht (HU), onderzoekt hoe je leeromgevingen zo kunt ontwerpen dat een innovatief, lerend systeem ontstaat, zonder sterke scheiding tussen onderwijs en praktijk. Op 25 maart gaf Zitter haar openbare les.
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In the course of the “energie transitie” hydrogen is likely to become a very important energy carrier. The production of hydrogen (and oxygen) by water electrolysis using electricity from sun or wind is the only sustainable option. Water electrolysis is a well-developed technique, however the production costs of hydrogen by electrolysis are still more expensive than the conventional (not sustainable) production by steam reforming. One challenge towards the large scale application of water electrolysis is the fabrication of stable and cheap (noble metal free) electrodes. In this project we propose to develop fabrication methods for working electrodes and membrane electrode stack (MEAs) that can be used to implement new (noble metal free) electrocatalysts in water electrolysers.
