Transmission, Distribution & Storage

Since the addition of Al to high-Mn steels is known to reduce their sensitivity to hydrogen-induced delayed fracture we investigate possible trapping effects connected to the presence of Al in the grain interior employing density-functional theory (DFT). The role of Al-based precipitates is also investigated to understand the relevance of short-range ordering effects. So-called E21-Fe3AlC κ-carbides are frequently observed in Fe-Mn-Al-C alloys. Since H te Read More

We present a selection of scale transfer approaches from the electronic to the continuum regime for topics relevant to hydrogen embrittlement. With a focus on grain boundary related hydrogen embrittlement we discuss the scale transfer for the dependence of the carbon solution behavior in steel on elastic effects and the hydrogen solution in austenitic bulk regions depending on Al content. We introduce an approximative scheme to estimate grain bo Read More

As a promising hydrogen storage medium methanol has many advantages such as a high hydrogen content (12.5 wt%) and low-cost. However conventional methanol–water reforming methods usually require a high temperature (>200 °C). In this research we successfully designed an effective strategy to fully convert methanol to hydrogen for at least 1900 min (∼32 h) at near-room temperature. The strategy involves two main procedures which are CH Read More

The carbide characteristics of 2.25Cr1Mo0.25V steel have an extremely important influence on the mechanical properties of welding joints. In addition hydrogen resistance behavior is crucial for steel applied in hydrogenation reactors. The carbide morphology was observed by scanning electron microscopy (SEM) and the carbide microstructure was characterized by transmission electron microscopy (TEM). Tensile and impact tests were carried out an Read More

Hydrogen is often described as the fuel of the future especially for application in hydrogen powered fuel-cell vehicles (HFCV’s). However its widespread implementation in this role has been thwarted by the lack of a lightweight safe on-board hydrogen storage material. Here we show that benign readily available hydrocarbon wax is capable of rapidly releasing large amounts of hydrogen through microwave-assisted catalytic decomposition. This di Read More

With the advent of large-scale application of hydrogen transportation becomes crucial. Reusing the existing natural gas transmission system could serve as catalyst for the future hydrogen economy. However a risk analysis of hydrogen transmission in existing pipelines is essential for the deployment of the new energy carrier. This paper focuses on the individual risk (IR) associated with a hazardous hydrogen jet fire and compares it with the natural gas ca Read More

There are multiple references to sample cleaning methods prior to hydrogen content determination or hydrogen spectroscopy analysis but there is still no unified criteria; different authors use their own “know-how” to perform this task. The aim of this paper is to solve or at least clarify this issue. In this work the most commonly used sample cleaning methods are compared. Then five different methodologies are applied on certified hydrogen content calibr Read More

Efficient and robust control strategies can greatly contribute to the reliability of fuel cell systems and a stable output voltage is a key criterion for evaluating a fuel cell system's reliability as a power source. In this study a polymer electrolyte fuel cell (PEFC) system model is developed and its performances under different operating conditions are studied. Then two different novel controllers—a proportional integral derivative (PID) controller and a model pre Read More

With the increase in renewable energy connected to the grid new challenges arise due to its variable supply of power. Therefore it is crucial to develop new methods of storing energy. Hydrogen can fulfil the role of energy storage and even act as an energy carrier since it has a much higher energetic density than batteries and can be easily stored. Considering that the offshore wind sector is facing significant growth and technical advances hydrogen has the Read More

Tension-compression fatigue tests were performed on two types of Ni-based superalloy 718 with different microstructures to which small artificial defects of various shapes and sizes were introduced. Similar tests were also conducted on hydrogen-charged specimens with defects with a solute hydrogen content ranging from 26.3 to 91.0 mass ppm. In the non-charged specimens in particular the fatigue strength susceptibility to defects varied significantly a Read More