Publications

Electrical power generation is changing dramatically across the world because of the need to reduce greenhouse gas emissions and to introduce mixed energy sources. The power network faces great challenges in transmission and distribution to meet demand with unpredictable daily and seasonal variations. Electrical Energy Storage (EES) is recognized as underpinning technologies to have great potential in meeting these challenges whereby energy is stored in a certain state according to the technology used and is converted to electrical energy when needed. However the wide variety of options and complex characteristic matrices make it difficult to appraise a specific EES technology for a particular application. This paper intends to mitigate this problem by providing a comprehensive and clear picture of the state-of-the-art technologies available and where they would be suited for integration into a power generation and distribution system. The paper starts with an overview of the operation principles technical and economic performance features and the current research and development of important EES technologies sorted into six main categories based on the types of energy stored. Following this a comprehensive comparison and an application potential analysis of the reviewed technologies are presented.

Coke oven gas (COG) is one of the most important by-products in the steel industry and the conversion of COG to value-added products has attracted much attention from both economic and environmental views. In this work we apply the chemical looping reforming technology to produce pure H2 from COG. A series of La1-xSrxFeO3 (x = 0 0.2 0.3 0.4 0.5 0.6) perovskite oxides were prepared as oxygen carriers for this purpose. The reduction behaviours of La1-xSrxFeO3 perovskite by different reducing gases (H2 CO CH4 and the mixed gases) are investigated to discuss the competition effect of different components in COG for reacting with the oxygen carriers. The results show that reduction temperatures of H2 and CO are much lower than that of CH4 and high temperatures (>800 °C) are requested for selective oxidation of methane to syngas. The co-existence of CO and H2 shows weak effect on the equilibrium of methane conversion at high temperatures but the oxidation of methane to syngas can inhibit the consumption of CO and H2. The doping of suitable amounts of Sr in LaFeO3 perovskite (e.g. La0.5Sr0.5FeO3) significantly promotes the reactivity for selective oxidation of methane to syngas and inhibits the formation of carbon deposition obtaining both high methane conversion in the COG oxidation step and high hydrogen yield in the water splitting step. The La0.5Sr0.5FeO3 shows the highest methane conversion (67.82%) hydrogen yield (3.34 mmol·g-1) and hydrogen purity (99.85%). The hydrogen yield in water splitting step is treble as high as the hydrogen consumption in reduction step. These results reveal that chemical looping reforming of COG to produce pure H2 is feasible and an O2-assistant chemical looping reforming process can further improve the redox stability of oxygen carrier.

The trial management philosophy of HyDeploy has been developed to enable the overall objectives of the project to be achieved; the safe demonstration of operating a Gas Distribution Network (GDN) on a blend of natural gas and hydrogen. This document provides an overview of the management and governance processes associated with the trial itself. The operational and safety related undertakings before during and after the trial are summarised within this report as well as the intrial experimental programme. The detailed operational procedures are covered in HyD-Rep09.<br/>The programme structure of HyDeploy consists of three phases: Phase 1: Enabling work for preparation of GS(M)R Exemption Phase 2: Construction and installation of process equipment and Phase 3: Safe injection of hydrogen – the trial.<br/>This report focuses on Phase 3 which has two parts; the Proving Trial and; the Trial. As Statutory Duty Holder Keele is accountable for operation of the network it owns over the course of the trial. Operation and maintenance of the network will be undertaken according to the provisions of the Exemption on the basis of agreed revised procedures (HyD-Rep09) by Keele and Cadent. A governance process is in place to manage the blending of hydrogen into the network. This isdescribed in Sections 2 and 3.<br/>Safety related undertakings will be actioned before during and after the trial to mitigate risks identified through the house-to-house testing (HyD-Rep06) procedural review (HyD-Rep09) and quantitative risk assessment (HyD-Rep02). This scope of the undertakings includes actions associated with the end appliances the network itself and the process equipment to be installed.<br/>The detail of these undertakings is given in Section 4.<br/>As part of the trial an experimental programme has been designed to provide further evidence relating to the interactions of a hydrogen blend on network materials and end appliances. The experimental programme is detailed in Section 5.<br/>Click the supplements tab to see the other documents from this report

Hydrothermal gasification (HTG) experiments were carried out to extract hydrogen from biomass. Although extensive research has been conducted on hydrogen production with HTG limited research exists on the use of biochar as a raw material. In this study woodland residues (wood chip) and biochar from wood-chip pyrolysis were used in HTG treatment to generate hydrogen. This research investigated the effect of temperature (300–425 °C) and biomass/water (0.5–10) ratio on gas composition. A higher temperature promoted hydrogen production because the water–gas shift reaction and steam-reforming reaction were promoted with an increase in temperature. The methane concentration was related positively to temperature because of the methanation and hydrogenation reactions. A lower biomass/water ratio promoted hydrogen production but suppressed carbon-monoxide production. Most reactions that produce hydrogen consume water but water also affects the water–gas shift reaction balance which decreases the carbon-monoxide concentration. By focusing on the practical application of HTG we attempted biochar treatment by pyrolysis (temperature of heating part: 700 °C) and syngas was obtained from hydrothermal treatment above 425 °C.

To find suitable sealing material with low permeability against hydrogen the elaborated evaluation techniques for hydrogen transport properties are necessary. We developed two techniques determining the permeability of hydrogen including software for diffusion behavior analysis. The techniques contain gas chromatography and volumetric collection of hydrogen gas. By measuring the hydrogen released from polymer samples with respect to the elapsed time after being decompressed from the high pressure total amount of adsorption and diffusivity (D) of hydrogen are evaluated with self-developed program of Fick's diffusion equation specified to a sample shape. The solubility (S) and permeability (P) of the polymers are determined through Henry's law and a relation of P=SD respectively. Developed techniques were applied to three kinds of spherical-shaped sealing rubbers NBR EPDM and FKM. The D S and P have been measured as function of pressure. The permeability obtained by both methods are discussed with Comsol simulation.

A pilot power system formed by photovoltaic panels alkaline electrolyser and fuel cell stacks was designed and set up to supply the heating system of an experimental greenhouse. The aim of this paper is to analyse the main safety aspects of this power system connected to the management of the pressured hydrogen such as the explosion limits of the mixture hydrogen-oxygen the extension of the danger zone the protection pressure vessels and the system to make unreactive the plant. The electrolyser unit is the core of this plant and from the safety point of view has been equipped with devices able to highlight the mal-functions before they cause damages. Alarm situations are highlighted and the production process is cut off in safe conditions in the event that the operational parameters have an abnormal deviation from the design values. Also the entire power system has been designed so that any failure to its components does not compromise the workers’ safety even if the risk analysis is in progress because technical operation are being carried out for enhancing the plant functionality making it more suitable to the designed task of supplying electrically the green-house heating system during cold periods. Some experimental data pertinent to the solar radiation and the corresponding hydrogen pro-duction rate are also reported. At present it does not exist a well-established safety reference protocol to design the reliability of these types of power plants and then the assumed safety measures even if related to the achieved pilot installation can represent an original base of reference to set up guidelines for designing the safety of power plants in the future available for agricultural purposes.

Green hydrogen can help to decarbonize parts of the transportation sector but its power sector interactions are not well understood so far. It may contribute to integrating variable renewable energy sources if production is sufficiently flexible in time. Using an open-source co-optimization model of the power sector and four options for supplying hydrogen at German filling stations we find a trade-of between energy efficiency and temporal flexibility. For lower shares of renewables and hydrogen more energy-efficient and less flexible small-scale on-site electrolysis is optimal. For higher shares of renewables and/or hydrogen more flexible but less energy-efficient large-scale hydrogen supply chains gain importance as they allow to temporally disentangle hydrogen production from demand via storage. Liquid hydrogen emerges as particularly beneficial followed by liquid organic hydrogen carriers and gaseous hydrogen. Large-scale hydrogen supply chains can deliver substantial power sector benefits mainly through reduced renewable curtailment. Energy modelers and system planners should consider the distinct flexibility characteristics of hydrogen supply chains in more detail when assessing the role of green hydrogen in future energy transition scenarios. We also propose two alternative cost and emission metrics which could be useful in future analyses.

This report presents the results of research into consumer perceptions and the subsequent degree of acceptance of blended hydrogen in domestic properties. Evidence from two trial sites of the HyDeploy programme: i) a private site trial at Keele University North Staffordshire; ii) and a public site trial at Winlaton Gateshead are discussed.

This research considers the potential role of hydrogen in meeting the UK’s carbon budgets. It was written by consultancy E4tech.<br/>The CCC develops scenarios for the UK’s future energy system to assess routes to decarbonisation and to advise UK Government on policy options. Uncertainty to 2050 is considerable and so different scenarios are needed to assess different trajectories targets and technology combinations. Some of these scenarios assess specific technologies or fuels which have the potential to make a significant contribution to future decarbonisation.<br/>Hydrogen is one such fuel. It has been included in limited quantities in some CCC scenarios but not extensively examined in part due to perceived or anticipated higher costs than some other options. But as hydrogen technology is developed and deployed the cost projections and other performance indicators have become more favourable.

The Paris Agreement marks a significant positive step in global action to tackle climate change. This report considers the domestic actions the UK Government should take as part of a fair contribution to the aims of the Agreement.<br/>The report concludes that the Paris Agreement is a significant step forward in global efforts to tackle climate change. It is more ambitious in its aims to limit climate change than the basis of the UK’s existing climate targets. However it is not yet appropriate to set new UK targets. Existing targets are already stretching and the priority is to take action to meet them.