Publications

Solar-driven hydrogen production from water using particulate photocatalysts is considered the most economical and effective approach to produce hydrogen fuel with little environmental concern. However the efficiency of hydrogen production from water in particulate photocatalysis systems is still low. Here we propose an efficient biphase photocatalytic system composed of integrated photothermal–photocatalytic materials that use charred wood substrates to convert liquid water to water steam simultaneously splitting hydrogen under light illumination without additional energy. The photothermal–photocatalytic system exhibits biphase interfaces of photothermally-generated steam/photocatalyst/hydrogen which significantly reduce the interface barrier and drastically lower the transport resistance of the hydrogen gas by nearly two orders of magnitude. In this work an impressive hydrogen production rate up to 220.74 μmol h−1 cm−2 in the particulate photocatalytic systems has been achieved based on the wood/CoO system demonstrating that the photothermal–photocatalytic biphase system is cost-effective and greatly advantageous for practical applications.

A compact air-breathing jet hybrid-electric engine coupled with solid oxide fuel cells (SOFC) is proposed to develop the propulsion system with high power-weight ratios and specific thrust. The heat exchanger for preheating air is integrated with nozzles. Therefore the exhaust in the nozzle expands during the heat exchange with compressed air. The nozzle inlet temperature is obviously improved. SOFCs can directly utilize the fuel of liquid natural gas after being heated. The performance parameters of the engine are acquired according to the built thermodynamic and mass models. The main conclusions are as follows. 1) The specific thrust of the engine is improved by 20.25% compared with that of the traditional jet engine. As pressure ratios rise the specific thrust increases up to 1.7 kN/(kg·s⁻¹). Meanwhile the nozzle inlet temperature decreases. However the temperature increases for the traditional combustion engine. 2) The power-weight ratio of the engine is superior to that of internal combustion engines and inferior to that of turbine engines when the power density of SOFC would be assumed to be that predicted for 2030. 3) The total pressure recovery coefficients of SOFCs combustors and preheaters have an obvious influence on the specific thrust of the engine and the power-weight ratio of the engine is strongly affected by the power density of SOFCs.

Study setting out a vision and plan for a multi-modal hydrogen transport hub within the UK. The study considers the:

• size of operational trials
• quantity of green hydrogen required
• research and development facilities which will support a living lab
• green hydrogen infrastructure required including:
• production
• storage
• distribution
• The study uses Tees Valley as an example region although the blueprint may be applied to other areas.

This report was independently produced on behalf of the Department for Transport by Mott Macdonald.

This article presents a summary of the main findings from a collaborative research project between Aalto University in Finland and partner universities. A comparative process synthesis modelling and thermal assessment was conducted for the production of Bio-synthetic natural gas (SNG) and hydrogen from supercritical water refining of a lipid extracted algae feedstock integrated with onsite heat and power generation. The developed reactor models for product gas composition yield and thermal demand were validated and showed conformity with reported experimental results and the balance of plant units were designed based on established technologies or state-of-the-art pilot operations. The poly-generative cases illustrated the thermo-chemical constraints and design trade-offs presented by key process parameters such as plant organic throughput supercritical water refining temperature nature of desirable coproducts downstream indirect production and heat recovery scenarios. The evaluated cases favoring hydrogen production at 5 wt. % solid content and 600 ◦C conversion temperature allowed higher gross syngas and CHP production. However mainly due to the higher utility demands the net syngas production remained lower compared to the cases favoring BioSNG production. The latter case at 450 ◦C reactor temperature 18 wt. % solid content and presence of downstream indirect production recorded 66.5% 66.2% and 57.2% energetic fuel-equivalent and exergetic efficiencies respectively

Based on data collection carried out between October and December 2020 and the testing of emerging findings with the Council’s regional communities during a series of digital workshops held during February 2021 the report has shown

• Energy leaders’ perceptions of areas of risk opportunity and priorities for action have radically changed over the last 12 months. While economic turbulence stemming from the ongoing reverberations of COVID-19 is the biggest area of uncertainty with uncertainty around economic trends increasing by a third over the previous year there is also a growing focus on the social agenda associated with a faster paced energy transition.

 

• There is an increased awareness of the societal and human impact of both recovery and the wider energy transition. The issue of energy affordability has rapidly risen up the industry’s priority list with its impact and uncertainty perceived 20% larger than a year ago. Energy affordability affects society across all geographies ranging from city dwellers in developed countries to the rural poor in developing ones.

 

• The emergence of a new generation of digital energy services and energy entrepreneurs. Increasingly agile disruptive technologies have taken advantage of the social upheaval to gain market share at the expense of supply-centric energy solutions. There is a growing focus on customer-centric demand-driven solutions and fast changing patterns of global and local demand.

The transition to hydrogen as a fuel source presents several challenges. One of the major hurdles is the cost-effective production of hydrogen in small quantities (less than 1MMscf/month). In the early demonstration phase hydrogen can be provided by bulk distribution of liquid or compressed gas from central production plants; however the next phase to fostering the hydrogen economy will likely include onsite generation and extensive pipeline networks to help effect a pervasive infrastructure. Providing inexpensive hydrogen at a fleet operator’s garage or local fuelling station is a key enabling technology for direct hydrogen Fuel Cell Vehicles (FCVs). The objective of this project was to develop a comprehensive turnkey stand-alone commercial hydrogen fuelling station for FCVs with state-of-the-art technology that is cost-competitive with current hydrocarbon fuels. Such a station would promote the advent of the hydrogen fuel economy for buses fleet vehicles and ultimately personal vehicles. Air Products partnering with the U.S. Department of Energy (DOE) The Pennsylvania State University Harvest Energy Technology and QuestAir developed a turnkey hydrogen fuelling station on the Penn State campus. Air Products aimed at designing a station that would have 65% overall station efficiency 82% PSA (pressure swing adsorption) efficiency and the capability of producing hydrogen at $3.00/kg (gge) H₂ at mass production rates. Air Products designed a fuelling station at Penn State from the ground up. This project was implemented in three phases. The first phase evaluated the various technologies available in hydrogen generation compression storage and gas dispensing. In the second phase Air Products designed the components chosen from the technologies examined. Finally phase three entailed a several-month period of data collection full-scale operation maintenance of the station and optimization of system reliability and performance. Based on field data analysis it was determined by a proprietary hydrogen-analysis model that hydrogen produced from the station at a rate of 1500 kg/day and when produced at 1000 stations per year would be able to deliver hydrogen at a price of $3.03/kg (gge) H₂. The station’s efficiency was measured to be 65.1% and the PSA was tested and ran at an efficiency of 82.1% thus meeting the project targets. From the study it was determined that more research was needed in the area of hydrogen fuelling. The overall cost of the hydrogen energy station when combined with the required plot size for scaled-up hydrogen demands demonstrated that a station using steam methane reforming technology as a means to produce on–site hydrogen would have limited utility in the marketplace. Alternative hydrogen supplies such as liquid or pipeline delivery to a refuelling station need to be included in the exploration of alternative energy site layouts. These avenues need to be explored before a definitive refuelling station configuration and commercialization pathway can be determined.

Developing high-performance electrocatalysts toward hydrogen evolution reaction is important for clean and sustainable hydrogen energy yet still challenging. Herein we report a single-atom strategy to construct excellent metal-organic frameworks (MOFs) hydrogen evolution reaction electrocatalyst (NiRu_0.13-BDC) by introducing atomically dispersed Ru. Significantly the obtained NiRu_0.13-BDC exhibits outstanding hydrogen evolution activity in all pH especially with a low overpotential of 36 mV at a current density of 10 mA cm⁻² in 1 M phosphate buffered saline solution which is comparable to commercial Pt/C. X-ray absorption fine structures and the density functional theory calculations reveal that introducing Ru single-atom can modulate electronic structure of metal center in the MOF leading to the optimization of binding strength for H₂O and H* and the enhancement of HER performance. This work establishes single-atom strategy as an efficient approach to modulate electronic structure of MOFs for catalyst design.

With the gradual popularization of hydrogen fuel cell vehicles (HFCVs) the construction and planning of hydrogen refueling stations (HRSs) are increasingly important. Taking operational HRSs in China’s coastal and major cities as examples we consider the main factors affecting the site selection of HRSs in China from the three aspects of economy technology and society to establish a site selection evaluation system for hydrogen refueling stations and determine the weight of each index through the analytic hierarchy process (AHP). Then combined with fuzzy comprehensive evaluation (FCE) method and artificial neural network model (ANN) FCE method is used to evaluate HRS in operation in China's coastal areas and major cities and we used the resulting data obtained from the comprehensive evaluation as the training data to train the neural network. So an intelligent site selection model for HRSs based on fuzzy comprehensive evaluation and artificial neural network model (FCE-ANN) is proposed. The planned HRSs in Shanghai are evaluated and an optimal site selection of the HRS is obtained. The results show that the optimal HRSs site selected by the FCE-ANN model is consistent with the site selection obtained by the FCE method and the accuracy of the FCE-ANN model is verified. The findings of this study may provide some guidelines for policy makers in planning the hydrogen refueling stations

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions which are the critical steps for both electrolysis and fuel cell operation especially at reduced temperatures. In this study a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode presenting superior electrochemical performance at 400~600 °C. More importantly the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction as confirmed by hydrogen permeation experiment remarkable hydration behavior and computations.

Hydrogen Fuelling Infrastructure Research and Station Technology (H2FIRST) is a project initiated by the DOE in 2015 and executed by Sandia National Laboratories and the National Renewable Energy Laboratory to address R&D barriers to the deployment of hydrogen fuelling infrastructure. One key barrier to the deployment of fuelling stations is the land area they require (i.e. ""footprint""). Space is particularly a constraint in dense urban areas where hydrogen demand is high but space for fuelling stations is limited. This work presents current fire code requirements that inform station footprint then identifies and quantifies opportunities to reduce footprint without altering the safety profile of fuelling stations. Opportunities analyzed include potential new methods of hydrogen delivery as well as alternative placements of station technologies (i.e. rooftop/underground fuel storage). As interest in heavy-duty fuelling stations and other markets for hydrogen grows this study can inform techniques to reduce the footprint of heavy-duty stations as well.



This work characterizes generic designs for stations with a capacity of 600 kg/day hydrogen dispensed and 4 dispenser hoses. Three base case designs (delivered gas delivered liquid and on-site electrolysis production) have been modified in 5 different ways to study the impacts of recently released fire code changes colocation with gasoline refuelling alternate delivery assumptions underground storage of hydrogen and rooftop storage of hydrogen resulting in a total of 32 different station designs. The footprints of the base case stations range from 13000 to 21000 ft².



A significant focus of this study is the NFPA 2 requirements especially the prescribed setback distances for bulk gaseous or liquid hydrogen storage. While the prescribed distances are large in some cases these setback distances are found to have a nuanced impact on station lot size; considerations of the delivery truck path traffic flow parking and convenience store location are also important. Station designs that utilize underground and rooftop storage can reduce footprint but may not be practical or economical. For example burying hydrogen storage tanks underground can reduce footprint but the cost savings they enable depend on the cost of burial and the cost land. Siting and economic analysis of station lot sizes illustrate the benefit of smaller station footprints in the flexibility and cost savings they can provide. This study can be used as a reference that provides examples of the key design differences that fuelling stations can incorporate the approximate sizes of generic station lots and considerations that might be unique to particular designs.