Production & Supply Chain

Photocatalytic water splitting which directly converts solar energy into hydrogen is one of the most desirable solar-energy-conversion approaches. The ultimate target of photocatalysis is to explore efficient and stable photocatalysts for solar water splitting. Tantalum (oxy)nitride-based materials are a class of the most promising photocatalysts for solar water splitting because of their narrow bandgaps and sufficient band energy potentials for water splitting. Tantalum (oxy)nitride-based photocatalysts have experienced intensive exploration and encouraging progress has been achieved over the past years. However the solar-to-hydrogen (STH) conversion efficiency is still very far from its theoretical value. The question of how to better design these materials in order to further improve their water-splitting capability is of interest and importance. This review summarizes the development of tantalum (oxy)nitride-based photocatalysts for solar water spitting. Special interest is paid to important strategies for improving photocatalytic water-splitting efficiency. This paper also proposes future trends to explore in the research area of tantalum-based narrow bandgap photocatalysts for solar water splitting.

Hydrogen production using anion exchange membrane water electrolysis (AEMWE) offers hope to the energy crisis faced by humanity. AEM electrolysis can be coupled with intermittent and renewable energy sources as well as with the use of low-cost electrocatalysts and other low-cost stack components. In AEM water electrolysis one of the biggest advantages is the use of low-cost transition metal catalysts instead of traditional noble metal electrocatalysts. AEMWE is still in its infancy despite irregular research on catalysts and membranes. In order to generate commercially viable hydrogen AEM water electrolysis technology must be further developed including energy efficiency membrane stability stack feasibility robustness ion conductivity and cost reduction. An overview of studies that have been conducted on electrocatalysts membranes and ionomers used in the AEMWEs is here reported with the aim that AEMWE research may be made more practical by this review report by bridging technological gaps and providing practical research recommendations leading to the production of scalable hydrogen.

This study focuses on a renewable energy power plant equipped with electrolytic hydrogen production system aiming to optimize energy management to smooth renewable energy generation fluctuations participate in peak shaving auxiliary services and increase the absorption space for renewable energy. A multi-objective energy management model and corresponding algorithms were developed incorporating considerations of cost pricing and the operational constraints of a renewable energy generating unit and electrolytic hydrogen production system. By introducing uncertain programming the uncertainty issues associated with renewable energy output were successfully addressed and an improved particle swarm optimization algorithm was employed for solving. A simulation system established on the Matlab platform verified the effectiveness of the model and algorithms demonstrating that this approach can effectively meet the demands of the electricity market while enhancing the utilization rate of renewable energies.

Microbial electrolysis cells (MECs) have attracted significant interest as sustainable green hydrogen production devices because they utilize the environmentally friendly biocatalytic oxidation of organic wastes and electrochemical proton reduction with the support of relatively lower external power compared to that used by water electrolysis. However the commercialization of MEC technology has stagnated owing to several critical technological challenges. Recently many attempts have been made to utilize nanomaterials in MECs owing to the unique physicochemical properties of nanomaterials originating from their extremely small size (at least <100 nm in one dimension). The extraordinary properties of nanomaterials have provided great clues to overcome the technological hurdles in MECs. Nanomaterials are believed to play a crucial role in the commercialization of MECs. Thus understanding the technological challenges of MECs the characteristics of nanomaterials and the employment of nanomaterials in MECs could be helpful in realizing commercial MEC technologies. Herein the critical challenges that need to be addressed for MECs are highlighted and then previous studies that used nanomaterials to overcome the technological difficulties of MECs are reviewed.

Turquoise hydrogen is produced from methane cracking a cleaner alternative to steam methane reforming. This study looks at two proposed systems based on solar methane cracking for low-carbon fuel production. The systems utilize different pathways to convert the hydrogen into a suitable form for transportation and utilize the carbon solid by-product. A direct carbon fuel cell is integrated to utilize the carbon and capture the CO2 emissions. The CO2 generated is utilized for fuel production using CO2 hydrogenation or co-electrolysis. An advanced exergetic analysis is conducted on these systems using Aspen plus simulations of the process. The exergetic efficiency waste exergy ratio exergy destruction ratio exergy recoverability ratio environmental effect factor and the exergetic sustainability index were determined for each system and the subsystems. Solar methane cracking was found to have an environmental effect factor of 0.08 and an exergetic sustainability index of 12.27.

Hydrogen is emerging as a new energy vector outside of its traditional role and gaining more recognition internationally as a viable fuel route. This review paper offers a crisp analysis of the most recent developments in hydrogen production techniques using conventional and renewable energy sources in addition to key challenges in the production of Hydrogen. Among the most potential renewable energy sources for hydrogen production are solar and wind. The production of H2 from renewable sources derived from agricultural or other waste streams increases the flexibility and improves the economics of distributed and semi-centralized reforming with little or no net greenhouse gas emissions. Water electrolysis equipment driven by off-grid solar or wind energy can also be employed in remote areas that are away from the grid. Each H2 manufacturing technique has technological challenges. These challenges include feedstock type conversion efficiency and the need for the safe integration of H2 production systems with H2 purification and storage technologies.

Green hydrogen production i.e. produced on a CO2 -neutral basis through the electrolysis of water employing renewable electricity has attracted increasing attention. The electricity required is generated from Renewable Energy Sources (RES) for example wind energy hydropower or solar energy. Since neither the process of production nor the end products of H2 and O2 are harmful to the environment green hydrogen is climate neutral. Developing electrolysis technology is therefore a research topic to follow. Anion Exchange Membrane (AEM) Water Electrolysis (WE) is an innovative technology that couples the advantages of the more mature technologies of Proton Exchange Membrane (PEM) and conventional alkaline electrolysis with the potential to eliminate the drawbacks of both. AEMWE technology is in an evolutionary stage and involves more investigation on several research topics such as membrane and catalyst development and stability as well as alternative feeding solutions that do not compromise the availability of fresh water. These topics are addressed in this paper mentioning the state-of-the-art materials new promising ones and providing future research directions to improve AEMWE towards a most mature technology.

Carbon capture and storage (CCS) and hydrogen will be a catalyst to deeply decarbonize the world’s energy system but not for another 15 years according to DNV’s Energy Transition Outlook. Many aspects from policy to technology developments can help to scale these technologies and accelerate the timeline.<br/>In the report A System-Approach to Data can Help Install Trust and Enable a Net Zero Future DNV considers what role data could play to support the initiation execution and operation of CCS and hydrogen projects.<br/>The research is based on interviews with representatives from across the UK energy supply chain. It focuses in particular on the emerging carbon and hydrogen industries and the cross sectoral challenges they face. It explores how data can facilitate the flow of the product both with respect to fiscal and technical risk matters.<br/>The report is intended for anyone involved in or has an interest in CCUS or hydrogen projects and in how data eco-systems will support the efficient operation and the transition to net-zero.<br/>DNV produced the report for and in partnership with the ODI an organization that advocates for the innovative use of open data to affect positive change across the globe.

LaNiO3 and LaCoO3 perovskites synthesized by self-combustion were characterised and studied in the ammonia decomposition reaction for obtaining hydrogen. Both the fuel to metal nitrates molar ratio and calcination temperature were found to be crucial to synthesize perovskites by self-combustion. Moreover generating non-precursor species during synthesis and small metal size were two factors which significantly influenced catalytic activity. Hence with a citric acid to metal nitrates molar ratio equal to one a LaNiO3 perovskite was obtained with suitable physicochemical properties (specific surface area lower impurities and basicity). In addition a lower calcination temperature (650 ◦C) resulted in small and well-dispersed Ni0 crystallite size after reduction which in turn promoted the catalytic transformation of ammonia into hydrogen. For cobalt perovskites calcination temperature below 900 ◦C did not have a significant influence on the size of the metallic cobalt crystallite size. The nickel and cobalt perovskite-derived catalysts calcined at 650 ◦C and 750 ◦C respectively yielded excellent H2 production from ammonia decomposition. In particular at 450 ◦C almost 100% of the ammonia was converted over the LaNiO3 under study. Furthermore these materials displayed admirable performance and stability after one day of reaction.

The greatest challenge of our times is to identify low cost and environmentally friendly alternative energy sources to fossil fuels. From this point of view the decarbonization of industrial chemical processes is fundamental and the use of hydrogen as an energy vector usable by fuel cells is strategic. It is possible to tackle the decarbonization of industrial chemical processes with the electrification of systems. The purpose of this review is to provide an overview of the latest research on the electrification of endothermic industrial chemical processes aimed at the production of H2 from methane and its use for energy production through proton exchange membrane fuel cells (PEMFC). In particular two main electrification methods are examined microwave heating (MW) and resistive heating (Joule) aimed at transferring heat directly on the surface of the catalyst. For cases the catalyst formulation and reactor configuration were analyzed and compared. The key aspects of the use of H2 through PEM were also analyzed highlighting the most used catalysts and their performance. With the information contained in this review we want to give scientists and researchers the opportunity to compare both in terms of reactor and energy efficiency the different solutions proposed for the electrification of chemical processes available in the recent literature. In particular through this review it is possible to identify the solutions that allow a possible scale-up of the electrified chemical process imagining a distributed production of hydrogen and its consequent use with PEMs. As for PEMs in the review it is possible to find interesting alternative solutions to platinum with the PGM (Platinum Group Metal) free-based catalysts proposing the use of Fe or Co for PEM application.