South Africa
Green Hydrogen Production through Ammonia Decomposition Using Non-Thermal Plasma
Sep 2023
Publication
Liquid hydrogen carriers will soon play a significant role in transporting energy. The key factors that are considered when assessing the applicability of ammonia cracking in large-scale projects are as follows: high energy density easy storage and distribution the simplicity of the overall process and a low or zero-carbon footprint. Thermal systems used for recovering H2 from ammonia require a reaction unit and catalyst that operates at a high temperature (550–800 ◦C) for the complete conversion of ammonia which has a negative effect on the economics of the process. A non-thermal plasma (NTP) solution is the answer to this problem. Ammonia becomes a reliable hydrogen carrier and in combination with NTP offers the high conversion of the dehydrogenation process at a relatively low temperature so that zero-carbon pure hydrogen can be transported over long distances. This paper provides a critical overview of ammonia decomposition systems that focus on non-thermal methods especially under plasma conditions. The review shows that the process has various positive aspects and is an innovative process that has only been reported to a limited extent.
A Review of the Optimization Strategies and Methods Used to Locate Hydrogen Fuel Refueling Stations
Feb 2023
Publication
Increasing sales of conventional fuel-based vehicles are leading to an increase in carbon emissions which are dangerous to the environment. To reduce these conventional fuel-based vehicles must be replaced with alternative fuel vehicles such as hydrogen-fueled. Hydrogen can fuel vehicles with near-zero greenhouse gas emissions. However to increase the penetration of such alternative fuel vehicles there needs to be adequate infrastructure specifically refueling infrastructure in place. This paper presents a comprehensive review of the different optimization strategies and methods used in the location of hydrogen refueling stations. The findings of the review in this paper show that there are various methods which can be used to optimally locate refueling stations the most popular being the p-median and flow-capture location models. It is also evident from the review that there are limited studies that consider location strategies of hydrogen refueling stations within a rural setting; most studies are focused on urban locations due to the high probability of penetration into these areas. Furthermore it is apparent that there is still a need to incorporate factors such as the safety elements of hydrogen refueling station construction and for risk assessments to provide more robust realistic solutions for the optimal location of hydrogen refueling stations. Hence the methods reviewed in this paper can be used and expanded upon to create useful and accurate models for a hydrogen refueling network. Furthermore this paper will assist future studies to achieve an understanding of the extant studies on hydrogen refueling station and their optimal location strategies.
Can Africa Serve Europe with Hydrogen Energy from Its Renewables?—Assessing the Economics of Shipping Hydrogen and Hydrogen Carriers to Europe from Different Parts of the Continent
Apr 2023
Publication
There exists no single optimal way for transporting hydrogen and other hydrogen carriers from one port to the other globally. Its delivery depends on several factors such as the quantity distance economics and the availability of the required infrastructure for its transportation. Europe has a strategy to invest in the production of green hydrogen in Africa to meet its needs. This study assessed the economic viability of shipping liquefied hydrogen (LH2 ) and hydrogen carriers to Germany from six African countries that have been identified as countries with great potential in the production of hydrogen. The results obtained suggest that the shipping of LH2 to Europe (Germany) will cost between 0.47 and 1.55 USD/kg H2 depending on the distance of travel for the ship. Similarly the transportation of hydrogen carriers could range from 0.19 to 0.55 USD/kg H2 for ammonia 0.25 to 0.77 USD/kg H2 for LNG 0.24 to 0.73 USD/kg H2 for methanol and 0.43 to 1.28 USD/kg H2 for liquid organic hydrogen carriers (LOHCs). Ammonia was found to be the ideal hydrogen carrier since it recorded the least transportation cost. A sensitivity analysis conducted indicates that an increase in the economic life by 5 years could averagely decrease the cost of LNG by some 13.9% NH3 by 13.2% methanol by 7.9% LOHC by 8.03% and LH2 by 12.41% under a constant distance of 6470 nautical miles. The study concludes with a suggestion that if both foreign and local participation in the development of the hydrogen market is increased in Africa the continent could supply LH2 and other hydrogen carriers to Europe at a cheaper price using clean fuel.
Advances in Hydrogen-Powered Trains: A Brief Report
Sep 2023
Publication
The majority of rail vehicles worldwide use diesel as a primary fuel source. Diesel engine carbon emissions harm the environment and human health. Although railway electrification can reduce emissions it is not always the most economical option especially on routes with low vehicle demand. As a result interest in hydrogen-powered trains as a way to reduce greenhouse gas (GHG) emissions has steadily grown in recent years. In this paper we discuss advancements made in hydrogen-powered freight and commuter trains as well as the technology used in some aspects of hydrogen-powered vehicles. It was observed that hydrogen-powered trains are already in use in Europe and Asia unlike most developing countries in Africa. Commuter trains have received most of the research and development (R&D) attention but interest in hydrogen-powered freight trains has recently picked up momentum. Despite the availability and use of gray and blue hydrogen green hydrogen is still the preferred fuel for decarbonizing the rail transport sector.
An Overview of Application-orientated Multifunctional Large-scale Stationary Battery and Hydrogen Hybrid Energy Storage System
Dec 2023
Publication
The imperative to address traditional energy crises and environmental concerns has accelerated the need for energy structure transformation. However the variable nature of renewable energy poses challenges in meeting complex practical energy requirements. To address this issue the construction of a multifunctional large-scale stationary energy storage system is considered an effective solution. This paper critically examines the battery and hydrogen hybrid energy storage systems. Both technologies face limitations hindering them from fully meeting future energy storage needs such as large storage capacity in limited space frequent storage with rapid response and continuous storage without loss. Batteries with their rapid response (90%) excel in frequent short-duration energy storage. However limitations such as a selfdischarge rate (>1%) and capacity loss (~20%) restrict their use for long-duration energy storage. Hydrogen as a potential energy carrier is suitable for large-scale long-duration energy storage due to its high energy density steady state and low loss. Nevertheless it is less efficient for frequent energy storage due to its low storage efficiency (~50%). Ongoing research suggests that a battery and hydrogen hybrid energy storage system could combine the strengths of both technologies to meet the growing demand for large-scale long-duration energy storage. To assess their applied potentials this paper provides a detailed analysis of the research status of both energy storage technologies using proposed key performance indices. Additionally application-oriented future directions and challenges of the battery and hydrogen hybrid energy storage system are outlined from multiple perspectives offering guidance for the development of advanced energy storage systems.
Review on the Thermal Neutrality of Application-orientated Liquid Organic Hydrogen Carrier for Hydrogen Energy Storage and Delivery
Aug 2023
Publication
The depletion and overuse of fossil fuels present formidable challenge to energy supply system and environment. The human society is in great need of clean renewable and sustainable energy which can guarantee the long-term utilization without leading to escalation of greenhouse effect. Hydrogen as an extraordinary secondary energy is capable of realizing the target of environmental protection and transferring the intermittent primary energy to the application terminal while its nature of low volumetric energy density and volatility need suitable storage method and proper carrier. In this context liquid organic hydrogen carrier (LOHC) among a series of storage methods such as compressed and liquefied hydrogen provokes a considerable amount of research interest since it is proven to be a suitable carrier for hydrogen with safety and stability. However the dehydrogenation of hydrogen-rich LOHC materials is an endothermic process and needs large energy consumption which hampers the scale up of the LOHC system. The heat issue is thus essential to be addressed for fulfilling the potential of LOHC. In this work several strategies of heat intensification and management for LOHC system including the microwave irradiation circulation of exhaust heat and direct LOHC fuel cell are summarized and analyzed to provide suggestions and directions for future research.
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