- Home
- A-Z Publications
- Publications
Publications
Energy Futures and Green Hydrogen Production: Is Saudi Arabia Trend?
May 2023
Publication
This paper explores the potential for hydrogen energy to become a future trend in Saudi Arabia energy industry. With the emergence of hydrogen as a promising clean energy source there has been growing interest and investment in this area globally. This study investigated whether the country is likely to pursue this trend given its current energy mix and policies. A study was conducted to provide an overview of the global trends and best practices in hydrogen energy adoption and investment. The outcomes of the analysis show that the country current energy mix has the potential to produce green hydrogen energy. The evaluation of its readiness and potential obstacles for hydrogen energy adoption has been drowned and there are several challenges that need to be addressed. The study outcomes also conclude with policy implications and recommendations for the country energy industry.
From Biogas to Hydrogen: A Techno-Economic Study on the Production of Turquoise Hydrogen and Solid Carbons
Sep 2022
Publication
Biogas is a renewable feedstock that can be used to produce hydrogen through the decomposition of biomethane. However the economics of the process are not well studied and understood especially in cases where solid carbons are also produced and which have a detrimental effect on the performance of the catalysts. The scale as well as product diversification of a biogas plant to produce hydrogen and other value-added carbons plays a crucial role in determining the feasibility of biogasto-hydrogen projects. Through a techno-economic study using the discounted cash flow method it has been shown that there are no feasible sizes of plants that can produce hydrogen at the target price of USD 3/kg or lower. However for self-funded anaerobic digestor plants retrofitting modular units for hydrogen production would only make financial sense at biogas production capacities of more than 412 m3/h. A sensitivity analysis has also shown that the cost competitiveness is dependent on the type of carbon formed and low-grade carbon black has a negative effect on economic feasibility. Hydrogen produced from biogas would thus not be able to compete with grey hydrogen production but rather with current green hydrogen production costs.
Underground Storage of Green Hydrogen—Boundary Conditions for Compressor Systems
Aug 2022
Publication
The large-scale storage of hydrogen in salt caverns modelled on today’s natural gas storage is a promising approach to storing renewable energy over a large power range and for the required time period. An essential subsystem of the overall gas storage is the surface facility and in particular the compressor system. The future design of compressor systems for hydrogen storage strongly depends on the respective boundary conditions. Therefore this work analyses the requirements of compressor systems for cavern storage facilities for the storage of green hydrogen i.e. hydrogen produced from renewable energy sources using the example of Lower Saxony in Germany. In this course a hydrogen storage demand profile of one year is developed in hourly resolution from feed-in time series of renewable energy sources. The injection profile relevant for compressor operation is compared with current natural gas injection operation modes
An MILP Approach for the Optimal Design of Renewable Battery-hydrogen Energy Systems for Off-grid Insular Communities
Jul 2021
Publication
The optimal sizing of stand-alone renewable H2-based microgrids requires the load demand to be reliably satisfied by means of local renewable energy supported by a hybrid battery/hydrogen storage unit while minimizing the system costs. However this task is challenging because of the high number of components that have to be installed and operated. In this work an MILP optimization framework has been developed and applied to the off-grid village of Ginostra (on the Stromboli island Italy) which is a good example of several other insular sites throughout the Mediterranean area. A year-long time horizon was considered to model the seasonal storage which is necessary for off-grid areas that wish to achieve energy independence by relying on local renewable sources. The degradation costs of batteries and H2-based devices were included in the objective function of the optimization problem i.e. the annual cost of the system. Efficiency and investment cost curves were considered for the electrolyzer and fuel cell components in order to obtain a more detailed and precise techno-economic estimation. The design optimization was also performed with the inclusion of a general demand response program (DRP) to assess its impact on the sizing results. Moreover the effectiveness of the proposed MILP-based method was tested by comparing it with a more traditional approach based on a metaheuristic algorithm for the optimal sizing complemented with ruled-based strategies for the system operation. Thanks to its longer-term storage capability hydrogen is required for the optimal system configuration in order to reach energy self-sufficiency. Finally considering the possibility of load deferral the electricity generation cost can be reduced to an extent that depends on the amount of load that is allowed to participate in the DRP scheme. This cost reduction is mainly due to the decreased capacity of the battery storage system.
Dynamic Investigation and Optimization of a Solar‐Based Unit for Power and Green Hydrogen Production: A Case Study of the Greek Island, Kythnos
Nov 2022
Publication
The aim of the present work is the analysis of a solar‐driven unit that is located on the non‐interconnected island of Kythnos Greece that can produce electricity and green hydrogen. More specifically solar energy is exploited by parabolic trough collectors and the produced heat is stored in a thermal energy storage tank. Additionally an organic Rankine unit is incorporated to generate electricity which contributes to covering the island’s demand in a clean and renewable way. When the power cannot be absorbed by the local grid it can be provided to a water electrolyzer; therefore the excess electricity is stored in the form of hydrogen. The produced hydrogen amount is compressed afterward stored in tanks and then finally can be utilized as a fuel to meet other important needs such as powering vehicles or ferries. The installation is simulated parametrically and optimized on dynamic conditions in terms of energy exergy and finance. According to the results considering a base electrical load of 75 kW the annual energy and exergy efficiencies are found at 14.52% and 15.48% respectively while the payback period of the system is deter‐ mined at 6.73 years and the net present value is equal to EUR 1073384.
Performance Analysis of a Zero-Energy Building Using Photovoltaics and Hydrogen Storage
Mar 2023
Publication
The exploitation of renewable energy sources in the building sector is a challenging aspect of achieving sustainability. The incorporation of a proper storage unit is a vital issue for managing properly renewable electricity production and so to avoid the use of grid electricity. The present investigation examines a zero-energy residential building that uses photovoltaics for covering all its energy needs (heating cooling domestic hot water and appliances-lighting needs). The building uses a reversible heat pump and an electrical heater so there is not any need for fuel. The novel aspect of the present analysis lies in the utilization of hydrogen as the storage technology in a power-to-hydrogen-to-power design. The residual electricity production from the photovoltaics feeds an electrolyzer for hydrogen production which is stored in the proper tank under high pressure. When there is a need for electricity and the photovoltaics are not enough the hydrogen is used in a fuel cell for producing the needed electricity. The present work examines a building of 400 m2 floor area in Athens with total yearly electrical demand of 23656 kWh. It was found that the use of 203 m2 of photovoltaics with a hydrogen storage capacity of 34 m3 can make the building autonomous for the year period.
Optimization of Small-Scale Hydrogen Production with Membrane Reactors
Mar 2023
Publication
In the pathway towards decarbonization hydrogen can provide valid support in different sectors such as transportation iron and steel industries and domestic heating concurrently reducing air pollution. Thanks to its versatility hydrogen can be produced in different ways among which steam reforming of natural gas is still the most commonly used method. Today less than 0.7% of global hydrogen production can be considered low-carbon-emission. Among the various solutions under investigation for low-carbon hydrogen production membrane reactor technology has the potential especially at a small scale to efficiently convert biogas into green hydrogen leading to a substantial process intensification. Fluidized bed membrane reactors for autothermal reforming of biogas have reached industrial maturity. Reliable modelling support is thus necessary to develop their full potential. In this work a mathematical model of the reactor is used to provide guidelines for their design and operations in off-design conditions. The analysis shows the influence of temperature pressures catalyst and steam amounts and inlet temperature. Moreover the influence of different membrane lengths numbers and pitches is investigated. From the results guidelines are provided to properly design the geometry to obtain a set recovery factor value and hydrogen production. For a given reactor geometry and fluidization velocity operating the reactor at 12 bar and the permeate-side pressure of 0.1 bar while increasing reactor temperature from 450 to 500 °C leads to an increase of 33% in hydrogen production and about 40% in HRF. At a reactor temperature of 500 °C going from 8 to 20 bar inside the reactor doubled hydrogen production with a loss in recovery factor of about 16%. With the reactor at 12 bar a vacuum pressure of 0.5 bar reduces hydrogen production by 43% and HRF by 45%. With the given catalyst it is sufficient to have only 20% of solids filled into the reactor being catalytic particles. With the fixed operating conditions it is worth mentioning that by adding membranes and maintaining the same spacing it is possible to increase hydrogen production proportionally to the membrane area maintaining the same HRF.
The Smart Community: Strategy Layers for a New Sustainable Continental Framework
Feb 2023
Publication
The topic investigated in this article is a comparison contrast and integration effort of European strategies for sustainable development with the evolving market initiatives that are beginning to fuel the fourth industrial revolution. Several regulatory initiatives from continental bodies come into effect to radically change access to finances for business development based on sustainability goals and an analysis of the legislation and trends becomes essential for an effective pivot tactic in the face of adversity as well as change management policies to pre-emptively adapt and perform. The general research question is “what the strategic tools are best employed to overcome the hurdles laid forth by the drastic changes legally required for a sustainable future?” The research methods include a quantitative analysis of norms regulations and legislation including strategic initiatives circulated in the European Union governmental bodies integrated with qualitative research of the literature. The study finds and draws synergies between national strategies that have recently been drafted or are currently evolving with sustainability-centric initiatives such as the hydrogen initiative the nuclear initiative the natural gas initiative the renewables initiative the synthetics and biomass initiative the ESG initiative the digital initiative. The findings are to contribute to the business administration field by providing an appropriate image of the organizational design model in the sustainability era and a strategy framework to build the optimum long-term vision founded on continental regulatory initiatives that have come into effect.
Resource Assessment for Green Hydrogen Production in Kazakhstan
Jan 2023
Publication
Kazakhstan has long been regarded as a major exporter of fossil fuel energy. As the global energy sector is undergoing an unprecedented transition to low-carbon solutions new emerging energy technologies such as hydrogen production require more different resource bases than present energy technologies. Kazakhstan needs to consider whether it has enough resources to stay competitive in energy markets undergoing an energy transition. Green hydrogen can be made from water electrolysis powered by low-carbon electricity sources such as wind turbines and solar panels. We provided the first resource assessment for green hydrogen production in Kazakhstan by focusing on three essential resources: water renewable electricity and critical raw materials. Our estimations showed that with the current plan of Kazakhstan to keep its water budget constant in the future producing 2–10 Mt green hydrogen would require reducing the water use of industry in Kazakhstan by 0.6–3% or 0.036–0.18 km3/year. This could be implemented by increasing the share of renewables in electricity generation and phasing out some of the water- and carbon-intensive industries. Renewable electricity potential in South and West Kazakhstan is sufficient to run electrolyzers up to 5700 and 1600 h/year for wind turbines and solar panels respectively. In our base case scenario 5 Mt green hydrogen production would require 50 GW solar and 67 GW wind capacity considering Kazakhstan's wind and solar capacity factors. This could convert into 28652 tons of nickel 15832 tons of titanium and many other critical raw materials. Although our estimations for critical raw materials were based on limited geological data Kazakhstan has access to the most critical raw materials to support original equipment manufacturers of low-carbon technologies in Kazakhstan and other countries. As new geologic exploration kicks off in Kazakhstan it is expected that more deposits of critical raw materials will be discovered to respond to their potential future needs for green hydrogen production.
Innovative Combustion Analysis of a Micro-gas Turbine Burner Supplied with Hydrogen-natural Gas Mixtures
Sep 2017
Publication
The author discusses in this paper the potential of a micro gas turbine (MGT) combustor when operated under unconventional fuel supplied. The combustor of C30 gas turbine is a reverse flow annular combustor. The CFD analysis of the reacting flow is performed with the 3D ANSYS-FLUENT solver. Specific computational experiments refer to the use of hydrogen – natural gas mixtures in order to define the optimal conditions for pilot and main injections in terms of combustion stability and NOx production. The author's methodology relies on an advanced CFD approach that compares different schemes like eddy dissipation concept together with the flamelet- PDF based approach coupled with an accurate study of the turbulent chemistry interaction. Extended kinetic mechanisms are also included in the combustion model. Some test cases are examined to make a comparison of combustion stability and efficiency and pollutant production with high hydrogen / natural gas ratios.
Drop-in and Hydrogen-based Biofuels for Maritime Transport: Country-based Assessment of Climate Change Impacts in Europe up to 2050
Nov 2022
Publication
Alternative fuels are crucial to decarbonize the European maritime transport but their net climate benefits vary with the type of fuel and production country. In this study we assess the energy potential and climate change mitigation benefits of using agricultural and forest residues in different European countries for drop-in (Fast Pyrolysis Hydrothermal Liquefaction and Gasification to Fischer-Tropsch fuels or Bio-Synthetic Natural Gas) and hydrogen-based biofuels (hydrogen ammonia and methanol) with or without carbon capture and storage (CCS). Our results show the combinations of countries and biofuel options that successfully achieve the decarbonization targets set by the FuelEU Maritime initiative for the next years including a prospective analysis that include technological changes projected for the biofuel supply chains until 2050. With the current technologies the largest greenhouse gas (GHG) mitigation potential per year at a European scale is obtained with bio-synthetic natural gas and hydrothermal liquefaction. Among carbon-free biofuels ammonia currently has higher mitigation but hydrogen can achieve a lower GHG intensity per unit of energy with the projected decarbonization of the electricity mixes until 2050. The full deployment of CCS can further accelerate the decarbonization of the maritime sector. Choosing the most suitable renewable fuels requires a regional perspective and a transition roadmap where countries coordinate actions to meet ambitious climate targets.
Policy Toolbox for Low Carbon and Renewable Hydrogen
Nov 2021
Publication
The report “Policy Toolbox for Low Carbon and Renewable Hydrogen” is based on an assessment of the performance of hydrogen policies in different stages of market maturity and segments of the value chain. 48 policies were shortlisted based on their economic efficiency and effectiveness and mapped to barriers across the value chain and over time. These policies were subsequently clustered into policy packages for three country archetypes: a self-sufficient hydrogen producer an importer and an exporter of hydrogen.
The paper can be found on their website.
The paper can be found on their website.
Analysis of Hydrogen-powered Propulsion System Alternatives for Diesel-electric Regional Trains
Aug 2022
Publication
Non-electrified regional railway lines with typically employed diesel-electric multiple units require alternative propulsion systems to meet increasingly strict emissions regulations. With the aim to identify an optimal alternative to conventional diesel traction this paper presents a model-based assessment of hydrogen-powered propulsion systems with an internal combustion engine or fuel cells as the prime mover combined with different energy storage system configurations based on lithium-ion batteries and/or double-layer capacitors. The analysis encompasses technology identification design modelling and assessment of alternative powertrains explicitly considering case-related constraints imposed by the infrastructure technical and operational requirements. Using a regional railway network in the Netherlands as a case we investigate the possibilities in converting a conventional benchmark vehicle and provide the railway undertaking and decision-makers with valuable input for planning of future rolling stock investments. The results indicate the highest fuel-saving potential for fuel cell-based hybrid propulsion systems with lithium-ion battery or a hybrid energy storage system that combines both energy storage system technologies. The two configurations also demonstrate the highest reduction of greenhouse gas emissions compared to the benchmark diesel-driven vehicle by about 25% for hydrogen produced by steam methane reforming and about 19% for hydrogen obtained from electrolysis of water with grey electricity.
Thermodynamic and Emission Analysis of a Hydrogen/Methane Fueled Gas Turbine
May 2023
Publication
The importance of hydrogen in the effort to decarbonize the power sector has grown immensely in recent years. Previous studies have investigated the effects of mixing hydrogen into natural gas for gas turbine combustors but limited studies have examined the resulting effects hydrogen addition has on the entire system. In this work a thermodynamic model of a gas turbine with combustion chemical kinetics integrated is created and the effects hydrogen addition (0-100 volume percent addition) has on the system performance emissions and combustion kinetics are analyzed. The maximum system performance is achieved when the maximum turbine inlet temperature is reached and the resulting optimal fuel/air equivalence ratio is determined. As hydrogen is added to the fuel mixture the optimal equivalence ratio shifts leaner causing non-linearity in emissions and system performance at optimal conditions. An analysis of variance is conducted and it is shown that isentropic efficiencies of the turbine and compressor influences the system performance the most out of any system parameter. While isentropic efficiencies of the turbine and compressor increase towards 100% an operating regime where the optimal system efficiency cannot be achieved is discovered due to the lower flammability limit of the fuel being reached. This can be overcome by mixing hydrogen into the fuel.
The Impact of Process Heat on the Decarbonisation Potential of Offshore Installations by Hybrid Energy Systems
Dec 2021
Publication
An opportunity to decarbonise the offshore oil and gas sector lies in the integration of renewable energy sources with energy storage in a hybrid energy system (HES). Such concept enables maximising the exploitation of carbon-free renewable power while minimising the emissions associated with conventional power generation systems such as gas turbines. Offshore plants in addition to electrical and mechanical power also require process heat for their operation. Solutions that provide low-emission heat in parallel to power are necessary to reach a very high degree of decarbonisation. This paper investigates different options to supply process heat in offshore HES while the electric power is mostly covered by a wind turbine. All HES configurations include energy storage in the form of hydrogen tied to proton exchange membrane (PEM) electrolysers and fuel cells stacks. As a basis for comparison a standard configuration relying solely on a gas turbine and a waste heat recovery unit is considered. A HES combined with a waste heat recovery unit to supply heat proved efficient when low renewable power capacity is integrated but unable to deliver a total CO2 emission reduction higher than around 40%. Alternative configurations such as the utilization of gas-fired or electric heaters become more competitive at large installed renewable capacity approaching CO2 emission reductions of up to 80%.
Review of Life Cycle Assessments for Steel and Environmental Analysis of Future Steel Production Scenarios
Oct 2022
Publication
The steel industry is focused on reducing its environmental impact. Using the life cycle assessment (LCA) methodology the impacts of the primary steel production via the blast furnace route and the scrap-based secondary steel production via the EAF route are assessed. In order to achieve environmentally friendly steel production breakthrough technologies have to be implemented. With a shift from primary to secondary steel production the increasing steel demand is not met due to insufficient scrap availability. In this paper special focus is given on recycling methodologies for metals and steel. The decarbonization of the steel industry requires a shift from a coal-based metallurgy towards a hydrogen and electricity-based metallurgy. Interim scenarios like the injection of hydrogen and the use of pre-reduced iron ores in a blast furnace can already reduce the greenhouse gas (GHG) emissions up to 200 kg CO2/t hot metal. Direct reduction plants combined with electrical melting units/furnaces offer the opportunity to minimize GHG emissions. The results presented give guidance to the steel industry and policy makers on how much renewable electric energy is required for the decarbonization of the steel industry
Methane Pyrolysis for CO2-Free H2 Production: A Green Process to Overcome Renewable Energies Unsteadiness
Aug 2020
Publication
The Carbon2Chem project aims to convert exhaust gases from the steel industry into chemicals such as methanol to reduce CO2 emissions. Here H2 is required for the conversion of CO2 into methanol. Although much effort is put to produce H2 from renewables the use of fossil fuels especially natural gas seems to be fundamental in the short term. For this reason the development of clean technologies for the processing of natural gas with a low environmental impact has become a topic of utmost importance. In this context methane pyrolysis has received special attention to produce CO2-free H2.
A Study of Thermoelectric Generation Coupled with Methanol Steam Reforming for Hydrogen Production
Nov 2022
Publication
Waste heat recovery was considered as a promising candidate for energy conservation and emission reduction. Methanol steam reforming was considered to be an effective means for hydrogen production because of its advantages. In this work a micro reactor was constructed and thermoelectric generation coupled with hydrogen production from methanol steam reforming was innovatively used to recycle waste heat which was simulated by hot air from a hot air gun. The waste heat was converted into electricity and hydrogen at the same time. The characteristic of thermoelectric generation coupled with methanol steam reforming was investigated. It was experimentally verified that both the hydrogen production rate and methanol conversion increased with the increasing inlet temperature but thermal efficiency increased firstly and then decreased with the increasing temperature. The methanol steam reforming could effectively maintain cold side temperature distribution of thermoelectric generation. In the case of the thermoelectric module (1) the highest temperature difference of 37 ◦C was determined and the maximum open circuit voltage of 2 V was observed. The highest methanol conversion of 64.26% was achieved at a space velocity of 0.98 h−1 when the temperature was 543 K comprehensively considering the CO content and thermal efficiency.
OIES Podcast – PolyGrid 2050: Integrating Hydrogen into the European Energy Transfer Infrastructure Landscape
Feb 2023
Publication
In this podcast David Ledesma talks with Rahmat Poudineh and Martin Palovic about their paper on integrating hydrogen into the European energy transfer infrastructure landscape. As hydrogen is expected to play an important role in European plans towards climate neutrality adequate hydrogen transport (and storage) infrastructure needs to be established. However hydrogen transport infrastructures are costly and have a long lead time. Furthermore hydrogen can be transported via a variety of means: it can be transported as a gas via pipelines or liquid via road rail and sea or even converted to derivatives such as ammonia or methanol for long distance transportation. It is also possible to transfer electrical energy instead of hydrogen and produce hydrogen in a decentralized way. From a system perspective all these infrastructures represent elements of a grand hydrogen ‘polygrid’ that will be the backbone of the future decarbonized energy system. This raises the fundamental question of how to prevent inefficiency and infrastructure redundancy across different modes of hydrogen transport. The task is made more challenging by technological uncertainty the unpredictability of future supply and demand for hydrogen network externality effects and investment irreversibility of grid-based infrastructures. In this podcast we discuss three possible coordination approaches to optimise future cross-sectoral investment into hydrogen transport infrastructure and highlight their strengths and shortcomings.
The podcast can be found on their website.
The podcast can be found on their website.
Solid Air Hydrogen Liquefaction, the Missing Link of the Hydrogen Economy
Mar 2023
Publication
The most challenging aspect of developing a green hydrogen economy is long-distance oceanic transportation. Hydrogen liquefaction is a transportation alternative. However the cost and energy consumption for liquefaction is currently prohibitively high creating a major barrier to hydrogen supply chains. This paper proposes using solid nitrogen or oxygen as a medium for recycling cold energy across the hydrogen liquefaction supply chain. When a liquid hydrogen (LH2) carrier reaches its destination the regasification process of the hydrogen produces solid nitrogen or oxygen. The solid nitrogen or oxygen is then transported in the LH2 carrier back to the hydrogen liquefaction facility and used to reduce the energy consumption cooling gaseous hydrogen. As a result the energy required to liquefy hydrogen can be reduced by 25.4% using N2 and 27.3% using O2. Solid air hydrogen liquefaction (SAHL) can be the missing link for implementing a global hydrogen economy.
No more items...