Production & Supply Chain

In the context of energy conservation and the reduction of CO2 emissions inconsistencies between the inevitable emission of CO2 in traditional hydrogen production methods and eco-friendly targets have become more apparent over time. The catalytic decomposition of methane (CDM) is a novel technology capable of producing hydrogen without releasing CO2 . Since hydrogen produced via CDM is neither blue nor green the term “turquoise” is selected to describe this technology. Notably the by-products of methane cracking are simply carbon deposits with different structures which can offset the cost of hydrogen production cost should they be harvested. However the encapsulation of catalysts by such carbon deposits reduces the contact area between said catalysts and methane throughout the CDM process thereby rendering the continuous production of hydrogen impossible. This paper mainly covers the CDM reaction mechanisms of the three common metal-based catalysts (Ni Co Fe) from experimental and modelling approaches. The by-products of carbon modality and the key parameters that affect the carbon formation mechanisms are also discussed.

Steam methane reforming (SMR) process is regarded as a viable option to satisfy the growing demand for hydrogen mainly because of its capability for the mass production of hydrogen and the maturity of the technology. In this study an economically optimal process configuration of SMR is proposed by investigating six scenarios with different design and operating conditions including CO₂ emission permits and CO₂ capture and sale. Of the six scenarios the process configuration involving CO₂ capture and sale is the most economical with an H₂ production cost of $1.80/kg-H₂. A wide range of economic analyses is performed to identify the tradeoffs and cost drivers of the SMR process in the economically optimal scenario. Depending on the CO₂ selling price and the CO₂ capture cost the economic feasibility of the SMR-based H₂ production process can be further improved.

This article presents a new technology for the generation of power and steam or other process heat with very low CO2 emissions. It is well known that cogeneration of electricity and steam is highly efficient and that amine units can be used to remove CO2 from combustion flue gas but that the amine unit consumes a significant amount of steam and power reducing the overall system efficiency. In this report the use of molten carbonate fuel cells (MCFCs) to capture CO2 from cogen units is investigated and shown to be highly efficient due to the additional power that they produce while capturing the CO2. Furthermore the MCFCs are capable of reforming methane to hydrogen simultaneous to the power production and CO2 capture. This hydrogen can either be recycled as fuel for consumption by the cogen or MCFCs or exported to an independent combustion unit as low carbon fuel thereby decarbonizing that unit as well. The efficiency of MCFCs for CO2 capture is higher than use of amines in all cases studied often by a substantial margin while at the same time the MCFCs avoid more CO2 than the amine technology. As one example the use of amines on a cogeneration unit can avoid 87.6% of CO2 but requires 4.91 MJ/kg of additional primary energy to do so. In contrast the MCFCs avoid 89.4% of CO2 but require only 1.37 MJ/kg of additional primary energy. The high thermal efficiency and hydrogen export option demonstrate the potential of this technology for widespread deployment in a low carbon energy economy.

An eco-friendly green synthesis of mesoporous iron oxide (hematite) using pomegranate peels through a low-cost and massive product method was investigated. The mass of pomegranate peels was varied to control the morphology of the produced hematite (Fe2O3). The structures textures and optical properties of the products were investigated by FTIR XRD FE-SEM and UV–Vis spectroscopy. Three different Fe2O3 morphologies were obtained; Fe2O3(I) nanorod like shape Fe2O3(II) nanoparticles and Fe2O3(III) nanoporous structured layer. The bandgap values for Fe2O3 (I) (II) and (III) were 2.71 2.95 and 2.29 eV respectively. The newly hematite samples were used as promising photoelectrodes supported on graphite substrate for the photoelectrochemical (PEC) water splitting toward the efficient production of solar hydrogen. The number of generated hydrogen moles was calculated per active area to be 50 molh−1 cm−2 for electrode III which decreased to 15.3molh−1 cm−2 for electrode II. The effects of temperature (30–70 ◦C) on the PEC behavior of the three electrodes were addressed. Different thermodynamic parameters were calculated for the three electrodes which showed activation energies of 13.4 16.8 and 15.2 kJmol−1 respectively. The electrode stability was addressed as a function of the number of runs and exposure time in addition to electrochemical impedance study. Finally the conversion efficiency of the incident photon to-current(IPCE) was estimated under the monochromatic illumination. The optimum value was ∼11% @ 390nm for Fe2O3(III) electrode

This paper discusses the techno-economic assessment of hydrogen production from biogas with conventional systems. The work is part of the European project BIONICO whose purpose is to develop and test a membrane reactor (MR) for hydrogen production from biogas. Within the BIONICO project steam reforming (SR) and autothermal reforming (ATR) have been identified as well-known technologies for hydrogen production from biogas. Two biogases were examined: one produced by landfill and the other one by anaerobic digester. The purification unit required in the conventional plants has been studied and modeled in detail using Aspen Adsorption. A pressure swing adsorption system (PSA) with two and four beds and a vacuum PSA (VPSA) made of four beds are compared. VPSA operates at sub-atmospheric pressure thus increasing the recovery: results of the simulations show that the performances strongly depend on the design choices and on the gas feeding the purification unit. The best purity and recovery values were obtained with the VPSA system which achieves a recovery between 50% and 60% at a vacuum pressure of 0.1 bar and a hydrogen purity of 99.999%. The SR and ATR plants were designed in Aspen Plus integrating the studied VPSA model and analyzing the behavior of the systems at the variation of the pressure and the type of input biogas. The SR system achieves a maximum efficiency calculated on the LHV of 52% at 12 bar while the ATR of 28% at 18 bar. The economic analysis determined a hydrogen production cost of around 5 €/kg of hydrogen for the SR case.

Thermochemical hydrogen production process is one of the candidates of industrial fossil fuel free hydrogen production. Japan Atomic Energy Agency (JAEA) has been conducting R&D of the thermochemical water splitting iodine-sulfur (IS) process since the end of 1980s. This paper presents the recent study on the IS process in JAEA. In 2005-2009 test-fabrication of components collection of design database improvement of process components for higher thermal efficiency and proposition of composition measurement method were carried out. On the basis of them the integrity test of process components is carried out in 2010-2014 to examine their integrities in severe process environments. At present a Bunsen reactor which produces acids and incidental equipments has been already manufactured using corrosion resistant materials such as glass lining steel and fluoroplastic lining steel. Flow tests to examine the functionality and integrity of the materials are planned in 2012.

Hydrogen (H2 ) is the most abundant element in the universe and it is also a neutral energy carrier meaning the environmental effects of using it are strictly related to the effects of creating the means of producing of that amount of Hydrogen. So far the H2 generation by water electrolysis research field did not manage to break the efficiency barrier in order to consider H2 production as a technology that sustains financially its self-development. However given the complexity of this technology and the overall environmental impacts an up-to-date research and development status review is critical. Thus this study aims to identify the main trends achievements and research directions of the H2 generation using pure and alkaline water electrolysis providing a review of the state of the art in the specific literature. Methods: In order to deliver this a Systematic Literature Review was carried out using PRISMA methodology highlighting the research trends and results in peer review publish articles over more than two years (2020–2022). Findings: This review identifies niches and actual status of the H2 generation by water and alkaline water electrolysis and points out in numbers the boundaries of the 2020–2022 timeline research.

Electricity-driven water splitting to convert water into hydrogen (H2) has been widely regarded as an efficient approach for H2 production. Nevertheless the energy conversion efficiency of it is greatly limited due to the disadvantage of the sluggish kinetic of oxidation evolution reaction (OER). To effectively address the issue a novel concept of hybrid water electrolysis has been developed for energy– saving H2 production. This strategy aims to replace the sluggish kinetics of OER by utilizing thermodynamically favorable organics oxidation reaction to replace OER. Herein recent advances in such water splitting system for boosting H2 evolution under low cell voltage are systematically summarized. Some notable progress of different organics oxidation reactions coupled with hydrogen evolution reaction (HER) are discussed in detail. To facilitate the development of hybrid water electrolysis the major challenges and perspectives are also proposed.

Beside steam reforming methane pyrolysis is an alternative method for hydrogen production. ‘Turquoise’ hydrogen with solid carbon is formed in the pyrolysis process contrary to ‘grey’ or ‘blue’ hydrogen via steam methane reforming where waste carbon dioxide is produced. Thermal pyrolysis is conducted at higher temperatures but catalytic decomposition of methane (CDM) is a promising route for sustainable hydrogen production. CDM is generally carried out over four types of catalyst: nickel carbon noble metal and iron. The applied reactors can be fixed bed fluidized bed plasma bed or molten-metal reactors. Two main advantages of CDM are that (i) carbon-oxide free hydrogen ideal for fuel cell applications is formed and (ii) the by-product can be tailored into carbon with advanced morphology (e.g. nanofibers nanotubes). The aim of this review is to reveal the very recent research advances of the last two years achieved in the field of this promising prospective technology.

The goal of achieving water electrolysis on a gigawatt scale faces numerous challenges regarding technological feasibility and market application. Here the flexibility of operation scenarios such as load changes and capacity of electrolysis plays a key role. This raises the question of how flexible electrolysis systems currently are and what possibilities there are to increase flexibility. In order to be able to answer this question in the following a systematic literature research was carried out with the aim to show the current technical possibilities to adapt load and capacity of electrolysis technologies and to determine limits. The result of the systematic literature research is an overview matrix of the electrolysis types AEL PEMEL HTEL and AEMEL already applied in the market. Technical data on the operation of the respective electrolysis stacks as well as details and materials for the respective stack structure (cathode anode electrolyte) were summarized. The flexibility of the individual technologies is addressed by expressing it in values such as load flexibility and startup-times. The overview matrix contains values from various sour1ces in order to make electrolysis comparable at the stack level and to be able to make statements about flexibility. The result of the overview article shows the still open need for research and development to make electrolysis more flexible.

Hydrogen produced by water electrolysis and electrochemical batteries are widely considered as primary routes for the long- and short-term storage of photovoltaic (PV) energy. At the same time fast power ramps and idle periods in PV power generation may cause degradation of water splitting electrochemical (EC) cells. Implementation of batteries in PV-EC systems is a viable option for smoothening out intermittence of PV power. Notably the spreading of PV energy over the diurnal cycle reduces power of the EC cell and thus its overpotential loss. We study these potential advantages theoretically and experimentally for a simple parallel connected combination of PV EC and battery cells (PV-EC-B) operated without power management electronics. We show feasibility of the unaided operation of PV-EC-B device in a relevant duty cycle and explore how PV-EC-B system can operate at higher solar-to-hydrogen efficiency than the equivalent reference PV-EC system despite the losses caused by the battery.

The power generation mix of the Association of Southeast Asian Nations (ASEAN) is dominated by fossil fuels which accounted for almost 80% in 2017 and are expected to account for 82% in 2050 if the region does not transition to cleaner energy systems. Solar and wind power are the most abundant energy resources but contribute negligibly to the power mix. Investors in solar or wind farms face high risks from electricity curtailment if surplus electricity is not used. Employing the policy scenario analysis of the energy outlook modelling results this paper examines the potential scalability of renewable hydrogen production from curtailed electricity in scenarios of high share of variable renewable energy in the power generation mix. The study found that ASEAN has high potential in developing renewable hydrogen production from curtailed electricity. The study further found that the falling cost of renewable hydrogen production could be a game changer to upscaling the large-scale hydrogen production in ASEAN through policy support. The results implied a future role of renewable hydrogen in energy transition to decarbonize ASEAN’s emissions.

Hydrogen fuel production from methane cracking is a cleaner process compared to steam methane reforming due to zero greenhouse gas emissions. Carbon black that is co-produced is valuable and can be marketed to other industries. As this is a high-temperature process using solar energy can further improve its sustainability. In this study an integrated solar methane cracking system is proposed and the efficient utilization of the hydrogen and carbon products is explored. The carbon by-product is used in a direct carbon fuel cell and oxy- combustion. These processes eliminate the need for carbon capture technologies as they produce pure CO2 exhaust streams. The CO2 produced from the systems is used for enhanced oil recovery to produce crude oil. The produced turquoise hydrogen is liquified to make it suitable for exportation. The process is simulated on Aspen Plus® and its energy and exergy efficiencies are evaluated by carrying out a detailed thermodynamic analysis. A reservoir simulation is used to study the amount of oil that can be produced using the captured CO2. The overall system is studied for oil production over 20 years and energy and exergy of efficiencies 42.18% and 40.18% respectively were found. Enhanced oil recovery improves the recovery rate from 24.8% to 64.3%.

Currently hydrogen energy is the most promising energy vector while gasification is one of the major routes for its production. However gasification suffers from various issues including slower carbon conversion poor syngas quality lower heating value and higher emissions. Multiple factors affect gasification performance such as the selection of gasifiers feedstock’s physicochemical properties and operating conditions. In this review the status of gasification key gasifier technologies and the effect of solid-fuel (i.e. coal biomass and MSW) properties on gasification performance are reviewed critically. Based on the current review the co-gasification of coal biomass and solid waste along with a partial utilisation of CO2 as a reactant are suggested. Furthermore a technological breakthrough in carbon capture and sequestration is needed to make it industrially viable

In recent years photocatalytic technology driven by solar energy has been extensively investigated to ease energy crisis and environmental pollution. Nevertheless efficiency and stability of photocatalysts are still unsatisfactory. To address these issues design of advanced photocatalysts is important. Cadmium sulphide (CdS) nanomaterials are one of the promising photocatalysts. Among them hollow-structured CdS featured with enhanced light absorption ability large surface area abundant active sites for redox reactions and reduced diffusion distance of photogenerated carriers reveals a broad application prospect. Herein main synthetic strategies and formation mechanism of hollow CdS photocatalysts are summarized. Besides we comprehensively discuss the current development of hollow-structured CdS nanomaterials in photocatalytic applications including H₂ production CO₂ reduction and pollutant degradation. Finally brief conclusions and perspectives on the challenges and future directions for hollow CdS photocatalysts are proposed.

Growing human activity has led to a critical rise in global energy consumption; since the current main sources of energy production are still fossil fuels this is an industry linked to the generation of harmful byproducts that contribute to environmental deterioration and climate change. One pivotal element with the potential to take over fossil fuels as a global energy vector is renewable hydrogen; but for this to happen reliable solutions must be developed for its carbon-free production. The objective of this study was to perform a comprehensive review on several hydrogen production technologies mainly focusing on water splitting by green-electrolysis integrated on hydrogen’s value chain. The review further deepened into three leading electrolysis methods depending on the type of electrolyzer used—alkaline proton-exchange membrane and solid oxide—assessing their characteristics advantages and disadvantages. Based on the conclusions of this study further developments in applications like the efficient production of renewable hydrogen will require the consideration of other types of electrolysis (like microbial cells) other sets of materials such as in anion-exchange membrane water electrolysis and even the use of artificial intelligence and neural networks to help design plan and control the operation of these new types of systems.

Proton Exchange Membrane (PEM) water electrolysis (WE) produces H2 with a high degree of purity requiring only water and energy. If the energy is provided from renewable energy sources it releases “Green H2” a CO2 -free H2 . PEMWE uses expensive and rare noble metal catalysts which hinder their use at a large industrial scale. In this work the electrocatalytic properties of Transition Metal Phosphides (TMP) catalysts supported on Carbon Black (CB) for Hydrogen Evolution Reaction (HER) were investigated as an alternative to Platinum Group Metals. The physico-chemical properties and catalytic performance of the synthesized catalysts were characterized. In the ex situ experiments the 25% FeP/CB 50% FeP/CB and 50% CoP/CB with overpotentials of −156.0 −165.9 and −158.5 mV for a current density of 100 mA cm−2 showed the best catalytic properties thereby progressing to the PEMWE tests. In those tests the 50% FeP/CB required an overpotential of 252 mV for a current density of 10 mA cm−2 quite close to the 220 mV of the Pt catalyst. This work provides a proper approach to the synthesis and characterization of TMP supported on carbon materials for the HER paving the way for further research in order to replace the currently used PGM in PEMWE.

Nowadays heterogeneous photocatalysis for water treatment and hydrogen production are topics gaining interest for scientists and developers from different areas such as environmental technology and material science. Most of the efforts and resources are devoted to the development of new photocatalyst materials while the modeling and development of reaction systems allowing for upscaling the process to pilot or industrial scale are scarce. In this work we present what is known on the upscaling of heterogeneous photocatalysis to purify water and to produce green H2. The types of reactors successfully used in water treatment plants are presented as study cases. The challenges of upscaling the photocatalysis process to produce green H2 are explored from the perspectives of (a) the adaptation of photoreactors (b) the competitiveness of the process and (c) safety. Throughout the text Green Chemistry and Engineering Principles are described and discussed on how they are currently being applied to the heterogeneous photocatalysis process along with the challenges that are ahead. Lastly the role of automation and high-throughput methods in the upscaling following the Green Principles is discussed.

Hydrogen constitutes the only carbon-free fuel that can be used for energy conversion producing water as the only by-product. With water being one of the most abundant and inexhaustible raw materials in the world and the required electricity input being provided by renewable resources the produced hydrogen via water electrolysis constitutes a green pathway towards sustainability. In this work a hybrid PV power-to-hydrogen storage and fuel cell system is proposed to satisfy the domestic load of a residential building. Identifying alkaline as a mandatory electrolysis technology the performance of alkaline electrolysis cells is assessed considering the inclusion of a two-switch buck-boost converter. Following a comprehensive formulation with respect to each distinguished system component the balance condition at DC and AC buses is determined. The proposed configuration is evaluated taking into account PV systems of different ratings namely 3 kW 5 kW and 7 kW. Based on actual data relating to both PV generation and domestic load for the year 2020 the obtained results from the annual simulations are compared with feed-in tariff and net-metering schemes. According to the results PV capacity firming is achieved creating great opportunities for autonomy enhancement not only for electricity but also in other energy sectors.

Titanium dioxide (TiO₂ ) has been widely investigated for photocatalytic H₂ evolution and photoelectrochemical (PEC) water splitting since 1972. However its wide bandgap (3.0–3.2 eV) limits the optical absorption of TiO₂ for sufficient utilization of solar energy. Blackening TiO₂ has been proposed as an effective strategy to enhance its solar absorption and thus the photocatalytic and PEC activities and aroused widespread research interest. In this article we reviewed the recent progress of black TiO₂ for photocatalytic H₂ evolution and PEC water splitting along with detailed introduction to its unique structural features optical property charge carrier transfer property and related theoretical calculations. As summarized in this review article black TiO₂ could be a promising candidate for photoelectrocatalytic hydrogen generation via water splitting and continuous efforts are deserved for improving its solar hydrogen efficiency.

Storing renewable energy in chemicals like hydrogen can bring various benefits like high energy density seasonal storability possible cost reduction of the final product and the potential to let renewable power penetrate other markets and to overcome their intermittent availability. In the last year’s production of this gas from renewable energy sources via electrolysis has grown its reputation as one feasible solution to satisfy future zero-emission energy demand. To extend the exploitation of Renewable Energy Source (RES) small-scale conversion plants seem to be an interesting option. In view of a possible widespread adoption of these types of plants the authors intend to present the experimental characterization of a small-scale hydrogen production and storage plant. The considered experimental plant is based on an alkaline electrolyser and an air-driven hydrogen compression and storage system. The results show that the hydrogen production-specific consumption is on average 77 kWh/kgH2 . The hydrogen compressor energy requirement is on average 15 kWh/kgH2 (data referred to the driving compressed air). The value is higher than data found in literature (4.4–9.3 kWh/kgH2 ) but the difference can be attributed to the small size of the considered compressor and the choice to limit the compression stages.

In this work the design of the hardware architecture to implement an algorithm for optimizing the Hydrogen Productivity Rate (HPR) in a Microbial Electrolysis Cell (MEC) is presented. The HPR in the MEC is maximized by the golden section search algorithm in conjunction with a super-twisting controller. The development of the digital architecture in the implementation step of the optimization algorithm was developed in the Very High Description Language (VHDL) and synthesized in a Field Programmable Gate Array (FPGA). Numerical simulations demonstrated the feasibility of the proposed optimization strategy embedded in an FPGA Cyclone II. Results showed that only.

Microwave heating offers a number of advantages over conventional heating methods such as rapid and volumetric heating precise temperature control energy efficiency and lower temperature gradient. In this article we demonstrate the use of 2450 MHz microwave traveling wave reactor to heat the catalyst bed for thermo-catalytic upgrading of pyrolysis vapors. HZSM-5 catalyst was tested at three different temperatures (290 330  and 370°C) at a catalyst to biomass ratio of 2. Results were compared with conventional heating and induction heating method of catalyst bed. The yields of aromatic compounds and coke deposition were dependent on temperature and method of heating. Microwave heating yielded higher aromatic compounds and lower coke deposition. Microwave heating was also energy efficient compared to conventional reactors. The rate of catalyst deterioration was lower for catalyst heated in microwave system.

Preventing humanity from serious impact of climate crisis requires carbon neutrality across all economic sectors including steel industry. Although fossil-free steelmaking routes receiving increasing attention fundamental process aspects especially approaches towards the improvement of efficiency and flexibility are so far not comprehensively studied. In this paper optimized process concepts allowing for a gradual transition towards fossil-free steelmaking based on the coupling of direct reduction process electric arc furnace and electrolysis are presented. Both a high-temperature and low-temperature electrolysis were modeled and possibilities for the integration into existing infrastructure are discussed. Various schemes for heat integration especially when using high-temperature electrolysis are highlighted and quantified. It is demonstrated that the considered direct reduction-based process concepts allow for a high degree of flexibility in terms of feed gas composition when partially using natural gas as a bridge technology. This allows for an implementation in the near future as well as the possibility of supplying power grid services in a renewable energy system. Furthermore it is shown that an emission reduction potential of up to 97.8% can be achieved with a hydrogen-based process route and 99% with a syngas-based process route respectively provided that renewable electricity is used.

Biochar (BCH) is a carbon‐based bio‐material produced from thermochemical conversion of biomass. Several activation or functionalization methods are usually used to improve physicochemical and functional properties of BCHs. In the context of green and sustainable future development activated and functionalized biochars with abundant surface functional groups and large surface area can act as effective catalysts or catalyst supports for chemical transformation of a range of bioproducts in biorefineries. Above the well‐known BCH applications their use as adsorbents to remove pollutants are the mostly discussed although their potential as catalysts or catalyst supports for advanced (electro)catalytic processes has not been comprehensively explored. In this review the production/activation/functionalization of metal‐supported biochar (M‐BCH) are scrutinized giving special emphasis to the metal‐functionalized biochar‐based (electro)catalysts as promising catalysts for bioenergy and bioproducts production. Their performance in the fields of biorefinery processes and energy storage and conversion as electrode materials for oxygen and hydrogen evolutions oxygen reduction and supercapacitors are also reviewed and discussed.

In this paper a multifunctional energy system (MES) is proposed for recovering energy from the extra of coke oven gas (COG) which is usually flared or vented out as a waste stream in coke making plants. The proposed system consists of a pressure swing adsorption (PSA) unit for extracting some of the hydrogen from COG a gas turbine for producing heat and power from PSA offgas and a heat recovery steam generator (HRSG) for generating the steam required by the plant's processes. o assess the performance of the system practically simulations are carried out on the basis of the design and operational conditions of Zarand Coke Making Plant in Iran. The results indicate that by utilizing about 4.39 tons of COG per hour 6.5 MW of net electric power can be approximately produced by the gas turbine which can supply the coke making plant's total electrical power demand. Furthermore through recovering heat from gas turbine's exhaust close to 57% of the plant's steam demand can be supplied by the HRSG unit. It is also found that around 350 kilograms per hour of nearly pure hydrogen (99.9% purity) at 200 bar can be produced by the PSA unit. According to the sensitivity analysis results if the hydrogen content of the coke oven gas decreases by about 10% the gross power output of the gas turbine also declines by around 5.2% due to the reduction of LHV of the PSA offgas. Moreover economic evaluation of the system shows that the payback period of the investment which is estimated at 36.1 M$ is about 5.5 years. The net present value (NPV) and internal rate of return on investment (ROI) are calculated to be 17.6% and 43.3 M$ respectively.

In response to problems involved in the current crisis of petrol in Algeria with the decrease in the price of the oil barrel the rate of growth in domestic electricity demand and with an associated acceleration of global warming as a result of significantly increased greenhouse gas (GHG) emissions renewable energy seems today as a clean and strategic substitution for the next decades. However the greatest obstacles which face electric energy comes from renewable energy systems are often referred to the intermittency of these sources as well as storage and transport problems the need for their conversion into a versatile energy carrier in its use storable transportable and environmentally acceptable are required. Among all the candidates answering these criteria hydrogen presents the best answer. In the present work particular attention is paid to the production of hydrogen from wind energy. The new wind map of Algeria shows that the highest potential wind power was found in Adrar Hassi-R'Mel and Tindouf regions. The data obtained from these locations have been analyzed using Weibull probability distribution function. The wind energy produced in these locations is exploited for hydrogen production through water electrolysis. The objective of this paper is to realize a technological platform allowing the evaluation of emergent technologies of hydrogen production from wind energy using four wind energy conversion systems of 600 1250 1500 and 2000 kW rated capacity. The feasibility study shows that using wind energy in the selected sites is a promising solution. It is shown that the turbine " De Wind D7" is sufficient to supply the electricity and hydrogen with a least cost and a height capacity factor. The minimum cost of hydrogen production of 1.214 $/kgH2 is obtained in Adrar.

On this episode of EAH the team is joined by Tim Yeo Chairman of Powerhouse Energy to talk about the work they are doing in the waste-to-energy space and how they see the sector evolving in the coming years.

The podcast can be found on their website

Water splitting has been regarded as a sustainable and environmentally-friendly technique to realize green hydrogen generation while more energy is consumed due to the high overpotentials required for the anode oxygen evolution reaction. Urea electrooxidation an ideal substitute is thus received increasing attention in assisting water-splitting reactions. Note that highly efficient catalysts are still required to drive urea oxidation and the facile generation of high valence state species is significant in the reaction based on the electrochemical-chemical mechanisms. The high cost and rareness make the noble metal catalysts impossible for further consideration in large-scale application. Ni-based catalysts are very promising due to their cheap price facile structure tuning good compatibility and easy active phase formation. In the light of the significant advances made recently herein we reviewed the recent advances of Ni-based powder catalysts for urea oxidation in assisting water-splitting reaction. The fundamental of urea oxidation is firstly presented to clarify the mechanism of urea-assisted water splitting and then the prevailing evaluation indicators are briefly expressed based on the electrochemical measurements. The catalyst design principle including synergistic effect electronic effect defect construction and surface reconstruction as well as the main fabrication approaches are presented and the advances of various Ni-based powder catalysts for urea assisted water splitting are summarized and discussed. The problems and challenges are also concluded for the Ni-based powder catalysts fabrication the performance evaluation and their application. Considering the key influence factors for catalytic process and their application attention should be given to structure-property relationship deciphering novel Ni-based powder catalysts development and their construction in the real device; specifically the effort should be directed to the Ni-based powder catalyst with multi-functions to simultaneously promote the fundamental steps and high anti-corrosion ability by revealing the local structure reconstruction as well as the integration in the practical application. We believe the current summarization will be instructive and helpful for the Ni-based powder catalysts development and understanding their catalytic action for urea-assisted hydrogen generation via water splitting technique.

This study proposes a novel hybrid solar-gas power and hydrogen-production system which is comprised by the solar tower thermal system gas-steam turbine combined cycle and organic Rankine cycle-based hydrogen-production system. Based on the Ebsilon code the operation processes of the hybrid system are simulated. The results show that the output power and electric efficiency of the hybrid system are 103.9 MW and 41.3% and the daily hydrogen output is 62.2 kg. The operation simulation results of the hybrid system reveal that the gas-steam combined cycle and solar island can both achieve stable operations and the power generation section and hydrogen-production device can both work effectively which means the hybrid system is technically feasible. The exergy estimate results of the hybrid system show that the combustion chamber and solar receiver have the two largest exergy destructions which are 56.5 MW and 45.3 MW. That means the performances of the two components can be further improved. For the hydrogen-production system the exergy destructions of the proton exchange membrane electrolyzer turbine condenser and evaporator of the organic Rankine cycle are 0.156 MW 0.111 MW 2.338 MW and 1.891 MW and the corresponding exergy efficiencies are 51.2% 92.6% 80.7% and 79.5% respectively.

Decarbonising ammonia production is an environmental imperative given that it independently accounts for 1.8% of global carbon dioxide emissions and supports the feeding of over 48% of the global population. The recent decline of production costs and its potential as an energy vector warrant investigation of whether green ammonia production is commercially competitive. Considering 534 locations in 70 countries and designing and operating the islanded production process to minimise the levelised cost of ammonia (LCOA) at each we show the range of achievable LCOA the cost of process flexibility the components of LCOA and therein the scope of LCOA reduction achievable at present and in 2030. These results are benchmarked against ammonia spot prices cost per GJ of refined fuels and the LCOE of alternative energy storage methods. Currently a LCOA of $473 t1 is achievable at the best locations the required process flexibility increases the achievable LCOA by 56%; the electrolyser CAPEX and operation are the most significant costs. By 2030 $310 t1 is predicted to be achievable with multiple locations below $350 t1 . At $25.4 GJ11 ) that do not have the benefit of being carbon-free.

The rising technology of green hydrogen supply systems is expected to be on the horizon. Hydrogen is a clean and renewable energy source with the highest energy content by weight among the fuels and contains about six times more energy than ammonia. Meanwhile ammonia is the most popular substance as a green hydrogen carrier because it does not carry carbon and the total hydrogen content of ammonia is higher than other fuels and is thus suitable to convert to hydrogen. There are several pathways for hydrogen production. The considered aspects herein include hydrogen production technologies pathways based on the raw material and energy sources and different scales. Hydrogen can be produced from ammonia through several technologies such as electro-chemical photocatalytic and thermochemical processes that can be used at production plants and fueling stations taking into consideration the conversion efficiency reactors catalysts and their related economics. The commercial process is conducted by using expensive Ru catalysts in the ammonia converting process but is considered to be replaced by other materials such as Ni Co La and other perovskite catalysts which have high commercial potential with equivalent activity for extracting hydrogen from ammonia. For successful engraftment of ammonia to hydrogen technology into industry integration with green technologies and economic methods as well as safety aspects should be carried out.

Hydrogen fuel production from methane cracking is a sustainable process compared to the ones currently in practice due to minimal greenhouse gas emissions. Carbon black that is co-produced is a valuable product and can be marketed to other industries. As this is a high-temperature process using concentrated solar energy can further improve its sustainability. In this study a detailed review is conducted to study the advancements in methane cracking for hydrogen production using different catalysts. Various solar reactors developed for methane cracking are discussed. The application of hydrogen to produce other valuable chemicals are outlined. Hydrogen carriers such as methanol dimethyl ether ammonia and urea can efficiently store hydrogen energy and enable easier transportation. Further research in the field of methane cracking is required for reactor scale-up improved economics and to reduce the problems arising from carbon deposition leading to reactor clogging and catalyst deactivation.

Recently the management of water and wastewater is gaining attention worldwide as a way of conserving the natural resources on the planet. The traditional wastewater treatment in Oman is such that the treated effluent produced is only reused for unfeasible purposes such as landscape irrigation cooling or disposed of in the sea. Introducing more progressive reuse applications can result in achieving a circular economy by considering treated effluent as a source of producing new products. Accordingly wastewater treatment plants can provide feedstock for green hydrogen production processes. The involvement of the wastewater industry in the green pathway of production scores major points in achieving decarbonization. In this paper the technical and economic feasibility of green hydrogen production in Oman was carried out using a new technique that would help explore the benefits of the treated effluent from wastewater treatment in Oman. The feasibility study was conducted using the Al Ansab sewage treatment plant in the governate of Muscat in Wilayat (region) Bousher. The results have shown that the revenue from Al Ansab STP in a conventional case is 7.02 million OMR/year while sustainable alternatives to produce hydrogen from the Proton Exchange Membrane (PEM) electrolyzer system for two cases with capacities of 1500 kg H2/day and 50000 kg H2/day would produce revenue of 8.30 million OMR/year and 49.73 million OMR/year respectively.

The energy transition calls for natural hydrogen exploration with most occurrences discovered either inadvertently or more recently at the location of potentially diffusive circles observed from a change of vegetation cover at the surface. However some notable hydrogen occurrences are not directly associated with the presence of diffusive circles like the Bourakebougou field in Mali. Thus the objective of this work was to highlight geological areas that have some potential to find natural hydrogen in Quebec a Canadian province where no diffusive circles have yet been documented but which is rich in potential source rocks and where no exploration for natural hydrogen has been undertaken so far. A review of the different geological regions of Quebec was undertaken to highlight the relevant characteristics and geographical distribution of geological assemblages that may produce or have produced natural hydrogen in particular iron-rich rocks but also uranium-rich rocks supramature shales and zones where significant structural discontinuities are documented or suspected which may act as conduits for the migration of fluids of mantle origin. In addition to regional and local geological data an inventory of available geochemical data is also carried out to identify potential tracers or proxies to facilitate subsequent exploration efforts. A rating was then proposed based on the quality of the potential source rocks which also considers the presence of reservoir rocks and the proximity to end-users. This analysis allowed rating areas of interest for which fieldwork can be considered thus minimizing the exploratory risks and investments required to develop this resource. The size of the study area (over 1.5 million km2 ) the diversity of its geological environments (from metamorphic cratons to sedimentary basins) and their wide age range (from Archean to Paleozoic) make Quebec a promising territory for natural hydrogen exploration and to test the systematic rating method proposed here.

Hydrogen is a colorless compound to which symbolic colors are attributed to classify it according to the resources used in production production processes such as electrolysis and energy vectors such as solar radiation. Green hydrogen is produced mainly by electrolysis of water using renewable electricity from an electricity grid powered by wind geothermal solar or hydroelectric power plants. For grid-powered electrolyzers the tendency is to go larger to reach the gigawatt-scale. An evolution in the opposite direction is the integration of the photophysics of sunlight harvesting and the electrochemistry of water molecule splitting in solar hydrogen generator units with each unit working at kilowatt-scale or less. Solar hydrogen generators are intrinsically modular needing multiplication of units to reach gigawatt-scale. To differentiate these two fundamentally different technologies the term ‘golden hydrogen’ is proposed referring to hydrogen produced by modular solar hydrogen generators. Decentralized modular production of golden hydrogen is complementary to centralized energy-intensive green hydrogen production. The differentiation between green hydrogen and golden hydrogen will facilitate the introduction of the additionality principle in clean hydrogen policy.

Fuel cells are electrochemical devices that are conventionally used to convert the chemical energy of fuels into electricity while producing heat as a byproduct. High temperature fuel cells such as molten carbonate fuel cells and solid oxide fuel cells produce significant amounts of heat that can be used for internal reforming of fuels such as natural gas to produce gas mixtures which are rich in hydrogen while also producing electricity. This opens up the possibility of using high temperature fuel cells in systems designed for flexible coproduction of hydrogen and power at very high system efficiency. In a previous study the flowsheet software Cycle-Tempo has been used to determine the technical feasibility of a solid oxide fuel cell system for flexible coproduction of hydrogen and power by running the system at different fuel utilization factors (between 60 and 95%). Lower utilization factors correspond to higher hydrogen production while at a higher fuel utilization standard fuel cell operation is achieved. This study uses the same basis to investigate how a system with molten carbonate fuel cells performs in identical conditions also using Cycle-Tempo. A comparison is made with the results from the solid oxide fuel cell study.

Steam natural gas reforming is the preferred technique presently used to produce hydrogen. Proposed in 1932 the technique is very well established but still subjected to perfections. Herein first the improvements being sought in catalysts and processes are reviewed and then the advantage of replacing the energy supply from burning fuels with concentrated solar energy is discussed. It is especially this advance that may drastically reduce the economic and environmental cost of hydrogen production. Steam reforming can be easily integrated into concentrated solar with thermal storage for continuous hydrogen production.

The use of green hydrogen as a fuel source for marine applications has the potential to significantly reduce the carbon footprint of the industry. The development of a sustainable and cost-effective method for producing green hydrogen has gained a lot of attention. Water electrolysis is the best and most environmentally friendly method for producing green hydrogen-based renewable energy. Therefore identifying the ideal operating parameters of the water electrolysis process is critical to hydrogen production. Three controlling factors must be appropriately identified to boost hydrogen generation namely electrolysis time (min) electric voltage (V) and catalyst amount (µg). The proposed methodology contains the following two phases: modeling and optimization. Initially a robust model of the water electrolysis process in terms of controlling factors was established using an adaptive neuro-fuzzy inference system (ANFIS) based on the experimental dataset. After that a modern pelican optimization algorithm (POA) was employed to identify the ideal parameters of electrolysis duration electric voltage and catalyst amount to enhance hydrogen production. Compared to the measured datasets and response surface methodology (RSM) the integration of ANFIS and POA improved the generated hydrogen by around 1.3% and 1.7% respectively. Overall this study highlights the potential of ANFIS modeling and optimal parameter identification in optimizing the performance of solar-powered water electrocatalysis systems for green hydrogen production in marine applications. This research could pave the way for the more widespread adoption of this technology in the marine industry which would help to reduce the industry’s carbon footprint and promote sustainability.

In this episode of the podcast Debra Jones Chemistry Knowledge Transfer Manager and Ray Chegwin Nuclear Knowledge Transfer Manager from Innovate UK KTN talk about nuclear uses for hydrogen with special guest Allan Simpson Technical Lead at the National Nuclear Laboratory.

The podcast can be found on their website.

Replacing fossil fuels with energy sources and carriers that are sustainable environmentally benign and affordable is amongst the most pressing challenges for future socio-economic development. To that goal hydrogen is presumed to be the most promising energy carrier. Electrocatalytic water splitting if driven by green electricity would provide hydrogen with minimal CO2 footprint. The viability of water electrolysis still hinges on the availability of durable earth-abundant electrocatalyst materials and the overall process efficiency. This review spans from the fundamentals of electrocatalytically initiated water splitting to the very latest scientific findings from university and institutional research also covering specifications and special features of the current industrial processes and those processes currently being tested in large-scale applications. Recently developed strategies are described for the optimisation and discovery of active and durable materials for electrodes that ever-increasingly harness first principles calculations and machine learning. In addition a technoeconomic analysis of water electrolysis is included that allows an assessment of the extent to which a large-scale implementation of water splitting can help to combat climate change. This review article is intended to cross-pollinate and strengthen efforts from fundamental understanding to technical implementation and to improve the ‘junctions’ between the field’s physical chemists materials scientists and engineers as well as stimulate much-needed exchange among these groups on challenges encountered in the different domains.

The development of hydropower industry is progressing rapidly in China and the installed capacity and power generation are increasing year by year. However due to factors such as transmission channels and power grid peaking capacity hydropower consumption in some areas is facing greater pressure. As an excellent medium for energy interconnection hydrogen energy can play an important role in promoting hydropower consumption. This paper introduces the current status and trends of hydrogen energy development in major developed countries and China and analyzes the current status of China’s hydropower abandoned water. Based on the production of hydrogen using surplus hydropower in the Dadu River Basin in Sichuan an integrated energy network research plan including hydropower electrolytic hydrogen production storage and transportation hydrogen refueling and hydrogen-powered vehicles is proposed. At the same time the development concept of hydrogen energy industry including hydrogen energy source economy hydrogen energy industry ecosphere and hydrogen energy sky road in western Sichuan is also proposed.

Hydrogen is a crucial raw materials to other industries. Globally nearly 90% of the hydrogen or HyCO gas produced is consumed by the ammonia methanol and oil refining industries. In the future hydrogen could play an important role in the decarbonisation of transport fuel (i.e. use of fuel cell vehicles) and space heating (i.e. industrial commercial building and residential heating). This paper summarizes the results of the feasibility study carried out by Amec Foster Wheeler for the IEA Greenhouse Gas R&D Programme (IEA GHG) with the purpose of evaluating the performance and costs of a modern steam methane reforming without and with CCS producing 100000 Nm3 /h H2 and operating as a merchant plant. This study focuses on the economic evaluation of five different alternatives to capture CO2 from SMR. This paper provides an up-to-date assessment of the performance and cost of producing hydrogen without and with CCS based on technologies that could be erected today. This study demonstrates that CO2 could be captured from an SMR plant with an overall capture rate ranging between 53 to 90%. The integration of CO2 capture plant could increase the NG consumption by -0.03 to 1.41 GJ per Nm3 /h of H2. The amount of electricity exported to the grid by the SMR plant is reduced. The levelised cost of H2 production could increase by 2.1 to 5.1 € cent per Nm3 H2 (depending on capture rate and technology selected). This translates to a CO2 avoidance cost of 47 to 70 €/t.

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.

Ammonia (NH3 ) is regarded as a promising medium of hydrogen storage due to its large hydrogen storage density decent performance on safety and moderate storage conditions. On the user side NH3 is generally required to decompose into hydrogen for utilization in fuel cells and therefore it is vital for the NH3 -based hydrogen storage technology development to study NH3 decomposition processes and improve the decomposition efficiency. Numerical simulation has become a powerful tool for analyzing the NH3 decomposition processes since it can provide a revealing insight into the heat and mass transfer phenomena and substantial guidance on further improving the decomposition efficiency. This paper reviews the numerical simulations of NH3 decomposition in various application scenarios including NH3 decomposition in microreactors coupled combustion chemical reactors solid oxide fuel cells and membrane reactors. The models of NH3 decomposition reactions in various scenarios and the heat and mass transport in the reactor are elaborated. The effects of reactor structure and operating conditions on the performance of NH3 decomposition reactor are analyzed. It can be found that NH3 decomposition in microchannel reactors is not limited by heat and mass transfer and NH3 conversion can be improved by using membrane reactors under the same conditions. Finally research prospects and opportunities are proposed in terms of model development and reactor performance improvement for NH3 decomposition.

The installed capacity electricity generation from wind and the curtailment of wind power in the UK between 2011 and 2021 showed that penetration levels of wind energy and the amount of energy that is curtailed in future would continue to rise whereas the curtailed energy could be utilised to produce green hydrogen. In this study data were collected technologies were chosen systems were designed and simulation models were developed to determine technical requirements and levelised costs of hydrogen produced and transported through different pathways. The analysis of capital and operating costs of the main components used for onshore and offshore green hydrogen production using offshore wind including alternative strategies for hydrogen storage and transport and hydrogen carriers showed that a significant reduction in cost could be achieved by 2030 enabling the production of green hydrogen from offshore wind at a competitive cost compared to grey and blue hydrogen. Among all scenarios investigated in this study compressed hydrogen produced offshore is the most cost-effective scenario for projects starting in 2025 although the economic feasibility of this scenario is strongly affected by the storage period and the distance to the shore of the offshore wind farm. Alternative scenarios for hydrogen storage and transport such as liquefied hydrogen and methylcyclohexane could become more cost-effective for projects starting in 2050 when the levelised cost of hydrogen could reach values of about £2 per kilogram of hydrogen or lower.

Integrating the exergy and economic analyses of water electrolyzers is the pivotal way to comprehend the interplay of system costs and improve system performance. For this a 3D numerical model based on COMSOL Multiphysics Software (version 5.6 COMSOL Stockholm Sweden) is integrated with the exergy and exergoeconomic analysis to evaluate the exergoeconomic performance of the proton exchange membrane water electrolysis (PEMWE) under different operating conditions (operating temperature cathode pressure current density) and design parameter (membrane thickness). Further the gas crossover phenomenon is investigated to estimate the impact of gas leakage on analysis reliability under various conditions and criteria. The results reveal that increasing the operating temperature or decreasing the membrane thickness improves both the efficiency and cost of hydrogen exergy while increasing the gas leakage through the membrane. Likewise raising the current density and the cathode pressure lowers the hydrogen exergy cost and improves the economic performance. The increase in exergy destroyed and hydrogen exergy cost as well as the decline in second law efficiency due to the gas crossover are more noticeable at higher pressures. As the cathode pressure rises from 1 to 30 bar at a current density of 10000 A/m2 the increase in exergy destroyed and hydrogen exergy cost as well as the decline in second law efficiency are increased by 37.6 kJ/mol 4.49 USD/GJ and 7.1% respectively. The cheapest green electricity source which is achieved using onshore wind energy and hydropower reduces hydrogen production costs and enhances economic efficiency. The growth in the hydrogen exergy cost is by about 4.23 USD/GJ for a 0.01 USD/kWh increase in electricity price at the current density of 20000 A/m2. All findings would be expected to be quite useful for researchers engaged in the design development and optimization of PEMWE.

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.

Green hydrogen produced by water splitting using renewable energy is the most promising energy carrier of the low-carbon economy. However the geographic mismatch between renewables distribution and freshwater availability poses a significant challenge to its production. Here we demonstrate a method of direct hydrogen production from the air namely in situ capture of freshwater from the atmosphere using hygroscopic electrolyte and electrolysis powered by solar or wind with a current density up to 574 mA cm−2 . A prototype of such has been established and operated for 12 consecutive days with a stable performance at a Faradaic efficiency around 95%. This so-called direct air electrolysis (DAE) module can work under a bone-dry environment with a relative humidity of 4% overcoming water supply issues and producing green hydrogen sustainably with minimal impact to the environment. The DAE modules can be easily scaled to provide hydrogen to remote (semi-) arid and scattered areas.

Hydrogen is one of the prospective clean energies that could potentially address two pressing areas of global concern namely energy crises and environmental issues. Nowadays fossil‐ based technologies are widely used to produce hydrogen and release higher greenhouse gas emis‐ sions during the process. Decarbonizing the planet has been one of the major goals in the recent decades. To achieve this goal it is necessary to find clean sustainable and reliable hydrogen pro‐ duction technologies with low costs and zero emissions. Therefore this study aims to analyse the hydrogen generation from solar and wind energy sources and observe broad prospects with hybrid renewable energy sources in producing green hydrogen. The study mainly focuses on the critical assessment of solar wind and hybrid‐powered electrolysis technologies in producing hydrogen. Furthermore the key challenges and opportunities associated with commercial‐scale deployment are addressed. Finally the potential applications and their scopes are discussed to analyse the important barriers to the overall commercial development of solar‐wind‐based hydrogen production systems. The study found that the production of hydrogen appears to be the best candidate to be employed for multiple purposes blending the roles of fuel energy carrier and energy storage modality. Further studies are recommended to find technical and sustainable solutions to overcome the current issues that are identified in this study.