Production & Supply Chain

Hydrogen produced via water electrolysis from renewable electricity is considered a key energy carrier to defossilize hard-to-electrify sectors. Solid oxide cells (SOC) based reactors can supply hydrogen not only in electrolysis but also in fuel cell mode when operating with (synthetic) natural gas or biogas at low conversion (polygeneration mode). However the scale-up of SOC reactors to the multi-MW scale is still a research topic. Strategies for transient operation depending on electricity intermittency still need to be developed. In this work a unique testing environment for SOC reactors allows reversible operation demonstrating the successful switching between electrolysis (− 75 kW) and polygeneration (25 kW) modes. Transient and steady state experiments show promising performance with a net hydrogen production of 53 kg day− 1 in SOEL operation with ca. − 75 kW power input. The experimental results validate the scaling approach since the reactor shows homogenous temperature profiles.

Hydrogen is increasingly recognized as a pivotal energy storage solution and a transformative alternative to conventional energy sources. This review summarizes the evolving landscape of global H2 production and consumption markets focusing on the crucial role of photothermal catalysts (PTCs) in driving Hydrogen evolution reactions (HER) particularly with regards to oxide selenide and telluride-based PTCs. Within this exploration the mechanisms of PTCs take center stage elucidating the intricacies of light absorption localized heating and catalytic activation. Essential optimization parameters ranging from temperature and irradiance to catalyst composition and pH are detailed for their paramount role in enhancing catalytic efficiency. This work comprehensively explores photothermal catalysts (PTCs) for hydrogen production by assessing their synthesis techniques and highlighting the current research gaps particularly in optimizing catalytic stability light absorption and scalability. The energy-efficient nature of oxide selenide and telluride-based PTCs makes them prime candidates for sustainable H2 production when compared to traditional materials. By analyzing a range of materials we summarize key performance metrics including hydrogen evolution rates ranging from 0.47 mmolh− 1 g− 1 for Ti@TiO2 to 22.50 mmolh− 1 g− 1 for Mn0.2Cd0.8S/NiSe2. The review concludes with a strategic roadmap aimed at enhancing PTC performance to meet the growing demand for renewable hydrogen as well as a critical literature review addressing challenges and prospects in deploying PTCs.

Disputed supply chains inappropriate weather and low investment followed by the Russian invasion of Ukraine has led to a phenomenal energy crisis especially in the Horn of Africa. Accordingly proposing eco-friendly and sustainable solutions to diversify the access of electricity in the Republic of Djibouti which has no conventional energy resources and is completely energy dependent on its neighboring countries has become a must. Therefore the implementation of sustainable renewable and energy storage systems is nationally prioritized. This paper deals for the first time with the exploitation of such an affordable and carbon-free resource to produce hydrogen from wind energy in the rural areas of Nagad and Bara Wein in Djibouti. The production of hydrogen and the relevant CO2 emission reduction using different De Wind D6 Vestas and Nordex wind turbines are displayed while using Alkaline and Proton Exchange Membrane (PEM) electrolyzers. The Bara Wein and Nagad sites had a monthly wind speed above 7 m/s. From the results the Nordex turbine accompanied with the alkaline electrolyzer provides the most affordable electricity production approximately 0.0032 $/kWh for both sites; this cost is about one per hundred the actual imported hydroelectric energy price. Through the ecological analysis the Nordex turbine is the most suitable wind turbine with a CO2 emission reduction of 363.58 tons for Bara Wein compared to 228.76 tons for Nagad. While integrating the initial cost of wind turbine implementation in the capital investment the mass and the levelized cost of the produced green hydrogen are estimated as (29.68 tons and 11.48 $/kg) for Bara Wein with corresponding values of (18.68 tons and 18.25 $/kg) for Nagad.

This review provides a comprehensive techno-economic assessment of four leading electrolyzer technologies such as the Alkaline Water Electrolyzers (AWE) Proton Exchange Membrane (PEM) electrolyzers Solid Oxide Electrolyzer Cells (SOEC) and Anion Exchange Membrane (AEM) systems for green hydrogen production. Drawing on more than 40 peer-reviewed studies and real-world deployment scenarios the analysis compares performance indicators such as levelised cost of hydrogen (LCOH) capital expenditure (CAPEX) operating expenditure (OPEX) efficiency stack durability and water treatment requirements. AWE is identified as the most cost-effective option for baseload power contexts while PEM offers superior dynamic response and gas purity at a higher cost. SOECs despite their high theoretical efficiency remain limited by thermal cycling and material degradation. AEMs though less mature hold promise for low-cost decentralized hydrogen production. Cost of electricity is more than 64 % of LCOH in all technologies so it is important to match electrolyzers with stable or hybrid renewable energy resources such as geothermal wind-solar or Concentrated Solar Power (CSP). Optimisation methods such as genetic algorithms and GIS-based siting also enhance system performance and economic value. The report also considers regional and policy dimensions of deployment underlining the need for site-specific solutions in the context of local energy portfolios water supply and infrastructure readiness. Recommendations are provided for advancing membrane longevity integrating smart control systems and optimizing techno-economic assessment models. This study is a policy decision-making tool for policymakers investors and researchers who are interested in accelerating the global scale-up of green hydrogen using contextrelevant and economically viable electrolyzer technologies.

Optimized operation of wind/hydrogen systems can increase the system efficiency and further reduce the hydrogen production cost. In this regard extensive research has been done but there is a lack of detailed electrolyzer models and effective management of multiple electrolyzers considering their physical restrictions. This work proposes electrolyzer models that integrate the efficiency variation caused by load level change start–stop cycle (including hot and cold start) thermal management and degradation caused by frequent starts. Based on the proposed models three operational strategies are considered in this paper: two traditionally utilized methods simple start–stop and cycle rotation strategies and a newly proposed rolling optimizationbased strategy. The results from daily operation show that the new strategy results in a more balanced load level among the electrolyzers and a more stable temperature. Besides from a yearly operation perspective it is found that the proposed rolling optimization method results in more hydrogen production higher system efficiency and lower LCOH. The new method leads to hydrogen production of 311297 kg compared to 289278 kg and 303758 kg for simple start–stop and cycle rotation methods. Correspondingly the system efficiencies for the new simple start–stop and cycle rotation methods are 0.613 0.572 and 0.587. The resulting LCOH from the new method is 3.89 e/kg decreasing by 0.35 e/kg and 0.21 e/kg compared to the simple start–stop and cycle rotation methods. Finally the proposed model is compared with two conventional models to show its effectiveness in revealing more operational details and reliable results.

The main purpose of this paper is the techno-economic analysis of hydrogen production from biogas via steam reforming in a pilot plant. Process flow modeling based on mass and energy balance is used to estimate the total equipment purchase and operating costs of hydrogen production. The pilot plant installation produced 250.67 kg/h hydrogen from 1260 kg/h biomethane obtained after purification of 4208 m3/h biogas using a heat and mass integration process. Despite the high investment cost the plant shows a great potential for biomethane reduction and conversion to hydrogen an attractive economic path with ecological possibilities. The conversion of waste into hydrogen is a possibility of increasing importance in the global energy economy. In the future such a plant will be expanded with a CO2 reduction module to increase economic efficiency and further reduce greenhouse gases in an economically viable manner.

This study introduces a method for identifying territories ideal for establishing photovoltaic (PV) plants for green hydrogen (GH2 ) production in the Antofagasta region of northern Chile a location celebrated for its outstanding solar energy potential. Assessing the viability of PV plant installation necessitates a balanced consideration of technical aspects and socio-environmental constraints such as the proximity to areas of ecological importance and indigenous communities to identify potential zones for solar and non-conventional renewable energy (NCRE)-based hydrogen production. To tackle this challenge we propose a methodology that utilizes geospatial analysis integrating Geographic Information System (GIS) tools with sensitivity analysis to determine the most suitable sites for PV plant installation in the Antofagasta region. Our geospatial analysis employs the QGIS software to identify these optimal locations while sensitivity analysis uses the Sørensen–Dice coefficient method to assess the similarity among chosen socio-environmental variables. Applying this methodology to the Antofagasta region reveals that a significant area within a 15 km radius of existing road networks and electrical substations is favorable for photovoltaic projects. Our sensitivity analysis further highlights the limiting effects of socio-environmental factors and their interactions. Moreover our research finds that enlarging areas of socio-environmental importance could increase the total hydrogen production by about 10% per commune indicating the impact of these factors on the potential for renewable energy production.

This study presents a technoeconomic analysis of renewables-based hydrogen production in Queensland Australia under Optimistic Reference and Pessimistic scenarios to address uncertainty in cost predictions. The goal of the work was to ascertain if the target fam-gate cost of AUD 3/kg (approx. USD 2/kg) could be reached. Economies of scale and the learning rate concept were factored into the economic model to account for the effect of scale-up and cost reductions as electrolyser manufacturing capacity grows. The model assumes that small-scale to large-scale wind turbine (WT)-based and photovoltaic (PV)-based power generation plants are directly coupled with an electrolyser array and utilises hourly generation data for the Gladstone hydrogen-hub region. Employing first a commonly used simplified approach the electrolyser array was sized based on the maximum hourly power available for hydrogen production. The initial results indicated that scale-up is very beneficial: the levelised cost of green hydrogen (LCOH) could decrease by 49% from $6.1/kg to $3.1/kg when scaling PV-based plant from 10 MW to 1 GW and for WT-based plant by 36% from $5.8/kg to $3.7/kg. Then impacts on the LCOH of incorporating curtailment of ineffective peak power and electrolyser overload capacity were investigated and shown to be significant. Also significant was the beneficial effect of recognising that electrolyser efficiency depends on input power. The latter two factors have mostly been overlooked in the literature. Incorporating in the model the influence on the LCOH of real-world electrolyser operational characteristics overcomes a shortcoming of the simplified sizing method namely that a large portion of electrolyser capacity is under-utilised leading to unnecessarily high values of the LCOH. It was found that AUD 3/kg is achievable if the electrolyser array is properly sized which should help to incentivise large-scale renewable hydrogen projects in Australia and elsewhere.

Thanks to investments in diversifying the supply of natural gas Poland did not encounter any gas supply issues in 2022 when gas imports from Russia were ceased due to the Russian Federation’s armed intervention in Ukraine. Over the past few years the supply of gas from routes other than the eastern route has substantially grown particularly the supplies of liquefied natural gas (LNG) via the LNG terminal in Swinouj´scie. The growing proportion of LNG in Poland’s gas supply ´ leads to a rise in ethane levels in natural gas as verified by the review of data taken at a specific location within the gas system over the years 2015 2020 and 2022. Using measurements of natural gas composition the effectiveness of the steam hydrocarbon reforming process was simulated in the Gibbs reactor via Aspen HYSYS. The simulations confirmed that as the concentration of ethane in the natural gas increased the amount of hydrogen produced and the heat required for reactions in the reformer also increased. This article aims to analyze the influence of the changes in natural gas quality in the Polish transmission network caused by changes in supply structures on the mass and heat balance of the theoretical steam reforming reactor. Nowadays the chemical composition of natural gas may be significantly different from that assumed years ago at the plant’s design stage. The consequence of such a situation may be difficulties in operating especially when controlling the quantity of incoming natural gas to the reactor based on volumetric flow without considering changes in chemical composition.

To address climate change energy security and waste management new sustainable energy sources must be developed. This study uses Aspen Plus software to extract bio-H2 from food waste with the goal of efficiency and environmental sustainability. Anaerobic digestion optimised to operate at 20-25°C and keep ammonia at 3% greatly boosted biogas production. The solvent [Emim][FAP] which is based on imidazolium had excellent performance in purifying biogas. It achieved a high level of methane purity while consuming a minimal amount of energy with a solvent flow rate of 13.415 m³/h. Moreover the utilization of higher temperatures (600-700°C) during the bio-H2 generation phase significantly enhanced both the amount and quality of hydrogen produced. Parametric and sensitivity assessments were methodically performed at every stage. This integrated method was practicable and environmentally friendly according to the economic assessment. H2 generation using steam reforming results in a TCC of 1.92×106 USD. The CO2 separation step has higher costs (TCC of 2.15×107 USD) due to ionic liquid washing and CO2 liquefaction. Compressor electricity consumption significantly impacts total operating cost (TOC) totaling 4.73×108 USD. showing its ability to reduce greenhouse gas emissions optimize resource utilization and promote energy sustainability. This study presents a sustainable energy solution that addresses climate and waste challenges.