Production & Supply Chain

Non-catalytic thermal methane cracking (TMC) is an alternative for hydrogen manufacturing and traditional commercial processes in small-scale hydrogen generation. Supplying the high-level temperatures (850–1800°C) inside the reactors and reactor blockages are two fundamental challenges for developing this technology on an industrial scale (Mahdi Yousefi and Donne 2021). A regenerative reactor could be a part of a solution to overcome these obstacles. This study conducted an experimental study in a regenerative reactor environment between 850 and 1170°C to collect the conversion data and investigate the reactor efficiency for TMC processes. The results revealed that the storage medium was a bed for carbon deposition and successfully supplied the reaction’s heat with more than 99.7% hydrogen yield (at more than 1150°C). Results also indicated that the reaction rate at the beginning of the reactor is much higher and the temperature dependence in the early stages of the reaction is considerably higher. However after reaching a particular concentration of Hydrogen at each temperature the influence of temperature on the reaction rate decreases and is almost constant. The type of produced carbon in the storage medium and its auto-catalytic effect on the reactions were also investigated. Results showed that carbon black had been mostly formed but in different sizes from 100 to 2000 nm. Increasing the reactor temperature decreased the size of the generated carbon. Pre-produced carbon in the reactor did not affect the production rate and is almost negligible at more than 850°C.

Currently global energy transformation and the promotion of renewable energy use are being taken care of to minimize the harm to the environment. However the disadvantage of renewable energy is the random change which leads to the regulation of grid operations which is very difficult when the capacity of renewable energy sources accounts for a large proportion. The hydrogen production technology from wind and solar energy sources is one of the possible methods to minimize adverse impacts on the utility grid and serve the load demand of industrial zones. In this study the photovoltaic (PV) hydrogen production potential for industrial zones in Vietnam is analyzed. The Homer was used to simulate and calculate power output. The results showed that the Hai Duong province has the lowest solar radiation so the solar power output is 3600389 kWh/year and the amount of hydrogen generated is less so it mainly serves the hydrogen load while the fuel cell can only generate very low amounts of electricity of about 4150 kWh/year for direct current (DC) load. The hybrid power systems in the typical industrial plant in Quang Nam province Binh Thuan province Can Tho city can generate about 17386 kg/year to 17422 kg/year to supply the operation of fuel cells based on the value of solar radiation of each province. The better the area with solar potential the lower the net present cost (NPC) cost of energy (COE) and operation cost so the economical and technical efficiency of the PV–Fuel cell hybrid power system will increase.

Methanol is currently considered one of the most useful chemical products and is a promising building block for obtaining more complex chemical compounds such as acetic acid methyl tertiary butyl ether dimethyl ether methylamine etc. Methanol is the simplest alcohol appearing as a colorless liquid and with a distinctive smell and can be produced by converting CO2 and H2 with the further benefit of significantly reducing CO2 emissions in the atmosphere. Indeed methanol synthesis currently represents the second largest source of hydrogen consumption after ammonia production. Furthermore a wide range of literature is focused on methanol utilization as a convenient energy carrier for hydrogen production via steam and autothermal reforming partial oxidation methanol decomposition or methanol–water electrolysis reactions. Last but not least methanol supply for direct methanol fuel cells is a well-established technology for power production. The aim of this work is to propose an overview on the commonly used feedstocks (natural gas CO2 or char/biomass) and methanol production processes (from BASF—Badische Anilin und Soda Fabrik to ICI—Imperial Chemical Industries process) as well as on membrane reactor technology utilization for generating high grade hydrogen from the catalytic conversion of methanol reviewing the most updated state of the art in this field.

While the effects of ongoing cost reductions in renewables batteries and electrolyzers on future energy systems have been extensively investigated the effects of significant advances in CO2 capture and storage (CCS) technologies have received much less attention. This research gap is addressed via a long-term (2050) energy system model loosely based on Germany yielding four main findings. First CCS-enabled pathways offer the greatest benefits in the hydrogen sector where hydrogen prices can be reduced by two-thirds relative to a scenario without CCS. Second advanced blue hydrogen technologies can reduce total system costs by 12% and enable negative CO2 emissions due to higher efficiencies and CO2 capture ratios. Third co-gasification of coal and biomass emerged as an important enabler of these promising results allowing efficient exploitation of limited biomass resources to achieve negative emissions and limit the dependence on imported natural gas. Finally CCS decarbonization pathways can practically and economically incorporate substantial shares of renewable energy to reduce fossil fuel dependence. Such diversification of primary energy inputs increases system resilience to the broad range of socio-techno-economic challenges facing the energy transition. In conclusion balanced blue-green pathways offer many benefits and deserve serious consideration in the global decarbonization effort.

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.

Electrochemical ammonia generation allows direct low pressure synthesis of ammonia as an alternative to the established Haber-Bosch process. The increasing need to drive industry with renewable electricity central to decarbonisation and electrochemical ammonia synthesis offers a possible efficient and low emission route for this increasingly important chemical. It also provides a potential route for more distributed and small-scale ammonia synthesis with a reduced production footprint. Electrochemical ammonia synthesis is still early stage but has seen recent acceleration in fundamental understanding. In this work two different ammonia electrolysis systems are considered. Balance of plant (BOP) requirements are presented and modelled to compare performance and determine trade-offs. The first option (water fed cell) uses direct ammonia synthesis from water and air. The second (hydrogen-fed cell) involves a two-step electrolysis approach firstly producing hydrogen followed by electrochemical ammonia generation. Results indicate that the water fed approach shows the most promise in achieving low energy demand for direct electrochemical ammonia generation. Breaking the reaction into two steps for the hydrogen fed approach introduces a source of inefficiency which is not overcome by reduced BOP energy demands and will only be an attractive pathway for reactors which promise both high efficiency and increased ammonia formation rate compared to water fed cells. The most optimised scenario investigated here with 90% faradaic efficiency (FE) and 1.5 V cell potential (75% nitrogen utilisation) gives a power to ammonia value of 15 kWh/kg NH3 for a water fed cell. For the best hydrogen fed arrangement the requirement is 19 kWh/kg NH3. This is achieved with 0.5 V cell potential and 75% utilisation of both hydrogen and nitrogen (90% FE). Modelling demonstrated that balance of plant requirements for electrochemical ammonia are significant. Electrochemical energy inputs dominate energy requirements at low FE however in cases of high FE the BOP accounts for approximately 50% of the total energy demand mostly from ammonia separation requirements. In the hydrogen fed cell arrangement it was also demonstrated that recycle of unconverted hydrogen is essential for efficient operation even in the case where this increases BOP energy inputs

By adding energy as hydrogen to the biomass-to-liquid (BtL) process several published studies have shown that carbon efficiency can be increased substantially. Hydrogen can be produced from renewable electrical energy through the electrolysis of water or steam. Adding high-temperature thermal energy to the gasifier will also increase the overall carbon efficiency. Here an economic criterion is applied to find the optimal distribution of adding electrical energy directly to the gasifier as opposed to the electrolysis unit. Three different technologies for electrolysis are applied: solid oxide steam electrolysis (SOEC) alkaline water electrolysis (AEL) and proton exchange membrane (PEM). It is shown that the addition of part of the renewable energy to the gasifier using electric heaters is always beneficial and that the electrolysis unit operating costs are a significant portion of the costs. With renewable electricity supplied at a cost of 50 USD/MWh and a capital cost of 1500 USD/kW installed SOEC the operating costs of electric heaters and SOEC account for more than 70% of the total costs. The energy efficiency of the electrolyzer is found to be more important than the capital cost. The optimal amount of energy added to the gasifier is about 37–39% of the energy in the biomass feed. A BtL process using renewable hydrogen imports at 2.5 USD/kg H2 or SOEC for hydrogen production at reduced electricity prices gives the best values for the economic objective.

Hydrogen production using solar energy is an important way to obtain hydrogen energy. However the inherent intermittent and random characteristics of solar energy reduce the efficiency of hydrogen production. Therefore it is necessary to add an energy storage system to the photovoltaic power hydrogen production system. This paper establishes a model of a photovoltaic power generation hydrogen system and optimizes the capacity configuration. Firstly the mathematical model is modeled and analyzed and the system is modeled using Matlab/Simulink; secondly the principle of optimal configuration of energy storage capacity is analyzed to determine the optimization strategy we propose the storage capacity configuration algorithm based on the low-pass filtering principle and optimal time constant selection; finally a case study is conducted whose photovoltaic installed capacity of 30 MW verifying the effectiveness of the proposed algorithm analyzing the relationship between energy storage capacity and smoothing effect. The results show that as the cut-off frequency decreases the energy storage capacity increases and the smoothing effect is more obvious. The proposed algorithm can effectively reduce the 1 h maximum power variation of PV power generation. In which the maximum power variation of PV generation 1 h before smoothing is 4.31 MW. We set four different sets of time constants the maximum power variation of PV generation 1 h after smoothing is reduced to 0.751 0.389 0.078 and 0.04 MW respectively.

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.

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.