Hydrogenics (Canada)

Abstract The wave reformer, developed by New Wave Hydrogen, Inc. (NWH2), harnesses shock waves resulting from the pressure exchange between two gases to initiate thermal decomposition reactions in a hydrocarbon gas to generate hydrogen. This article investigates the influence of various operating parameters, including driver gas mixtures and operating pressure on the overall hydrogen conversion within an 8-ports wave reformer. The objective is to start with a peak pressure region and reaction zone away from the end-wall toward the center of the wave reformer, allowing for more time for high-temperature initiation. The main intention of the work is to consider the role of the gas composition of the driver gas (energy input) on the pyrolysis of methane using shock-wave heating. This study provides a comprehensive comparative analysis of the effects of driver gas properties on the flow rate, velocity, temperature, and pressure distribution within the wave reformer. Utilizing a Quasi-2D (Q2D) model, simulations yield valuable insights into how these parameters impact the performance of the technology. Key findings include the critical role of driven outlet back pressure in driving mass flow within the cycle and its subsequent influence on maximum temperature. Most interestingly, the choice of driver gases was found to profoundly influence the temperature and density fields and plays a significant role in the mass flow ratio of the two gases. This research enhances our understanding of wave reformer technology and its sensitivity to various operational parameters. The insights gained are instrumental in optimizing wave reformer performance for efficient hydrogen conversion.

This paper presents an adaptive Energy Management Strategy (EMS) designed to distribute the power demand among four small fuel cell modules (short stack + auxiliaries) to extend the lifetime of the entire Multi-Fuel Cell Stacks (MFCS) system and minimize its hydrogen consumption. Indeed, using an MFCS system composed of several fuel cell modules seems to be an up-and-coming alternative, given the various challenges associated with using a single high-powered fuel cell system in a Fuel Cell Hybrid Electric Vehicle (FCHEV). These challenges are the short lifetime, reduced reliability, and the narrowness of the energy-efficient operating range of a single fuel cell system. To improve the durability and minimize the hydrogen consumption using an MFCS system, the EMS proposed in this paper is based on dynamic predictions of the Remaining Useful Life (RUL) of each stack made by a real context prognostic algorithm. The simulations have been carried out in Matlab/Simulink environment. The results showed that the proposed strategy could extend the MFCS system lifetime by about 30% compared to the equidistributional strategy and by about 12% compared to the Daisy-Chain strategy.

Abstract The need for fossil fuels has steadily increased over the past many decades due to human-made activities which have resulted in numerous environmental issues, including climate change and pollution. Thus, the search for alternative fuels is of utmost importance today. In this chapter, ammonia is proposed as an alternative energy solution to fossil fuels. Sectoral utilization of ammonia is also discussed.

The "Hydrogen Economy Roadmap of Korea," which was released by the government, included an overseas source of hydrogen to consolidate the supply chain. The ultimate goal of hydrogen economy would be established by using green hydrogen from renewables. However, blue hydrogen is expected to form a considerable proportion of the hydrogen supply chain in the initial stage of hydrogen economy. To develop a new path of blue hydrogen supply, it is inevitable to build collaborative strategies with international oil producers or technologically advanced countries. By investigating the required technologies and collaborative environments of countries that have high potentials, the scheme of blue hydrogen supply was proposed. The business model integrated with CCS-EOR would be competitive, and UAE, USA, and Canada should be preferentially considered for collaborative target countries. To acquire commercial-level feasibility, it is necessary to perform an integrated pilot project, which includes overseas hydrogen production, CCS-EOR, and transportation.

In the current study, conventional resources-based ammonia generation routes are comparatively studied through a comprehensive life cycle assessment. The selected ammonia generation options range from mostly used steam methane reforming to partial oxidation of heavy oil. The chosen ammonia synthesis process is the most common commercially available Haber-Bosch process. The essential energy input for the methods are used from various conventional resources such as coal, nuclear, natural gas and heavy oil. Using the life cycle assessment methodology, the environmental impacts of selected methods are identified and quantified from cradle to gate. The life cycle assessment outcomes of the conventional resources based ammonia production routes show that nuclear electrolysis-based ammonia generation method yields the lowest global warming and climate change impacts while the coal-based electrolysis options bring higher environmental problems. The calculated greenhouse gas emission from nuclear-based electrolysis is 0.48 kg CO2 equivalent while it is 13.6 kg CO2 per kg of ammonia for coal-based electrolysis method.

A three-dimensional (3D), two-phase numerical model was developed and presented as a useful tool for investigating oxygen bubble propagation in porous transport layers (PTLs) (otherwise known as gas diffusion layers (GDLs)) of polymer electrolyte membrane (PEM) electrolyzers. The volume-of-fluid (VoF) technique was employed to simulate the liquid-gas interface movement through liquid-saturated porous media designed to be representative of PEM electrolyzer PTLs. The circulation of the liquid within the channel and the porous domain was included in the model. Bubble propagation patterns and bulk saturations for porous material representations of commonly used PTLs were determined as a function of time leading up to the moment of breakthrough. Previously conducted experimental microfluidic investigations were used for model validation, and it was found that the numerical results were in good agreement with the numerical predictions. The validated model was used to calculate pressure variations in bubbles during propagation, and the highest threshold capillary pressure corresponding to a critical throat was introduced as a means to measure the efficacy of oxygen bubble removal. The information obtained from the developed numerical tool can be used for designing and evaluating PTL microstructures for next generation electrolyzer materials.

Mg-based Mg-Ti binary alloys have been synthesized by mechanical alloying of Mg and Ti powder blends. It was found that mechanical alloying of Mg and Ti results in a nanocrystalline Mg-Ti alloy and an extended solubility of Ti in Mg, due to the favorable size factor and the isomorphous structure of Mg and Ti. In the case of Mg-20at.%Ti, about 12.5% Ti is dissolved in the Mg lattice when the mechanical alloying process reaches a stable state. The rest (about 7.5 at.%) remains as fine particles in the size of 50–150 nm in diameter. Dissolution of 12.5 at.% Ti in the Mg lattice causes a contraction of the unit cell volume from 0.0464 to 0.0442 nm3 and a decrease of the c/a ratio from 1.624 to 1.612 of the hexagonal structure. The supersaturated solid solution Mg-Ti alloy decomposes upon thermal annealing at temperatures above 200°C. Hydrogenation enhances the decomposition process at lower temperatures.

Electrochemical reduction of oxygen has been studied in detail employing rotating disk and ring‐disk electrode techniques in aqueous solutions of various concentrations at various temperatures. Analysis of voltammetric results recorded at the rotating disk electrode (RDE) indicates that there are two clearly defined Tafel regions of low (60 mV/decade) and high Tafel slopes. In general, electrode kinetics improves and Tafel slopes of the low‐slope region decreases slightly as the basicity of the electrolyte solution increases. The rotating ring‐disk electrode (RRDE) results were analyzed according to a simple model for oxygen reduction, first proposed by Damjanovic et al. The model is in agreement with experimental results at lower concentrations of . Rate constants for oxygen reduction directly to and , and for to were calculated at four different disk electrode potentials. The rate constant of direct reduction of oxygen to increases with the overpotential, but the plots of rate constants for oxygen reduction to and for reduction vs. potential pass through a maximum at about 0.85V vs. DHE. All these rate constants are shown to be slightly dependent on temperature.