Canada

Our previous reported experiments revealed that the reflection of high-speed deflagrations in hydrogenair and hydrogen-oxygen mixtures produces higher mechanical loading and reflected pressures than reflecting detonations. This surprising result was shown to correlate with the onset of detonation in the gases behind the reflected shock. We revisit these experiments with the aim of developing a closed-form model for the pressure evolution due to the shock-induced ignition and rapid transition to detonation. We find that the reflection condition of fast deflagrations corresponds to the chain-branching crossover regime of hydrogen ignition in which the reduced activation energy is very large and the reaction characteristic time is very short compared to the induction time. We formulate a closed-form model in the limit of fast reaction times as compared to the induction time which is used to predict a square wave pressure profile generated by self-similar propagation of internal Chapman-Jouguet detonation waves followed by Taylor expansion waves. The model predictions are compared with Navier-Stokes numerical simulations with full chemistry as well as simple Euler calculations using calibrated one-step or twostep chain-branching models. Both simplified numerical models were found to be in good agreement with the full chemistry model. We thus demonstrate that the end pressure evolution due to the reflection of high-speed deflagrations can be well predicted analytically and numerically using relatively simple models in this ignition regime of main interest for safety analysis and explosion mitigations. The slight departures from the square wave model are investigated based on the physical wave processes occurring in the shocked gases controlling the shock-to-detonation transition. Using the two-step model we study how the variations of the rate of energy release control the pressure evolution in the end gas extending the analysis of Sharpe to very large rates of energy release.

The present study comprehensively examines the application of hydro wave tidal undersea current and geothermal energy sources of Canada for green hydrogen fuel production. The estimated potential capacity of each province is derived from official data and acceptable assumptions and is subject to discussion and evaluation in the context of a viable hydrogen economy. According to the findings the potential for green hydrogen generation in Canada is projected to be 48.86 megatons. The economic value of the produced green hydrogen results in an equivalent of 21.30 billion US$. The top three provinces with the highest green hydrogen production potential using hydro resources including hydro wave tidal undersea current and geothermal are Alberta Quebec and British Columbia with 26.13 Mt 7.34 Mt and 4.39 Mt respectively. Quebec is ranked first by only considering the marine sources including 4.14 Mt with hydro 1.46 Mt with wave 0.27 Mt underwater current and 1.45 Mt with tidal respectively. Alberta is listed as the province with the highest capacity for hydrogen production from geothermal energy amounting up to 26.09 Mt. The primary objective is to provide comprehensive hydrogen maps for each province in Canada which will be based on the identified renewable energy potential and the utilization of electrolysers. This may further be examined within the framework of the prevailing policies implemented by local communities and officials in order to develop a sustainable energy plan for the nation.

This study presents a new three-step Cu-Cl cycle that can operate with heat input without electrolysis. While the sensitivity analyses of the system are performed to evaluate the system performance through the Aspen Plus thermodynamic analyses of the system are performed with energetic and exergetic approaches. The highest exergy destruction among the components in the system was the decomposition reactor with a rate of 50.6%. Furthermore the energy and exergy values for the simulated system to produce 1 mol of hydrogen were determined by calculating the energy requirements of all components in the system. The total energy required for the system to generate 1 mol of hydrogen is calculated to be 997.81 kJ/mol H2. It was found that the component that required the most energy 504.76 kJ/mol H2 in the system was the decomposition reactor. Moreover the overall energy and exergy efficiencies are calculated to be 72.50% and 46.70% respectively.

Green hydrogen stands as a promising clean energy carrier with potential net-zero greenhouse gas emissions. However different system-level configurations for green hydrogen production yield different levels of efficiency cost and maturity necessitating a comprehensive assessment. This review evaluates the components of hydrogen production plants from technical and economic perspectives. The study examines six renewable energy sources—solar photovoltaics solar thermal wind biomass hydro and geothermal—alongside three types of electrolyzers (alkaline proton exchange membrane and solid oxide electrolyzer cells) and five hydrogen storage methods (compressed hydrogen liquid hydrogen metal hydrides ammonia and liquid organic hydrogen carriers). A comprehensive assessment of 90 potential system configurations is conducted across five key performance indicators: the overall system cost efficiency emissions production scale and technological maturity. The most cost-effective configurations involve solar photovoltaics or wind turbines combined with alkaline electrolyzers and compressed hydrogen storage. For enhanced system efficiency geothermal sources or biomass paired with solid oxide electrolyzer cells utilizing waste heat show significant promise. The top technologically mature systems feature combinations of solar photovoltaics wind turbines geothermal or hydroelectric power with alkaline electrolyzers using compressed hydrogen or ammonia storage. The highest hydrogen production scales are observed in systems with solar PV wind or hydro power paired with alkaline or PEM electrolyzers and ammonia storage. Configurations using hydro geothermal wind or solar thermal energy sources paired with alkaline electrolyzers and compressed hydrogen or liquid organic hydrogen carriers yield the lowest life cycle GHG emissions. These insights provide valuable decision-making tools for researchers business developers and policymakers guiding the optimization of system efficiency and the reduction of system costs.

The introduction of gaseous hydrogen (H2) into the intake air of a heavy-duty diesel engine results in H2-diesel dual-fuel (HDDF) combustion which offers a near-term pathway to reduce CO2 emissions in heavy-duty longhaul trucking. Since H2 introduction impacts oxygen availability combustion characteristics and emissions simultaneously it is imperative to appropriately optimize and control the input parameters including intake air pressure diesel injection timing and EGR ratio. This study investigates the impacts of these controlling parameters on the combustion characteristics limiting factors and emissions of an HDDF engine. Experimental tests were conducted on a 2.4 L single-cylinder research engine under medium load and speed conditions (1200 rpm 8 bar brake mean effective pressure) with varying H2 fractions. The results show that engine performance and combustion parameters are not solely influenced by H2 introduction. Instead the key factor is how H2 introduction affects combustion phasing and fuels equivalence ratio at various intake air pressures and diesel injection timings. The findings demonstrate that technical challenges in HDDF combustion such as combustion harshness (indicated by maximum rate of pressure rise) and unburned H2 (“H2 slip”) can be addressed through coordinated control of intake air pressure diesel injection timing and EGR ratio based on H2 energy ratio. At high H2 energy ratios adding 20% EGR effectively reduced combustion harshness by up to 40% and NOx emissions by 68% with negligible impact on brake thermal efficiency and H2 slip. At a given EGR level precise control of combustion phasing and intake pressure enabled the introduction of 40% H2 energy ratio resulting in 40% reduction in CO₂ emissions and 55% reduction in particulate matter emissions with no increase in NOx levels compared to the baseline diesel operation. These outcomes establish simultaneous adjustment of key engine control parameters as a practical strategy to maximize H2 introduction while addressing technical challenges in HDDF combustion. This ensures comparable engine performance with significantly lower CO2 emissions compared to conventional heavy-duty diesel engines.

Hydrogen production and carbon dioxide removal are considered two of the critical pieces to achieve ultimate sustainability target. This study proposes and investigates a new variation of potassium hydroxide thermochemical cycle in order to combine hydrogen production and carbon dioxide removal synergistically. An alkali metal redox thermochemical cycle developed where the potassium hydroxide is considered by using a nonequilibrium reaction. Also the multigeneration options are explored by using two stage steam Rankine cycle multi-effect distillation desalination Li-Br absorption chiller which are integrated with potassium hydroxide thermochemical cycle for hydrogen production carbon capture power generation water desalination and cooling purposes. A comparative assessment under different scenarios is carried out. The energy and exergy efficiencies of the hydrogen production thermochemical cycle are 44.2% and 67.66% when the hydrogen generation reaction is carried out at 180°C and the separation reactor temperature set at 400°C. Among the multigeneration scenarios a trigeneration option of hydrogen power and water indicates the highest energy efficiency as 66.02%.

This study introduces a novel hydrogen production system using the three-step copper chlorine (Cu-Cl) cycle. The proposed thermochemical cycle offers an innovative configuration that performs hydrogen production without an electrolysis step eliminating high-cost components such as membranes catalysts and electricity. The Cu-Cl cycle enables large-scale hydrogen production and is examined in various configurations including two- three- four- and five-step Cu-Cl cycles. Microscale experimental studies are conducted on a novel three-step Cu-Cl thermochemical cycle that works entirely on thermal energy input without electrolysis. In experimental studies some parameters that directly affect the amount of hydrogen production are investigated. The effects of parameters such as temperature steam/copper (S/C) ratio and reaction time on hydrogen production in the hydrolysis step are evaluated. The investigation also examined the impact of increasing temperature in the hydrolysis reaction on the generation of undesirable byproducts. Additionally the effect of increased temperatures in the decomposition process on oxygen formation is examined. In the optimization studies the individual and interactive effects of the parameters are analyzed using the Response Surface Methodology (RSM) and BoxBehnken Design (BBD) of experimental methods. The results of this study further show that the conditions with the highest hydrogen production are a S/C ratio of 55 a temperature of 400 ◦C and a reaction time between 30 and 40 min. It is also observed that hydrogen concentration increases with the increase in temperature and time and that the maximum level of 134.8 ppm is reached under optimum conditions.

Alkaline water electrolysis is a promising clean hydrogen production technology that accounts for a small percentage of global hydrogen production. Therefore the technique requires further research and development to achieve higher efficiencies and lower hydrogen production costs to replace the utilization of non-renewable energy sources for hydrogen production. In this study electrodes are fabricated through fused deposition modelling 3D printing technology for practical and accessible electrolyzer manufacturing where an initial nickel (Ni) catalyst layer is formed on the 3D printed electrode surface followed by copper modified nickel zinc iron oxide (NiZnFe4O4) layer to investigate a unique electrocatalyst. An alkaline electrolyzer is developed with Ni-NiZnFe4O4 coated 3D printed cathodes and stainless steel anodes to determine the hydrogen production capacities and efficiencies of the electrolysis process. Electrochemical measurements are used to assess the catalyst coated 3D printed electrodes ranging from physical electrochemistry to electrochemical impedance measurements. The results show that the triangular Ni-NiZnFe4O4 coated electrode with the highest aspect ratio exhibits the greatest current density of −183.17 mA/cm2 at −2.05 V during linear sweep voltammetry (LSV) tests where it also reaches a current density of −94.35 mA/cm2 at −1.2 V during cyclic voltammetry (CV) measurements. It is concluded that modification of surface geometry is also a crucial aspect of electrode performance as 30% lower overpotentials are achieved by the rectangular electrodes in this study. The hydrogen production capacities of the alkaline electrolyzer developed range from 4.22 to 5.82 × 10−10 kg/s operating at a cell voltage of 2.15 V. Furthermore the energy and exergy efficiencies of the alkaline electrolyzer are evaluated through the first and second laws of thermodynamics revealing the highest energy and exergy efficiencies of 14.34% and 13.86% for the highest aspect ratio rectangular electrode.

The current study comprehensively examines the application of wave tidal and undersea current energy sources of Turkiye for green hydrogen fuel production and cost analysis. The estimated potential capacity of each city is derived from official data and acceptable assumptions and is subject to discussion and evaluation in the context of a viable hydrogen economy. According to the findings the potential for green hydrogen generation in Turkiye is projected to be 7.33 million tons using a proton exchange membrane electrolyser (PEMEL). Cities with the highest hydrogen production capacities from marine applications are Mugla Izmir Antalya and Canakkale with 998.10 kt 840.31 kt 605.46 kt and 550.42 kt respectively. The study calculations obviously show that there is a great potential by using excess power in producing hydrogen which will result in an economic value of 3.01 billion US dollars. This study further helps develop a detailed hydrogen map for every city in Turkiye using the identified potential capacities of renewable energy sources and the utilization of electrolysers to make green hydrogen by green power. The potentials and specific capacities for every city are also highlighted. Furthermore the study results are expected to provide clear guidance for government authorities and industries to utilize such a potential of renewable energy for investment and promote clean energy projects by further addressing concerns caused by the usage of carbon-based (fossil fuels dependent) energy options. Moreover green hydrogen production and utilization in every sector will help achieve the national targets for a net zero economy and cope with international targets to achieve the United Nation's sustainable development goals.

This paper examines the crucial elements of pipeline-based hydrogen transportation highlighting the particular difficulties and technical developments required to guarantee the sustainable effective and safe supply of hydrogen. This study lists the essential phases of hydrogen pipeline management from design to repair as the relevance of hydrogen infrastructure in the worldwide energy transition continues to rise. It discusses the upkeep monitoring operation and rehabilitation procedures for aged pipelines with an emphasis on the cutting-edge techniques and technology used to mitigate the dangers related to hydrogen’s unique features such as leakage and embrittlement. Together with highlighting the legislative and regulatory frameworks that enable the infrastructure this paper also discusses the material economic and environmental difficulties related to hydrogen pipelines. Lastly it emphasizes how crucial it is to fund research create cutting-edge materials and implement sophisticated monitoring systems to guarantee the long-term dependability and safety of hydrogen pipelines. These initiatives will be crucial in allowing hydrogen’s contribution to the future of renewable energy together with international collaboration on regulatory standards.