Canada

Governments around the world are leveraging unprecedented amounts of capital to respond to the pandemic and bailing out struggling industries. Trends in energy-related spending indicate that despite the green push the world’s largest economies have still favoured fossil energy over clean energy.<br/><br/>We evaluate energy-related spending in Canada in 2020 (since the onset of COVID-19) using data from the Energy Policy Tracker. Trends in Canada are then compared to flagship policies in key jurisdictions with recent progressive climate policy announcements including France Germany and the United Kingdom. The brief ends with broad recommendations on how Canada can better align its recovery funding with climate action and fossil fuel subsidy reform.<br/><br/>This brief is one of three International Institute for Sustainable Development (IISD) policy briefs in its Recovery Through Reform series which assesses how efforts to achieve a green recovery from COVID-19 in Canada rely on—and can contribute to—fossil fuel subsidy reform.

This paper presents an analysis of computational fluid dynamic models of compressed hydrogen gas leaks into the air under different conditions to determine the volume of the hydrogen/air mixture and the extents of the lower flammable limit. The necessary hole size was calculated to determine a reasonably expected hydrogen leak rate from a valve or a fitting of 5 and 20 cfm under 400 bars resulting in a 0.1 and 0.2 mm effective diameter hole respectively. The results were compared to calculated hypothetical volumes from IEC 60079-10 for the same mass flowrate and in most cases the CFD results produced significantly smaller hydrogen/air volumes than the IEC standard. Prescriptive electrical classification distances in existing standards for hydrogen and compressed natural gas were examined but they do not consider storage pressure and there appears to be no scientific basis for the distance determination. A proposed table of electrical classification distances incorporating hydrogen storage volume and pressure was produced based on the hydrogen LFL extents from a 0.2 mm diameter hole and the requirements of existing standards. The PHOENICS CFD software package was used to solve the continuity momentum and concentration equations with the appropriate boundary conditions buoyancy model and turbulence models. Numerical results on hydrogen concentration predictions were obtained in the real industrial environment typical for a hydrogen refuelling or energy station.<br/><br/>

Power- and biomass-to-liquid fuel processes (PBtL) can utilize renewable energy and residual forestry waste to produce liquid synthetic fuels which have the potential to mitigate the climate impacts of the current transportation infrastructure including the long-haul aviation sector. In a previous study we demonstrated that implementing a solid oxide electrolysis cell (SOEC) in the PBtL process can significantly increase the energy efficiency of fuel production by supplying the produced hydrogen to a reverse water gas shift (RWGS) reactor to generate syngas which is then fed downstream to a Fischer–Tropsch (FT) reactor. The tail gas emitted from the FT reactor consists primarily of a mixture of hydrogen carbon monoxide and methane and is often recycled to the entrained flow gasifier located at the beginning of the process. In this analysis we investigate the efficiency gains of the PBtL process as a result of redirecting the tail gas of the FT reactor to the anode of an SOEC to serve as fuel. Supplying fuel to an SOEC can lower the electrical work input required to facilitate steam electrolysis when reacting electrochemically with oxide ions in the anode which in turn can reduce oxygen partial pressures and thus alleviate material degradation. Accordingly we develop a thermodynamic framework to reveal the performance limits of fuel-assisted SOECs (FASOECs) and provide strategies to minimize oxygen partial pressures in the SOEC anode. Additionally we elucidate how much fuel is required to match the heating demands of a cell when steam is supplied to the cathode over a broad range of inlet temperatures and demonstrate the influence of a set of reaction pathways of the supplied fuel on the operating potential of an FASOEC and the corresponding efficiency gain of the PBtL process. Based on preliminary calculations we estimate that implementing an FASOEC in the PBtL process can increase the energy efficiency of fuel production to more than 90% depending on the amount of FT tail gas available to the system.

The safety and convenience of hydrogen storage are significant for fuel cell vehicles. Based on mass conservation equation and energy conservation equation two thermodynamic models (single zone model and dual zone model) have been established to study the hydrogen gas temperature and tank wall temperature for compressed hydrogen storage tank. With two models analytical solution and Euler solution for single zone (gas zone) charge-discharge cycle have been compared Matlab/Simulink solution and Euler solution for dual zone (gas zone wall zone) charge-discharge cycle have been compared. Three charge-discharge cycle cases (Case 1 constant inflow temperature; Case 2 variable inflow temperature; Case 3 constant inflow temperature variable outflow temperature) and two compressed hydrogen tanks (Type III 25L Type IV 99L) charge-discharge cycle are studied by Euler method. Results show Euler method can well predict hydrogen temperature and tank wall temperature.

The paper will present results of hydrogen/oxygen mixtures ignited by using electric sparks electrostatic discharges a heating element and a flame. Measurements of the lower flammability limit (LFL) was done for each ignition method. The hydrogen mixtures of different concentrations were ignited at the bottom of a combustion chamber leading to an upward propagation of the resulting flame. At some level of concentration the combustion was partial due to the limited upward propagation. The complete combustion of the whole mixture was observed at concentration limits higher than the known LFL of 4% vol. for hydrogen in air. The paper will describe the test facilities and the resulting ignition probabilities for different ignition methods.

Overview of advances in the technology of solid state hydrogen storage methods applying different kinds of novel materials is provided. Metallic and intermetallic hydrides complex chemical hydride nanostructured carbon materials metal-doped carbon nanotubes metal-organic frameworks (MOFs) metal-doped metal organic frameworks covalent organic frameworks (COFs) and clathrates solid state hydrogen storage techniques are discussed. The studies on their hydrogen storage properties are in progress towards positive direction. Nevertheless it is believed that these novel materials will offer far-reaching solutions to the onboard hydrogen storage problems in near future. The review begins with the deficiencies of current energy economy and discusses the various aspects of implementation of hydrogen energy based economy.

The effects of temperature on bulk hydrogen concentration and diffusion have been tested with the Devanathan–-Stachurski method. Thus a model based on hydrogen potential diffusivity loading frequency and hydrostatic stress distribution around crack tips was applied in order to quantify the temperature’s effect. The theoretical model was verified experimentally and confirmed a temperature threshold of 320 K to maximize the crack growth. The model suggests a nanoscale embrittlement mechanism which is generated by hydrogen atom delivery to the crack tip under fatigue loading and rationalized the ΔK dependence of traditional models. Hence this work could be applied to optimize operations that will prolong the life of the pipeline.

The valorization of biomass-based solid wastes for both geotechnical engineering purposes and energy needs has been reviewed to achieve eco-friendly eco-efficient and sustainable engineering and reengineering of civil engineering materials and structures. The objective of this work was to review the procedure developed by SWI-NaOH-OCE Model for the valorization of biomass through controlled direct combustion and the sequestration of hydrogen gas for energy needs. The incineration model gave a lead to the sequestration of emissions released during the direct combustion of biomass and the subsequent entrapment of oxides of carbon and the eventual release of abundant hydrogen gas in the entrapment jar. The generation of geomaterials ash for the purpose of soil stabilization concrete and asphalt modification has encouraged greenhouse emissions but eventually the technology that has been put in place has made it possible to manage and extract these emissions for energy needs. The contribution from researchers has shown that hydrogen sequestration from other sources requires high amount of energy because of the lower energy states of the compounds undergoing thermal decomposition. But this work has presented a more efficient approach to release hydrogen gas which can easily be extracted and stored to meet the energy needs of the future as fuel cell batteries to power vehicles mobile devices robotic systems etc. More so the development of MXene as an exfoliated two-dimensional nanosheets with permeability and filtration selectivity properties which are connected to its chemical composition and structure used in hydrogen gas extraction and separation from its molecular combination has presented an efficient procedure for the production and management of hydrogen gas for energy purposes.

This paper presents experiments performed at Canadian Nuclear Laboratories (CNL) to examine the dispersion behaviour of helium in a polycarbonate enclosure that was representative of a residential parking garage. The purpose was to gain a better understanding of the effect of buoyancy- or winddriven natural ventilation on hydrogen dispersion behaviour. Although hydrogen dispersion studies have been reported extensively in the literature gaps still exist in predictive methods for hazard analysis. Helium a simulant for hydrogen was injected near the centre of the floor with a flow rate ranging from 5 to 75 standard litres per minute through an upward-facing nozzle resulting in an injection Richardson number ranging between 10-1 and 102. The location of the nozzle varied from the bottom of the enclosure to near the ceiling to examine the impact of the nozzle elevation on the development of a stratified layer in the upper region of the enclosure. When the injection nozzle was placed at a sufficiently low elevation the vertical helium profile always consisted of a homogenous layer at the top overlaying a stratified layer at the bottom. To simulate outdoor environmental conditions a fan was placed in front of each vent to examine the effect of opposing or assisting wind on the dispersion. The helium transients in the uniform layer predicted with analytical models were in good agreement with the measured transients for the tests with injection at lower elevations or with no wind. Model improvements are required for adequately predicting transients with significantly stratified profiles or with wind.

In this paper a new gasification system is developed for the three useful outputs of electricity heat and hydrogen and reported for practical energy applications. The study also investigates the composition of syngas leaving biomass gasifier. The composition of syngas is represented by the fractions of hydrogen carbon dioxide carbon monoxide and water. The integrated energy system comprises of an entrained flow gasifier a Cryogenic Air Separation (CAS) unit a double-stage Rankine cycle Water Gas Shift Reactor (WGSR) a combined gas–steam power cycle and a Proton Exchange Membrane (PEM) electrolyzer. The whole integrated system is modeled in the Aspen plus 9.0 excluding the PEM electrolyzer which is modeled in Engineering Equation Solver (EES). A comprehensive parametric investigation is conducted by varying numerous parameters like biomass flow rate steam flow rate air input flow rate combustion reactor temperature and power supplied to the electrolyzer. The system is designed in a way to supply the power produced by the steam Rankine cycle to the PEM electrolyzer for hydrogen production. The overall energy efficiency is obtained to be 53.7% where the exergy efficiency is found to be 45.5%. Furthermore the effect of the biomass flow rate is investigated on the various system operational parameters.