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Core-shell composite phase change materials (PCMs) with a PCM core and non-PCM shell are promising for the latent heat thermal energy storage process. While the non-PCM shell layer could enhance the heat conductivity and cyclic stability of the material, it inevitably reduces the heat storage density of the composite materials. It is important to understand how various structural parameters impact the thermal conductivity of the core-shell composites and estimate the effective heat transfer coefficient and energy storage density of the core-shell composite PCMs. Using Open Pore Network Modeling (Openpnm), a python source code library for pore network modeling of porous media, we developed a one-dimensional transient heat transfer model to simulate Paraffin@SiO2, a paraffin-based core-shell PCM. The structural parameters were obtained from the Paraffin@SiO2 synthesized in our laboratory using the in-situ emulsion interfacial hydrolysis and polycondensation methods. The effects of various structural parameters of coreshell composite PCMs, including paraffin core diameter, SiO2 shell layer thickness, and SiO2 encapsulation rate, on the PCMs’ thermal energy storage properties, i.e., thermal energy storage density and effective heat transfer coefficient, were investigated. Moreover, the effects of material porosity on thermal storage properties were also studied. The modeling results would provide guidance for further optimization of the synthesis process and design of core-shell composite PCMs to meet different requirements in advanced energy systems., Résumé de la communication présentée lors du congrès international tenu conjointement par Canadian Society for Mechanical Engineering (CSME) et Computational Fluid Dynamics Society of Canada (CFD Canada), à l’Université de Sherbrooke (Québec), du 28 au 31 mai 2023.

Ammonia is a versatile chemical that is distributed and traded widely as a commodity for the fertilizer and refrigeration industries, and it also has the potential to be a low-emission fuel, hydrogen carrier and energy storage medium. Converting clean electricity to ammonia (i.e., power-to-ammonia, or P2A) is a critical process to decarbonize the use of ammonia in agriculture, transportation, and energy sectors. To understand the viability of P2A, we conducted a techno-economic analysis to study the electrified ammonia production process. The levelized cost of ammonia was found to be highly dependent on the electrolyzer efficiency and the plant’s capacity factor. Then, we designed a P2A plant using offshore wind power from Sable Island, Nova Scotia. Even though the offshore wind farms in Atlantic Canada are expected to have high-capacity factors, we still found it necessary to connect the plant with the electrical grid to maintain high ammonia outputs. Grid-connection, however, may raise the carbon intensities of the P2A process to a higher level than the conventional fossil-fuel based ammonia production. Furthermore, we studied the potential economic benefits and risks of using excess electricity for P2A in a combined ammonia use scenario, including local fertilizer sales, export, and energy storage. Results show that with higher prices and larger export demands for low-carbon ammonia, as well as technology development, the combined use scenario will be profitable compared with selling excess electricity at low prices., Résumé de la communication présentée lors du congrès international tenu conjointement par Canadian Society for Mechanical Engineering (CSME) et Computational Fluid Dynamics Society of Canada (CFD Canada), à l’Université de Sherbrooke (Québec), du 28 au 31 mai 2023.

AbstractMixed ionic‐electronic conducting (MIEC) membranes have gained growing interest recently for various promising environmental and energy applications, such as H2 and O2 production, CO2 reduction, O2 and H2 separation, CO2 separation, membrane reactors for production of chemicals, cathode development for solid oxide fuel cells, solar‐driven evaporation and energy‐saving regeneration as well as electrolyzer cells for power‐to‐X technologies. The purpose of this roadmap, written by international specialists in their fields, is to present a snapshot of the state‐of‐the‐art, and provide opinions on the future challenges and opportunities in this complex multidisciplinary research field. As the fundamentals of using MIEC membranes for various applications become increasingly challenging tasks, particularly in view of the growing interdisciplinary nature of this field, a better understanding of the underlying physical and chemical processes is also crucial to enable the career advancement of the next generation of researchers. As an integrated and combined article, it is hoped that this roadmap, covering all these aspects, will be informative to support further progress in academics as well as in the industry‐oriented research toward commercialization of MIEC membranes for different applications.

Bioavailability of weakly basic drugs may be disrupted by dramatic pH changes or unexpected pH alterations in the gastrointestinal tract. Conventional organic acids or enteric coating polymers cannot address this problem adequately because they leach out or dissolve prematurely, especially during controlled release applications. Thus, a non-leachable, multifunctional terpolymer nanoparticle (TPN) made of cross-linked poly(methacrylic acid) (PMAA)-polysorbate 80-grafted-starch (PMAA-PS 80-g-St) was proposed to provide pH transition-independent release of a weakly basic drug, verapamil HCl (VER), by a rationally designed bilayer-coated controlled release bead formulation. The pH-responsive PMAA and cross-linker content in the TPN was first optimized to achieve the largest possible increase in medium uptake alongside the smallest decrease in drug release rate at pH 6.8, relative to pH 1.2. Such TPNs maintained an acidic microenvironmental pH (pHm) when loaded in ethylcellulose (EC) films, as measured using pH-indicating dyes. Further studies of formulations revealed that with the 1:2 VER:TPN ratio and 19% coating weight gain, bilayer-coated beads maintained a constant release rate over the pH transition and exhibited extended release up to 18 h. These results demonstrated that the multifunctional TPN as a pHm modifier and pH-dependent pore former could overcome the severe pH-dependent solubility of weakly basic drugs.