ABSTRACT
Various toxic and flammable gases exist in the fertilizer industry whose release quantification is very important regarding emergency preparedness, planning and response, and well-being of the community. ALOHA threat zones and threat at a point coupled with MARPLOT are evaluated for ammonia, methane, carbon dioxide and hydrogen release, and outdoor and indoor concentrations of these gases in nearby residences and highways calculated. These footprints are calculated using ALOHA which requires inputs such as site data, site location, building type, gas name, atmospheric inputs, release source information and dispersion model to display the threat zone, which can then be shown on MARPLOT. Potential impact of these releases on the community is mitigated through releasing equipment isolations, water sprays for dilutions, dilutions through steam or air and emergency sirens for information. This article covers hazards in the fertilizer industry, and provides general guidelines for operational staff of any industry to mitigate hazards.
ABSTRACT
In this study, BaZr0.87Y0.1M0.03O3-δ perovskite electrolytes with sintering aids (M = Mn, Co, and Fe) were synthesized by a sustainable approach using spinach powder as a chelating agent and then compared with chemically synthesized BaZr0.87Y0.1M0.03O3-δ (M = Mn, Co, and Fe) electrolytes for intermediate temperature SOFCs. This is the first example of such a sustainable synthesis of perovskite materials with sintering aids. Structural analysis revealed the presence of a cubic perovskite structure in BaZr0.87Y0.1M0.03O3-δ (M = Mn, Co, and Fe) samples synthesized by both green and conventional chemical methods. No significant secondary phases were observed in the samples synthesized by a sustainable approach. The observed phenomena of plane shift were because of the disparities between ionic radii of the dopants, impurities, and host materials. The surface morphology analysis revealed a denser microstructure for the electrolytes synthesized via green routes due to metallic impurities in the organic chelating agent. The absence of significant impurities was also observed by compositional analysis, while functional groups were identified through Fourier-transform infrared spectroscopy. Conductivity measurements showed that BaZr0.87Y0.1M0.03O3-δ (M = Mn, Co, and Fe) electrolytes synthesized by oxalic acid have higher conductivities compared to BaZr0.87Y0.1M0.03O3-δ (M = Mn, Co, and Fe) electrolytes synthesized by the green approach. The button cells employing BaZr0.87Y0.1Co0.03O3-δ electrolytes synthesized by the chemical and green routes achieved peak power densities 344 and 271 mW·cm-2 respectively, suggesting that the novel green route can be applied to synthesize SOFC perovskite materials with minimal environmental impact and without significantly compromising cell performance.
ABSTRACT
The massive use of non-renewable energy resources by humankind to fulfill their energy demands is causing severe environmental issues. Photocatalysis is considered one of the potential solutions for a clean and sustainable future because of its cleanliness, inexhaustibility, efficiency, and cost-effectiveness. Significant efforts have been made to design highly proficient photocatalyst materials for various applications such as water pollutant degradation, water splitting, CO2 reduction, and nitrogen fixation. Perovskite photocatalyst materials are gained special attention due to their exceptional properties because of their flexibility in chemical composition, structure, bandgap, oxidation states, and valence states. The current review is focused on perovskite materials and their applications in photocatalysis. Special attention has been given to the structural, stoichiometric, and compositional flexibility of perovskite photocatalyst materials. The photocatalytic activity of perovskite materials in different photocatalysis applications is also discussed. Various mechanisms involved in photocatalysis application from wastewater treatment to hydrogen production are also provided. The key objective of this review is to encapsulate the role of perovskite materials in photocatalysis along with their fundamental properties to provide valuable insight for addressing future environmental challenges.
