CAREER: On the Prevention of Selenium and Arsenic Release into the Atmosphere

职业：关于防止硒和砷释放到大气中的建议工作的目标是帮助防止挥发性金属，硒和砷从煤燃烧的烟气中释放出来。已经开展了广泛的研究工作，旨在捕获汞并了解其在烟气中的形态，但对化学复杂的烟气环境中的硒和砷所知甚少。拟议的研究还将检查捕获这些微量元素的新型吸附剂技术，并确定其保留的机制。模型开发将通过高水平从头算能量学计算进行。提出的研究活动将通过发展两个动力学模型来推动发现，这将首次阐明硒和砷在钙基吸附剂上的保留机制。此外，拟议的计划还包括制定一项高中外展计划，该计划将涉及本科生培训高中教师将计算化学和分子建模技术纳入其科学课程。研究和教育活动的结合将通过在课堂上结合分子计算应用来促进理解，这将为大学和高中学生提供使用基于多媒体的有效教学方法获得对化学相互作用更深层次理解的机会。了解烟气环境中硒和砷的形态对于开发控制其排放的有效技术至关重要。涉及这些物质的均相反应将通过从量子力学推导的势能面得到的速率常数的理论预测来检验。包括相对论效应的有效核心势将被纳入基集，这将在使用二次配置相互作用（QCI）和耦合簇（CC）技术的所有计算中进行。非均相反应研究也将进行，以阐明机制负责砷和硒的钙基吸附剂的保留。非均相速率常数预测将通过使用电感耦合等离子体质谱计（ICP-MS）对反应吸附材料的分析进行实验验证。总的来说，这项研究将使科学界受益，因为将对燃烧过程烟气中这些微量元素的形态有更深入的了解，并进一步了解涉及捕获它们的方法。这项拟议中的研究可能对社会产生的影响是可能防止这些有毒元素释放到大气中。

CAREER: On the Prevention of Selenium and Arsenic Release into the AtmosphereThe goal of the proposed work is to aid in the prevention of the release of the volatile metals, selenium and arsenic, from the flue gases of coal combustion. There have been extensive research efforts aimed at capturing mercury and understanding its speciation in flue gases, but not as much is known of selenium and arsenic in the chemically complex flue gas environment. The proposed research will also examine novel sorbent technologies for the capture of these trace elements, and a mechanism responsible for their retention will be determined. Model development will take place through high level ab initio energetics calculations. The research activities proposed will advance discovery through the development of two kinetic models that will elucidate, for the first time ever, the mechanism of retention of selenium and arsenic on calcium based sorbents. In addition, the proposed plan includes the development of a high school outreach program, which will involve undergraduate students training high school teachers on the incorporation of computational chemistry and molecular modeling techniques into their science courses. The research and educational activities combined will advance understanding through the incorporation of molecular computational applications in the classroom, which will provide both college and high school students the opportunity to gain a deeper understanding of chemical interactions using multimedia-based approaches for effective teaching. Understanding the speciation of selenium and arsenic in the flue gas environment is essential for developing effective technologies to control their emissions. Homogeneous reactions involving these species will be examined through the theoretical prediction of rate constants obtained from quantum mechanical derived potential energy surfaces. Effective core potentials that include relativistic effects will be incorporated into the basis sets, and this will be carried out for all calculations using both Quadratic Configuration Interaction (QCI) and Coupled Cluster (CC) techniques. Heterogeneous reaction investigations will also take place to elucidate the mechanisms responsible for the retention of arsenic and selenium on calcium-based sorbents. Heterogeneous rate constant predictions will be experimentally validated through the analysis of the reacted sorbent material using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS). In total, this research will benefit the scientific community in that there will be a greater understanding of the speciation of these trace elements in the flue gases of combustion processes and also further understanding on methods involving their capture. The impact that the proposed research could have on society is the possible prevention of the release of these toxic elements into the atmosphere.