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

职业：防止硒和砷释放到大气中

• 批准号: 0848283
• 负责人: Jennifer Wilcox
• 金额: --
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0848283&HistoricalAwards=false
• 关键词: CAREER; Prevention; Selenium; Arsenic; Release

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.

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燃煤烟气中释放。 已经有广泛的研究工作旨在捕获汞并了解其在烟道气中的形态，但对化学复杂的烟道气环境中的硒和砷知之甚少。 拟议的研究还将研究用于捕获这些微量元素的新型吸附剂技术，并确定负责保留这些元素的机制。 模型开发将通过高水平从头算能量计算进行。 提出的研究活动将通过两个动力学模型的开发来推进发现，这两个动力学模型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他们的科学课程。 研究和教育活动相结合，将通过在课堂上纳入分子计算应用，这将为大学和高中学生提供机会，获得更深入的了解化学相互作用，使用基于多媒体的方法进行有效的教学。 了解烟气环境中硒和砷的形态对于开发有效的技术来控制其排放至关重要。 涉及这些物种的均相反应将通过从量子力学推导的势能面获得的速率常数的理论预测进行检查。 有效的核心潜力，包括相对论效应将被纳入基组，这将进行所有的计算使用二次组态相互作用（QCI）和耦合集群（CC）技术。 非均相反应的调查也将发生，以阐明负责保留砷和硒的钙基吸附剂的机制。 将通过使用电感耦合等离子体质谱仪（ICP-MS）分析反应的吸附剂材料，对非均相速率常数预测进行实验验证。 总的来说，这项研究将有利于科学界，因为将有更多的了解这些微量元素在燃烧过程的烟道气中的形态，也进一步了解涉及其捕获的方法。 拟议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。