NSF/EPA Partnership for Environmental Research: New Methods for Carbon Dioxide Separation and Recovery [TSE01-F]

NSF/EPA 环境研究伙伴关系：二氧化碳分离和回收的新方法 [TSE01-F]

• 批准号: 0124445
• 负责人: Mary Rakowski DuBois
• 金额: $ 37.5万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-15 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0124445&HistoricalAwards=false
• 关键词: NSF; EPA; Partnership; Environmental; Research

CTS-0124445New Methods for Carbon Dioxide Separation and Recovery M. Rakowski DuBois and R. D. NobleUniversity of Colorado, Boulder, CO AbstractThe broad objective of this project is to develop an efficient electrochemical pumping process for separating an acid gas from emission sources and concentrating it for recovery and/or disposal. The electrochemical pumping approach is being applied to the specific problem of removing and recovering CO2 from dilute gas streams. The research activities include the identification and synthesis of appropriate molecular carriers for CO2. Three different types of molecular-based carriers for CO2, which differ in their advantages and disadvantages, are being evaluated. In one approach, a redox-active quinone is reduced to produce a base of sufficient strength to bind CO2 directly in absorption from the waste-stream source. After CO2 is captured in this manner, the quinone-CO2 complex is oxidized electrochemically to release concentrated CO2 and to regenerate the oxidized form of the carrier. A second approach develops redox-active metal complexes that function in a similar cycle with bicarbonate ion. These have the advantage of being air-stable and water-soluble. A third approach investigates quinone carriers that produce an electrochemically controlled pH swing. CO2 is complexed at high pH by hydroxide ions generated by quinone reduction and released at low pH produced by quinone oxidation. Work on each carrier system includes electrochemical studies of the reaction-absorption rates and binding constants of CO2 as functions of carrier oxidation state and studies of the electrochemical-pumping systems to determine appropriate operating parameters, characteristics of reproducibility and stability, and energy efficiencies. In addition, process-modeling studies and investigations of absorption/desorption and related mass transport phenomena are being carried out. Current CO2 concentrations in the atmosphere have increased significantly from pre-industrial levels, and as the use of fossil fuels continues, CO2 levels will continue to rise. In this scenario, climate models predict a significant global warming with serious environmental impacts. Efficient methods must be developed in which CO2 is captured and stored for future use or sequestered in a stable form. The easiest point to capture CO2 is from the waste streams of large producers such as power plants, chemical plants, etc. before the CO2 is diluted by mixing with the atmosphere. It is estimated, however, that with today's best technology the recovery of CO2 from the exhaust of power plants will result in a 20-30% reduction in their overall efficiency. Estimates based on prior research and modeling studies suggest that an electrochemical pumping process with appropriate molecular carriers can be much more efficient than current conventional approaches for CO2 recovery. As appropriate carriers are developed, this process should find application in the efficient removal of CO2 as well as other acid gases from waste streams of industrial plants.

M. Rakowski DuBois和R. D. NobleUniversity of Colorado, Boulder, CO .摘要该项目的主要目标是开发一种高效的电化学泵送工艺，用于从排放源中分离酸性气体，并将其浓缩用于回收和/或处理。电化学泵送方法正被应用于从稀释气流中去除和回收二氧化碳的具体问题。研究活动包括鉴定和合成合适的CO2分子载体。目前正在评估三种不同类型的基于分子的CO2载体，它们的优缺点各不相同。在一种方法中，氧化还原活性醌被还原以产生足够强度的碱，以直接结合二氧化碳从废物流源吸收。在以这种方式捕获CO2后，醌-CO2络合物被电化学氧化以释放浓缩的CO2并再生载体的氧化形式。第二种方法是开发氧化还原活性金属配合物，它与碳酸氢盐离子在类似的循环中起作用。它们具有空气稳定性和水溶性的优点。第三种方法研究醌载体产生电化学控制的pH值波动。CO2在高pH下与醌还原产生的氢氧化物离子络合，在低pH下醌氧化产生的氢氧化物离子释放。每个载体系统的工作包括对反应吸收速率和二氧化碳结合常数作为载体氧化态函数的电化学研究，以及对电化学泵送系统的研究，以确定适当的操作参数、再现性和稳定性的特征以及能源效率。此外，正在进行过程模拟研究和吸收/解吸及有关的质量传递现象的调查。目前大气中的二氧化碳浓度已较工业化前水平显著增加，而且随着化石燃料的继续使用，二氧化碳浓度将继续上升。在这种情况下，气候模型预测全球变暖将带来严重的环境影响。必须开发有效的方法，以捕获和储存二氧化碳以供将来使用或以稳定的形式隔离。捕获二氧化碳最容易的点是在二氧化碳与大气混合稀释之前，从发电厂、化工厂等大型生产商的废物流中捕获二氧化碳。然而，据估计，使用当今最好的技术，从发电厂的废气中回收二氧化碳将导致其整体效率降低20-30%。基于先前的研究和建模研究的估计表明，使用合适的分子载体的电化学泵送过程可以比目前的常规方法更有效地回收二氧化碳。随着适当载体的开发，这一过程应能有效地从工业工厂的废物流中去除二氧化碳和其他酸性气体。