Setting the foundations for a highly selective fractional crystallization scheme to capture carbon dioxide from coal-fired boiler emissions

在这个应用程序中，我建议奠定理论和实验基础，最终导致一个成本较低的技术，以消除二氧化碳从燃烧前或燃烧后的气体流的燃煤电厂。半笼形物是当气体如CO2与盐如四正丁基溴化铵（TBAB）的水溶液在适当的温度和压力条件下接触时形成的结晶材料。半笼形化合物与天然气水合物有许多相似之处。像气体水合物一样，半笼形物提供了能够选择性地捕获诸如CO2的分子的水分子的分子笼。然而，在TBAB的水溶液中形成的半笼形物在给定温度下在比气体水合物低得多的压力下形成。 尽管最近在理解半笼形物方面取得了进展，但在人们可以开始设计工业规模的方法以通过用TBAB半笼形物分级结晶来除去CO2之前，仍然缺少两个基本部分。第一个缺失的部分是计算水在固体半笼形物相中的化学势的热力学模型。由于TBAB分子直接将其自身以半笼形物的形式并入水分子网络中，因此描述气体水合物的热力学模型是无效的。其次，没有关于半笼形物形成的动力学的实验数据，这是形成半笼形物的工艺设备的详细设计所需要的。因此，本建议的范围是双重的，开发和测试的热力学模型计算的热力学性质的半笼形物，其次，获得实验数据的动力学半笼形物的形成和分解。应当指出，这些研究尚未以任何形式进行，这些研究的成功完成将有助于使加拿大处于半包合物研究的前沿。

In this application, I am proposing to lay the theoretical and experimental foundations that will eventually lead to a less costly technique to remove CO2 from either the pre- or post-combustion gas stream of a coal-fired power plant. Semi-clathrates are a crystalline material that form when gases such as CO2 are contacted with an aqueous solution of a salt such as Tetra-n-butyl ammonium bromide (TBAB) under the appropriate set of temperature and pressure conditions. Semi-clathrates have many similarities to gas-hydrates. Like gas hydrates, semi-clathrates provide a molecular cage of water molecules that are capable of selectively trapping molecules such as CO2. However, semi-clathrates formed in aqueous solutions of TBAB form at substantially lower pressures, at a given temperature, than gas-hydrates. In spite of the recent gains which have been made in understanding semi-clathraes, there are still two fundamental pieces missing before one can begin to design an industrial scale process to remove CO2 via fractional crystallization with TBAB semi-clathrates. The first missing piece is a thermodynamic model to compute the chemical potential of water in the solid semi-clathrate phase. Since TBAB molecules directly incorporate themselves into the network of water molecules in a semi-clathrate, the thermodynamic model that describes gas hydrates is not valid. Secondly, there are no experimental data available on the kinetics of semi-clathrate formation and this is required for the detailed design of process equipment in which semi-clathrates would be formed. Thus, the scope of this proposal is twofold; to develop and test a thermodynamic model for computing the thermodynamic properties of semi-clathrates and secondly, to obtain experimental data on the kinetics of semi-clathrate formation and decomposition. It should be noted that these studies have not been undertaken in any form and their successful completion will be a contribution that puts Canada at the forefront of semi-clathrate research.