Towards a novel approach to capture CO2 in hierarchically organized chemically functionalized materials

燃烧产生的CO2的捕获将仍然是碳基能源使用的可持续长期情景中的关键任务。为了解决这个问题，有必要开发在高空速下具有快速有效的CO2吸收的材料，这些材料在水蒸气存在下稳定并且易于再生。为了应对这一挑战，提出了基于知识的开发一种新型的分级结构的胺官能化的二氧化硅基颗粒材料家族。在该项目中，我们已经确定胺基的密度和可及性是设计成功材料的关键参数。与伯，仲和二元胺基团的功能化进行了研究和CO2和基本功能之间的局部相互作用进行了研究。分子间的相互作用占主导地位的二元分子中的碳链似乎是不够灵活的分子内结合的CO2，这将是有利的有效捕获CO2。因此，我们建议开发的材料，这将使CO2与两个胺基团存在于同一胺分子锚定的SiO2球的相互作用。由于CSS工艺将在不干燥烟道气流的情况下进行，因此我们将讨论表面化学、宏观吸收能力和水蒸气存在下的吸收速率。将研究吸附和再生过程的动力学，并优化孔隙系统的直径和疏水性。作为项目的最后一点，我们将评估CO2吸附剂的反应再生概念，这将允许直接将与H2结合的CO2转化为甲醇等能量载体。这将有助于克服目前在CO2储存方面的限制，并能够在偏远的CO2排放源异地利用这项技术。

The capture of combustion generated CO2 will remain a critical tasks in a sustainable long term scenario for carbon based energy use. To address this issue, the development of materials with fast and efficient CO2 uptake at high space velocities, which are stable in presence of water vapor and easy to regenerate, is necessary. To address this challenge, the knowledge-based development of a novel family of hierarchically structured amine functionalized silica based particulate materials is proposed. Within the project we have already identified the density and accessibility of the amine groups to be crucial parameters for the design of a successful material. Functionalization with primary, secondary and bibasic amine groups was investigated and the local interaction between CO2 and the basic functionality was studied. Intermolecular interactions dominated as the carbon chain in the bibasic molecules appeared to be not flexible enough for an intramolecular binding of CO2, which would be advantageous for an efficient capturing of CO2. Thus we propose to develop materials which will enable the interaction of CO2 with two amine groups present in the same amine molecule anchored to the SiO2 spheres. As the CSS processes will be carried out without drying the flue gas stream we will address the surface chemistry, the macroscopic uptake capacities and the uptake rates in the presence of water vapor. The kinetics of the adsorption and regeneration processes will be investigated and the diameters as well as the hydrophobicity of the pore systems will be optimized. As final point in the project we will evaluate concepts for a reactive regeneration of the CO2 sorbents, which shall allow to directly convert the CO2 bound on the materials with H2 to energy carries such as methanol. This will allow to overcome the current restrictions in CO2 storage and enables delocalized utilization of this technology at remote CO2 emission sources.