Adsorption of carbon dioxide on solid amine

Developing efficient technologies for carbon capture is one of the biggest challenges of the future. Therefor, adsorption-based processes are considered to be very promising methods and amine-functionalized solid sorbents emerge as the most suitable materials for this task. To judge the techno-economic viability of such new materials, the investigation of process performance is necessary. Yet accurate but simple models representing the thermodynamic and kinetic properties of these materials are still lacking. For instance, the kinetics of CO2 adsorption on amine-functionalized sorbents are still widely discussed. Common pseudo-first-order and pseudo-second-order models cannot describe the corresponding adsorption kinetics accurately. In comparison, Avrami’s kinetic model and the generalized fractional-order kinetic model are more suitable to describe experimental data. Unfortunately, for these models the adsorption kinetics are a power function of the adsorption time. But, the fitted parameters of Avrami’s kinetic model and the generalized fractional-order kinetic model often depend on the specific operation conditions, e.g. CO2 mole fraction or temperature, and any reasonable correlation between the operation conditions and adsorption parameters can be derived. Furthermore, the time dependence makes the models unsuitable for the simulation of dynamic and periodic processes such as temperature swing adsorption. Too overcome these severe limitations, we present a dual kinetic model (DKM). We show that the model can describe the adsorption and desorption kinetics for different amine-functionalized materials surprisingly well, even more accurately than time-dependent adsorption models. This new model can now be easily incorporated into dynamic swing adsorption simulations to investigate new carbon capture processes.

中文翻译：

开发高效的碳捕集技术是未来最大的挑战之一。因此，基于吸附的方法被认为是非常有前途的方法，并且胺官能化的固体吸附剂作为用于该任务的最合适的材料而出现。为了判断此类新材料的技术经济可行性，必须对工艺性能进行调查。然而，仍然缺乏表示这些材料的热力学和动力学性质的准确而简单的模型。例如，CO 2的动力学胺官能化吸附剂上的吸附仍在广泛讨论。普通的伪一级和伪二级模型不能准确地描述相应的吸附动力学。相比之下，Avrami动力学模型和广义分数阶动力学模型更适合描述实验数据。不幸的是，对于这些模型，吸附动力学是吸附时间的幂函数。但是，Avrami动力学模型和广义分数阶动力学模型的拟合参数通常取决于特定的操作条件，例如CO 2可以得出摩尔分数或温度，以及操作条件和吸附参数之间的任何合理相关性。此外，时间依赖性使模型不适用于动态和周期性过程（例如变温吸附）的模拟。为了克服这些严格的限制，我们提出了双重动力学模型（DKM）。我们表明，该模型可以很好地描述不同胺官能化材料的吸附和解吸动力学，甚至比时间依赖性吸附模型更准确。现在，可以轻松地将此新模型合并到动态摆动吸附模拟中，以研究新的碳捕获过程。