Adsorptive gas dehydration with supported ionic liquids

负载型离子液体吸附气体脱水

基本信息

批准号：
213570037
负责人：
Professor Dr.-Ing. Andreas Jess
金额：
--
依托单位：
Lehrstuhl für Chemische Verfahrenstechnik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2012
资助国家：
德国
起止时间：
2011-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/213570037?language=en
关键词：
Adsorptive gas dehydration supported ionic

项目摘要

In the course of the DFG-project, which was completed in November 2015, ionic liquids (ILs) have been successfully studied with regard to their use for drying of gases by absorption (gas scrubbing). As a result, it has been found that the IL [EMIM][MeSO3] is a suitable alternative to triethyleneglycol (TEG) currently used for industrial gas drying and surpasses the TEG in important performance features: The required height of the adsorption column is lower compared to TEG; losses due to evaporation in the regeneration step are avoided because of its very low vapor pressure and the much lower regeneration temperatures needed; furthermore its stability against oxidation enables regeneration of the IL with air as stripping agent; in contrast, TEG is sensitive to oxygen. Based on these results first measurements with supported ionic liquid ([EMIM][MeSO3] on silica) have shown that such a system can be also used for gas drying. A main advantage is the much lower regeneration temperature compared to commonly used adsorption agents such as silica gel or zeolites. Within the applied new research project (application for continuation of funding), this research on supported ILs for gas drying should be continued in order to get a better and deeper insight into the new adsorption system. (Remark: Strictly speaking, steam is absorbed in the ionic liquid, which is supported on porous solid; nevertheless, the term adsorption is used here, because parallel to the absorption in the IL a real adsorption may also take place on the solid support and the process is conducted in a fixed bed typically for adsorption.) In addition to the already (partly) characterized IL [EMIM][MeSO3], two other promising ionic liquids, [EMIM][acetate] and [EMIM][Cl], are of interest for detailed investigation. At first, the focus lies on the determination of the important physicochemical data for gas drying (activity coefficient of H2O, vapor pressure) of the remaining two ILs; in addition, systematic measurements with regard to the thermodynamics of H2O-adsorption (adsorption isotherms) have to be conducted. Based on these measurements, the decision will be made which combination of IL and porous support is the best for further studies in a fixed-bed adsorber. Thereby, the pore filling degree as well as the particle size has to be varied in order to determine the influence of mass transfer (pore diffusion) on the kinetics of adsorption. This will be experimentally explored by the analysis of breakthrough curves and the height of the transfer zone, respectively. Along with these experiments, modelling of the adsorption process in the fixed-bed is crucial, on both the level of a single particle as well as the entire fixed-bed. Therefore, the differential equations considering the processes in a single particle (diffusion, adsorption) and in a fixed-bed have to be solved; by comparison of the data gained in the simulations with the experimental data, the adsorber model can be proven.

在2015年11月完成的DFG项目过程中，已经成功地研究了它们通过吸收（气清除）来干燥气体的使用。结果，已经发现IL [EMIM] [MESO3]是当前用于工业气体干燥的三乙二醇（TEG）的合适替代品，并超过了重要性能特征的TEG：与TEG相比，吸附柱的所需高度较低；由于其非常低的蒸气压和所需的更低的再生温度，因此避免了由于再生步骤蒸发而造成的损失；此外，其对氧化的稳定性使IL以空气为剥离剂再生；相反，TEG对氧气敏感。基于这些结果，用支持的离子液体（[EMIM] [Meso3]）的首先测量表明，这种系统也可用于气体干燥。与常用的吸附剂（例如硅胶或沸石）相比，重新生成的温度要低得多。在应用的新研究项目（用于延续资金的应用程序）中，应继续进行对燃气干燥的ILS的研究，以便对新的吸附系统更好，更深入地了解。（备注：严格地说，蒸汽在离子液体中被吸收，该液体在多孔固体上得到支持；但是，此处使用了术语的吸附，因为与IL中的吸收相似，因为在固体支撑上也可能会在固体支撑上进行真正的吸附，并且该过程也可以在固定的床上进行，并在固定的床上进行了两次，通常是在固定的床上进行。液体，[EMIM] [乙酸]和[EMIM] [Cl]是详细研究的关注。首先，重点在于确定其余两个IL的重要物理化学数据（H2O的活性系数，蒸气压力）；此外，必须进行有关H2O-AD吸附热力学（吸附等温度）的系统测量。基于这些测量值，将决定哪种IL和多孔支持的组合是在固定床的吸附者中进一步研究的最佳方法。因此，必须改变孔隙填充度以及粒径，以确定传质（孔扩散）对吸附动力学的影响。通过分析突破曲线和转移区的高度，将对这一实验进行实验探讨。除了这些实验外，在单个粒子和整个固定床的水平上，固定床中吸附过程的建模都是至关重要的。因此，必须求解单个粒子（扩散，吸附）和固定床中的过程的微分方程；通过比较模拟中获得的数据与实验数据，可以证明吸附者模型。