Enhancing CO_2 Adsorption Capacity and Cycling Stability of Mg-MOF-74

摘要

Mitigation of carbon dioxide emitted from burning fossil fuels is essential to overcome climate change issues. Adsorptiontechnology could significantly help in capturing CO_2 and, thereby minimizing global warming with low-cost penalties. Mg-MOF-74 was reported as a distinguished adsorbent that has high adsorption capacity at flue gas conditions. In the presentstudy, an improvement of crystallinity, porosity, and capacity of Mg-MOF-74 was investigated through controlling the heatsurface area of the sample solution during the synthesis process. The results showed that the increase in the heat surface areaduring the synthesis process increased BET surface area and pore volume of the adsorbent by 38% and 44%, respectively,over those obtained by the reported method in the literature. For additional improvement in the cyclic CO_2 uptake, multiwalledcarbon nanotubes (MWCNT) were incorporated with Mg-MOF-74. The adsorption cycling stability was performedusing three techniques: temperature swing adsorption (TSA), vapor swing adsorption (VSA), and temperature vacuum swingadsorption (TVSA). It was observed that the incorporation of MWCNT with Mg-MOF-74 resulted in higher CO_2 recyclingcapacity (14.4%) using thermal-based regeneration processes (i.e., TSA and TVSA) due to the enhancement in the thermaltransport properties of the new composite (MWCNT/Mg-MOF-74).