Synthesis of Zeolite 13X and 4A Monolith for CO2 Adsorption

Abstract

Fossil fuels are one of the most abundant fuel resources in the world, the combustion of which fulfills much of our energy needs. Such energy resources with high CO2 emissions contribute a lot to global climate change. To alleviate the atmospheric concentration of CO2, some tangible measures are required. Carbon capture and storage is a technique that has presented some promising results toward the reduction of climate change and global warming. Carbon capture is the most important part of the process. Gas separation has made extensive use of solid adsorbents. Nonporous inorganic materials called zeolites have applications as adsorbents in carbon capture. This thesis explores the fabrication, characterization, and adsorption analysis of 13X and 4A zeolites, monolith synthesized using these zeolites and their mixture. Zeolite 13X + 4A monolith had the highest uptake of carbon dioxide. Zeolites have the potential for a wide range of applications, because of their large surface area, specific pore sizes, low cost, and molecular sieving ability. The zeolite samples were analyzed for adsorption and desorption activities of CO2 using a high-pressure sorption analyzer, also analyzed their surface characteristics were studied and morphology using SEM analysis, and X-ray diffraction to see the crystallinity of samples, and the presence of different functional groups was confirmed using FTIR spectroscopy. At a temperature of 50°C and a pressure of 0-15 bar, the adsorption and desorption of these samples were investigated. In general, monoliths are synthesized with high surface area, easy-to-regenerate, defined structure designs, and high pore volume presenting higher adsorption/desorption capacity for carbon dioxide. Zeolite 13X+4A had the highest molar adsorption of 4.90mmol/g amongst the five studied samples. The monolith of zeolite 4A and 13X had the adsorption capacity of 2.50 and 3.68 mmol/g, respectively. While the 4A and 13X had an adsorption capacity of 1.20 and 2.94 mmol/g, respectively. Also, the adsorption of carbon dioxide increased in each case with the increase in pressure because of higher collisions.