Study of CO2 adsorption into various functional adsorbents : a thermodynamic framework with experimental investigation

• Main Author: Ong, Wee Jiat
• Other Authors: Anutosh Chakraborty
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/78571
• Institution: Nanyang Technological University

Over the past decade, greenhouse gases are constantly being increased, and one of the main greenhouse gases is carbon dioxide (CO2). The increasing levels of CO2 is becoming a major concern, and researchers around the world are finding ways to reduce CO2. One popular performed method of Carbon Capture and Storage (CCS) is in the underground. Adsorption is another method, where CO2 can be captured in the confined space of adsorbent materials. Zeolites and Metal Organic Frameworks (MOFs) are generally used in CCS. Therefore, the project deals with the study of CO2 gas adsorption employing volumetric methods. The research objectives are to measure the characteristics of zeolites and MOFs by N2 adsorption method, and finally the CO2 uptakes are measured for various temperatures and pressures. In this project, two zeolites, namely AQSOA-Z01 and AQSOA-Z02, and two MOFs, namely Aluminium Fumarate and MIL-101 (Cr), are experimentally tested using a volumetric setup. The experiments are conducted at temperatures ranging from 280K to 320K, at pressures up to 10 bar. The calibration of the equipment is performed to minimise errors, thus improving the accuracy as well as the precision of raw experimental data. Although the synthetization of adsorbent requires the use of energy hence introducing more CO2 into the atmosphere, the experimental analysis of CO2 adsorption is justifiable as the captured CO2 can be further reused for industrial applications, i.e., production of welding systems, refrigerated systems, and carbonated beverages. The amount of CO2 is calculated as a function of time for various temperature and pressure. Based on the data under equilibrium conditions, isotherms are plotted. Later, isosteric heats with respect to various uptakes are calculated by pressure-temperature uptake co-ordinate system i.e. Clausius-Clapeyron equation for three different temperatures of 280K, 300K and 320K. At 300K, AQSOA-Z02 zeolite shows the best CO2 adsorption capacity at low pressure (below 2 bar) as compared with other adsorbents, which is a new finding in the project. However, at higher pressure (above 2 bar), MIL-101 (Cr) MOF shows the best uptake results. On the other hand, the uptake rates for ALFUM are found faster at 300K.