Date of Award
Master of Science
Due to current global climate conditions, it has become imperative to reduce CO2 emissions all around the world. The capture of CO2 gas from the environment and storing it into carbon sinks (underground or oceanic storage) is well known as carbon sequestration. In this project, we seek to understand the feasibility of carbon sequestration through chemical reaction of CO2 gas and aqueous Ca(OH)2 which is known to generate CaCO3 precipitates. The experiments on displacement of aqueous glycerol Ca(OH)2 solution with different molar concentrations (0, 5, 10, 15 and 20 mM) and viscosity (0.186 and 0.437 Pa-s) by pressurized CO2 gas in a capillary tube were performed. The experiments were also performed for various volumes of aqueous glycerol Ca(OH)2 solution (15, 17.5, 20 and 22.5 µl) and different pressures of CO2 gas with a range of 0.2 psig < P < 1.0 psig with an increment of 0.2 psig.
The pendant drop experiments were conducted to measure the equilibrium surface tension values (γeq) of aqueous glycerol Ca(OH)2 solution in pressurized CO2 gas in order to obtain Capillary numbers, Ca . Further, the fluid fraction left in the capillary tube represented by `m' is calculated from the gas-fluid displacement experiments: m= (U-U_m)/U; where U_m is the mean velocity of the fluid ahead of the interface in the fluid displacement and U is the tip velocity of the interface. The experimental data for no-chemical reaction case and chemical reaction case are compared and analyzed through ‘m vs Ca’ plots. In contradiction to past studies, the experiments presented here are the first to study the fluid slugs displaced by a gas at constant pressure. We have observed a new m=〖Ca〗^(1/3) relation for the displacement with no chemical reaction and m= 〖Ca〗^(1/3.5) relation for the displacement with chemical reaction. The visual representation of gas-fluid interfaces for different liquid volumes and gas pressures were also interpreted.
Sasetty, Sravya, "CO2 sequestration in a capillary tube via an interfacial chemical reaction between pressurized CO2 gas and aqueous glycerol Ca(OH)2 solution." (2019). Graduate Theses and Dissertations. 17094.