Light gas solubility in Deep Eutectic Solvents under high pressure

Author(s)

Fernanda Paludetto Pelaquim

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2023-02-24

Examining board members

Mariana Conceição da Costa; Marcelo Lanza; Evertan Antonio Rebelatto; Klicia Araujo Sampaio; Rafael Mengotti Charin

• Advisor: Irede Angela Lucini Dalmolin; Mariana Conceição da Costa

Abstract

Increasing global levels of greenhouse gases (GHGs), especially CO2 emissions, cause environmental damage and problems that affect humanity and the ecosystem. Carbon dioxide (CO2) is the GHG that most contributes to these problems due to the combustion of coal, oil and natural gas, transportation, and other industrial processes. Carbon capture and storage (CCS) is an effective method for reducing CO2 emissions. Absorption is the most used technology to capture pre- and post-combustion CO2. Monoethanolamine (MEA) has proven to be the most efficient chemical solvent. However, MEA is environmentally harmful. The commercial Selexol process, which uses polyethylene glycol dimethyl ether as the physical solvent, is also widely used for CO2 capture, but its high viscosity increases operating costs. Thus, it is necessary to develop more environmentally friendly solvents for CO2 captures, such as Deep Eutectic Solvents (DESs) and eutectic solvents (ESs). DESs or ESs are formed by mixing up to three components of high purity and usually low cost, which, due to attractive forces, form a eutectic mixture. They can be produced on large scale, are biodegradable, and have been suggested in several studies as substitutes for organic solvents in the absorption of gases such as CO2, but only at atmospheric pressure. Thus, this Ph.D. project had as main objectives: (I) to determine the phase equilibrium diagram of six types of pure ESs at high pressures, up to 250 bar; (II) to obtain the CO2 solubility data in six ESs at high pressures, to verify which ES is the best gas absorber; (III) to study the influence of temperature and pressure on the absorption process; (IV) to perform thermodynamic modeling using equations of state and COSMO-RS for the solubility of light gases in ESs found in the literature. The data were modeled using Peng- Robinson and Cubic Plus Association (CPA) Equations of State (EoS) to predict the behavior of the phases and their properties as a function of pressure and temperature (AU)

• FAPESP's process: 18/19198-9 - Light gas solubility data determination in Deep Eutectic Solvents at high pressure
• Grantee: Fernanda Paludetto Pelaquim
• Support Opportunities: Scholarships in Brazil - Doctorate