Gas separation technologies

Abstract

Biomethane is a sustainable alternative to fossil gas and has recognized potential to contribute to global net zero goals. It can be directly injected in the gas grid, used as vehicle fuel or to generate electricity. However, a major challenge to the increased uptake of this renewable energy source is the need for costly and complex stripping steps to remove impurities from biogas for biomethane production. This project centers around carbon dioxide/methane (CO2/CH4) separation, which is the major separation in biogas upgrading. The goal is to create industrially viable systems which could potentially replace those found industrially today. We therefore judge these materials initially on capacity and selectivity for CO2 over CH4 but also on relevant factors such as viscosity, cost and stability. DES have been proposed as an alternative solvent for this process. Chapter 1 focused on biogas upgrading in general followed by emerging technologies which may be used in the future. In chapter 2 a full literature review of CO2 solubility in DES has been carried out. This was followed by description of a new methodology to measure gas solubility in various classes of materials in chapter 3. In chapter 4 phosphine oxide based DES are investigated for their ability to strip multiple common contaminants from a biogas stream. The final chapter consists of a synthesis for a deuterated randomly methylated beta-cyclodextrin which was then used for neutron scattering experiments investigating the liquid structure of SUPRADES.

Date of Award	Jul 2025
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	EPSRC Internal Schemes
Supervisor	Leila Moura (Supervisor)