Gas purification technologies

"Biomethane is obtained from the purification, or upgrading, of biogas, a mixture of carbon dioxide (CO2) and methane (CH4). Biomethane is considered a carbon-neutral energy source that makes use of waste to produce energy that can be injected into natural gas grids and also used as clean vehicle fuel. Current upgrading technologies, although established and mature, present a relatively high environmental and energetic cost, devaluing the carbon-neutrality of the biomethane production process.
The aim of this project is to develop materials for the purification of gas streams, with application in biogas upgrading. By developing efficient, sustainable and economic alternatives to the highly energy and chemical intensive multi-step operations currently in place we hope to contribute to the decrease of the GHG emissions of these purification operations.
The research will focus on strategies to gas purification issues in a comprehensive way with a variety of absorbents such as liquids, polymers and membranes. The objective is to design, produce, and evaluate these new materials to selectively scrub impurities, based for example in ionic liquids (ILs), deep eutectic solvents (DES), molten salts (MS), molecularly imprinted polymers (MIPs) and supramolecular materials such as cyclodextrins (CD). The materials will be tested as bulk liquid absorbents, supported or solid absorbents (to be applied in chemical looping scenarios) or as supported-liquid membranes.
This will involve a combination of organic and polymer synthesis techniques, combined with characterisation by NMR and mass spectroscopy, TGA (thermogravimetric analysis), DSC (differential scanning calorimetry), GC (gas chromatography), powder and single crystal X-ray and neutron diffraction. Gas purification ability and efficiency of new materials will be performed by headspace gas chromatography and by a multifunctional gas-liquid equilibria equipment designed by the research group.
The multifunctional gas system allows for the determination of gas solubility and selectivity under real conditions (pressures up to 5 bar, wide temperature range and mixed gas streams). The gases are added to a gas mixing chamber and the exact composition is determined by headspace gas chromatography (HS-GC via a GC vial adaptor). After equilibration with the liquid absorbents (in the equilibrium chamber) the headspace is again sampled to determine the composition change of the gas mixture. The temperature and pressure of the system are closely monitored by pressure transmitters. With this information and an appropriate equation of state we can calculate the real gas absorption capacity and selectivity provided by the absorbents.
Furthermore, the gas system also provides a safe and reliable way to perform the fast screening of absorbent materials. A large variety of absorbents can be quickly screened by addition to HS-GC vials that are then filled with gas mixtures at controlled compositions and pressures. Only the most promising absorbents, i.e. the highest selective absorption for one of the gases, are retained for detailed testing in the gas system. These results and tendencies observed will, in turn, allow for the design of optimised materials for biogas upgrading.
The works will be based in QUILL (the Queen's University Ionic Liquid Laboratories), which has excellent facilities for fundamental research on ionic liquids and strong links to industry and fosters a culture of interdisciplinary collaboration in an international environment, and appreciation for both high-quality science and collegial spirit.
Informal collaborations with partners organisations will allow the exchange of knowledge, ideas and research visits (if allowed by travel restrictions).

Informal project partner organisations:
Professor Sophie Fourmentin, ULCO, Dunkirk, France"