Nearly two thirds of global carbon emissions are created by small polluters including vehicles and diesel power generators. The purpose of this PhD research project is to study the feasibility of a Hollow Fibre Based Adsorption System for onboard carbon capture. For this we propose different CO2 solvents (i.e. ionic liquids, carbon xerogels, and metal organic frameworks) to be studied. Taking into account the industrial importance of the topic, this PhD research project is a collaboration between the School of Engineering (University of Edinburgh) and Repsol S.A. (Spain), a world-leading company in the energy sector.
Our hypothesis is that 40-50 Vol% of the CO2 emitted in mobile applications can be captured using a Hollow Fibre Based Adsorption System (see Fig.1). This novel technology consists of two major components: (i) outstanding CO2 solvent (i.e. ionic liquid, carbon xerogel, and metal organic framework), (ii) high surface area to volume ratio micro-structured hollow fibre substrate.
Ionic liquids, carbon xerogels, and metal organic frameworks have been proposed as a feasible alternative for currently available CO2 solvents due to their ability to capture this molecule at low temperature and pressure. Likewise, as can be seen in Fig. 2, hollow fibre based micro-structured supports offer unprecedented surface area to volume ratios without compromising pressure drops. As a result, the CO2 solvent loading can be significantly increased per volume unit. In addition, the morphology of the hollow fibre support allows the CO2 solvent being evenly spread, overcoming the major limitation faced by traditional packed-bed column systems for carbon capture.
Compared to traditional carbon capture systems (i.e. packed-bed column systems), the Hollow Fibre Based Adsorption System is: i) more efficient since the micro-structured support intensifies the contact between the reactants and the CO2 solvent and improves the residence time distribution, ii) provides design flexibility since it is smaller due to the high surface area to volume ratio of the hollow fibre ceramic support. This PhD research project has three main objectives: (i) Synthesis and design of multichannel high surface area to volume ratio hollow fibre ceramic supports, (ii) Identify the most promising CO2 solvent so it can be deposited inside the hollow fibre ceramic support, (iii) Proof of concept for the application of a Hollow Fibre Based Adsorption System for carbon capture under both pre-combustion and post-combustion typical operation conditions.