Development of novel nanocomposite membranes and facilitated transport membranes for CO2 capture

Abstract

The implementation of Carbon Capture and Storage (CCS) is a critical action to reduce the CO2 emissions from power production and industrial sources and thereby reach the 2 °C target of the Paris Agreement. There are several advantages of using membranes for CO2 separation compared to more conventional separation methods. First of all, due to the absence of chemicals released during the separation process, it is a more environmentally friendly method. It has a low footprint and the potential for lower energy consumption. In order to be used at an industrial scale, membranes with both high efficiency (CO2 throughput/ CO2 flux) and purity (CO2/N2 selectivity) are needed. The current commercially available polymeric membranes do not meet this efficiency requirement. The goal of this PhD project has therefore been to improve the separation performance of polymeric membranes. To achieve this goal, hydrophilic facilitated transport membranes and novel bio-based nanocomposite membranes have been developed. The facilitated transport membranes take advantage of the facilitated transport mechanism, the quick reaction of CO2 promoted by carriers and the high diffusion rate of gases or ions in water swollen polymers. In the nanocomposite membranes, the introduction of hydrophilic nanocellulose creates water-rich pathways that improves the CO2 transport. Although the interest in applying nanocellulose in membrane fabrication has increased in the recent years, systematic investigation of nanocellulose properties and how it can optimize CO2 separation performance is limited and is hence investigated in the current project. It has been demonstrated that both types of membranes developed in this work have a higher efficiency as compared to the reference polymeric membranes. Moreover, tailored nanocelluloses were developed in this project and used as nanofillers in nanocomposite membranes, which may promote the exploitation of bio-products from one of Norway's most important natural resources, i.e. trees. The success of the proposed new technology could significantly reduce the environmental and climate impacts.