High Resolution Electrical Capacitance Tomography using insights from Magnetic Resonance Imaging and Compressed Sensing

The performance of many key industrial processes, from amine scrubbing in carbon capture technology to Fisher-Tropsch synthesis of next generation liquid fuels, is determined by the complex dynamics inherent to multiphase flows. In an effort to aid our understanding of these flows, advanced tomographic techniques including magnetic resonance imaging (MRI) and electrical capacitance tomography (ECT) have been developed. However, the spatial and temporal resolution of these techniques is limited, which has restricted their ability to provide the fundamental experimental evidence needed to improve our understanding of multiphase flows. This project seeks to improve the spatial and temporal resolution of both ECT and MRI by exploiting recent developments in the field of compressed sensing.

The overall goal of this study will be to develop methods to study the dynamics of multiphase flows over a hierarchy of length scales, from the micro-scopic processes such as interfacial drag through to macro-scopic processes such as flow regime transitions. To achieve this, it is proposed to use MR and ECT in a complementary manner. This has great importance industrially and academically because MR cannot be used for large-scale reactors, whereas ECT, which could provide almost equivalent information, is applicable to both laboratory- and process-scale equipment. Furthermore, ECT has not yet been accepted as a widespread diagnostic tool because of uncertainty surrounding the image reconstruction. By performing a direct comparison of ECT and MRI on similar scale systems this project will be able to provide a quantitative demonstration of the accuracy and resolution that is achievable with ECT.

Multiphase flows underpin crucial processes in the production of clean energy - from the safe cooling of nuclear reactors, through to the technology behind both pre- and post-combustion carbon capture and storage (CCS) and throughout the chemical industry. At present industrial processes that rely on multiphase flow are over-sized by factors of between 30% and 100% in order to ensure that the process performs to design specification. This over-sizing leads to significant increases in the cost of these processes and in the emissions associated with the process. In CCS technologies, where efficiency is particularly critical, the increases in costs associated with this oversizing can make capture technology impractical economically. The research proposed here will provide a detailed set of experimental measurements that will feed directly into the latest numerical modelling techniques being developed for multiphase flows. These new modelling techniques will enable significant efficiencies in the design and operation of chemical processes, including CCS technologies, thereby reducing their cost and increasing their economic viability. Furthermore, there is an increasing trend toward producing transportation fuels using e.g. the Fisher-Tropsch gas-to-liquid technique, which is dependent on multiphase flow reactors. The higher quality fuels that result from this process have been estimated to improve the efficiency of automotive engines over conventional petrol engines by 20 - 40%, which would translate into a reduction in global CO2 emissions from transport alone of at least 300 million tons annually - in addition to any benefit that may result from these fuels being derived from biomass. Therefore, this research will reduce global CO2 emissions through reduced energy demand and improved capture technologies.

To ensure that the results of this research are disseminated as widely as possible, the work will be published in a variety of international, peer reviewed journals; pre-prints of the work will be made available on the PI's website. In addition, the work will be presented at a variety of international meetings including the International Conference on Multiphase Flow and the World Congress on Industrial Process Tomography. The PI is co-organising the upcoming International Conference on Magnetic Resonance Microscopy, where the work will also be show-cased. Furthermore, the PI will continue to work with a variety of industrial partners to ensure that the research is translated into industrial practice.