Developments and applications of electromagnetic tomography in process engineering

In the processing industry, monitoring, control, development and optimization are major performance improving activities. In this industry multiphase mixtures flow within enclosed domains such as process vessels or pipelines, with sometimes complex and harsh process conditions, such as high standards of hygiene or high temperatures and pressures, and require to be monitored and analysed for the purpose of continuous improvements in process control. Electromagnetic Tomography (EMT) is a promising tomographic technique which employs contactless non-invasive inductive sensing coils to evaluate the passive electromagnetic properties of what exists within a sensing domain. Although the potential applications of EMT are widespread throughout various industries such as the medical, environmental, geological and mining industries, this paper focuses on evaluating research focused on applications of this promising technique to the processing arena, with the purpose of identifying research gaps for future evaluation. Research in this area has been divided into two groups based on their purpose: developments in the technique with the purpose of enhancing its capabilities, and exploring the technique's various applications. As one of the more recent tomography techniques, EMT still has a lot of potential remaining to be discovered which would come about with further advancements in its hardware, i.e., sensor unit and excitation unit, and also with improvements in the data processing unit, i.e., data reconstruction. Combining different modalities, which would expand the capabilities of the resulting unit, is an interesting area with high potential, requiring further exploration. EMT remains to be studied in the future on countless other processes, unit operations and media and for several objectives. The application of EMT to other areas such as Food, Dairy, Pulp and paper processes also remain to be developed.