Dimitrios Tsaoulidis' Webpage

Photo of Dimitrios Tsaolidis Postgraduate Researcher

Phone: +44 (0)20 7679 2643
Email: dimitrios.tsaoulidis.10@ucl.ac.uk
Department of Chemical Engineering
University College London
Torrington Place
London WC1E 7JE
United Kingdom

Dimitrios Tsaoulidis received his five-year Diploma in Chemical Engineering, which is equivalent to Master of Science in Engineering degree (MSc), from the Department of Chemical Engineering of the Faculty of Engineering, at Aristotle University of Thessaloniki in Greece.

During his studies he obtained two extra certificates, namely, “Certificate in Energy” and “Certificate in Food-Biotechnology” by attending many laboratory experiments and successfully completing extended reports. In addition, he managed to accomplish a comprehensive thesis concerning the “Technological and economical evaluation of an industrial Formaldehyde production unit”.

His Diploma Thesis “Hydrogen Production via water-splitting in the thermo-chemical sulfur-based cycles: The catalytic decomposition of sulfuric acid into SO­­2 and O­­2” was part of a general Project (HYCYCLES) and was elaborated in the CERTH (The Centre for Research & Technology Hellas).

Research project

Title: Development of micro-extractors for the intensification of the liquid-liquid separations in the spent nuclear fuel reprocessing cycle

Supervisors: Dr Panagiota Angeli

The worldwide energy demands are growing rapidly whilst the sources via fossil fuels seems to become an unattractive solution due to their availability and their impact on the climate change. Renewable energy sources seems to be an alternative to fossil fuels, but their limitations such as high cost implementation, low efficiency and limited storage capacity confine their use. Nuclear energy is currently considered as a serious alternative due to its sufficient amounts of energy produced using only a small amount of fission material and due to negligible amounts of carbon or other pollutants generated in the process. However, one of the main concerns in the use of the nuclear energy is the management of the radioactive waste from the nuclear reactor which can remain toxic for thousands of years. Currently only about a third of the nuclear reactor effluent (spent nuclear fuel) is recycled (spent fuel reprocessing) while the rest needs to be disposed of. Efficient spent fuel reprocessing can reduce both the volume and the toxicity of the waste to be stored.

Liquid-liquid extractions are one of the main processes in reprocessing, usually carried out in micro-settlers or centrifugal reactors. Such units are complex and not well characterised which brings severe limitations to their efficiency and ability to scale up. The pressing demand on sustainable, portable, efficient, cheaper and safer flow processes makes micro-fluidic devices an attractive option for chemical, bio-chemical, and energy applications for operation including, synthesis, extraction, production, analysis, and screening. In the small channels the thin fluid films formed enhance mass transfer rates while the high surface to volume ratio increases the importance of interfacial phenomena and favours the formation of regular patterns with well characterised properties (such as segmented flow). In order to design and control precisely a micro-device it is essential to have a good understanding of the hydrodynamic flow characteristics of the various flow patterns, pressure drop, and mass and heat transfer rates.

The extraction processes developed for spent nuclear fuel treatment and recovery utilize organic solvents that are volatile, hazardous, toxic, flammable and unstable towards the radiation and heat generated by spent nuclear fuel. Since the undesirable properties of these conventional solvents may pose several threats and problems both to plant operation and to environment, ionic liquids (ILs) have been suggested as alternatives to organic solvents because of their negligible volatility and flammability at common industrial conditions, which reduce solvent loss and make them inherently safe and environmentally friendly. Ionic liquids are salts that are liquid even at room temperature.

The aim of this project is to develop micro-extractors that can intensify the liquid-liquid separations occurring during the nuclear spent fuel reprocessing cycle using advanced process engineering experimental and modelling methodologies. A systematic study on the extraction of U(VI) from nitric acid solutions (aqueous phase) by TBP dissolved in diluents such as ionic liquids (ILs) or other organic diluents in microchannels will be conducted.

The National Nuclear Laboratory (NNL) will be involved in the project.

Selected publication

Tsaoulidis, D., Dore, V., Seddon, R.K., Plechkova, V.N., Angeli, P. (2011) Liquid-liquid flows in microchannels. 3rd Micro and Nano Flows Conference 2011.

Page last modified on 15 sep 11 09:47