Dimitrios Tsaoulidis

Extraction of {UO2}2+ in Intensified Separators of Different Sizes Using Ionic Liquids

In this work the extraction of dioxouranium(VI) from aqueous nitric acid solutions (3M) into TBP/ionic liquid mixtures (30% v/v), is studied in intensified small scale separator channels of different sizes. High speed imaging is used to obtain the important hydrodynamic features of the flow (i.e. plug velocity and plug length) which are related to mass transfer and extraction efficiency. It was found that the overall mass transfer coefficients varied between 0.07 and 0.24 s−1 and increase by decreasing the channel size. The extraction efficiency was also affected by the channel size. A decrease in channel size leads to higher extraction efficiencies, while for a certain channel size the extraction efficiency decreases by increasing the mixture velocity.

Conclusions and Future Developments

The worldwide energy demand is growing rapidly, whilst the use of fossil fuels becomes an unattractive solution because of reduced availability and impact on climate change. Nuclear energy is currently considered as a serious low carbon alternative which can provide sufficient amounts of energy using only a small amount of fission material. Moreover, the pressing demands of sustainable, efficient and safer processes make operations in intensified small scale devices an appealing option.

Circulation Patterns and Mixing Characteristics of Liquid-Liquid Flows in Small Channels

In this chapter, circulation patterns and mixing characteristics within aqueous plugs were investigated by means of μ-PIV (micro Particle Image Velocimetry).

Liquid-Liquid Mass Transfer Using Ionic Liquids

In this chapter the mass transfer during liquid-liquid plug flow in small channels is presented. The extraction of dioxouranium(VI) ions from nitric acid solutions into TBP/IL mixtures (Table 3.2), relevant to spent nuclear fuel reprocessing was investigated.

Liquid-Liquid Flows in Micro and Small Channels: Hydrodynamics and Pressure Drop

In this chapter the hydrodynamic characteristics and the pressure drop of liquid-liquid flows in small circular channels are presented. Two liquid-liquid flow systems are considered for the experiments, i.e. ionic liquid-deionised water, and TBP/ionic liquid (30 % v/v)-nitric acid solutions. The channels tested were made either of glass or Teflon. Channel sizes varied in internal diameter from 0.2 to 2 mm.

Modelling of a Micro-Extractor

In liquid-liquid systems several parameters that affect the performance of the extractor (with or without chemical reaction) such as channel size, flow patterns, fluid properties, mixing zone, and flow orientation have been investigated

{UO2}2+ Extraction Using Ionic Liquids in Intensified Extractors

The extraction of dioxouranium(VI) from aqueous nitric acid solutions (3M) into TBP/ionic liquid mixtures (30% v/v), relevant to spent fuel reprocessing, was investigated experimentally in intensified small channel extraction units. The intensified extractor consisted of a “T” shaped inlet and a FEP channel of 0.5 mm internal diameter. Important hydrodynamic characteristics such as, plug length, and plug speed were determined by means of bright field imaging, and were related to the extraction performance of the extraction unit. The amount of dioxouranium(VI) extracted was measured online by using UV-Vis spectroscopy.Copyright