DE10118616A1 - Extracting substance from liquid comprises contacting it with non-miscible liquid, setting up oscillating reaction producing product with higher solubility in second liquid and separating it - Google Patents

Abstract

Extracting a substance from a first liquid (F1) comprises: (a) forming a contact surface with a second liquid (F2), which is not miscible with F1, in a reaction chamber; (b) setting up and maintaining an oscillating reaction in which the substance oscillates between two states, in one of which it has a higher solubility in F2; (c) enriching its content in this state in F2; (d) separating the liquids; and (e) separating the substance from F2. An Independent claim is included for an apparatus for carrying out the above process.

Description

With the help of an oscillating, catalytic reaction in one fluid ( 1 ), in a second fluid ( 2 ) that is immiscible with ( 1 ), oscillating substances ( 5 ) that are directly or directly involved in the reaction in ( 1 ) are indirectly involved, extract and enrich.

The oscillating extractions can be carried out in reactors with a volume in the range from pico-liters (10 ^-12 l) (microreactors; approx. 10 µm diameter) up to the order of liters (laboratory scale).

State of the art

It is known to use two immiscible fluids for extraction. The different solubility of the substance to be extracted (E) in the two fluids ( 1 ) and ( 2 ) leads to the fact that the substance (E) to be extracted accumulates in one of the two fluids. For this purpose, the two fluids are closely mixed and separated again after extraction. The substance (E) to be extracted is only present in one state in ( 1 ), which often makes it difficult to separate it from other substances that are almost equally soluble in the fluids ( 1 ) and ( 2 ) by means of extraction.

It is known that in an oscillating catalytic reaction (e.g. Beloussow-Zhabotinskii reaction, Briggs-Rauscher reaction) the concentrations of the substances involved in the reaction ( 5 ) including the intermediates (Z) and catalysts (K) (e.g. B. Cerium, ruthenium complexes, ferroin, manganese) change over time. In particular, it is known that the state of the catalyst also changes over time in an oscillating catalytic reaction. The concentration of these catalyst states (K1) and (K2) in ( 1 ) (e.g. Ce ³⁺ and Ce ⁴⁺ ) also changes with time in an oscillatory manner.

It is known that substances in different states (e.g. with different valences of ions) have different solution and complex formation behavior compared to the same fluid ( 2 ).

Object of the invention

The object of the invention is to use oscillating catalytic reactions in the fluid ( 1 ) in order to extract reaction participants ( 5 ) therefrom with the aid of the fluid ( 2 ).

Solution of the task

The components of the oscillating catalytic reaction are introduced into a reactor together with the fluid ( 1 ) in such a way that the reaction assumes an oscillating or chaotic state. The substances to be separated and extracted (E1 to EN) (e.g. lanthanides, actinides) are separately dissolved in a low concentration in a mixture with other substances, also in the fluid serving as a solvent ( 1 ). This solution is also fed continuously to the reactor. Suitable measures must be taken to ensure that the desired state of oscillation or chaos is reached or that it remains.

The solution consisting of the fluid ( 2 ) and suitable additives is continuously added in such a way that the state of oscillation or chaos in the fluid ( 1 ) is retained, but a large phase interface is nevertheless formed between the two fluids ( 1 ) and ( 2 ).

By means of a suitable mixing of the two immiscible fluids ( 1 ) and ( 2 ), a large phase interface is generated, via which the extraction from the fluid ( 1 ) into the fluid ( 2 ) takes place.

The two fluids are then separated in a conventional manner using a separator.

Possible designs M1 Macro-Reactors - Laboratory-scale reactors M11 single reactor ( Fig. 1)

In the case of the use of reactors on a laboratory scale (from a volume of a few milliliters (approx. 8 ml) to a few liters, the fluid ( 1 ) is preferably a flow-through stirred tank reactor which is operated under CSTR conditions The fluid ( 2 ) enters the fluid ( 1 ) in finely divided form in order to produce a large phase interface and is drawn off, together with the extract, over the outlet (A2), cleaned of the extracted substances and returned to the process The other outlet (A1) is mixed with the fluid ( 1 ) with all the substances involved in the reaction drawn off according to the inflow, worked up and returned to the process.The other possibility is discontinuous operation of the individual reactor on a laboratory scale the reactor is filled with the oscillating fluid ( 1 ) and with the bottle serving as extractant uid ( 2 ) overlays. The oscillating reaction then also takes place under CSTR-like conditions, but in batch mode, so that the oscillatable system is always in a transient state. In principle, certain stationary oscillatory or chaotic states cannot be maintained in this way, but the extraction can also be carried out in this way, especially at low cost.

M12 Coupled Reactors - Double Reactor ( Fig. 2)

In the case of laboratory-scale reactors, there is another very efficient embodiment Specify the shape of the oscillating extraction. It consists of two masses together coupled reactors.

Together with the substances to be extracted (E1 to EN), the fluid ( 1 ) is placed in the first continuously stirred reactor in such a way that the state of oscillation or chaos can be maintained in a controlled manner. The fluid ( 1 ) is overlaid with the fluid ( 2 ).

The oscillating fluid ( 1 ) is then preferably transferred to the second continuously stirred reactor, where it is also constantly in a controlled state of oscillation or chaos. Here too, the fluid ( 2 ) is overlaid, which is fed continuously from the first reactor.

This fluid ( 2 ) of the second reactor is directly pumped back into the first reactor. After a certain time, part of the fluid ( 2 ) is removed from this circuit and processed.

The fluid ( 1 ) from the second reactor leaves it constantly at a low rate and is worked up.

In this way, a high efficiency in the separation performance of the extractables can be achieved Fabrics E1 to EN.  

M2 mini-reactor system ( Fig. 3) M21 light / potential coupled oscillating extraction ( Fig. 4)

In the case of a mini reactor (approx. 0.01 - approx. 8 ml), the desired oscillatory or chaotic operating state is achieved by self-control of several mini reactors working in parallel, which interact with each other via light and / or the electrical potential in the fluid ( 1 ) are coupled. Both fluids ( 1 ) and ( 2 ) with their respective components and the solution consisting of the fluid ( 1 ) and the substances to be extracted (E1) are fed separately to the reactor. The electrical potential of the reaction is tapped u. U. zeitver sets (0 ≦ Δt) passed on to the reactors as a light signal or electrical signal.

The phase separation of the fluid ( 2 ) loaded with the extract from the fluid ( 1 ) takes place after leaving the reactor via a membrane separation or conventionally via a separator. The fluid "cleaned" from the extract ( 2 ) as well as the cleaned fluid ( 1 ) and its components are fed back into the reactor.

M22 Oscillating emulsion extraction

In the case of a Minni reactor, a second method for oscillatory extraction can also be used. It is based on the hydrodynamic structure formation in the interface between immiscible fluids ( 1 ) and ( 2 ) flowing past one another.

To achieve a large interface, it is necessary for the extractant (fluid ( 2 )) to be finely dispersed in very small bubbles, emulsified in the fluid ( 1 ).

Here also care should be paid to that the volume of permeated with bubbles of the fluid (2) fluid (1) is large enough to be able to maintain an oscillation or chaos state. A static "micromixer" (IMM patent .. No. ..) can be used to produce a corresponding emulsion. The actual reactor, in which the oscillatory extraction takes place, connects to the emulsion generator.

The control to maintain the state of oscillation or chaos takes place again via the potential / light coupling between those separated in terms of mass transport several micro-emulsion reactors operated from one another, as in the case of the mini-reactors described or by direct control of the individual reactors.

The phase separation of the fluid ( 2 ) loaded with the extract from the fluid ( 1 ) takes place conventionally via separators after leaving the micro-emulsion reactor. The fluid ( 2 ) "cleaned" from the extract as well as the cleaned fluid ( 1 ) and its components are fed back into the reactor.

M3 micro-reactor plants ( Fig. 5, 6)

When using microreactors (volume less than about 0.01 ml) a Rohrman telströmung is used - the fluid ( 1 ) with the oscillating substances and the substance to be extracted (E1) or the intermediate product (Z) is enveloped by the extraction fluid ( 2 ). This ensures that the reactor volume necessary for maintaining the oscillation state or the state of chaos can be made available by choosing a suitable length or a suitable diameter for the interior of the jacket reactor. This also ensures the necessary size of the contact surface between the two immiscible liquids.

The control to maintain the state of oscillation or chaos takes place again via the potential / light coupling between those separated in terms of mass transport several jacket reactors operated from one another as described for the mini-reactors or by direct control of the individual reactors.

The phase separation of the fluid ( 2 ) loaded with the extract from the fluid ( 1 ) takes place after leaving the reactor via a membrane separation or conventionally via a separator.

The fluid "cleaned" from the extract ( 2 ) as well as the cleaned fluid ( 1 ) and its components are fed back into the reactor.

benefits

With regard to their dissolving behavior, very similar substances are conventionally difficult to separate by extraction. These include a. the elements of the lanthanides and the acti halides. But different isotopes of an element can also be created in this way with high Separate efficiency

The oscillating extraction uses the change of state of the redox catalysts (K) and their thus changing solution behavior in the fluid ( 2 ) in order to extract and separate the catalyst K and chemically related substances (E1 to EN).

The oscillating extraction has the advantage of extracting intermediate products (Z) which are difficult to access from the reaction system into the fluid ( 2 ).

In particular, radioactive materials and isotopes can be extracted by oscillating extraction fectively separated from one another and wastewater is recycled

When using mini or micro reactors, large contact areas can be very fast extraction processes can be realized.

When using mini or microreactors, the system can control itself a complex external control (e.g. chaos control) of the individual mini or microsys There are no systems, which considerably minimizes the investment costs per reactor can do what is necessary with higher throughputs and thus several reactors would.

In the case of the laboratory reactor, external non-linear control of the non-linear Pro zesses (oscillation state) or external chaos control (in the case of the chaos state) of the  desired oscillation state or chaos state used for the high effective extraction become.

Claims (1)

1. A method for extracting a substance (E) to be extracted from a first fluid ( 1 ) by means of a second fluid ( 2 ), the first fluid ( 1 ) not being miscible with the second fluid ( 2 ) and being in contact with the two fluid forms a phase boundary and in the first fluid (1) an oscillating catalytic reaction, in particular a Belousov-Zhabontinskii reaction or a Briggs-Rauscher reaction proceeds, so that the concentration of at least one substance contained in the first fluid (1) ( 5 ) changes in an oscillating time, the substance (E) to be extracted having a different solubility or a different complexing behavior in the two fluids, characterized in that the second fluid ( 2 ) is supplied and removed from the first fluid ( 1 ) in a manner is that the oscillating reaction in the first fluid ( 1 ) does not come to a standstill.