DE3239992A1 - Process for converting chemical energy into electrical energy with thermal regeneration - Google Patents

Abstract

The invention relates to a process for converting chemical energy into electrical energy, wherein electrochemical cells similar to those usual in batteries and accumulators deliver a utilisable current. The electrodes discharged when current is taken are recharged in a continuous process. For this purpose, the electrodes are moved into other cells and/or the recharging is effected in a changed electrolyte which allows a reversal of the discharge step at a voltage lower than the discharge voltage. The change in the electrolyte is effected by heating and concentrating in the low-temperature range. In the present invention, copper electrodes are predominantly used, of which some dip into aqueous ammonia solution and some dip into liquid ammonia. In this way, a potential difference of about 1 volt between the discharge step and charge step can be exploited. <IMAGE>

Description

Process for converting chemical into electrical

Energy with thermal regeneration Electrical energy from chemical The advantage of processes is that they are generally without conscious parts and therefore without the sound of stepping in a machine can be won, anytime and instantly is available and that the system in which it is produced is usually only minimal Maintenance required.

Dom opposes as a disadvantage, among other things, that the cl trochemical Cells from which the energy is obtained either gur not as in @ rimärelement, for example d @ Leclanche element, or only on with serious powers are rechargeable in different ways.

Recharging tolls often involves expensive energy like the electric current that is supplied from the outside and is also not available everywhere is, so for the .e i r with the lead or Hickel cadmium accumulators, od @@ d @@ exchange of electrodes and electrolytes such as the B @ is @@ in some zinc-air elements or by thermal @@@ ration as applied in cells with lithium hydride @@ The The present invention is intended primarily for the regeneration of used cells Bring progress over early @ procedures.

The recharge of used cells is history through @@ partial current from the cells that supply electricity to cells with a modified electrolyte, which is responsible for recharging with low voltage enables s @ the voltage difference to be available in the discharge process between discharging with high voltage and charging with low voltage is used for Generation of usable electricity. The energy required for this is aug @@@@ ll of the cells added in the form of heat. It causes the change in the electrolyte in the Way that the recharge of the cells can be done with low voltage.

In the end, only one is needed to regenerate the used electrodes Heat source from the low temperature range (up to 1000 C) required.

The system is hermetically sealed. The parts that will bet are moved slowly so that the device ir, Principle for a long time Time o) lne substantial change in the ability to work can be carried out.

The present invention makes use of the peculiarity that certain metals in different electrolytes have very different potentials can have. Very high potential differences with simultaneously high electrical Conductivity and easy separability of the electrolytes as well as good feversibility of the electrode processes occur in a system in which electrodes made of copper, Silver or mercury on the one hand in concentrated ammonia solution or liquid Immerse ammonia and, on the other hand, in weak ammonia solution. The potential difference for example between copper in aqueous solution and copper in liquid ammonia is approx. 1 volt (see W.A. Pleskow in G. Kortüm, textbook on electrochemistry, Weinheim 1972, page 323). In the main marriage it arises from the fact that it is liquid Ammonia higher ammoniacates of copper to Cu (NH3) 10 ++ are formed, which in aqueous solution are not stable and can be replaced by Aquokomplexe.

Except for a combination of liquid ammonia or more concentrated Ammonia solution with dilute aqueous ammonia solution is also available instead of the latter in combination with methyl alcohol, acetonitrile, CH3CN and other solvents conceivable.

There is a wall to prevent the two electrolytes from mixing required in the cells. It can bribe from an ordinary diaphragm, However, if the conductivity is sufficiently high, this is generally a fairly large diffusion between the electrolyte. Ion exchange membranes are also possible, but better partitions made of conductive material that is porous, for example active carbon, and its pores with a liquid ion exchanger such as D @ EHPA (Di = (@ - ethylbexylphosphoric acid)) are filled. It then just finds. an exchange of ions without mixing the Electrolytes instead.

According to a proposal of the invention (Fig. 1), the electrodes (1) arranged to be rotatable about an axis (2). With one that is impermeable to electricity and ions Partition wall (3) and an irenu wall (4) permeable to electricity and ions become four Sub-cells educated. If the slices are pressed evenly and smoothly, they prick themselves always the same halves of the electrode disks facing each other and immersing alternately in the two different electrolytes, liquid ammonia in the sub-cells (5) and aqueous ammonium salt solution in the sub-cells (6). the electrode halves are alternately to the anode and. to the cathode. When an external connection is made and copper electrodes are used, will be located in the sub-cells that are connected to liquid ammonia, a complex copper compound bil @ which is in liquid Ammonia is not soluble. When turning @ electrodes this complex connection becomes hydrolyzed by the aqueous solution and it becomes metallic by the passage of current Copper deposited on the Elcktrode, the further turning of the electrode in the Partial cells with flüs @@ ammonia are oxidized again to the complex compound so that the potentials of two electrode halves are not within the electrode disks by a short circuit @, the electrode disks are in electrical disconnection divided into separate segments. The segments, each of which is immersed in a partial location, can deliver their electrical spansur via a collision gate (7).

According to another proposal of the invention (Fig. 2) are @ electrode disks (8) can be used on both sides, for example a porous electrically conductive material is used The electrode disks are separated from each other by partitions (9) so that that a series connection is effected. l @ Electrode disks can be used in this The arrangement of the partial cells must be electrically conductive throughout, since a @ r @ the same electrode halves are not facing each other.

When using copper electrodes, the copper is in the sub-cells oxidized with liquid ammonia (10) to a complex compound, which is then after Rotation of the electrode t 180 ° in other sub-cells (11) hydrolyzed and again is reduced to copper. The copper created in this way passed a further turn 180 ° back into a sub-cell with liquid ammonia, where it again becomes a complex Compound is oxidized.

A special feature of this arrangement is the part cells how otherwise copper will be oxidized or reduced in the cells because the electrodes will not be pushed more into other sub-cells in which the process surrounds itself.

That sub-cell at one end of the row in which the anode (12) should therefore contain an aqueous solution of ammonium chloride. at The passage of current results from nitrogen trichloride through a pipe is pumped into the sub-cell at the other end of the row, in which the cathode (13) is located. The nitrogen trichloride is reduced again to ammonium chloride and transported back to the first sub-cell.

Instead of the redox process, ammonium chloride / nitrogen trichloride another redox process such as Fe II / Fe III or Sn II / Sn IV can also be used or Ti II / Ti III step.

flat a third proposal of the invention instead of the discs ribbon-shaped electrodes are used.

A tape (14) can be used according to a design (Fig. 3), which runs through all cells one after the other and connected to an endless belt may be. The tape should be made of strip-shaped electrodes (15), which cross are arranged to the direction of travel. As long as the electrodes pass the cells, like they are connected in an electrically conductive manner at the edge by a chain-like connection (16) be. The electrical connection should be interrupted at at least one point can be used to allow the electrical petentials from the cells through collectors (17) can be tapped.

The interruption may take place in such a way that the chain-like connection the single lump separated into two part chains like a zipper and is reunited. (See Fig. 2 The current can only flow as long as the electrically conductive pins (18) of the two partial chains interlock.

According to another design (Fig. 5), a belt (19) runs through only two Sub-cells. ES can be electrically conductive throughout and can form several cells into one Connect a series connection.

In the case of cells operated with belts, it is recommended that the transition point of the tape from the anode to the cathode compartment through a non-conductive liquid to isolate.

This liquid should be used for easier separation from the electrolyte lower transition (20) heavier than the electrolyte and at least at the upper transition (21) be lighter than the existing solution.

According to a fourth proposal, the invention relates to movable discs or ribbons are dispensed with at all (Fig. 6) u instead @ partitions made of mercury or other suitable metals such as antimony are used, which are transported with the z Form cations such as, for example, copper alloy (22). About transportation of copper to Example that in the partial cell (23) filled with aqueous solution at the cathode deposited, migrates by diffusion through the cathode and can in the with liquid Ammonia or concentrated ammoniacal solution-filled partial cell (24) is oxidized will. It is advisable not to use liquid ammonia alone in sub-cell (23), but a mixture of liquid ammonia and water that has sufficient solubility for the complex copper salts, so that these n @ an evaporation of the ammonia in an apparatus au @ c @@ the cells, the aqueous solution can be fed back can. The other partitions (25) are just as written above b.

When the cells are in operation, the higher ammonia levels in copper, which is formed in concentrated ammoniacal solution or in liquid ammonia were, upon movement, the dilute aqueous solution hydrolytically split, i.e.

the ammine complex is replaced by an aquokomplez and ammonia accumulates in the solution. Another hon @ tration of the evaporated ammoniacal Solution occurs b current increase through the migration of M4 + ions through the dividing wall, or the ion exchanger. At the same time a concentration of ammonium arises In the watery lion To maintain a constant charge the cells need the increasing concentrations of ammonia and ammonium salt in the aqueous solution.

This is expediently done in known evaporator devices in which the volatile ammonia evaporates in the heat.

The vapors are cooled and can be under the evaporation.

condense pressure.

The ammonium salt likes because of its lower solubility in cold The solution crystallizes out by cooling outside the cells and the concentrated Ammoniaklö solution or the liquid ammonia are fed.

Claims (14)

Process for converting chemical into electrical energy with thermal regeneration P a t e n t a n s p r ü c h e 1. Process and device to convert chewic energy into electrical energy, d u r c h e k e n n n dignifies that you use a chemical redox system that is regenerated by heat is cash. 2. The method according to claim 1, d a d u r c h g e k e n n z e i c h n e t that liquid ammonia and ammonia solution are used. 3. The method according to claim 2, d a d u r c h g e k e n n z e i c h n e t, that hydrazine is used instead of ammonia. 4. The method according to claim 1, d a d u r c h g e k e n n z e i c h N e t, since copper, silver or mercury are used as electrodes. 5. The method according to claim 1, d a d u r c h g e k e n n z e i c h with amalgam electrodes or Elcktroden, with metals diffusing, such as copper through antimony. 6. The method according to claim 1, d a d u r c h g e k e n n z e i c h n e t, because for the roenerating of the electrolyte ammonia or hydr @@ in @ its solution is evaporated and condensed. 7. The method according to claim 6, d a d u r c h g e k e n n z e i c h n e t, de @ the solvent is absorbed and driven again by heating. 8. Device for converting chemical energy into electrical energy according to claim 1, d a d u r c h g e k e n n z e i c h n e t that gie from several Cells, each separated by partitions such as Diaph a @ men, Membraneno or Iorenauschermomb @@ en are divided. 9. Apparatus according to claim 4, d a d u r c h g e k e n n z e i c n e t, the electrodes are arranged drchbar about their axis. 10, the device according to claim 9, characterized in that the Electrodes consist of electrically separated segments that are tapped with collocators can be. 11, the device according to claim 9, d a d u r c h e k e n n z e i n e t that the electrodes can be used on both sides, so that they can be used when drilling another sub-cell not of the previous counterelectrodo but of a different electrode face. 12, the device according to claim 8, d a d u r c h g e k e n n z e i c h n e t that the partition between the sub-cells is electrically conductive and porous and contains a liquid ion exchanger in the @ores. 13. The apparatus of claim 8, d a d u r c h g e k e n n z e i c h n e t that ribbon-shaped electrodes are used. 14.Vorrichtung according to claim 13, d a d u r c h g e k e n n z e i c h n e t that the band-shaped electrodes consist of strip-like partial electrodes.