DE102019133916B4 - System and method for cleaning process gases resulting from the treatment of electrochemical energy storage devices - Google Patents

Abstract

System for cleaning process gases produced during the treatment of electrochemical energy storage devices (11) in connection with the recovery of valuable substances contained therein using at least one injection condenser (15) through which the process exhaust gases to be cleaned are passed, comprising at least one with one Lye-operated injection condenser (15), the gas inlet of which is connected or can be connected to a line carrying the exhaust gas to be cleaned, - a collecting tank (20) for collecting the condensate-cooling liquid mixture, which is fed via a condensate line (21) to the at least one injection condenser ( 15) is connected, - a caustic reservoir (17), which is connected to the collecting tank (20) via a caustic line (18) for introducing caustic solution, - a pump (24) for conveying cooling liquid from the collecting tank (20) into the injection condenser (15), - one in the flow path of the exhaust gases, the injection condenser Sator (15) downstream surface condenser (13) with a condensate collection tank (14) connected to it, - a suction pump (4) for conveying the exhaust gas through the process exhaust gas cleaning system (6) and - a controller for operating the process exhaust gas cleaning system (6), characterized in that - By means of the controller, the process exhaust gases are passed through the process exhaust gas cleaning system (16) up to a first temperature without the at least one injection condenser (15) being operated, but the surface condenser (13) connected downstream of the injection condenser (15) is in operation in order from to condense electrolytes carried along in the process exhaust gas, and that at process exhaust gas temperatures which are above this first temperature, the surface capacitor (13) is deactivated and the at least one injection capacitor (15) is activated.

Description

The subject matter of the invention is a system for cleaning process gases produced during processing of electrochemical energy stores in connection with the recovery of valuable substances contained therein using at least one injection condenser through which the process exhaust gases to be cleaned are passed. A method for operating such a system is also described.

Electro-chemical energy storage devices are rechargeable batteries such as lithium-ion accumulators, nickel-metal hydride accumulators and electrolytic capacitors. Such energy stores, in particular lithium-ion accumulators, are used as so-called stand-alone batteries, but to a greater extent also in the form of battery modules for operating electrical consumers, such as mobile computers, cell phones, power tools and, increasingly, also in connection with electromobility , especially used in relation to motor vehicles. The electro-chemical energy storage devices that are used for motor vehicles must have a high storage density and be able to store the required power. In many cases, these energy storage devices are high-voltage batteries.

The increasing use of such electrochemical energy storage systems, which can be observed worldwide, especially in connection with the increasing electromobility, leads to a growing number of disused energy storage systems, so-called end-of-life batteries or battery modules. The higher production rates to meet the increased demand have the consequence that the production scrap also increases in terms of quantity. In addition, the natural resources from which the elements required for the production of such energy storage devices are obtained are limited. Against this background, various approaches have been proposed to recover the raw materials contained therein as secondary raw materials from the electrochemical energy stores that can no longer be used - namely end-of-life batteries or battery modules as well as production waste. In order for such a process to establish itself on the market, it must be controllable and feasible at reasonable costs. In addition, such a process must be suitable that it can also be used to treat larger quantities, several 1,000 t per year.

For the thermal treatment of electrochemical energy storage devices, a vacuum furnace can be used, in which the thermal decomposition takes place. This is kept at a constant low pressure of less than 10 mbar over the entire thermal treatment period. The gases drawn off from the heated process chamber are fed to a process exhaust gas treatment facility for cleaning the process exhaust gases. Such a process exhaust gas treatment is from “WEYHE, Reiner Thomas; FRIEDRICH, Bernd; ACCUREC Recycling GmbH: Final report on the joint project EcoBatRec: Demonstration system for cost-neutral, resource-efficient processing of disused Li-ion batteries from electromobility. Mülheim ad R., 2016. pp. 1-113. URL: https://www.erneuerbar-mobil.de/sites/default/files/2017 - 01 / EcoBatRec_16EM1002.pdf [accessed on 2020-01-15] . - Company typeface known. In this previously known process exhaust gas treatment system, an injection condenser is used in order to remove pollutants carried along in the process exhaust gases by condensation. Oil is used as the coolant. The substances carried along, such as electrolytes, decomposition products, cracked products of the plastic components and the like, condense on the surface of the injected oil droplets, which is cool with regard to the temperature of the process exhaust gases. By this measure, the process exhaust gas is cooled at the same time.

The oil condensate mixture emerging from the injection condenser is collected in a collecting tank. In order to be able to use the coolant - oil - in a circuit, it must be separated from the condensate.

According to this prior art, the process exhaust gas cleaning system is connected to a vacuum furnace in which electrochemical energy stores, in particular lithium-ion accumulators, are thermally (pyrolytically) unlocked.

A system very similar to WEYHE (see above) for cleaning process gases that arise during the preparation of lithium-ion batteries is out CN 106362571 A known.

In DE 25 09 692 B2 a method for removing sulfur dioxide from exhaust gases is known. This process was developed to remove sulfur dioxide from the combustion gases of sulphurous coal. In this process, the exhaust gas is first brought into contact with an aqueous scrubbing solution in a gas scrubbing unit. This is then passed through a gas flow deaeration device, in which part of the wastewater is returned to the gas scrubbing unit. Another portion of the wastewater is fed to a thickening tank where salts are precipitated and a clarified overflow fluid is obtained. This in turn is fed to the gas flow deaeration device.

Even if this previously known process exhaust gas cleaning system can be used to remove contaminants from the process exhaust gases that arise during the thermal digestion of electrochemical energy storage devices, it would be desirable if the process exhaust gas cleaning system could be made simpler and more economical.

On the basis of the prior art described above, the invention is based on the object of proposing such a system. In addition, the invention is based on the object of providing a method with which such a system can be operated appropriately.

• - zumindest einen mit einer Lauge als Kühlflüssigkeit betriebenen Einspritzkondensator, dessen Gaseingang an eine das zu reinigende Abgas führende Leitung angeschlossen oder anschließbar ist,
• - einen Sammeltank zum Auffangen des Kondensat-Kühlflüssigkeitsgemisches, der über eine Kondensatleitung an den zumindest einen Einspritzkondensator angeschlossen ist,
• - einen Laugenvorrat, der zum Einbringen von Lauge in den Sammeltank über eine Laugenleitung mit diesem verbunden ist,
• - eine Pumpe zum Fördern von Kühlflüssigkeit aus dem Sammeltank in den Einspritzkondensator,
• - einen im Strömungsverlauf der Abgase dem Einspritzkondensator nachgeschalteten Oberflächenkondensator mit einem daran angeschlossenen Kondensatsammeltank,
• - eine Saugpumpe zum Fördern des Abgases durch die Prozessabgasreinigungsanlage und
• - eine Steuerung zum Betreiben der Prozessabgasreinigungsanlage,
• - wobei mittels der Steuerung die Prozessabgase bis zu einer ersten Temperatur durch die Prozessabgasreinigungsanlage geleitet werden, ohne dass der zumindest eine Einspritzkondensator betrieben wird, jedoch der dem Einspritzkondensator nachgeschaltete Oberflächenkondensator in Betrieb ist, um von im Prozessabgas mitgeführte Elektrolyte zu kondensieren, und dass bei Prozessabgastemperaturen, die oberhalb dieser ersten Temperatur liegen, der Oberflächenkondensator deaktiviert und der zumindest eine Einspritzkondensator aktiviert ist.

The system-related aspect of the above object is achieved by a system for cleaning process gases arising during the treatment of electrochemical energy storage devices in connection with the recovery of valuable substances contained therein using an injection condenser through which the process exhaust gases to be cleaned are passed

• - At least one injection condenser operated with a lye as cooling liquid, the gas inlet of which is connected or can be connected to a line carrying the exhaust gas to be cleaned,
• - A collection tank for collecting the condensate-cooling liquid mixture, which is connected to the at least one injection condenser via a condensate line,
• - a caustic supply that is connected to the collecting tank via a caustic line for introducing caustic into the collecting tank,
• - a pump for pumping coolant from the collection tank into the injection condenser,
• - a surface condenser connected downstream of the injection condenser in the flow path of the exhaust gases with a condensate collection tank connected to it,
• - A suction pump for conveying the exhaust gas through the process exhaust gas cleaning system and
• - a control for operating the process exhaust gas cleaning system,
• - whereby by means of the controller, the process exhaust gases are passed through the process exhaust gas cleaning system up to a first temperature without the at least one injection condenser being operated, but the surface condenser downstream of the injection condenser is in operation in order to condense electrolytes carried along in the process exhaust gas, and that at process exhaust gas temperatures that are above this first temperature, the surface capacitor is deactivated and the at least one injection capacitor is activated.

The process-related aspect of this object is achieved by a method for cleaning process gases that arise during the treatment of electrochemical energy storage devices in connection with the recovery of valuable substances contained therein, using such a system in which the process exhaust gases up to a first temperature through the process exhaust gas cleaning system be conducted without the at least one injection condenser being operated, but the surface condenser connected downstream of the injection condenser is in operation in order to condense electrolytes carried along in the process exhaust gas, and in which at process exhaust gas temperatures above this temperature, the surface condenser is deactivated and the at least one Injection capacitor is activated.

This system for cleaning the process exhaust gases from the processing of electrochemical energy storage devices is characterized on the one hand by the fact that the injection condenser is operated as a coolant with a lye, for example sodium hydroxide solution. Surprisingly, this leads to a significant simplification of the cleaning process. The lye or the lye droplets injected into the at least one injection condenser as cooling liquid cause substances entrained therein in vapor form to condense due to their cooler temperature compared to the process exhaust gases. The hydrofluoric acid vapors contained therein are problematic in the process exhaust gases from pyrolytically digested electro-chemical energy storage devices. These condense on the cooler alkali droplets, which at the same time neutralize them and thus reduce their acidic aggressiveness. At the same time, the hydrofluoric acid is bound in the lye or mixes with it. It is thus possible to control the hydrofluoric acid, which is contained in the form of vapor in such process exhaust gases, without any additional measures. In such a process exhaust gas cleaning system, it is also advantageous that the condensate / coolant mixture as such, basically without prior processing in which these substances would have to be separated from one another, can be used again as coolant for operating the at least one injection condenser. To adjust the pH value of the acid diluted by the hydrofluoric acid condensate, an alkali supply is used, which is connected to the collecting tank via an alkali line. Depending on the amount of condensed hydrofluoric acid, the pH value of the condensate Coolant mixture increased. However, the amount of condensate, in particular the proportion of hydrofluoric acid contained therein, is relatively small compared to the amount of coolant introduced into the at least one injection condenser - the lye - so that if the coolant is to be injected into the at least one injection condenser with a uniform pH value, this is guaranteed by introducing a certain, small amount of lye from the lye supply into the collecting tank. This system expediently has a pH meter for measuring the pH value in the collecting tank and / or in the condensate line with which the at least one injection condenser is connected to the collecting tank.

Another special feature of this process exhaust gas cleaning system is that, in addition to the at least one injection condenser, it has at least one surface condenser connected downstream of it in the flow path of the exhaust gases. Substances to be recovered can be recovered via this condenser without direct contact with the coolant. This capacitor is typically a vacuum capacitor. The provision of two differently working capacitors - at least one injection capacitor and at least one downstream surface capacitor - allows the process exhaust gas cleaning system to be operated in order to recover substances carried along in vapor form, such as electrolytes. This makes use of the fact that the electrolytes contained in the thermally treated electrochemical energy storage devices evaporate at low temperatures so that they can be recovered from the process exhaust gases when the surface capacitor is in operation. When the surface condenser is in operation, the upstream injection condenser is not in operation, since otherwise the substances to be recovered at the surface condenser would not reach it. Using the low evaporation temperature of the electrolytes, such a process exhaust gas cleaning system can be operated that in a first exhaust gas cleaning step, in which the process exhaust gas does not yet have an excessively high temperature, therefore has a temperature at which it primarily contains electrolytes, the injection condenser is switched off in order to prevent this To recover substances on the surface condenser that is in operation for this purpose. When the constituents of the electrochemical energy storage device are further decomposed at higher temperatures, the surface capacitor is deactivated and the at least one injection capacitor is activated in order to remove the pollutants then carried along, in particular the hydrofluoric acid contained therein in vapor form, from the process exhaust gases by operating the injection capacitor .

Ultimately, any suction pump that is suitable for guiding the process exhaust gases through the process exhaust gas cleaning system can be used as a suction pump for operating such a system. If the process exhaust gas cleaning system is connected to a vacuum furnace in which the electrochemical energy storage is pyrolytically unlocked, the process exhaust gas cleaning system is switched on in the suction line of the vacuum pump to generate the vacuum in the vacuum oven. One and the same pump is then used to generate the negative pressure desired in the vacuum furnace and to operate the process exhaust gas cleaning system.

As a rule, it is sufficient to use a single injection condenser in such a process exhaust gas cleaning system. An injection condenser working in countercurrent will preferably be used for this purpose.

Such a process exhaust gas cleaning system is not only suitable for cleaning the process output of process exhaust gases that arise in a vacuum furnace during the pyrolytic decomposition of electrochemical energy stores, in particular lithium-ion accumulators, but also when such process exhaust gases are generated elsewhere. Such a process exhaust gas cleaning system can also be connected to a furnace operated under atmospheric conditions for the thermal treatment or unlocking of electro-chemical energy storage devices or to a mechanical treatment system in which process exhaust gases, especially dusts, are generated. Even with such treatments, electrolytes can evaporate, which can then be recovered via the process exhaust gas cleaning system.

The variability in the operation of such a process exhaust gas cleaning system and the possibility of recovering substances entrained in the process exhaust gases make process management simple and economical. This also contributes to the fact that the coolant circuit for operating the injection condenser, which is conventionally operated with oil as the coolant, has to be serviced or cleaned much less frequently.

The invention is based on an exemplary embodiment with reference to the enclosed 1 described. 1 shows a schematic representation in the manner of a block diagram of a process exhaust gas processing system, connected to a thermal treatment system for the thermal unlocking of electrochemical energy stores.

The thermal treatment plant 1 includes one in the one shown Exemplary embodiment vacuum furnace that can be heated indirectly by an electrical heating device 2 . For operating the vacuum furnace 2 , ie: for evacuating its process chamber 3 , a vacuum pump is used 4th . This is via a suction line 5 to the vacuum furnace 2 connected. Switched on in the suction line 5 is an overall with the reference number 6th identified process exhaust gas treatment (also referred to as process exhaust gas cleaning system), through which the process chamber 3 of the vacuum furnace 1 withdrawn process gases are processed. Switched on in the suction line 5 is also the process exhaust gas treatment 6th downstream a pressure control valve 16 . In the process chamber 3 of the vacuum furnace 2 opens an inert gas supply line 7th into which a valve 8th for controlling an inert gas supply into the process chamber 3 is turned on. The valve 8th can be controlled electrically. The valve 8th is in a manner not shown in the operation of the thermal treatment plant 1 controlling control unit connected. The vacuum furnace 2 has a fan 9 for circulating in the process chamber 3 Process gases generated during the thermal breakdown of energy storage devices located therein. The fan 9 is preferably located behind a facing of the process chamber, for example provided by a grid 3 . In the illustrated embodiment, the fan is located 9 in the upper area of the process chamber 3 . The one from the fan 9 generated gas flow is directed downwards. In the process chamber 3 there is a receptacle, not shown in detail, for receiving a container containing a large number of electrochemical energy stores, in particular lithium-ion accumulators - also of different types 10 . With the container 10 it is a so-called lattice box. The container 10 of the illustrated embodiment is open on the top, but executed closed in the area of its side walls and its bottom. Thus, as a result of the thermal treatment of the energy storage device, process gases generated or exiting therefrom can escape upwards. It is also entirely possible to use a container with perforated side walls and / or a perforated base.

The one in the container 10 contained energy storage 11 provide a batch of thermally unlocked energy storage systems 11 In fluid communication with the process chamber 3 is a pressure measuring sensor 12th for detecting the in the process chamber 3 prevailing pressure arranged. In the illustrated embodiment, the pressure measurement sensor 12th to the first section of the suction line 5 connected.

For the thermal breakdown of a batch of electro-chemical energy storage devices 11 these are in a container 10 inserted and then the container 10 with the energy storage 11 into the process chamber 3 of the vacuum furnace 2 set. The one in the container 10 contained energy storage 11 are of different types and therefore have a different residual charge. The energy storage 4th are not completely discharged. Is the container 10 with its energy storage 11 into the process chamber 3 the vacuum furnace is used 2 closed.

Then the process chamber 3 by operating the vacuum pump 4th evacuated. During this time, the process exhaust gas processing units are in operation 6th not in use. At the same time, they are in the container 10 containing energy storage 11 warmed up. The first process step is started with the evacuation and the start of the heating process. In this first process step, the pressure is lowered and the energy storage is reduced 11 heated to such an extent that the electrolytes contained therein - ethylene carbonates, dimethyl carbonates and ethyl methyl carbonates - evaporate. The pressure in the process chamber 3 is lowered to less than 10 mbar, approximately to 5 to 7 mbar. The negative pressure is used so that the electrolytes contained in the energy storage devices evaporate at low temperatures and thus even at low heating. By doing this within the closed energy store 11 resulting vapor pressure these are opened. Depending on the design of the energy storage 11 this is done by opening the safety valves, the pole cover or the housing (with pouch cells). Inside the process chamber 3 This results in process exhaust gases containing the vaporized electrolytes in the vapor phase. Through the suction operation using the vacuum pump 4th these are taken from the process chamber 3 via the suction line 5 sucked off. Starting at a temperature at which the electrolytes begin to evaporate, a will flow into the suction line 5 switched on vacuum capacitor 13th (Surface condenser) put into operation in order to recover electrolytes contained in the process exhaust gases. These are in one attached to the vacuum condenser 13th connected electrolyte collection tank 14th collected. To ensure that everything is in the container 10 contained energy storage 11 are opened by the evaporation of the electrolytes contained therein, at the end of the process step the temperature is kept at a temperature for a short time, in the illustrated embodiment at about 200 ° C. This is also roughly the temperature of the process exhaust gases when they enter the injection condenser 15th pour in. The temperature holding time ensures that everything is in the container 10 contained energy storage 11 opened by the evaporation of the electrolytes contained therein and the electrolyte is evaporated. The temperature holding time can be a predefined period of time, determined, for example, from examinations. The electrolytes can also be recovered from the Vacuum capacitor 13th the evaporation process of the electrolytes in the process chamber 3 can be controlled via the amount of condensed electrolyte per unit of time. This can be used to allow the temperature holding time at the end of the first process step to last until the electrolyte deposition rate falls below a predetermined lower limit value.

The second process step begins with a temperature increase for further thermal treatment of the electrochemical energy storage 11 by controlling the furnace heating accordingly. The process exhaust gases flowing into the injection condenser are then correspondingly warmer. Through the further heating of the energy storage 11 the separators contained therein are decomposed. This has the consequence that in the energy storage 11 internal short circuits take place, reducing the energy storage 11 be completely discharged. This becomes noticeable in a further rise in temperature within the process chamber 3 . At the end of the process step or at the beginning of the process step, the vacuum pump 4th switched off with the result that it is inside the process chamber 3 a pressure builds up. Alternatively, the pressure control valve 16 getting closed. As a result, arises in the process chamber 3 an atmosphere formed from the process gases. Due to the chemical nature of the substances involved in the composition of the process gases, this is reducing. The further pyrolytic digestion of the energy storage 11 In this process, a reducing atmosphere is desired so that the metals released by the decomposition process do not form any oxidic compounds as far as possible. Investigations have shown that this measure of pyrolytic digestion in a reducing atmosphere significantly reduces the proportion of metal oxides in the pyrolytically digested material compared to other digestion methods. In the downstream processing, the non-oxide metal compounds can at least for the most part be separated from the digested material in a simple manner by a magnetic separator after a preceding comminution process.

The inert gas supply line 7th is only provided in the illustrated embodiment for safety reasons, so in the event of an unexpectedly violent reaction in the process chamber 3 this can be flooded with inert gas.

In addition to this advantage, it benefits itself in the process chamber 3 forming atmosphere also the mutual heating of the energy storage 11 in the container 10 as a result of the in the container 10 incoming convection. A circulation of the process gases in the container is supported 10 by operating the fan 9 , which is located above the opening on the top of the container 10 in the process chamber 3 is located and its air flow in the direction of the energy storage 11 is directed. The result of the heat and, in the illustrated embodiment, also through the operation of the fan 9 The intended circulation of the process gases is used as a heat transfer medium to heat the individual energy stores 11 to equalize. Depending on their degree of warming, these give off heat to the surrounding process gas atmosphere, which means that they store energy 11 Heat is supplied, which have a lower temperature than the temperature of the process gases. This takes place against the background that the residual discharge in every energy store 11 generated heat is different. This also compensates for a different heating of the individual energy stores due to the inductive heating, depending on the respective content of ferromagnetic material.

In the illustrated embodiment, the pressure increase is controlled, namely that it ends at around 600 mbar. The vacuum pump is used to maintain this residual negative pressure in relation to the ambient pressure 4th operated accordingly.

The temperature rise is controlled to ensure that it does not exceed a temperature of around 600 ° C, against the background that a melting of aluminum, the lowest melting metal from the group of secondary raw materials to be recycled, does not melt. At the end of the process step or at the beginning of the process step, the vacuum capacitor is 13th deactivated and on in the flow direction of the process exhaust gases to the vacuum condenser 13th upstream injection capacitor 15th activated. During the process step is the injection capacitor 15th deactivated so that the through the suction line 5 flowing process exhaust gases unaffected by this through the injection condenser 15th be passed through. Between the injection condenser 15th and the vacuum capacitor 13th there is another pressure measuring sensor 16 for pressure monitoring in the suction line 5 .

The injection capacitor in operation in the second process step 15th serves to clean the process exhaust gases, in particular to remove hydrofluoric acid contained therein in vapor form. The injection condenser is operated 15th with a lye that is in a lye tank 17th is in stock. In the illustrated embodiment, sodium hydroxide solution is used as the lye. The lye tank 17th is over a line 18th with the interposition of a valve 19th to a collection tank 20th connected to the in the injection condenser 15th generated condensates via a condensate line 21 be introduced. The collection tank 20th is with a level detection 22nd equipped. The exit of the collection tank 20th is via an injection line 23 to the injection port of the injection condenser 15th connected. A pump is used to convey the lye 24 . Via a pH meter 25th becomes the pH of the from the injection condenser 15th escaping condensate captured. The pH meter is connected to the condensate line 21 . According to the measured pH value through the condensate line 21 flowing condensate becomes lye from the lye tank 17th in the collection tank 20th introduced to neutralize the hydrofluoric acid and to have an injection liquid that is approximately neutral.

Downstream of the pump is a heat exchanger 26th .

The one through the injection condenser 15th Purified exhaust gases can then, if necessary, be fed to a thermal post-combustion to remove the hydrocarbons contained therein and the cracking products of the separators, which are typically made of PP or PE.

If desired, hydrocarbons can also be removed from the process exhaust gas stream in the process step.

The individual sensors and actuators of the process exhaust gas cleaning system 6th are connected to a controller that controls the operation of the process exhaust gas cleaning system 6th controls.

List of reference symbols

1

Thermal treatment plant

2

Vacuum furnace

3

Process chamber

4th

Vacuum pump

5

Suction line

6th

Process exhaust treatment

7th

Inert gas supply line

8th

Valve

9

Fan

10

Container

11

Energy storage

12th

Pressure control valve

13th

Vacuum capacitor

14th

Electrolyte collection tank

15th

Injection condenser

16

Pressure measuring sensor

17th

Lye tank

18th

management

19th

Valve

20th

Collection tank

21

Condensate line

22nd

Level detection

23

Injection line

24

pump

25th

pH meter

26th

Heat exchanger

Claims (11)

System for cleaning process gases arising during the treatment of electrochemical energy storage devices (11) in connection with the recovery of valuable substances contained therein using at least one injection condenser (15) through which the process exhaust gases to be cleaned are passed, comprising - at least one with a Injection condenser (15) operated with lye as cooling liquid, the gas inlet of which is connected or can be connected to a line carrying the exhaust gas to be cleaned, - a collecting tank (20) for collecting the condensate-cooling liquid mixture, which is fed via a condensate line (21) to the at least one injection condenser ( 15) is connected, - a caustic reservoir (17), which is connected to the collecting tank (20) via a caustic line (18) for introducing caustic solution, - a pump (24) for conveying cooling liquid from the collecting tank (20) into the injection condenser (15), - one in the flow path of the exhaust gases to the injection condenser ondensator (15) downstream surface condenser (13) with a condensate collection tank (14) connected to it, - a suction pump (4) for conveying the exhaust gas through the process exhaust gas cleaning system (6) and - a controller for operating the process exhaust gas cleaning system (6), characterized in that - By means of the control, the process exhaust gases are passed through the process exhaust gas cleaning system (16) up to a first temperature without the at least one injection condenser (15) being operated, but the surface condenser (13) connected downstream of the injection condenser (15) is in operation in order to to condense electrolytes carried along in the process exhaust gas, and that at process exhaust gas temperatures which are above this first temperature, the surface capacitor (13) is deactivated and the at least one injection capacitor (15) is activated. Plant after Claim 1 , characterized in that the suction pump is a vacuum pump (4). Plant after Claim 1 or 2 , characterized in that the pump (24) for conveying the cooling liquid into the injection condenser (15) is followed by a heat exchanger (26) in the cooling liquid circuit. Plant according to one of the Claims 1 to 3 , characterized in that a pH meter (25) for measuring the pH value of the condensate-cooling liquid mixture is arranged on the condensate line (21). Plant according to one of the Claims 1 to 4th , characterized in that the collecting tank (20) is equipped with a level sensor system (22) and / or is assigned to it. Plant according to one of the Claims 1 to 5 , characterized in that the at least one injection condenser (15) is a countercurrent condenser. Plant according to one of the Claims 1 to 6th , characterized in that the process exhaust gas cleaning system (6) has a single injection condenser (15). Plant according to one of the Claims 1 to 7th , characterized in that the process exhaust gas cleaning system (6) is connected to a thermal treatment system (1) for the thermal decomposition of electro-chemical energy storage devices (11) and the process exhaust gases resulting from the thermal decomposition are available at the gas inlet of the at least one injection condenser (15). Plant after Claim 8 , characterized in that the thermal treatment system comprises a vacuum furnace (2). A method for cleaning process gases produced during the treatment of electrochemical energy stores (11) in connection with the recovery of valuable substances contained therein using a system (6) according to one of the Claims 1 to 9 , characterized in that the process exhaust gases are passed through the process exhaust gas cleaning system (6) up to a first temperature without the at least one injection condenser (15) being operated, but the surface condenser (13) connected downstream of the injection condenser is in operation in order to reduce the amount of in the process exhaust gas to condense entrained electrolytes, and that at process exhaust gas temperatures which are above this temperature, the surface capacitor (13) is deactivated and the at least one injection capacitor (15) is activated. Procedure according to Claim 10 , characterized in that the first temperature is 180 ° Celsius to 200 ° Celsius and the operation of the process exhaust gas cleaning system (6) is switched to its injection condenser operation when the process exhaust gas temperature is above this temperature.

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