A plant and a method for off-gas treatment in a battery recycling process

Abstract

The present invention refers to a plant for recycling lithium ion battery material, comprising a battery material processing facility (100) and a gas incineration facility (200), wherein the battery material processing facility (100) comprises a monitoring unit (120) configured to provide a data signal with information about a current off-gas outflow, and the gas incineration facility (200) comprises at least a combustion chamber (210) with a flare (211), at least one off-gas supply line (231, 232), at least one heating gas supply line, at least one combustion-promoting gas supply (213), and a control unit (220) configured to capture the data signal provided by the monitoring unit (120) and to adjust setting parameters for combustion in the combustion chamber (210) depending on the information contained in the captured data signal.

Description

[0001] A plant and a method for off-gas treatment in a battery recycling process

[0002] Field of the invention

[0003] The present disclosure relates to a plant for recycling lithium ion battery materials, in particular lithium ion batteries, to a method for off-gas treatment in a battery recycling process and to a gas incineration facility for off-gas treatment in a battery recycling process.

[0004] Background

[0005] A recycling process for recovering valuable materials from lithium ion battery material generally includes mechanical treatment steps such as discharging, dismantling, shredding, extraction, drying and separation of the valuable materials from spent lithium ion battery material, as well as others.

[0006] During the mechanical treatment steps organic components from an electrolyte contained in the spent lithium ion battery material evaporate and the off-gas therefore contains significant amounts of flammable solvent vapour with volatile organic components from the electrolyte. That may form an off-gas that exceeds emission limits. Therefore, the released off-gas has to be purged. It is known to purge such off-gas, e.g., by a combination of condensation and adsorption. Condensation recovers a part of the electrolyte components. However, technically feasible and sufficient purification only by condensation can not be achieved. Hence, a final purification step is to be performed, which has so far been attempted through adsorption. It is to be noted that a composition of the volatile organic components (VOC) depends on the battery type whose battery material is to be recycled, and on treatment during recycling, and an overall amount of the volatile organic components varies over time, as off-gas streams from continuous and discontinuous process steps of the overall recycling process are combined. Generally, a concentration of VOC in the offgas is relatively high so that a life time of an activated carbon filter (ACF) that is generally used as adsorber means is extremely short and a regeneration of such an activated carbon filter produces a further off-gas and / or waste water that have to be disposed. Furthermore, an activated carbon filter would have to be correspondingly large due to the large amount of VOC in the off-gas.

[0007] WO 2020 021 365 A1 describes a plant for disposing and recovering lithium ion batteries, comprising: a storage area, a supply area, a crushing area, submerged in liquid solution and in inert gas, for destroying the batteries through cutting discs and milling cutters; a torch for burning the gaseous residue and possible organic solvents; a centrifugation and screening area, an evaporation area, for removing the volatile solvents and concentrating the lithium in solution, a recovery area for recovery of heavy metals and a recovery area for recovery of lithium.

[0008] CN 111495925 (A) provides a waste lithium battery pyrolyzation, defluorination and dechlorination method which comprises the steps of discharging and dismantling waste lithium batteries; conducting primary crushing, drying a crushed product, conducting primary separation on the dried crushed product, conducting secondary crushing and secondary separation, conducting pyrolyzation, defluorination, dechlorination and in-situ fluorine and chlorine absorption on a separated material, scattering and screening a pyrolyzed product to obtain black powder, conducting washing and separation on copper and aluminum foil to obtain copper and aluminum products, pyrolyzing and drying flue gas, conducting condensing, dust removal, spraying, adsorption and ignition on the flue gas, and then discharging the flue gas.

[0009] It was an object of the present invention to provide a possibility to ensure a sufficient purification of an off-gas produced during a battery recycling process, even with varying amounts and type of volatile organic components, resulting in a cleaned off-gas that does not exceed allowed emission limits. Summary of the invention

[0010] To solve this problem, a plant with the features of claim 1 , a method with the features of claim 11 and a gas incineration facility with the features of claim 15 are provided.

[0011] A plant for recycling lithium ion battery materials is provided which comprises a battery material processing facility and a gas incineration facility. The battery material processing facility comprises at least: at least one battery material treatment device which comprises at least one off-gas outlet for an off-gas, i.e. a flue gas, produced during treatment, a monitoring unit configured to provide a data signal with information about a current off-gas outflow from the at least one off-gas outlet, and the gas incineration facility comprises at least: a combustion chamber with a flare, at least one off-gas supply line to at least one of the at least one off-gas outlet, at least one heating gas supply line to a heating gas supply unit, at least one combustion-promoting gas supply, i.e. a supply for a gas that promotes combustion such as atmospheric oxygen, i.e. oxygen in the air, or pure oxygen, and at least one gas outlet, and a control unit configured to capture, e.g. to receive and / or to retrieve, the data signal provided by the monitoring unit of the battery material processing facility, and to monitor, adjust and / or regulate setting parameters for combustion in the combustion chamber depending on the information contained in the captured data signal. That means that the control unit is configured to monitor, adjust and / or regulate setting parameters for combustion in the combustion chamber according to the information contained in the captured data signal.

[0012] The control unit has at least a first data connection to the monitoring unit of the battery material processing facility and a second data connection to the combustion chamber. In one embodiment, the control unit is a microprocessor control unit, i.e. the control unit is implemented on a microprocessor.

[0013] The setting parameters for combustion comprise at least one of a flare temperature setpoint, a volume flow of off-gas supplied from the at least one offgas outlet, a volume flow of heating gas supplied from the heating gas supply unit, a volume flow of combustion-promoting gas supplied from the combustionpromoting gas supply.

[0014] Generally, the supply of a certain volume flow of the heating gas requires the supply of a coordinated volume flow of the combustion-promoting gas in order to achieve a sufficient combustion.

[0015] The terms "off-gas", "flue gas", and "exhaust gas" are used synonymously herein.

[0016] In one embodiment, the monitoring unit is configured to provide the data signal in real time and / or the control unit is configured to capture, e.g. receive and / or retrieve via the first data connection the data signal from the monitoring unit in real time and to monitor, adjust and / or regulate via the second data connection setting parameters for combustion in the combustion chamber, such as a flare temperature setpoint, ignition and flame of the flare, and / or a supply of the respective gases in real time. In some embodiments, the flare is also controlled dependent on an oxygen content of the supplied off-gas wherein the oxygen content is determined by the monitoring unit and provided to the control unit via the data signal. The control unit is also configured to inform, e.g. via the first data connetion, the monitoring unit that the gas incineration facility, e.g. the combustion chamber, the flare, is ready for operation or not ready for operation, so that if the gas incineration facility is not ready for operation the monitoring unit can stop the off-gas supply. The gas incineration facility provides for switchoff points at which the gas incineration facility is automatically switched off. If, for example, the temperature in the combustion chamber exceeds or falls below an upper or lower threshold value, the control unit causes the gas incineration facility to be switched off and / or at least some of the gas supplies to be shut off. Generally, the off-gas is produced in the plant discontinuously and must be discharged accordingly. For this purpose, the monitoring unit provides the data signal that triggers an immediate adjustment of the setting parameters for combustion in the combustion chamber as soon as off-gas is created which needs to be discharged and fed in the combustion chamber.

[0017] In some embodiments, the gas that promotes combustion is oxygen. The oxygen can be supplied in the form of air. The air can be supplied directly from the surroundings, e.g. controlled by appropriately designed blinds or flaps. In one possible embodiment, the flaps are arranged at the bottom of the combustion chamber and their position, i.e. their opening position is set and controlled by the control unit.

[0018] In another embodiment, the combustion-promoting gas is supplied via a combustion-promoting gas supply line from a combustion-promoting gas supply unit, e.g. oxygen is supplied as pure oxygen via a supply line from an oxygen supply unit. In one embodiment, the combustion-promoting gas is supplied via a fan or blower, with the fan or blower being adjusted and controlled by the control unit.

[0019] The term "real time", according to DIN 44300, refers to an operation of a computer system such as the monitoring unit or the control unit in which respective computer programmes that process received data are constantly ready for operation. Thereby, results of the data processing, such as the provision of the data signal by the monitoring unit and / or the capturing of the data signal by the control unit can be output and an initiation of reactions thereto, can take place within a previously defined period of time, also called latency period. In the present disclosure, this further means in one possible embodiment that an off-gas outflow from the at least one off-gas outlet of the at least one battery material treatment device is reacted to by initiating adjusting and regulating setting parameters for combustion in the combustion chamber, such as ignition and flame of the flare, a flare temperature setpoint, and / or a supply of the respective gases within a precisely defined maximum time span, e.g. in the range from 20ms to 100ms. Capturing the data signal by the control unit triggers the setting of the parameters for combustion in the combustion chamber, whereby a conversion time for realising the set parameters for a respective actuator in the combustion chamber is in the range of 20 ms to 5 minutes, in a possible embodiment in the range of 20 ms to 1 minute. Such actuator may be, for example, one of an actuator regulating a supply of heating gas, such as natural gas, and an actuator regulating a supply of combustionpromoting gas, such as oxygen, e.g. in the form of air, into the combustion chamber.

[0020] The data signal provided by the monitoring unit is to be supplied to the control unit for combustion control in the combustion chamber. The data signal is based on sensor data supplied to the monitoring unit from the at least one battery material treatment device and optional additional sensor data of the plant. The monitoring unit takes over the sensor data continuously or at certain times and in a time window selected in such a way that the data signal generated on the basis of these sensor data represents a snapshot of the plant, in particular of the current off-gas outflow from the at least one off-gas outlet of the at least one battery material treatment device. In some embodiments, the data signal includes information on plant parameters that have a direct or indirect influence on the current off-gas outflow. For example, a flap position of a drying device of the plant can influence the current off-gas outflow. This data signal is then provided by the monitoring unit. The monitoring unit can send the data signal to the control unit which receives the data signal or the control unit retrieves the data signal from the monitoring unit. The data signal is transferred from the monitoring unit to the control unit via the first data connection. Thereby, the data signal can be transmitted by wire or wirelessly using a suitable communication protocol, such as a TCP- or UDP based protocol, Bluetooth, NFC, WLAN or the like. The setting parameters, e.g. flare temperature setpoint, ignition and flame of the flare, and / or a supply of the respective gases, for the gas incineration facility, i.e. the combustion chamber are then calculated and implemented, e.g. by the control unit, in response to this data signal. The setting parameters on the respective actuators concerned within the gas incineration facility are set via a wireless or wired connection, respectively, herein shortly called second data connection.

[0021] In one embodiment, the flare is a high temperature flare. In a further embodiment, the flare is a shielded high temperature flare. The flare is always on and its temperature setpoint is set, e.g. higher or lower, depending on the information contained in the respective data signal provided by and received and / or retrieved from the monitoring unit of the battery material processing facility. In some embodiments, the control unit is configured to set the flare temperature setpoint in the combustion chamber from an initial temperature value in the range from 800°C to 1000°C to a setpoint, which is 50 - 300 K (K=Kelvin) higher than the initial value, to accommodate off-gas peaks. In some embodiments, the control unit is configured to set the flare temperature setpoint in the combustion chamber from an initial temperature value in the range from 800°C to 1000°C to a setpoint in a range from 1230°C to 1250°C. The minimum combustion chamber operating temperature is in the range from 800°C to 1200°C. The maximum combustion chamber operating temperature is in the range from 1200°C to 1400°C. In some embodiments, the maximum combustion chamber operating temperature is 1250°C. For this, the combustion chamber is refractory lined, e.g. with high temperature wool and / or ceramic combustion chamber insulation and / or brick lining. A peak limit for insulation of the combustion chamber is about 1400°C.

[0022] All temperature setpoints of the combustion chamber or of the flare are accessible and changeable.

[0023] In another embodiment, the gas incineration facility is designed to accommodate off-gas peaks so that the flare temperature setpoint, e.g. at 1000°C, is not changed, and combustion in the combustion chamber is controlled by an adjustable and controllable supply of heating gas, such as natural gas, and combustion-promoting gas, such as oxygen, e.g. in the form of air, into the combustion chamber.

[0024] In one embodiment, the gas incineration facility is rated in compliance with TA Luft 2021. After capturing the data signal provided by the monitoring unit, the control unit, caused by the captured (received and / or retrieved) data signal, adjusts and regulates (in real time) a flare temperature setpoint, ignition and flame of the flare, and / or a supply via the respective gas supply lines, depending on the information contained in the captured data signal.

[0025] In some embodiments, the gas incineration facility comprises a deflagration protection unit arranged along at least one of the at least one off-gas supply line, and being controlled by the control unit. In some embodiments, the gas incineration facility comprises the deflagration protection unit arranged along the second off-gas supply header line, and being controlled by the control unit.

[0026] In one embodiment, the data signal that is provided by the monitoring unit of the battery material processing facility is a binary signal.

[0027] The data signal is used to time-correlate the setting of the setting parameters for combustion in the combustion chamber with the generation and discharge of off-gas from the battery material processing facility. In one embodiment, the battery material processing facility comprises as the at least one battery material treatment device with the at least one off-gas outlet at least one of: a comminuting device configured to comminute lithium ion battery material in a comminuting space and comprising at least one first off-gas outlet for a first off-gas; a drying device arranged downstream of the comminuting device and comprising a drying space with at least one second off-gas outlet for a second off-gas; an intermediate storage device, e.g. a silo, arranged downstream of the comminuting device and / or the drying device and comprising an intermediate storage space with at least one third off-gas outlet for a third off-gas; and an airlock arranged upstream of the comminuting device and comprising at least one fourth off-gas outlet for a fourth off-gas.

[0028] In still a further embodiment, the gas incineration facility comprises as the at least one off-gas supply line at least one of: a first off-gas supply line to the at least one first off-gas outlet, a second off-gas supply line to the at least one second off-gas outlet, a second off-gas supply header line connected to a second off-gas discharge header line leading to the at least one first off-gas outlet and the at least one second off-gas outlet, a third off-gas supply line to the at least one third off-gas outlet, a fourth off-gas supply line to the at least one fourth off-gas outlet, a first off-gas supply header line connected to a first off-gas discharge header line leading to the at least one third off-gas outlet and the at least one fourth off-gas outlet.

[0029] In another embodiment, an additional third off-gas supply header line connected to a third off-gas discharge header line is provided for pressure protection of at least one of the comminuting device, the drying device and an optionally provided gas scrubber system. Only small discontinuous quantities of off-gas come out of the gas scrubber system during normal operation.

[0030] In one embodiment, the first off-gas supply header line connected to the first offgas discharge header line and / or the second off-gas supply header line connected to the second off-gas discharge header line are designed in such a way that any off-gas produced during a plant start-up and / or shut-down is also channelled through at least one of these lines, i.e. pipes, to the the gas incineration facility, i.e. to the combustion chamber. In some embodiments, fans and / or compressors are provided in these lines I pipes to generate a necessary overpressure.

[0031] In another embodiment, the battery material processing facility comprises a condensation unit and a gas washer, i.e. a gas scrubber system, in sequence along the second off-gas discharge header line in the direction of discharge, the condensation unit being configured to separate electrolyte from the off-gas as the off-gas passes through it and the gas washer being configured to remove some particulates and / or gases from the off-gas. The gas washer is connected to the third off-gas discharge header line mentioned above via a valve.

[0032] In the course of battery material treatment various off-gases, which require an off-gas treatment, are produced, each with a different composition. That means that different off-gases with different compositions emerge from the various battery material treatment devices or their off-gas outlets. Furthermore, the produced off-gases or their respective compositions can also vary over time, i.e. with a progress of a respective processing step in a respective battery material treatment device. The produced off-gases or their respective compositions also depend on the battery type whose battery material is to be recycled. As at least some off-gas streams from continuous and discontinuous process steps of the overall battery recycling process in the plant are combined, an overall amount of the volatile organic components can also vary over time. As some of the off-gas streams are combined, e.g. the off-gas from the comminuting device and the drying device in the second off-gas discharge header line and the second offgas supply header line or the off-gas from the intermediate storage device and the airlock in the first off-gas discharge header line and the first off-gas supply header line, an overall amount of the volatile organic components varies over time.

[0033] In one embodiment, the first off-gas emerging from the at least one first off-gas outlet of the comminuting device has a composition with a 02 content in the range of 0 Vol.-% to less than 4 Vol.-% and a N2 content in the range of 90 Vol.-% to 100 Vol.-%. The content of organic compounds, TVOC, is comparatively high e.g. equal or greater than 65 g / m3 stp.("stp" means "at standard temperature and pressure", which refers to a pressure of 1 .01325 bar, a temperature of 0°C and, in the case of air, a relative humidity of 0 %).

[0034] In one embodiment, the drying off-gas, i.e. the second off-gas emerging from the at least one second off-gas outlet of the drying device, has a composition with a 02 content less than 4 Vol.-% The content of organic compounds, TVOC, is comparatively high, e.g. up to 200 g / m3 stp.

[0035] In one embodiment, the third off-gas emerging from the at least one third offgas outlet of the intermediate storage device, also called silo, has a composition with a 02 content in the range of 15 Vol.-% to 21 Vol.-% and a N2 content in the range of 75 Vol.-% to 90 Vol.-%. The content of organic compounds, TVOC, is comparatively low, e.g. equal or smaller than 10,0 g / m3 stp.

[0036] In one embodiment, the airlock off-gas, i.e. the fourth off-gas emerging from the at least one fourth off-gas outlet of the airlock, has a composition with a 02 content in the range of less than 4 Vol.-% to 21 Vol.-% and a N2 content in the range of 75 Vol.-% to 100 Vol.-%. The content of organic compounds, TVOC, (TVOC means total volatile organic compounds) is comparatively low, e.g. equal or smaller than 10,0 g / m3 stp. "stp" means "at standard temperature and pressure". In the following, various off-gases, their respective composition and operational parameters, are given as examples under points 1 to 5, as they may occur, i.e. be produced, during operation of the plant, in particular during executing the mechanical treatment steps of a respective recycling process, and shall be incinerated by the flare:

[0037] 1 . Start-up and Shut-down inertisation

[0038] During inertisation before start-up and / or after shut-down of the plant a total volume flow, i.e. a flow rate, of maximum about 100 m3 / h stp. air, mixtures of air and nitrogen as well as pure nitrogen at ambient temperature and at ambient pressure will be disposed to the combustion chamber.

[0039] 2. Intermediate storage device (silo)

[0040] The intermediate storage device will be filled with material discharged from the drying device within about 2 to 10 min at intervals in a range from 10 min to 3 hours. The filling process creates an oxygen rich-off gas at ambient temperature and ambient pressure with a volume flow, i.e. a flow rate, of about 40 m3 / h stp (about 21 Vol.-% oxygen and less than 3 g TV0C / m3 stp. In the course of the sequential filling intervals, the oxygen content of the off-gas will decrease and the nitrogen content will increase accordingly. A release of the fourth off-gas from the intermediate storage device to the combustion chamber, i.e. to the high temperature flare (HT flare) might cause temperature swings.

[0041] 3. Airlock

[0042] The airlock is filled at intervals of 5 to 30 min, e.g. of about 14 min. After filling, the airlock is evacuated, e.g., within 1 min with a flow rate of about 170 m3 / h stp (about 21 Vol.-% oxygen and about 0,1 g TV0C / m3 stp), then refilled with nitrogen and evacuated again, e.g., within 1 min with a flow rate of 170 m3 / h stp (about 9,4 Vol.-% oxygen and about 0,1 g TV0C / m3 stp). After the battery material has been discharged (e.g. about 4 min after a second evacuation); the atmosphere in the airlock is evacuated again, e.g., with a volume flow (flow rate) of about 170 m3 / h stp (about 4,2 Vol.-% oxygen and about 5,0g TV0C / m3 stp). Other flushing of the airlock is also conceivable, e.g. without vacuum. The third off-gas is released at ambient temperature. The release of airlock off-gas, i.e. the third off-gas, to the combustion chamber, i.e. the HT flare, might cause temperature swings. The third off-gas will regularly occur simultaneously with the fourth off-gas, i.e. the off-gas of the intermediate storage device.

[0043] 4. Comminuting device

[0044] Shredding in the comminuting device is a continuous process, which generates an (first) off-gas at a flow rate of, e.g., about 40 m3 / h stp with a high TVOC content of up to 88 g / m3 stp and less than 3 Vol.-% oxygen content. The oxygen content of the first off-gas is continuously monitored by an onlineanalyser. If the oxygen content reaches 3 Vol.-%, the off-gas flow to the gas incineration facility, i.e. to the HT flare, will be stopped.

[0045] 5. Drying device

[0046] Drying in the drying device is a batch process which generates an (second) offgas at a flow rate of, e.g., about 100 m3 / h stp with a high TVOC content of, e.g., up to 172 g / m3 stp and less than 3 Vol.-% oxygen content. Drying is realized by a vacuum process, the oxygen content of the second off-gas is continuously monitored by an online-analyser, if the oxygen content reaches 3 Vol.-%, the second off-gas flow to the gas incineration facility, i.e. the HT flare, will be stopped.

[0047] In one embodiment, the first off-gas discharge header line and the first off-gas supply header line contain or transport the third off-gas from the intermediate storage device, the fourth off-gas from the airlock and the fifth off-gas from the start-up or shut-down inertisation. In other words, the third off-gas from the intermediate storage device, the fourth off-gas from the airlock and the fifth offgas from the start-up or shut-down inertisation are passed through the first offgas discharge header line and the first off-gas supply header line. That means that the first off-gas discharge header line and the first off-gas supply header line are designed to contain or transport oxygen rich off-gases. The first off-gas discharge header line and the first off-gas supply header line are connected with each other and then form a combined first off-gas header line (also called Header I). The start-up or shut-down inertisation off-gas, i.e. the fifth off-gas will not occur simultaneously with any other off-gas. The airlock off-gas, i.e. the fourth off-gas may occur with a higher frequency than the Silo off-gas, i.e. the third off-gas, and both off-gases may occur simultaneously.

[0048] In one embodiment, the first off-gas discharge header line and the first off-gas supply header line are designed for off-gases, which do not form an explosive atmosphere. There may be a single valve in the merging or interconnected offgas lines, i.e. the first off-gas discharge header line and the first off-gas supply header line wherein the valve is oriented in direction to the combustion chamber, i.e. the flare. The combined off-gas of the intermediate storage device and the airlock is passed through the first off-gas discharge header line and the first off-gas supply header line.

[0049] An example of a combined off-gas of the intermediate storage device and the airlock has a flow rate in a range of 40 m3 / h stp to 210 m3 / h stp, a temperature in a range of 2°C to 100°C, a pressure in a range of 10 mbarg to 100 mbarg, and a density in a range of 1 ,25 kg / m3 stp to 1 ,29 kg / m3 stp. "mbarg" is a unit of pressure and designates a pressure measured in "mbar" above athmospheric pressure.

[0050] In one embodiment, the second off-gas discharge header line and the second off-gas supply header line contain or transport the first off-gas from the comminuting device and the second off-gas from the drying device. In other words, the first off-gas from the comminuting device and the second off-gas from the drying device are passed through the second off-gas discharge header line and the second off-gas supply header line. That means that the second offgas discharge header line and the second off-gas supply header line are designed to contain or transport organic rich off-gases. The second off-gas discharge header line and the second off-gas supply header line are connected with each other and then form a combined second off-gas header line (also called Header II).

[0051] In one embodiment, the second off-gas discharge header line and the second off-gas supply header line are designed for an explosive atmosphere (in accordance with national directives, such as e.g. ATEX, NEC / CEC, lECEx). In another embodiment, the second off-gas discharge header line and the second off-gas supply header line are designed for a non explosive atmosphere.

[0052] There may be two valves in the merging or interconnected off-gas lines, i.e. the combined second off-gas header line, i.e. the second off-gas discharge header line and the second off-gas supply header line wherein the valves are oriented in direction to the combustion chamber, i.e. to the flare. An example of a combined off-gas of the comminuting device and the drying device that is passed through the second off-gas discharge header line and the second offgas supply header line has a flow rate in a range of 60 m3 / h stp to 140 m3 / h stp, a temperature in a range of 2°C to 20°C, a pressure in a range of 10 mbarg to 80 mbarg, and a density in a range of 1 ,30 g / m3 stp to 1 ,40 kg / m3 stp.

[0053] In one embodiment, the gas incineration facility is rated as an incineration device for halogenated off-gas components in compliance with TA Luft 2021 (Technische Anleitung Luft 2021 ). In one embodiment, the gas incineration facility is designed for the following conditions:

[0054] - minimum off-gas 02 content: 5 Vol.-%

[0055] - minimum combustion chamber operating temperature:

[0056] 1000°C / 1200°C maximum combustion chamber operating temperature: 1250 °C minimum flue gas (i.e. off-gas) residence time in the combustion chamber: 0,3 s Design requirements and set-points like minimum combustion temperature and residence time vary depending on the local legal requirements. The above is applicable for Germany only.

[0057] The off-gas produced after incineration and being discharged from the gas outlet of the combustion chamber must comply and complies with emission limits in accordance with local legal requirements, e.g TA Luft 2021 , WGCBREV etc..

[0058] The control unit is configured to control the flame of the flare such that the flare temperature setpoint is set (raised) from an initial temperature value (in a range from 800 °C to 1000°C) to at a setpoint value which is 50 K to 300 K (K=Kelvin) higher than the initial temperature value, e.g. in a range from 1230°C to 1250°C, and maintained at the setpoint value as soon as and as long as off-gas is fed to the combustion chamber through the at least one off-gas supply line, e.g. Header I and / or Header II.

[0059] In a further embodiment, the monitoring unit is configured to aggregate the information contained in the data signal, wherein the information about the current off-gas outflow from the at least one off-gas outlet comprises at least one of a start time of the current off-gas outflow, a composition of the off-gas, a throughput of the off-gas, a pressure of the off-gas, an oxygen content of the off-gas, which of the at least one off-gas outlet is used for the current off-gas outflow, an end time of the current off-gas outflow, an operating parameter of the plant that directly or indirectly influences the current off-gas outflow.

[0060] In another embodiment, the control unit is configured to keep the flare temperature setpoint constant and to control and regulate the combustion in the combustion chamber merely by adapting the heating gas supply through the at least one heating gas supply line and I or the combustion-promoting gas supply depending on the off-gas supply through the at least one off-gas supply line. As mentioned before, the gas that promotes combustion can be oxygen. The oxygen can be supplied in the form of air. The air can be supplied to the combustion chamber directly from the surroundings, e.g. controlled by appropriately designed blinds or flaps. In another embodiment, the combustionpromoting gas is supplied via a supply line from a combustion-promoting gas supply unit. Keeping the flare temperature constant requires an additional supply of cooling air which is also controlled by the control unit. The cooling air can be supplied via a separate supply or via the same supply as the air promoting the combustion.

[0061] The following cases can be distinguished, whereby according to the invention a suitable adjustment of the supply of heating gas and / or combustion-promoting gas, as also mentioned below, is carried out in each case.

[0062] Case 1 : If an off-gas with a low heating value is supplied to the combustion chamber in a small volume flow, the control unit regulates the setting parameters for combustion in the combustion chamber such that heating gas, e.g. natural gas, is supplied with a minimum flowrate and the combustionpromoting gas, e.g. air, is supplied with a low flowrate.

[0063] Case 2: If an off-gas with a low heating value is supplied to the combustion chamber in a high volume flow, the control unit regulates the setting parameters for combustion in the combustion chamber such that heating gas, e.g. natural gas, is supplied with a maximum flowrate and the combustion-promoting gas, e.g. air, is supplied with a high flowrate.

[0064] Case 3: If an off-gas with a high heating value is supplied to the combustion chamber in a low volume flow, the control unit regulates the setting parameters for combustion in the combustion chamber such that heating gas, e.g. natural gas, is supplied with a minimum flowrate and the combustion-promoting gas, e.g. air, is supplied with a flowrate that is higher than in case 2. Case 4: If an off-gas with a high heating value is supplied to the combustion chamber in a high volume flow, the control unit regulates the setting parameters for combustion in the combustion chamber such that heating gas, e.g. natural gas, is supplied with a maximum flowrate and the combustion-promoting gas, e.g. air, is supplied with a maximum flowrate.

[0065] A second aspect of the invention is a method for off-gas treatment in a lithium battery material recycling process using a plant as described herein, i.e. according to an embodiment of the invention, the method comprising at least the following steps: a. providing a data signal by the monitoring unit, the data signal containing information about a current off-gas outflow from the at least one off-gas outlet, b. capturing the provided data signal by the control unit, c. setting, adjusting and / or monitoring setting parameters for combustion in the combustion chamber depending on the information contained in the provided data signal.

[0066] In one embodiment, step c) causes at least some of the following steps to be executed depending on the information contained in the provided data signal: d. supplying an off-gas from the at least one off-gas outlet to the combustion chamber of the gas incineration device, e. supplying heating gas from a heating gas supply unit via the at least one heating gas supply line to the combustion chamber of the gas incineration device; f. supplying combustion-promoting gas from a combustion-promoting gas supply to the combustion chamber of the gas incineration device, g. combusting the supplied off-gas in the combustion chamber, and (optionally) h. stopping the supply of the off-gas, the heating gas and / or the combustion-promoting gas. "Depending on the information contained in the captured data signal" means on the one hand which steps of the above listed steps are to be carried out and on the other hand how, e.g. at what flow rate and how much of a particular gas is to be supplied to the combustion chamber and how, i.e. with which setting parameters, the combustion is to be carried out.

[0067] According to one embodiment, the method also includes the execution of the steps initiated I caused by the control unit.

[0068] According to one embodiment of the method, for combusting the off-gas, the control unit regulates a flare temperature setpoint in the combustion chamber to a setpoint value in a range of 1200°C to 1250 °C, in particular to a setpoint value of 1250°C. In one embodiment of the method, at least 99,9%, particularly 100% of the off-gas, in particular of the VOC of the off-gas that is supplied to the combustion chamber is combusted.

[0069] In still a further embodiment of the method, the control unit maintains the flare temperature setpoint at the above mentioned setpoint value as long as the offgas is fed / supplied to the combustion chamber through the at least one off-gas supply line and resets the flare temperature setpoint to an initial temperature value after combustion has finished and / or supply of off-gas to the combustion chamber has been (at least temporarily) stopped.

[0070] According to another embodiment of the method, for combusting the off-gas, the control unit keeps the flare temperature setpoint constant, e.g. at a temperature value of about 1000°C, and controls the combustion by merely regulating a volume flow of the supplied heating gas and a volume flow of the combustion-promoting gas matched to it. For keeping the flare temperature constant, cooling air is also supplied to the combustion chamber. In some embodiments, the control unit keeps a flare temperature setpoint constant and, to combust the supplied off-gas, regulates a volume flow of the supplied heating gas, a volume flow of the supplied combustion-promoting gas and optionally a volume flow of a supplied cooling gas appropriately in each case.

[0071] According to still a further embodiment, the off-gas that is transported through the second off-gas discharge header line and the second off-gas supply header line is channelled through a deflagration protection device before it is passed on to the combustion chamber.

[0072] It is possible, according to another embodiment of the method that the monitoring unit aggregates and makes available in the data signal as information about the current off-gas outflow from the at least one off-gas outlet at least one of a start time of the current off-gas outflow, a composition of the off-gas, an oxygen content of the off-gas, a throughput of the off-gas, a pressure of the off-gas, which of the at least one off-gas outlet is used for the current off-gas outflow, an end time of the current off-gas outflow.

[0073] In one embodiment of the method, the monitoring unit of the battery material processing facility sends a data signal, e.g. as a binary signal, via the first data connection to the control unit of the gas incineration facility as soon as off-gas is ready to be fed to the combustion chamber, so that the control unit can set the setting parameters for combustion in the combustion chamber instantaneously, i.e. in real time without any recognizable time delay, the setting parameters being adapted to the off-gas to be combusted. In one example, the monitoring unit sends a respective data signal at the end of a filling process of the airlock, so that a desired flare temperature setpoint in the combustion chamber is raised from e. g. 1200°C to e. g. 1250°C and maintained at this setpoint for the duration of the airlock evacuation that takes, e.g., about 7.5 minutes, as per data signal from the monitoring unit. When the airlock off-gas with a temperature of about 25°C enters the combustion chamber, an actual temperature in the combustion chamber may temporarily drop to 800°C to 850°C which is still sufficiently high to destroy all critical compounds within the off-gas to be combusted. It should also be noted that potentially environmentally hazardous off-gases formed in the battery material processing facility, e.g. in the comminuting device, the intermediate storage device, the airlock and / or the drying device, are firstly supplied to a gas washer of a known type, optionally via a condensation unit of a known type, on their way to the combustion chamber. The person skilled in the art is familiar with the components that the condensation unit and the gas washer can or should comprise depending on the off-gas components produced. For this reason, a detailed discussion of the design and function of the condensation unit and the gas washer can be dispensed with at this point.

[0074] A third aspect of the invention is a gas incineration facility that is configured to be implemented as gas incineration facility in a plant according to an embodiment of the invention and as described herein and / or to carry out a method according to an embodiment of the invention together with a monitoring unit of a battery material processing facility.

[0075] A further aspect of the invention is a computer program product, comprising a digital storage medium storing a program code. The digital storage medium may comprise a hard disk, a solid state disk (SSD), a digital versatile disk (DVD), a Universal Serial Bus (USB) stick, a random access memory (RAM) and the like and be provided locally or in a cloud connected to the internet, i.e. an internet cloud. The program code may be executed immediately from the storage medium or after an installation.

[0076] According to the invention, the program code causes a computing device to carry out a method according to an embodiment of the invention as a monitoring unit of the battery material processing facility or as a control unit of the gas incineration device when being executed by a processor of the computing device. An essential advantage of the inventive method and the inventive plant is that they allow a safe off-gas treatment in compliance with local requirements, such as the standards of TA Luft. As the generation of the off-gas during the battery material treatment steps is directly correlated with its combustion in the combustion chamber, it is ensured that hazardeous off-gas is not accumulated within the plant, but disposed of without delay.

[0077] It shall be understood that the features described previously and to be described subsequently may be used not only in the indicated combinations but also in different combinations or on their own without leaving the scope of the present invention.

[0078] The invention is described in detail by means of an exemplary embodiment and with reference to the drawings. Like components are indicated by like reference numerals throughout the drawings.

[0079] Brief description of the drawings

[0080] Fig. 1 schematically shows a section of a plant according to a first embodiment of the invention.

[0081] Fig. 2 schematically shows a section of a plant according to a second embodiment of the invention.

[0082] Fig. 3 schematically shows a section of a plant according to a third embodiment of the invention.

[0083] Fig. 4 schematically shows a section of a plant according to a fourth embodiment of the invention.

[0084] Detailed description of the drawings

[0085] The same reference symbols are assigned to the same components across all figures Fig. 1 schematically shows a section of a plant for recycling lithium ion battery material according to an embodiment of the invention. The section shows relevant off-gas generators of the plant, whose off-gas is to be combusted according to the invention. The section of the plant comprises a battery material processing facility 100 and a gas incineration facility 200. The battery material processing facility 100 comprises a plurality of battery material treatment devices, each comprising one off-gas outlet for an off-gas produced during treatment in the respective treatment device. The plurality of battery material treatment devices comprise a comminuting device 111 with a first off-gas outlet 1110 for a first off-gas, a drying device 112 with a second off-gas outlet 1120 for a second off-gas, an intermediate storage device 113 with a third off-gas outlet 1130 for a third off-gas and an airlock 114 with a fourth off-gas outlet 1140 for a fourth off-gas. The third off-gas outlet 1130 of the intermediate storage device 113 is connected to a first off-gas discharge header line 131 . The fourth off-gas outlet 1140 of the airlock 114 is also connected to the first off-gas discharge header line 131. Shown purely schematically is a fifth off-gas outlet 1150 for a fifth off-gas, which is produced when the plant is started up or shut down 115 and which must also be fed into the combustion chamber, as exemplarily shown here, via the first off-gas discharge header line 131. As the third off-gas, the fourth off-gas and the fifth off-gas are all oxygen rich off-gases, the first off-gas discharge header line 131 is designed for non explosive atmosphere.

[0086] The first off-gas outlet 1110 of the comminuting device 111 is connected to a second gas discharge header line 132. The second off-gas outlet 1120 of the drying device 112 is also connected to the second gas discharge header line 132. As the first off-gas and the second off-gas are all organic rich off-gases, the second gas discharge header line 132 is designed for an explosive atmosphere in accordance with national directives, such as ATEX, NEC / CEC, lECEx.

[0087] There is a condensation unit, i.e. a condenser, 116 and a gas washer unit, i.e. a scrubber, 117 arranged one behind the other along the second gas discharge header line 132 towards the gas incineration facility 200. The off-gases, i.e. the first off-gas and the second off-gas flow through both the condensation unit 116 and the gas washer unit 117 in succession as they flow along the second gas discharge header line 132.

[0088] The battery material processing facility 100 further comprises a monitoring unit 120. The monitoring unit 120 is configured to provide, particularly in real time, a data signal with information about a current off-gas outflow from the at least one off-gas outlet, i.e. the first off-gas outlet 1110, the second off-gas outlet 1120, the third off-gas outlet 1130, the fourth off-gas outlet 1140, the fifth off-gas outlet 1150.

[0089] The monitoring unit 120 is configured to aggregate the information contained in the data signal, wherein the information about the current off-gas outflow from the at least one off-gas outlet comprises at least one of a start time of the current off-gas outflow, a composition of the off-gas, an oxygen content of the off-gas, a throughput of the off-gas, a pressure of the off-gas, which of the at least one off-gas outlet is used for the current off-gas outflow, an end time of the current off-gas outflow. The monitoring unit 120 may provide the data signal as a binary signal. The data signal may be based on sensor data supplied to the monitoring unit 120 from the at least one battery material treatment device 111 , 112, 113, 114 and optional additional sensor data of the battery material processing facility 100. The monitoring unit 120 takes over the sensor data continuously or at certain times and in a time window selected in such a way that the data signal generated on the basis of these sensor data represents a snapshot of the plant 100, in particular of the current off-gas outflow from the at least one off-gas outlet of the at least one battery material treatment device. The monitoring unit 120 is configured to generate and to provide the data signal.

[0090] The gas incineration facility 200 comprises a combustion chamber 210 and a control unit 220. The control unit 220 is connected with the monitoring unit 120 via a first data connection line 221 and with the combustion chamber 210 via a second data connection line 222. The combustion chamber 210 comprises a shielded high temperature flare 211 , two off-gas supply lines, a first off-gas supply header line 231 connected with the first off-gas discharge header line 131 and a second off-gas supply header line 232 connected with the second off-gas discharge header line 132. Via the respective off-gas discharge header lines, the respective off-gas supply header lines are indirectly connected to the respective off-gas outlets that are connected with the respective off-gas discharge header lines. That means that the first off-gas supply header line is indirectly connected to the third off-gas outlet, the fourth off-gas outlet and the fifth off-gas outlet, and the second off-gas supply header line is indirectly connected to the first off-gas outlet and the second off-gas outlet. The first offgas supply header line 231 and the first off-gas discharge header line 131 can form a common first off-gas header line (Header I). The second off-gas supply header line 232 and the second off-gas discharge header line 132 can form a common second off-gas header line (Header II).

[0091] The combustion chamber 210 further comprises a heating gas supply line 212 to a heating gas supply unit (not shown) and a combustion-promoting gas supply 213. The combustion-promoting gas can be oxygen. The oxygen can be supplied in the form of air. The air can be supplied directly from the surroundings, e.g. controlled by appropriately designed blinds or flaps. In another embodiment, the combustion-promoting gas can also be supplied via a combustion-promoting gas supply line from a combustion-promoting gas supply unit. Furthermore, the combustion chamber 210 comprises a gas outlet 214 for the finally combusted off-gas.

[0092] The control unit 220 is configured to capture, e.g. to receive and / or retrieve via the first data connection 221 the data signal provided by the monitoring unit 120 of the battery material processing facility 100, particularly in real time, and to monitor, adjust and regulate, particularly in real time, via the second data connection 222 setting parameters for combustion in the combustion chamber. Such setting parameters for combustion comprise at least one of a flare temperature setpoint, a volume flow of a heating gas supplied from the heating gas supply unit via the supply line 212, a volume flow of a combustionpromoting gas supplied from the combustion-promoting gas supply via the supply 213, and / or a supply via the respective off-gas supply lines 231 , 232 depending on the information contained in the data signal provided by and received and / or retrieved from the monitoring unit 120 of the battery material processing facility 100.

[0093] Figure 2 schematically shows a section of a plant for recycling lithium ion battery material according to a second embodiment of the invention. Figure 2 shows the same components as Figure 1. Compared to Figure 1 , the gas incineration facility 200 comprises an additional third off-gas supply header line

[0094] 233 connected to a third off-gas discharge header line 133 of the battery material processing facility 100. Both lines, i.e. the third off-gas supply header line 233 and the third off-gas discharge header line 133, together form a common third off-gas header line (Header III). Header III is provided for pressure protection of the comminuting device 111 and the drying device 112 and the gas washer unit 117. Only small discontinuous quantities of off-gas come out of the gas washer unit 117 during normal operation. The gas washer unit 117 is connected to the third off-gas discharge header line 133 via a valve. The first off-gas outlet 1110 and the second off-gas outlet 1120 are each connected to the the third off-gas discharge header line 133 via a bursting disc.

[0095] Figure 3 schematically shows a section of a plant for recycling lithium ion battery material according to a third embodiment of the invention. Figure 3 shows the same components as Figure 1. Compared to Figure 1 , the gas incineration facility 200 comprises an additional third off-gas supply header line

[0096] 234 connected to a third off-gas discharge header line 134 of the battery material processing facility 100. Both lines, i.e. the third off-gas supply header line 234 and the third off-gas discharge header line 134, together form a common third off-gas header line (Header III). Header III is provided for pressure protection of the gas washer unit 117. Only small discontinuous quantities of off-gas come out of the gas washer unit 117 during normal operation. The gas washer unit 117 is connected to the third off-gas discharge header line 134 via a valve.

[0097] Figure 4 schematically shows a section of a plant for recycling lithium ion battery material according to a fourth embodiment of the invention. Figure 4 shows the same components as Figure 1. Compared to Figure 1 , the gas incineration facility 200 comprises an additional third off-gas supply header line 235 connected to a third off-gas discharge header line 135 of the battery material processing facility 100. Both lines, i.e. the third off-gas supply header line 235 and the third off-gas discharge header line 135, together form a common third off-gas header line (Header III). Header III is provided for pressure protection of the comminuting device 111 and the drying device 112. The first off-gas outlet 1110 and the second off-gas outlet 1120 are each connected to the the third off-gas discharge header line 135 via a bursting disc.

[0098] The plant 100 is configured for carrying out the following method according to an embodiment of the invention and / or is operated by carrying out this method. a. The monitoring unit 120 generates and provides a data signal wherein the data signal contains information about a current off-gas outflow from the first off-gas outlet 1110, the second off-gas outlet 1120, the third off-gas outlet 1130, the fourth off-gas outlet 1140 and / or the fifth off-gas outlet 1150. The information may be aggregated by the monitoring unit 120, wherein the information about the current off-gas outflow comprises at least one of a start time of the current off-gas outflow, a composition of the off-gas, an oxygen content of the off-gas, a throughput of the off-gas, a pressure of the off-gas, which of the at least one off-gas outlet discharges off-gas for the current off-gas outflow, an end time of the current off-gas outflow. Depending on the off-gas outlets 1110, 1120, 1130, 1140, 1150 that are currently discharging off-gas for the current off-gas outflow, it can be determined on which supply line, the first off-gas supply header line 231 , the second off-gas supply header line 232, and I or the third off-gass supply header line 233, 234, 235 off-gas is currently being fed with the current off-gas outflow to the combustion chamber 210.

[0099] In operation, the communiting device 111 discharges off-gas via the first off-gas outlet 1110 with a flow rate in the range from 0 to 40 m3 / h stp, the drying device 112 discharges off-gas via the second off-gas outlet 1120 with a flow rate in the range from 30 to 100 m3 / h stp. Both feed the discharged off-gas to the second off-gas discharge header line 132. The second off-gas discharge header line 132 carries off-gas at a flow rate in the range from 30 to 140 m3 / h stp and with a pressure in the range from 80 to 120 mbarg.

[0100] In operation, the intermediate storage device 113 discharges off-gas via the third off-gas outlet 1130 with a flow rate in the range from 0 to 40 m3 / h stp, the airlock 114 discharges off-gas via the fourth off-gas outlet 1140 with a flow rate in the range from 0 to 170 m3 / h stp, during start-up and shut-down inertisation 115 off-gas is discharged via the fifth off-gas outlet 1150 with a flow rate in the range from 40 to 300 m3 / h stp. All three off-gas outlets feed the discharged offgas to the first off-gas discharge header line 131. The first off-gas discharge header line 131 carries off-gas at a flow rate in the range from 0 to 300 m3 / h stp and with a pressure in the range from 10 to 100 mbarg. b. The control unit 220 captures, e.g. retrieves or receives the provided data signal, particularly in real time, and initiates that: c. The control unit 220 sets, adjusts and / or monitors setting parameters for combustion in the combustion chamber depending on the information contained in the provided data signal. This causes that at least some of the following steps are automatically and instantenously executed, depending on the information contained in the provided data signal: d. Depending on which of the at least one off-gas outlet discharges off-gas for the current off-gas outflow, the respective off-gas is supplied from the respective off-gas outlet 1110, 1120, 1130, 1140, 1150 via the respective offgas discharge header line 131 , 132, 133, 134, 135 and off-gas supply header line 231 , 232, 233, 234, 235 to the combustion chamber 210 of the gas incineration facility 200.

[0101] In the case that off-gas is discharged from the first off-gas outlet 1110 and / or from the second off-gas outlet 1120, the off-gas is combined in the second offgas discharge header line 132 and / or in the third off-gas discharge header line 133. The off-gas being carried by the second off-gas discharge header line 132 is channeled through the condenser unit 116 where electrolyte is separated. Subsequently the off-gas is channeled through a gas washer 117 before being fed to the combustion chamber 210 through the second off-gas supply header line 232 directly connected to the second off-gas discharge header line 132. Before being fed to the combustion chamber 210, the off-gas is channeled through a deflagration protection unit 215. For deflagration, pressurized air is supplied to the deflagration protection unit 215 via a gas inlet 216.

[0102] In the case that off-gas is discharged from the third off-gas outlet 1130 and / or from the fourth off-gas outlet 1140 and / or durng start-up or shut-down intertisation from the fifth off-gas outlet 1150, the off-gas is combined in the first off-gas discharge header line 131 and fed to the combustion chamber 210 through the first off-gas supply header line 231 directly connected to the first offgas discharge header line 131. e. Depending on a composition of the off-gas supplied to the combustion chamber 210 which may be directly associated with the off-gas outlet(s) from which the off-gas is discharged, a specific amount of heating gas from a heating gas supply unit is supplied via the at least one heating gas supply line 212 to the combustion chamber 210. The heating gas is supplied with a flow rate in the range of about 40m3 / h stp. In some embodiments, the heating gas, also called fuel gas, is chosen from the group comprising natural gas, hydrocarbons (such as methane and propane), hydrogen. f. Depending on a composition of the off-gas supplied to the combustion chamber 210 which may be directly associated with the gas outlet(s) from which the off-gas is discharged, a specific amount of combustion-promoting gas is supplied from the at least one combustion-promoting gas supply 213 to the combustion chamber 210. The combustion-promoting gas can be oxygen. The oxygen can be supplied in the form of air. The air can be supplied directly from the surroundings, e.g. controlled by appropriately designed blinds or flaps. In another embodiment, the combustion-promoting gas can also be supplied via a combustion-promoting gas supply line from an combustion-promoting gas supply unit. Both possibilities, the flaps as well as the supply line are represented in Figure 1 as supply 213. The flaps may be arranged at the bottom of the combustion chamber 210 and their position, i.e. their opening position, is set and controlled by the control unit 220. g. The supplied off-gas is combusted in the combustion chamber 210. The supplied off-gas is (almost) 100% incinerated. The off-gas ultimately produced after combustion is discharged via the gas outlet 214 of the combustion chamber 210 with a gas flow rate in the range from 0 to 1000 Nm3 / h, particularly in the range from 180 to 1000 Nm3 / h. A gas flow rate of off-gas of 0 Nm3 / h is given, when the plant does not produce off-gas and the flare is operated with pure heating gas, such as natural gas.

[0103] To combust the off-gas, the incineration facility 200 can be operated in two modes, a heating mode or a cooling mode, depending on the configuration of the incineration facility 200.

[0104] According to the heating mode, the control unit 220 regulates the flare temperature setpoint, in the combustion chamber 210 to a setpoint value in a range of 1200°C to 1400°C, preferably in a range of 1250°C to 1300 °C. The control unit 220 maintains the flare temperature setpoint at that setpoint value as long as the off-gas is fed / supplied to the combustion chamber 210 through the at least one off-gas supply line 231 , 232, 233, 234, 235 and resets the flare temperature setpoint to an initial temperature value after combustion and / or after supply of off-gas has been (at least temporarily) stopped.

[0105] According to the cooling mode, the flare temperature setpoint is kept constant and combustion is exclusively regulated by adapting the volume flow of the heating gas via the at least one heating gas supply line 212 and the volume flow of the combustion-promoting gas, such as oxygen, via the supply 213. For keeping the flare temperature constant, cooling air is also supplied to the combustion chamber 210. The cooling air may be supplied via the same supply 213 as the combustion-promoting air. Both, the supply of the cooling air as well as the supply of the combustion-promoting gas are controlled by the control unit 220. h. The supply of the off-gas, the heating gas and / or the combustionpromoting gas is stopped. Stopping the supply of the heating gas and / or the combustion-promoting gas can be triggered by an end time specified in the data signal provided by the monitoring unit 120 and / or by a current off-gas outflow that has fallen to almost zero.

[0106] In one embodiment, the execution of the method steps initiated (caused) by the control unit 220 is also included in the method.

[0107] Reference Numerals

[0108] 1 section of a plant for recycling lithium ion battery material

[0109] 100 battery material processing facility

[0110] 200 gas incineration facility

[0111] 111 comminuting device

[0112] 112 drying device

[0113] 113 intermediate storage device

[0114] 114 airlock

[0115] 115 start-up and shut-down

[0116] 1110 first gas outlet

[0117] 1120 second gas outlet

[0118] 1130 third gas outlet

[0119] 1140 fourth gas outlet

[0120] 1150 fifth gas outlet

[0121] 131 first off-gas discharge header line

[0122] 132 second off-gas discharge header line

[0123] 133 third gas discharge header line

[0124] 134 third gas discharge header line

[0125] 135 third gas discharge header line

[0126] 120 monitoring unit

[0127] 116 condensation unit

[0128] 117 gas washer

[0129] 210 combustion chamber

[0130] 211 flare

[0131] 212 combustion gas supply line

[0132] 213 combustion-promoting gas supply

[0133] 214 gas oulet

[0134] 215 deflagration protection unit

[0135] 216 gas inlet

[0136] 220 control unit

[0137] 221 first data connection

[0138] 222 second data connection 231 first off-gas supply header line

[0139] 232 second off-gas supply header line

[0140] 233 third gas discharge header line

[0141] 234 third gas discharge header line 235 third gas discharge header line

Claims

Claims1. A plant for recycling lithium ion battery material, comprising a battery material processing facility (100) and a gas incineration facility (200), wherein the battery material processing facility (100) comprises at least:- at least one battery material treatment device (111 , 112, 113, 114, 115) which comprises at least one off-gas outlet (1110, 1120, 1130,1140,1150) for an off-gas produced during treatment,- a monitoring unit (120) configured to provide a data signal with information about a current off-gas outflow from the at least one off-gas outlet (1110, 1120, 1130, 1140, 1150), and the gas incineration facility (200) comprises at least:- a combustion chamber (210) with- a flare (211 ),- at least one off-gas supply line (231 , 232) to at least one of the at least one off-gas outlet (1110, 1120, 1130, 1140, 1150),- at least one heating gas supply line (212) to a heating gas supply unit,- at least one combustion-promoting gas supply (213), and- at least one gas outlet (214), and- a control unit (220) configured to capture the data signal provided by the monitoring unit (120) of the battery material processing facility (100), and to monitor, adjust and / or regulate setting parameters for combustion in the combustion chamber (210) depending on the information contained in the captured data signal.

2. The plant according to claim 1 wherein the battery material processing facility (100) comprises as the at least one battery material treatment device with the at least one off-gas-outlet at least one of:- a comminuting device (110) configured to comminute lithium ion battery material in a comminuting space and comprising at least one first off-gas outlet (1110) for a first off-gas;- a drying device (112) comprising a drying space with at least one second off-gas outlet (1120) for a second off-gas;- an intermediate storage device (113) comprising an intermediate storage space with at least one third off-gas outlet (1130) for a third off-gas; and- an airlock (114) comprising at least one fourth off-gas outlet (1140) for a fourth off-gas.

3. The plant according to claim 2 wherein the gas incineration facility (200) comprises as the at least one off-gas supply line at least one of:- a first off-gas supply line to the at least one first off-gas outlet (1110),- a second off-gas supply line to the at least one second off-gas outlet (1120),- a second off-gas supply header line (232) connected to a second off-gas discharge header line (132) leading to the at least one first off-gas outlet (1110) and the at least one second off-gas outlet (1120),- a third off-gas supply line to the at least one third off-gas outlet (1130),- a fourth off-gas supply line to the at least one fourth off-gas outlet (1140),- a first off-gas supply header line (231 ) connected to a first offgas discharge header line (131) leading to the at least onethird off-gas outlet (1130) and the at least one fourth off-gas outlet (1140).

4. The plant according to claim 3, wherein the battery material processing facility (100) comprises a condensation unit (116) and a gas washer (117) in sequence along the second off-gas discharge header line (132) in the direction of the combustion chamber, the condensation unit (116) being configured to separate electrolyte from the off-gas as the off-gas passes through it.

5. The plant according to claim 4 wherein the second off-gas discharge header line (132) and the second off-gas supply header line (232) are designed for an explosive atmosphere in accordance with national directives.

6. The plant according to claim 5, wherein the second off-gas discharge header line (132) and the second off-gas supply header line (232) are designed for an explosive atmosphere in accordance with one or more of the ATEX directives, the NEC directives, the CEC directives and the lECEx directives.

7. The plant according to any one of the preceding claims wherein the control unit (220) is configured to monitor, adjust and / or regulate as setting parameter for combustion in the combustion chamber at least one of a flare temperature setpoint, a volume flow of a heating gas supplied from the heating gas supply unit, a volume flow of a combustion-promoting gas supplied from the combustion-promoting gas supply.

8. The plant according to claim 7 wherein the control unit (220) is configured to set the flare temperature setpoint in the combustion chamber (210) from an initial temperature value in the range from 800°C to 1000°C to a setpoint value, which is 50 to 300 K higherthan the initial value, and to maintain the flare temperature setpoint at said setpoint value as soon as and as long as off-gas is fed to the combustion chamber (210) through the at least one off-gas supply line (231 , 232).

9. The plant according to claim 8 wherein the control unit (220) is configured to set the flare temperature setpoint in the combustion chamber (210) from an initial temperature value in the range from 800°C to 1000°C to a setpoint value in a range from 1230 °C to 1250 °C, and to maintain the flare temperature setpoint at said setpoint value as soon as and as long as off-gas is fed to the combustion chamber (210) through the at least one off-gas supply line (231 , 232).

10. The plant according to claim 7 wherein the control unit (220) is configured to keep a flare temperature setpoint constant and to regulate the volume flow of the heating gas supplied through the at least one heating gas supply line (212) and I or the volume flow of the combustion-promoting gas from the at least one combustionpromoting gas supply depending on the off-gas supplied through the at least one off-gas supply line (231 , 232).11 . The plant according to one of the preceding claims wherein the monitoring unit (120) is configured to aggregate the information contained in the data signal, wherein the information about the current off-gas outflow from the at least one off-gas outlet (1110, 1120, 1130, 1140, 1150) comprises at least one of a start time of the current off-gas outflow, a composition of the off-gas, an oxygen content of the off-gas, a throughput of the off-gas, a pressure of the off-gas, which of the at least one off-gas outlet is used for the current off-gas outflow, an end time of the current off-gas outflow.

12. The plant according to any one of the preceding claims wherein the gas incineration facility (200) comprises a deflagration protection unit(215) arranged along at least one of the at least one off-gas supply line (231 , 232), and being controlled by the control unit (220).

13. The plant according to claim 12 wherein the gas incineration facility (200) comprises a deflagration protection unit (215) arranged along the second off-gas supply header line (232), and being controlled by the control unit (220).

14. A method for off-gas treatment in a lithium ion battery material recycling process using a plant according to any one of the preceding claims, the method comprising at least the following steps: a. providing a data signal by the monitoring unit (120), the data signal containing information about a current off-gas outflow from the at least one off-gas outlet (1110, 1120, 1130, 1140, 1150), b. capturing the provided data signal by the control unit (220), c. setting, adjusting and / or monitoring setting parameters for combustion in the combustion chamber depending on the information contained in the provided data signal.

15. The method according to claim 14 wherein step c) causes at least some of the following steps to be executed depending on the information contained in the provided data signal: d. supplying an off-gas from the at least one off-gas outlet (1110, 1120, 1130, 1140, 1150) to the combustion chamber (210) of the gas incineration facility (200); e. supplying heating gas from a heating gas supply unit via the at least one heating gas supply line (212) to the combustion chamber (210) of the gas incineration facility (200); f. supplying combustion-promoting gas from a combustionpromoting gas supply (213) to the combustion chamber (210) of the gas incineration facility (200), g. combusting the supplied off-gas in the combustion chamber (210).

16. The method according to claim 15, wherein, to combust the off-gas, the control unit (220) regulates a flare temperature setpoint of the flare in the combustion chamber (210) to a setpoint value in a range from 1200°C to 1250°C, and maintains the flare temperature setpoint at said setpoint value as long as the off-gas is fed to the combustion chamber (210) through the at least one off-gas supply line (231 , 232) and resets the flare temperature setpoint to an initial temperature value after combustion.

17. The method according to claim 16 wherein, to combust the off-gas, the control unit (220) regulates the flare temperature setpoint of the flare in the combustion chamber (210) to a setpoint value of 1250°C.

18. The method according to claim 15, wherein the control unit (220) keeps a flare temperature setpoint constant and, to combust the supplied off-gas, regulates a volume flow of the supplied heating gas and a volume flow of the supplied combustion-promoting gas.

19. The method according to claim 18, wherein the control unit (220) keeps a flare temperature setpoint constant and, to combust the supplied off-gas, regulates a volume flow of the supplied heating gas, a volume flow of the supplied combustion-promoting gas and a volume flow of a supplied cooling gas appropriately in each case.

20. A gas incineration facility configured to be implemented as off-gas incineration facility in a plant according to any one of claims 1 to 13 and / or to carry out a method according to one of claim 14 to 19 together with a monitoring unit (120) of a battery material processing facility (100).

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