Refrigerator recycling system
Patent Information
- Authority / Receiving Office
- TR · TR
- Patent Type
- Patents
- Current Assignee / Owner
- ANDRITZ AG
- Filing Date
- 2024-02-08
- Publication Date
- 2026-06-22
AI Technical Summary
The challenge in recycling refrigerators is the recovery of volatile hydrocarbons like CFCs and pentane from insulation materials and refrigeration circuits while ensuring an environmentally friendly, energy-efficient, and cost-effective process.
A refrigerator recycling plant with a sealed process chamber, inert gas source, dehumidification cooling, compression, and membrane separation system that liquefies hydrocarbons at non-cryogenic temperatures, using a mechanical shredding device and heat exchangers to enhance gas release and separation efficiency.
The system effectively recovers hydrocarbons without cryogenic cooling, reducing energy consumption and complexity, minimizing water icing risks, and ensuring safe operation by controlling oxygen content, thus achieving efficient and cost-effective recycling.
Abstract
Description
[0001] The invention relates to a refrigerator recycling plant.
[0002] A challenge in recycling refrigerators is that the volatile hydrocarbons contained within them, such as CFCs and / or pentane, for example in their insulation material (which is usually made of foamed material using blowing agent / propellant gas) or in their refrigeration circuit, should be recovered as much as possible to prevent them from entering the atmosphere. Furthermore, this recycling process should also be energy- and cost-efficient.
[0003] From EP 1 473 071 A1, a plant and a process for cleaning exhaust gas, in particular solvent-containing exhaust gas originating from the recycling of refrigerators, are known, wherein the following steps are carried out: cryogenic condensation of the exhaust gas dried via dehumidifier and pressurized via compressor, separation of the condensed components from the remaining exhaust gas, passing the cold, pressurized, cleaned exhaust gas through an adsorber to adsorb the remaining condensed solvents, purging the adsorber with a heated gas stream and reprocessing the desorbed gas from the adsorber.
[0004] Accordingly, the invention aims to create a refrigerator recycling plant with which refrigerators can be recycled in an environmentally friendly, energy-efficient and cost-effective manner.
[0005] For this purpose, the invention provides a refrigerator recycling plant which comprises: A refrigerator shredding device comprising a sealed process chamber and a mechanical shredding device arranged within the process chamber for the mechanical shredding of, for example, an essentially complete refrigerator; an inert gas source, optionally a nitrogen gas source, connected to the process chamber from which inert gas, optionally nitrogen gas, can be supplied to the process chamber; a dehumidification cooling device connected to the process chamber (e.g., immediately downstream of it) via a process gas line to obtain process gas discharged from the process chamber, which contains hydrocarbon gas resulting from the mechanical shredding of the refrigerator, and which is configured to cool the process gas to a dehumidification temperature, optionally in the range of 5°–20°C, so that water is separated from the process gas via condensation to dehumidify the process gas; a compressor.a cooling device arranged downstream of the dehumidification cooling device in the process gas line (e.g., immediately downstream of the dehumidification cooling device) and configured to compress the dehumidified process gas, optionally to a pressure in the range of 10-15 bar; a cooling device arranged downstream of the compressor in the process gas line (e.g., immediately downstream of the compressor) and configured to cool the compressed process gas to a separation operating temperature in the range of 5-15°C in order to separate the hydrocarbon contained in the process gas as liquid hydrocarbon via condensation; a gas-liquid separation device arranged downstream of the cooling device in the process gas line (e.g., immediately downstream of the cooling device) and configured to separate the hydrocarbon separated from the compressed and cooled process gas.to separate liquid hydrocarbons (which may and / or may contain further residual liquid moisture) from the remaining process gas, a membrane device which is connected to the gas-liquid separator via a process gas return line to obtain the remaining process gas, which is configured such that a hydrocarbon-enriched return process gas is obtained from the remaining process gas on a permeate side of the membrane device and a hydrocarbon-poor onward process gas on a retentate side of the membrane device, the permeate side of which is connected via a hydrocarbon-enriched gas return line to the process gas line at a return point upstream of the compressor, optionally between the dehumidification cooling device and the compressor, in order to return the hydrocarbon-enriched return process gas to the process gas at this return point,to increase its hydrocarbon content, and whose retentate side is connected to a low-hydrocarbon gas transfer line to convey the low-hydrocarbon process gas.
[0006] The membrane device can be designed, for example, in the manner of a gas separation membrane device as described in EP 0 329 962 A2.
[0007] In the invention, by increasing the hydrocarbon content of the process gas supplied to the compressor via the membrane device, the liquefaction of the hydrocarbon in the cooling unit downstream of the compressor can be achieved in temperature ranges well above 0°C at pressures attainable with an acceptable energy consumption using a compressor (e.g., 10-15 bar). Since cryogenic cooling / liquefaction is therefore unnecessary, the system according to the invention can be operated cost-effectively and is also less complex to construct.The inventors further recognized that by simply cooling the process gas downstream of the comminution device and upstream of the compressor, the water content in the process gas can be reduced sufficiently for the subsequent processes (compression, cooling for hydrocarbon separation) in a simple and cost-effective manner, so as not to impede these subsequent processes. Because the cooling process for liquefying the volatile hydrocarbons is non-cryogenic, there is also no or minimal risk of water icing of the plant components involved in the liquefaction process via the residual moisture still present in the process gas after dehumidification.
[0008] The refrigerator shredding unit can, for example, be equipped with a heating device connected to the process chamber to heat the chamber to a shredding process temperature, optionally in the range of 70° to 80°C. It has been shown that higher temperatures improve the release of gases, including volatile hydrocarbon gases, from, for example, foamed refrigerator insulation elements. An electric heating device can be used as the heating element.
[0009] The mechanical comminution device includes, for example, a rotary impact device, which has one or more rotating bodies arranged in the process chamber, optionally at the bottom of the process chamber, so as to be rotatable about an axis of rotation, and which each is provided with at least one impact chain, e.g. with at least or exactly two impact chains, which (e.g. each of which) are attached with one chain end to the rotating body outside its axis of rotation and which (e.g. each of which) have another, free chain end, wherein the respective impact chain optionally has a length in the range of 30-50cm, and wherein the respective impact chain is optionally designed as a ring chain.It has been shown that, by means of this mechanically relatively simple design of the mechanical comminution device, it is possible to comminute foamed refrigerator insulation material into a granular form, which has proven to be effective / supportive with regard to the release of the gases contained in the insulation material.
[0010] The cooling system can, for example, include a first cooling system heat exchanger, which is further arranged in the process gas return line between the gas-liquid separator and the diaphragm device (e.g., immediately downstream of the compressor) and is configured to allow the remaining process gas in the process gas return line to exchange heat with the compressed process gas. This first cooling system heat exchanger enables efficient and cost-effective cooling of the compressed process gas (e.g., the first cooling process), as it simply utilizes the remaining process gas, e.g., untreated, from the gas-liquid separator. In this configuration, the first cooling system heat exchanger is, for example, connected directly between the gas-liquid separator and the diaphragm device.
[0011] The cooling system comprises, for example, a first cooling unit, which includes a refrigeration unit, a second cooling unit heat exchanger, and a refrigerant line connecting the refrigeration unit and the second cooling unit heat exchanger. A refrigerant circulates in this line, which can be cooled by the refrigeration unit. The second cooling unit heat exchanger is located between the first cooling unit heat exchanger and the gas-liquid separator (e.g., immediately upstream of the gas-liquid separator) and is configured to allow the refrigerant to exchange heat with the compressed process gas. This allows, for example, the compressed process gas to be cooled to the separation operating temperature in the range of 5-15°C, so that hydrocarbons contained in the process gas are separated as liquid hydrocarbons via condensation. Optionally, the dehumidification cooling unit can be, for example,designed as a dehumidification heat exchanger, which is arranged downstream (e.g. immediately downstream) of the second cooling device heat exchanger in the refrigerant line and is designed to allow the refrigerant to exchange heat with the process gas in order to cool the process gas to the dehumidification temperature.
[0012] Because the refrigerator recycling system operates without cryogenics, the refrigeration unit can be smaller and therefore more cost-effective. If the refrigerant is also used as a cooling medium for the dehumidification cooling unit (an option mentioned), the system's efficiency can be further increased.
[0013] The cooling system includes, for example, a second cooling unit comprising an air cooler with a cooling fan, a third cooling unit heat exchanger, and a coolant line connecting the air cooler and the third cooling unit heat exchanger. A coolant circulates in this line, which can be air-cooled by the air cooler via the cooling fan. The third cooling unit heat exchanger is positioned between the first and second cooling unit heat exchangers and is configured to allow the coolant to exchange heat with the compressed process gas. Air cooling is cost-effective and allows the refrigeration unit of the first cooling unit to be even smaller.
[0014] In the refrigerator recycling plant described herein, the low-hydrocarbon gas transfer line can, for example, be connected to the process chamber, allowing the low-hydrocarbon transfer process gas to be fed into the process chamber. Additionally or alternatively, the low-hydrocarbon gas transfer line can, for example, be connected to a pressure-swapping adsorption unit (PSA unit) which has two or more storage tanks containing activated carbon material. The hydrocarbon remaining in the transfer process gas can be adsorbed by the activated carbon material to generate essentially hydrocarbon-free exhaust air. This exhaust air can be discharged to the environment via an exhaust line connected to the respective storage tank and / or fed via a regeneration line to the storage tank whose activated carbon material needs to be regenerated.The refrigerator recycling plant can therefore be operated flexibly to supply clean exhaust air as needed or at all times, whereby the remaining volatile hydrocarbons (HCs) can be fed back into the hydrocarbon separation process.
[0015] The refrigerator recycling plant can also be equipped with, for example, a liquid-liquid separation device. which is either integrally formed with the gas-liquid separator or which is connected to the gas-liquid separator via a liquid discharge line to obtain the separated liquid hydrocarbon from it, and which is configured to separate any remaining water from the separated liquid hydrocarbon. The liquid-liquid separator operates, for example, simply by gravity, with the water, being heavier than the liquid hydrocarbon, separating itself essentially automatically.
[0016] The refrigerator recycling plant can also be equipped, for example, with a small material removal device connected to the process chamber to remove the material shredded by the mechanical shredding device from the process chamber.
[0017] The inert gas source and / or the retentate side of the membrane device can further be connected, for example, via a respective additional inert gas supply line to the hydrocarbon-enriched gas return line and / or between the dehumidifying cooling device and the compressor to the process gas line at an associated additional inert gas supply point, so that inert gas originating from the inert gas source and / or hydrocarbon-enriched gas can be supplied to the process gas via the associated additional inert gas supply point in order to reduce the oxygen content in the process gas, wherein an oxygen sensor is arranged in the process gas line downstream of the respective additional inert gas supply point to detect the oxygen content in the process gas, and wherein the refrigerator recycling plant further, for example,The system is equipped with an electronic control device, which is electrically connected to the oxygen sensor and to a respective additional inert gas control valve located in the associated additional inert gas supply line. This control device is configured to operate the respective additional inert gas control valve based on the oxygen content received as electrical signals from the oxygen sensor, such that a predetermined oxygen content in the process gas is set at the level of the oxygen sensor. The predetermined oxygen content is optionally less than or equal to an oxygen limit concentration (OLC) for the propellant, or optionally, in conjunction with nitrogen gas as the inert gas, less than or equal to 9.3 mol%. This system configuration allows, for example, the following:to efficiently adjust a desired predetermined oxygen content in the process gas upstream of the compressor without unduly hindering the hydrocarbon separation process and minimizing potential explosion risks.
[0018] The term limiting oxygen concentration (LOC) used here refers to the maximum oxygen concentration (mole fraction) in a mixture of a flammable substance with air and an inert gas (e.g., inert gas) in which an explosion cannot occur regardless of the fuel content. The LOC depends on the flammable gas or vapor and the inert gas used.
[0019] The heating device of the refrigerator recycling plant, for example, has a heat pump device which includes: a heat pump supply line, which is connected to the coolant line of the second cooling device via an inlet point and a return point, a heat pump, which is connected to the heat pump supply line, a heat pump discharge line, which is connected to the heat pump and to a heat exchanger of the heating device arranged at the process chamber, by means of which the heat can be transferred from the heat pump to the process chamber.
[0020] This can, for example, eliminate the need for an electric heating device or reduce its energy consumption, and further increase the energy efficiency of the refrigerator recycling plant.
[0021] The invention further provides a method for recycling refrigerators, optionally by means of a refrigerator recycling plant as described in this application, e.g. as above, comprising the steps: Feeding, optionally individual feeding, of the refrigerators into a (e.g., the) process chamber, feeding of inert gas, optionally of nitrogen gas, into the process chamber, mechanical comminution of the respective refrigerator in the process chamber, extraction of the gas present in the process chamber as process gas from the process chamber and feeding of the process gas to a (e.g., the) dehumidification cooling device, cooling of the process gas by means of the dehumidification cooling device to a temperature that is optionally in the range of 5-20°C in order to dehumidify the process gas by condensing and separating the water contained in the process gas, compression of the dehumidified process gas by means of a (e.g., the) compressor, optionally to a pressure in the range of 10-15 bar, cooling of the compressed process gas in a (e.g., the) cooling device to a (e.g.,The separation operating temperature is in the range of 5-15°C in order to separate the hydrocarbon contained in the process gas as liquid hydrocarbon via condensation. The liquid hydrocarbon separated from the compressed and cooled process gas is then separated from the remaining process gas by means of a gas-liquid separator (e.g., a gas-liquid separator). The remaining process gas is fed to a membrane device (e.g., a membrane device), from which a hydrocarbon-enriched recirculation process gas is obtained on a permeate side of the membrane device (e.g., a permeate side) and a hydrocarbon-poor recirculation process gas is obtained on a retentate side of the membrane device (e.g., a retentate side). The recirculation process gas is then returned to the process gas in the process gas line at a (e.g.,the) return point upstream of the compressor, optionally between the dehumidification cooling device and the compressor, to increase the hydrocarbon content of the process gas.
[0022] The procedure may, for example, also include: Additional supply of inert gas, optionally nitrogen gas, and / or of the process gas being fed into the process gas at an (e.g.) associated additional inert gas supply point between the compressor and the dehumidification cooling device, and / or to the recirculated process gas at an (e.g.) correspondingly associated additional inert gas supply point in a recirculation-controlled (or regulated) manner such that the oxygen content of the process gas entering the compressor is less than or equal to an oxygen limit concentration (OLC) for the propellant, optionally in conjunction with nitrogen gas as an inert gas, e.g. less than or equal to 9.3 mol%.
[0023] The process can also include, for example: feedback-controlled (e.g., regulated) heating of the process chamber in order to set a predetermined comminution process temperature, which is optionally in the range of 70-80°.
[0024] The procedure may also include, for example: Removing refrigerator compressors and, optionally, refrigerator refrigerant lines from the refrigerators before feeding the refrigerators into the process chamber, whereby the refrigerators, with the exception of the removed compressors and, optionally, the removed refrigerant lines, are otherwise fed into the process chamber completely as received. This can, for example, reduce the mechanical load on a mechanical shredding device and also improve the composition of the shredded materials, for example, with regard to further separation.
[0025] In this process, mechanical comminution is carried out, for example, by reducing the foamed insulation material present in the refrigerators to particles with a maximum diameter of 2 mm, or optionally a maximum diameter of 1 mm. It has been shown that this type of particle formation makes the extraction of hydrocarbons from the refrigerator insulation material very efficient.
[0026] The invention is described below with reference to exemplary embodiments, which, however, do not limit the invention. When the above and following descriptions refer to a first, second, etc. component (or, for example, step), this does not necessarily establish a specific sequence in which these components (or, for example, steps) occur; i.e., the first component (or, for example, step) could also be the second or third component (or, for example, step), and vice versa.
[0027] The drawing shows: Figure 1 a schematic view of a refrigerator recycling plant according to a first embodiment of the invention, Figure 2 a schematic view of a refrigerator recycling plant according to a second embodiment of the invention, Figure 3a schematic view of a refrigerator recycling plant according to a third embodiment of the invention, Figure 4 a schematic view of a refrigerator shredding device with, connected to it, a refrigerator feed device and small material removal device of the refrigerator recycling plant according to an embodiment of the invention, Figure 5 a cross-sectional view of the sealed process chamber of the refrigerator recycling plant Fig. 4 along line AA, Figure 6 a cross-sectional view of the sealed process chamber of the refrigerator recycling plant Fig. 4 along line BB, Figure 7 a flowchart of a process for recycling refrigerators, and Figure 8 a flowchart of the process for recycling refrigerators according to Figure 7 with additional steps.
[0028] In Figure 1Figure 1 shows a schematic view of a refrigerator recycling plant 1 according to a first embodiment of the invention, which has a refrigerator shredding device 10, a sealed process chamber 12 and a mechanical shredding device 20 arranged in the process chamber 12 for mechanically shredding a refrigerator 22 (see e.g. Fig. 4The refrigerator recycling plant 1 also has an inert gas source 30, which is connected to the process chamber 12 via an inert gas line 32 and is located, for example, directly upstream of the process chamber 12. Inert gas, optionally nitrogen gas, can be supplied from the inert gas source 30 to the process chamber 12 in order to inertize the gases generated during the mechanical shredding of the refrigerators 22 in the process chamber 12 and thus minimize the risk of explosion within the process chamber 12. Inert gases other than nitrogen gas, e.g., CO2, could have disadvantages with regard to diffusion behavior, for example, when using membrane technologies (see, for example, the membrane device described below).
[0029] Furthermore, the refrigerator recycling plant 1 includes a dehumidification cooling device 40, which is connected to the process chamber 12 via a process gas line 50. The dehumidification cooling device 40 is designed to obtain process gas discharged from the process chamber 12, which contains hydrocarbon gas resulting from the mechanical shredding of the refrigerator 22. The dehumidification cooling device 40 is also designed to cool the process gas to a dehumidification temperature, which is optionally in the range of 5°–20°C, so that water can be separated from the process gas via condensation through a wastewater line 42 to dehumidify the process gas.
[0030] The refrigerator recycling plant 1 further comprises a compressor 60, which is arranged downstream of the dehumidification cooling device 40 in the process gas line 50. The compressor 60 is configured to compress the dehumidified process gas, optionally to a pressure in the range of 10-15 bar.
[0031] Furthermore, the refrigerator recycling plant 1 has a cooling device 70, which is arranged in the process gas line 50 downstream of the compressor 60 and, for example, immediately after the compressor 60. The cooling device 70 is designed to cool the compressed process gas to a separation operating temperature in the range of 5-15°C in order to separate the hydrocarbon contained in the process gas as liquid hydrocarbon via condensation.
[0032] Furthermore, the refrigerator recycling plant 1 has a gas-liquid separator 80, which is arranged downstream of and immediately after the cooling unit 70 in the process gas line 50. The gas-liquid separator 80 is designed to separate the liquid hydrocarbon separated from the compressed and cooled process gas from the remaining process gas via a liquid discharge line 82.
[0033] The refrigerator recycling plant 1 further comprises a membrane device 90, which is connected to the gas-liquid separator 80 via a process gas return line 100. The membrane device 90 is configured to receive the remaining process gas from the gas-liquid separator 80 via the process gas return line 100. The membrane device 90 is also configured to obtain a hydrocarbon-enriched recirculation process gas from the remaining process gas on a permeate side 92 of the membrane device 90 and a hydrocarbon-poor recirculation process gas on a retentate side 94 of the membrane device 90.The permeate side 92 of the membrane device 90 is connected via a hydrocarbon-enriched gas return line 110 to the process gas line 50 at a return point 112 upstream of the compressor 60, between the dehumidification cooling device 40 and the compressor 60, in order to return the hydrocarbon-enriched return process gas to the process gas at this return point 112 in order to increase its hydrocarbon content. The retentate side 94 of the membrane device 90 is connected to a low-hydrocarbon gas transfer line 120 to transfer the low-hydrocarbon transfer process gas. According to the present embodiment, the low-hydrocarbon gas transfer line 120 is connected to the process chamber 12 to supply the process chamber 12 with low-hydrocarbon transfer gas.
[0034] In this embodiment, the refrigerator shredding unit 10 of the refrigerator recycling plant 1 is also equipped with a heating device 130. The heating device 130 is directly connected to the process chamber 12 in order to heat the process chamber 12 to a shredding process temperature, which is optionally in the range of 70° to 80°, in order to improve the release of gases from, for example, the foamed refrigerator insulation elements. An electric heating device can be used as the heating device 130.
[0035] The refrigerator shredding unit 10 of the refrigerator recycling plant 1 is configured so that the refrigerators 22 to be shredded can be fed from outside to the process chamber 12 by means of a refrigerator feed unit 140, in order to supply the mechanical shredding device 20 with refrigerators 22 to be shredded and to shred them. The refrigerator recycling plant 1 is also equipped with a small material discharge unit 150 to remove material 152 shredded by the mechanical shredding device 20 (see e.g. Fig. 4 ) of the refrigerators 22 from the process chamber 12. The small material removal device 150 is connected to the process chamber 12 and is configured to separate the shredded material 152 from the refrigerators 22 depending on the material properties of the shredded material 152, in order to subsequently recycle and / or reuse it.
[0036] The cooling device 70, which is located directly downstream of the compressor 60 and is designed to cool the process gas heated by the compressor 60 to the separation operating temperature in the range of 5-15°C, has a first cooling device heat exchanger 160. The first cooling device heat exchanger 160 is arranged both in the process gas line 50 and in the process gas return line 100, specifically between the gas-liquid separator 80 and the membrane device 90. The first cooling device heat exchanger 160 is configured to allow the remaining process gas in the process gas return line 100 to exchange heat with the compressed process gas. By means of this first cooling device heat exchanger 160, the compressed process gas is cooled (e.g., firstly or as the first cooling process) in an efficient / cost-efficient manner, since for this purpose the e.g.The untreated process gas remaining from the gas-liquid separation device 80 is used as a heat exchange medium for cooling. For this purpose, the first cooling device heat exchanger 160 is located, for example, directly after the compressor 60 in the process gas line 50.
[0037] The cooling unit 70 further comprises a first cooling unit 170, which in turn includes a refrigeration unit (e.g., an electrically operated refrigeration unit) 172, a second cooling unit heat exchanger 174, and a refrigerant line 176. The refrigerant line 176 connects the refrigeration unit 172 and the second cooling unit heat exchanger 174 and circulates a refrigerant that can be cooled by the refrigeration unit 172. The second cooling unit heat exchanger 174 is arranged between the first cooling unit heat exchanger 160 and the gas-liquid separator 80 in the process gas line 50 and is configured to allow the refrigerant to exchange heat with the compressed process gas. Accordingly, hydrocarbons contained in the process gas can be separated via condensation in the second cooling unit heat exchanger 174.
[0038] In this embodiment, the dehumidification cooling device 40 is designed as a dehumidification heat exchanger, which is arranged in the process gas line 50 and in the refrigerant line 176 between (e.g., as here, directly between) the second cooling device heat exchanger 174 and the refrigeration unit 172 in the refrigerant line 176. The dehumidification cooling device 40, designed as a dehumidification heat exchanger, is configured to allow the refrigerant to exchange heat with the process gas in order to cool the process gas to the dehumidification temperature by means of residual cooling from the refrigerant, thereby further increasing the efficiency of the refrigerator recycling plant 1.
[0039] The cooling unit 70 of the refrigerator recycling plant 1 further comprises a second cooling unit 180, which in turn includes an air cooler 182 with a cooling fan (e.g., an electrically operated cooling fan) 186, a third cooling unit heat exchanger 184, and a coolant line 188. The coolant line 188 connects the air cooler 182 and the third heat exchanger 184 and circulates a coolant that can be air-cooled by the air cooler 182 via the cooling fan 186. Additionally, the coolant line 188 is connected, for example, to the refrigeration unit 172 of the first cooling unit 170, or can be selectively connected to it, in order to be able to cool the coolant additionally (e.g., optionally, selectively, or in a switchable manner). The third cooling unit heat exchanger 184 is connected between (e.g.,The second cooling unit heat exchanger 174 is arranged and configured directly between the first cooling unit heat exchanger 160 and the second cooling unit heat exchanger 174 in the process gas line 50 to allow the coolant to exchange heat with the compressed process gas. The second cooling unit heat exchanger 174 is also connected to the gas-liquid separator 80 via the process gas line 50. (e.g. directly connected), to supply the process gas with the hydrocarbon-containing condensate to the gas-liquid separator 80.
[0040] In this embodiment, the refrigerator recycling plant 1 has a liquid-liquid separator 190 that is separate from the gas-liquid separator 80. The liquid-liquid separator 190 is connected to the gas-liquid separator 80 via a liquid discharge line 192 and is designed to separate the water, which is heavier than the liquid hydrocarbon, essentially automatically by gravity. The water and the liquid hydrocarbon separated by the liquid-liquid separator 190 can each be discharged via a wastewater connection line 194 and a propellant discharge line 196 of the refrigerator recycling plant 1, respectively. The wastewater connection line 194 is also connected to the wastewater line 42 of the dehumidifying cooling unit 40 to further discharge the separated water into the wastewater system.The propellant discharge line 196 can, for example, be used to supply the liquid hydrocarbon to a propellant filling plant.
[0041] The refrigerator recycling plant 1, for example, further comprises a pressure-swapping adsorption unit 200, which is connected to the low-hydrogen gas transfer line 120 between the membrane device 90 or its retentate side 94 and the process chamber 12 of the refrigerator shredding unit 10. The pressure-swapping adsorption unit 200 has two or more storage tanks 202 containing activated carbon material, an exhaust line 204, a regeneration line 206, and a first and a second control valve 208, 209. The pressure-swapping adsorption unit 200 is capable of adsorbing the hydrocarbon remaining in the transfer process gas onto the activated carbon material in order to generate essentially hydrocarbon-free exhaust air.The essentially hydrocarbon-free exhaust air can be discharged to the environment via an exhaust air line 204 connected to the respective storage tank 202 by actuating the two control valves 208, 209 and / or supplied via the regeneration line 206 to the storage tank 202 whose activated carbon material is to be regenerated.
[0042] The refrigerator recycling plant 1 optionally features an additional inert gas supply line 210. The additional inert gas supply line 210 is connected to the inert gas source 30 and / or to the retentate side 94 of the membrane device 90 and is further connected between the dehumidifying cooling device 40 and the compressor 60, or, for example, between the process chamber 12 and the dehumidifying cooling device 40, to the process gas line 50 at an associated additional inert gas supply point 212. Inert gas originating from the inert gas source 30 and / or hydrocarbon-enriched gas can be supplied to the process gas via the associated additional inert gas supply point 212, for example, to reduce the oxygen content in the process gas if required.
[0043] The process gas line 50 of the refrigerator recycling plant 1, for example, has an oxygen sensor 220 downstream of the additional inert gas supply point 212 between the dehumidifying cooling device 40 and the compressor 60. The oxygen sensor 220 is configured to detect the oxygen content in the process gas, whereby the predetermined oxygen content is optionally less than or equal to an oxygen limit concentration (OLC) for the propellant, optionally in conjunction with nitrogen gas as an inert gas, e.g., less than or equal to 9.3 mol%.
[0044] The refrigerator recycling plant 1, for example, further comprises an electronic plant control device 230, which is electrically connected to the oxygen sensor 200 and to a respective additional inert gas control valve 240 located in the respective associated additional inert gas supply line 210. The electronic plant control device 230 is configured to control the respective additional inert gas control valve 240, based on the oxygen content received as electrical signals from the oxygen sensor 220, such that a predetermined oxygen content in the process gas is set at the level of the oxygen sensor 220.
[0045] Figure 2Figure 1 shows a refrigerator recycling plant 1 according to a second embodiment of the invention. The refrigerator recycling plant 1 according to the second embodiment is essentially identical to that of the first embodiment, so reference is made to the preceding description regarding the similarities, and the corresponding reference numerals in Figure 1 are also included. Figure 2 are listed. Therefore, only the differences will be discussed below.
[0046] In contrast to the exemplary embodiment of Figure 1 The exemplary embodiment of Figure 2 a three-phase separation device 250, which replaces the gas-liquid separator 80 and the liquid-liquid separator 190 from the previous embodiment and which combines the functions of both the gas-liquid separator 80 and the liquid-liquid separator 190. That is, in the embodiment of Figure 2The gas-liquid separator 80 and the liquid-liquid separator 190 are integrally designed in the form of the three-phase separation unit 250, or the liquid-liquid separator 190 is integrated into the gas-liquid separator 80. The three-phase separation unit 250 is capable of separating the process gas discharged from the cooling unit 70, containing liquid hydrocarbons, into a recirculated process gas, liquid hydrocarbons, and water. The recirculated process gas is then fed to the membrane device 90 via the process gas return line 100, as in the first embodiment, and the water and the liquid hydrocarbons are discharged separately via the wastewater connection line 194 and the propellant filling line 196, respectively. The three-phase separation unit 250 can, for example, be used to separate the process gas 70 from the liquid hydrocarbons.The complexity of refrigerator recycling plant 1 is reduced and the hydrocarbon recovery process is further simplified.
[0047] Figure 3 Figure 1 shows a refrigerator recycling plant 1 according to a third embodiment of the invention. The refrigerator recycling plant 1 according to the third embodiment is essentially identical to that of the first embodiment, so reference is made to the preceding description regarding the similarities, and the corresponding reference numerals in Figure 1 are also included. Figure 3 are listed. Therefore, only the differences will be discussed below.
[0048] In contrast to the exemplary embodiment of Figure 1 The heating device 130 in the exemplary embodiment of Figure 3A heat pump device 260 is included, which has a heat pump supply line 261. The heat pump supply line 261 is connected to the coolant line 188 of the second cooling device 180 via an inlet point 262 after (in this case immediately after) the third cooling device heat exchanger 184 and is connected again to the coolant line 188 of the second cooling device 180 via a return point 263 before (in this case immediately before) the air cooler 182, whereby coolant from the third cooling device heat exchanger 184 is supplied to a heat pump 264 by means of the heat pump supply line 261 and the coolant is then returned from the heat pump 264 to the air cooler 182.
[0049] The heat pump device 260 further comprises the heat pump 264, which is connected to the heat pump supply line 261 between the inlet point 262 and the return point 23 of the heat pump supply line 262 and is configured to generate heat. The heat pump 264 may also include, for example, a pump for circulating the coolant and / or heat pump control valves (not shown).
[0050] Furthermore, the heat pump device 260 has a heat pump discharge line 265, which is connected to the heat pump 264 and to a heat exchanger 266 (which is part of the heating device 130) arranged at the process chamber 12, in order to transfer the heat generated by the heat pump 264 from the heat pump 264 to the process chamber 12. The heat pump device 260 also has a coolant line control valve 267, which is arranged in the coolant line 188 between the inlet 262 and the return 263 of the heat pump supply line 261 and is configured to block or allow the flow of coolant in the coolant line 188.Furthermore, the heating device 130 has a supply control valve 268 and a return control valve 269, which are arranged between the supply point 262 and the heat pump 264, and between the heat pump 264 and the return point 263, respectively, and control the coolant flow in the heat pump supply line 261. The coolant line control valve 267, the supply control valve 268, and the return control valve 269 can be controlled / adjusted relative to each other by means of the electronic system control device 230. For example, the supply control valve 268 and the return control valve 269 can be open (e.g., in an open state) when the coolant line control valve 267 is closed (e.g., in a closed state), and vice versa.
[0051] The residual cooling effect of the refrigerant flowing from the third cooling unit heat exchanger 184 to the air cooler 182 can be reused by means of the heat pump device 260 to supply the heat pump 264, which generates heat according to the principle of a heat engine and in turn supplies the heat to the process chamber 12 via the heat exchanger 266 to reach the shredding process temperature. This further increases the energy efficiency of the refrigerator recycling plant.
[0052] Figure 4 Figure 1 shows a schematic view of a refrigerator shredding device 10 with, connected to it, a refrigerator feed device 140 and a small material discharge device 150 of the refrigerator recycling plant 1 according to an exemplary embodiment, which is shown, for example, in the embodiment examples of Figure 1 and 2 can be used.
[0053] The refrigerator feed device 140, e.g., a conveyor belt, is configured to sequentially, and optionally singulate, feed refrigerators 22 to the refrigerator shredding device 10 and consequently to the process chamber 12, and is located, e.g., directly upstream of the refrigerator shredding device 10. The material 152 from the refrigerators 22 shredded within the process chamber 12 is, among other things, in granular form, and the small material discharge device 150 is configured to remove the shredded material 152 from the refrigerators 22 from the process chamber 12 and separate it according to the material properties of the shredded materials 152.
[0054] With reference to Figure 5According to one embodiment of the present invention, the mechanical comminution device 20 comprises, for example, exactly one rotary impact device 270. This device is arranged in the process chamber 12, optionally at its base, and has a rotating body 272. The rotating body 272 is rotatable about a rotational axis A and is provided with two impact chains 274, which here, for example, are designed as ring chains. The impact chains 274 are each attached to the rotating body 272 outside its rotational axis A at their chain ends 276 and each has a free chain end 268.The impact chains 274 with the free chain ends 268 are designed to generate a swirling material flow of the shredded material 152 by rotating the rotating body 272 and thus the impact chains 274. This creates an interaction not only between the refrigerators 22 to be shredded and the rotating impact device 270, but also within the shredded material 152 itself. This intensifies the mechanical stress on the shredded material 152, and in conjunction with an interaction between the shredded material 152 and the process chamber 12, as well as the swirling material flow, the granular form of the shredded material 152 is formed.
[0055] Figure 6 shows a sectional view of the sealed process chamber 12 of the refrigerator recycling plant 1. Fig. 4along line BB. In this embodiment, four rotary impact devices 270 are arranged within the process chamber 12, which are opposite each other in, for example, a rectangular arrangement. For example, the ones shown in the view in Fig. 6Horizontally opposed rotary impact devices 270 are provided with the same direction of rotation, and vertically opposed rotary impact devices 270 are provided with opposite directions of rotation (see rotation arrows R), so that in addition to the swirling material flow of each rotary impact device 270, a translational material flow (translation arrow T) is also generated, for example, through the process chamber 12 towards the small material discharge device 150, in order to feed the crushed material 152 in the direction of the small material discharge device 150. This exemplary arrangement of the rotary impact devices 270, including the respective directions of rotation, can be configured in any way to generate a directed material flow of the crushed material 152 within the process chamber 12.
[0056] Figure 7Figure 1 shows a flowchart of a process S300 for recycling refrigerators 22, which can be carried out, for example, with the refrigerator recycling plant 1 according to the first embodiment of the invention. In a first step S320, refrigerators 22 are fed, optionally singulated, into the process chamber 12 of the refrigerator shredding device 20 by means of the refrigerator feeding device 140, e.g., the conveyor belt.
[0057] In a second step, S330, inert gas, optionally nitrogen gas, is supplied to process chamber 12, into which the refrigerators 22 were fed by means of the refrigerator feeder 140, in order to inertize the process chamber 12. The supply of inert gas can, for example, be carried out continuously during the process to maintain a consistently high inert gas concentration in process chamber 12.
[0058] In a third step S350, the supplied refrigerators 22 are mechanically shredded by means of at least one or more rotary impact devices 270 of the mechanical shredding device 20. The mechanical shredding S350 is carried out such that the foamed insulation material present in the refrigerators 22 is shredded by the mechanical shredding device 20 into particles with a maximum circumference of 2 mm, optionally with a maximum circumference of 1 mm.
[0059] In a fourth step S360, the gas present in the process chamber 12 is removed as hydrocarbon-containing process gas from the process chamber 12 via the process gas line 50 (e.g. extracted) and then fed to the dehumidification cooling device 40, which is located downstream of the process chamber 12.
[0060] In a fifth step S370, the process gas supplied from process chamber 12 via process gas line 50 is cooled by the dehumidification cooling unit 40, which is designed as a dehumidification heat exchanger. The process gas is preferably cooled to a temperature in the range of 5-20°C in order to dehumidify it via condensation and discharge the condensate via the wastewater line 42 connected to the dehumidification cooling unit 40. The dehumidified gas is then fed to the compressor 60 via process gas line 50.
[0061] In a sixth step, S390, the dehumidified process gas supplied to compressor 60 is compressed to a pressure, optionally in the range of 10-15 bar, which heats the dehumidified process gas. The pressure increase serves to raise the dew point of the hydrocarbons present in the process gas, thus enabling their simpler and more energy-efficient separation.
[0062] In a seventh step (S400), the compressed process gas is fed to the cooling unit 70 via the process gas line 50, where it is subsequently cooled to a temperature in the range of 5-15°C by means of the heat exchangers 160, 174, and 184. Due to the increased dew point caused by the cooling of the process gas, hydrocarbons are again separated via condensation, and the process gas containing liquid hydrocarbons is fed to the gas-liquid separator 80 via the process gas line 50.
[0063] In an eighth step S410, the hydrocarbon, which is now largely liquid in the process gas, is separated from the remaining process gas in the gas-liquid separator 80 by removing the liquid hydrocarbon through the liquid discharge line 82 and conveying the remaining process gas via the process gas return line 100.
[0064] In a ninth step S420, the remaining process gas in the process gas return line 100 is fed to the membrane device 90. From this, the hydrocarbon-enriched return process gas is obtained on the permeate side 92 of the membrane device 90, and the hydrocarbon-poor onward process gas is obtained on the retentate side 94 of the membrane device 90.
[0065] In a tenth step S430, the recirculated process gas is returned to the process gas. For this purpose, the recirculated process gas is fed via the hydrocarbon-enriched gas return line 110 at the return point 112 upstream of the compressor 60, optionally between the dehumidification cooling device 40 and the compressor 60, to the process gas in the process gas line 50 in order to increase the hydrocarbon content of the process gas in the process gas line 50.
[0066] Figure 8 shows a flowchart of the S300 process for recycling refrigerators 22 according to Figure 7with additional steps. In an additional step S340, the process chamber 12 is heated using a recirculating control system (this control can be implemented, for example, using the plant control device 230 of the refrigerator recycling plant 1) to set the predetermined shredding process temperature, which is optionally in the range of 70-80°C. The recirculating heating S340 can, for example, occur in parallel with the previous steps S310-S330 and, for example, continuously throughout the entire process S300 to maintain the temperature of the process chamber 12 at a constant level.
[0067] In a further additional step S310, the refrigerator compressors of the (to be recycled) refrigerators 22 and, optionally, the refrigerator refrigerant lines of the (to be recycled) refrigerators 22 are removed from the refrigerators 22 before the refrigerators 22 are fed S320 into the process chamber 12. The refrigerators 22, with the exception of the refrigerator compressors and, optionally, the removed refrigerator refrigerant lines, are otherwise fed completely, as received by the refrigerator feeding device 140, into the process chamber 12 for mechanical shredding S350. This serves, for example, to prevent high wear on the impact chains 274 of the rotary impact device 22 caused by metal parts of the refrigerator compressors and / or refrigerator refrigerant lines striking them.
[0068] In a further additional step S380, inert gas, optionally nitrogen gas, and / or recirculating process gas are added to the process gas at the associated additional inert gas supply point 212 between the compressor 60 and the dehumidification cooling device 40. Furthermore, inert gas, optionally nitrogen gas, and / or recirculating process gas can also be added to the recirculated process gas at the corresponding additional inert gas supply point 212, either in parallel or independently. The additional supply S380 is carried out, for example, in a recirculation-controlled manner such that the oxygen content of the process gas entering the compressor 60 is less than or equal to the limiting oxygen concentration (LOC) for the propellant, optionally in conjunction with nitrogen gas as the inert gas, e.g., less than or equal to 9.3 mol%, thus enabling efficient operation of the membrane device 90. Reference list:
[0069] 1 Refrigerator recycling plant 10 Refrigerator shredding unit 12 Process chamber 20 Mechanical shredding unit 22 Refrigerator 30 Inert gas source 32 Inert gas line 40 Dehumidification cooling unit 42 Wastewater line 50 Process gas line 60 Compressor 70 Cooling unit 80 Gas-liquid separation unit 82 Liquid discharge line 90 Membrane unit 92 Permeate side 94 Retentate side 100 Process gas return line 110 KW enriched gas return line 112 Return point 120 KW low gas discharge line 130 Heating unit 140 Refrigerator feed unit 150 Small material discharge unit 152 Shredded material 160 First cooling unit heat exchanger 170 First cooling unit cooling unit 172 Refrigeration unit 174 Second cooling unit heat exchanger 176 Refrigerant line 180 Second cooling unit device 182 Air cooler 184 Third cooling unit heat exchanger 186 Cooling air blower 188 Coolant line 190 Liquid-liquid separator 192 Liquid drain line194 Wastewater connection line 196 Propellant discharge line 200 Pressure-changing adsorption unit 202 Storage tank 204 Exhaust air line 206 Regeneration line 208 First control valve 209 Second control valve 210 Additional inert gas supply line 212 Additional inert gas supply point 220 Oxygen sensor 230 System control device 240 Additional inert gas control valve 250 Three-phase separator 260 Heat pump device 261 Heat pump supply line 262 Inlet point 263 Return point 264 Heat pump 265 Heat pump discharge line 266 Heat exchanger 267 Heat pump control valve 268 Inlet control valve 269 Return control valve 270 Rotating impact device 272 Rotating body 274 Impact chain 276 Chain end
Claims
1. Refrigerator recycling plant (1) with - a refrigerator shredding device (10) which has a sealed process chamber (12) and a mechanical shredding device (20) arranged in the process chamber (12) for mechanically shredding a refrigerator (22), - an inert gas source (30), optionally a nitrogen gas source, which is connected to the process chamber (12) and from which inert gas, optionally nitrogen gas, can be supplied to the process chamber (12), - a dehumidification cooling device (40) connected to the process chamber (12) via a process gas line (50) in order to obtain process gas discharged from the process chamber (12), which contains hydrocarbon gas resulting from the mechanical shredding of the refrigerator (22), and which is configured to cool the process gas to a dehumidification temperature, which is optionally in the range of 5°-20°, so that water is separated from the process gas via condensation in order to dehumidify the process gas, - a compressor (60) arranged downstream of the dehumidification cooling device (40) in the process gas line (50) and configured to compress the dehumidified process gas, optionally to a pressure in the range of 10-15 bar, - a cooling device (70) arranged downstream of the compressor (60) in the process gas line (50) and configured to cool the compressed process gas to a separation operating temperature in the range of 5-15°C, to thereby separate hydrocarbon, contained in the process gas, as liquid hydrocarbon via condensation, - a gas-liquid separation device (80) arranged downstream of the cooling device (70) in the process gas line (50) and configured to separate the liquid hydrocarbon separated from the compressed and cooled process gas from the remaining process gas, - a membrane device (90), - which is connected to the gas-liquid separation device (80) via a process gas return line (100) in order to obtain the remaining process gas, - which is configured such that it obtains, from the remaining process gas, a hydrocarbon-enriched return process gas on a permeate side (92) of the membrane device (90) and a low-hydrocarbon forward process gas on a retentate side (94) of the membrane device (90), - whose permeate side (92) is connected via a hydrocarbon-enriched gas return line (110) to the process gas line (50) at a return point (112) upstream of the compressor (60), optionally between the dehumidification cooling device (40) and the compressor (60), in order to return the hydrocarbon-enriched return process gas to the process gas at this return point (112) in order to increase hydrocarbon content thereof, and - whose retentate side (94) is connected to a low-hydrocarbon gas forward line (120) to forward the low-hydrocarbon forward process gas.
2. Refrigerator recycling plant (1) according to claim 1, wherein the refrigerator shredding device (10) is provided with a heating device (130) connected to the process chamber (12) to heat the process chamber (12) to a shredding process temperature optionally in the range of 70° to 80°.
3. Refrigerator recycling plant (1) according to claim 1 or 2, wherein the mechanical shredding device (20) has a rotary impact device (270) which has one or more rotary bodies (272) which are arranged in the process chamber (12), optionally at the bottom of the process chamber (12), to be rotatably driven about a rotational axis (A) and are each provided with at least one impact chain (274) which is attached with one chain end to the rotating body (276) outside its rotational axis (A) and has another, free chain end (268), wherein the respective impact chain (272) optionally has a length in a range of 30-50 cm, and wherein the respective impact chain (272) is optionally designed as a ring chain.
4. Refrigerator recycling plant (1) according to one of claims 1-3, wherein the cooling device (70) has a first cooling device heat exchanger (160), which is furthermore arranged in the process gas return line (100) between the gas-liquid separation device (80) and the membrane device (90) and which is configured to allow the remaining process gas present in the process gas return line (100) to exchange heat with the compressed process gas.
5. Refrigerator recycling plant (1) according to claim 4, wherein the cooling device (70) comprises a first cooling device cooling apparatus (170) which has a refrigeration unit (172), a second cooling device heat exchanger (174) and a refrigerant line (176) connecting the refrigeration unit (172) and the second cooling device heat exchanger (174) to each other and in which a refrigerant circulates which can be cooled by the refrigeration unit (172), wherein the second cooling device heat exchanger (174) is arranged between the first cooling device heat exchanger (160) and the gas-liquid separation device (80) and is configured to allow the refrigerant to exchange heat with the compressed process gas, wherein, optionally, the dehumidification cooling device (40) is designed as a dehumidification heat exchanger, which is arranged downstream of the second cooling device heat exchanger (174) in the refrigerant line (176) and is configured to allow the refrigerant to exchange heat with the process gas in order to cool the process gas to the dehumidification temperature.
6. Refrigerator recycling plant (1) according to claim 5, wherein the cooling device (70) comprises a second cooling device cooling apparatus (180) comprising an air cooler (182) with a cooling air fan (186), a third cooling device heat exchanger (184) and a coolant line (188) which connects the air cooler (182) and the third cooling device heat exchanger (184) to each other and in which a coolant circulates which is air-coolable by the air cooler (182) by means of the cooling air fan (186), wherein the third cooling device heat exchanger (184) is arranged between the first cooling device heat exchanger (184) and the second cooling device heat exchanger (174) and is configured to allow the coolant to exchange heat with the compressed process gas.
7. Refrigerator recycling plant (1) according to one of claims 1-6, - wherein the low-hydrocarbon gas forward line (120) is connected to the process chamber (12) so that the low-hydrocarbon forward process gas can be supplied to the process chamber (12), and / or - wherein the low-hydrocarbon gas forward line (120) is connected to a pressure swing adsorption device (200) (DWA device) which has two or more storage containers (202) with activated carbon material, wherein the hydrocarbon remaining in the forward process gas can be adsorbed by the activated carbon material, to thereby generate substantially hydrocarbon-free exhaust air which can be discharged to the environment via an exhaust air line (204) connected to the respective storage container (202) and / or can be fed via a regeneration line (206) to that of the storage containers (202) whose activated carbon material is to be regenerated.
8. Refrigerator recycling plant (1) according to one of claims 1-7, further comprising a liquid-liquid separation device (190), - which is either integrally formed with the gas-liquid separation device (80, 82) or which is connected to the gas-liquid separation device (80) via a liquid discharge line (192) in order to receive the separated liquid hydrocarbon from the latter, and - which is configured to separate residual water from the separated liquid hydrocarbon.
9. Refrigerator recycling plant (1) according to one of claims 1-8, further comprising a small material discharge device (150) which is connected to the process chamber (12) in order to discharge the material (152) shredded by the mechanical shredding device (20) from the process chamber (12).
10. Refrigerator recycling plant (1) according to one of claims 1-9, wherein the inert gas source (30) and / or the retentate side (94) of the membrane device (90) is / are further connected via a respective additional inert gas supply line (210) - with the hydrocarbon-enriched gas return line (110) and / or - between the dehumidification cooling device (40) and the compressor (60) with the process gas line (50) at an associated additional inert gas supply point (212), so that inert gas originating from the inert gas source (30) and / or hydrocarbon-enriched gas can be supplied to the process gas via the associated additional inert gas supply point (212) in order to reduce the oxygen content in the process gas, wherein an oxygen sensor (220) is arranged in the process gas line (50) downstream of the respective additional inert gas supply point (212) in order to detect the oxygen content in the process gas, and wherein the refrigerator recycling plant (1) is further provided with an electronic plant control device (230) which is electrically connected to the oxygen sensor (220) and to a respective additional inert gas control valve (240) arranged in the respectively associated additional inert gas supply line (210), and which is configured to control the respective additional inert gas control valve (240) on the basis of the oxygen contents received as electrical signals from the oxygen sensor (220) in such a way that a predetermined oxygen content in the process gas is set at the level of the oxygen sensor (220).
11. Refrigerator recycling plant (1) according to one of claims 7-10, provided that in combination with claims 2 and 6, wherein the heating device (130) comprises a heat pump device (260) which comprises: - a heat pump supply line (261) connected to the coolant line (188) of the second cooling device apparatus (180) via a supply point (262) and a return point (263), - a heat pump (264) connected to the heat pump supply line (261), - a heat pump discharge line (265) connected to the heat pump (264) and to a heat transferring device (266), arranged on the process chamber (12), of the heating device (130), by means of which the heat from the heat pump (264) can be transferred to the process chamber (12).
12. Method (S300) for recycling refrigerators (22), optionally by means of a refrigerator recycling plant (1) according to one of claims 1-10, comprising the steps of: - feeding (S320), optionally individually feeding, the refrigerators (22) into a process chamber (12), - supplying (S330) inert gas, optionally nitrogen gas, into the process chamber (12), - mechanically shredding (S350) the respective refrigerator (22) in the process chamber (12), - discharging (S360) gas present in the process chamber (12) as process gas from the process chamber (12) and feeding the process gas to a dehumidifying cooling device (40), - cooling (S370) the process gas by means of the dehumidifying cooling device (40) to a temperature that is optionally in the range of 5-20°C in order to dehumidify the process gas via condensation and separation of water contained in the process gas, - compressing (S390) the dehumidified process gas by means of a compressor (60), optionally to a pressure in the range of 10-15 bar, - cooling (S400) the compressed process gas in a cooling device (70) to a separation operating temperature in the range of 5-15°C, to thereby separate hydrocarbon, contained in the process gas, as liquid hydrocarbon via condensation, - separating (S410) the liquid hydrocarbon separated from the compressed and cooled process gas from the remaining process gas by means of a gas-liquid separation device (80), - feeding (S420) the remaining process gas to a membrane device (90), by which, from the remaining process gas, a hydrocarbon-enriched return process gas is obtained on a permeate side (92) of the membrane device (90) and a low-hydrocarbon forward process gas is obtained on a retentate side (94) of the membrane device (90), - returning (S430) the return process gas to the process gas in the process gas line (50) at a return point (112) upstream of the compressor (60), optionally between the dehumidification cooling device (40) and the compressor (60), in order to increase the hydrocarbon content of the process gas.
13. Method (S300) according to claim 12, further comprising - additionally supplying (S380) inert gas, optionally nitrogen gas, and / or the forward process gas to the process gas at an associated additional inert gas supply point (212) between the compressor (60) and the dehumidifying cooling device (40), and / or to the return process gas at a correspondingly assigned additional inert gas feed point (212) in a feedback-controlled manner such that the oxygen content of the process gas entering the compressor (60) is less than or equal to an oxygen limit concentration (SGK) for the expanding agent, and optionally - feedback-controlled heating (S340) of the process chamber (12) in order to set a predetermined shredding process temperature therein, which is optionally in the range of 70-80°.
14. Method (S300) according to claim 12 or 13, further comprising removing (S310) refrigerator compressors and optionally removing refrigerator refrigerant lines from the refrigerators (22) before feeding (S320) the refrigerators (22) into the process chamber (12), wherein the refrigerators (22), with the exception of the removed refrigerator compressors and optionally with the exception of the removed refrigerator refrigerant lines, are otherwise fed into the process chamber (12) completely as received.
15. Method (S300) according to one of claims 12-14, wherein the mechanical shredding is carried out in such a way that foamed insulation material present in the refrigerators (22) is shredded into particles with a size having a maximum circumscribed circle diameter of 2 mm, optionally with a maximum circumscribed circle diameter of 1 mm.