Apparatus for treating a liquid or solid sample with supercritical carbon dioxide

Abstract

This apparatus comprises: - a tank (20) capable of containing supercritical carbon dioxide, - at least one cartridge (C1-C3) capable of containing a sample to be treated and supercritical carbon dioxide, and - an intake valve (V1,1 – V1,3) fluidically connected between the tank (20) and the cartridge, this intake valve being movable between: - a closed position in which it prevents the supercritical carbon dioxide contained in the tank from being fed into the cartridge, and - an open position in which it allows the supercritical carbon dioxide contained inside the tank to be fed into the cartridge. The volume of the tank (20) is ten times greater than the interior volume (70) of the cartridge (C1-C3).

Description

[0001] Apparatus for treating a liquid or solid sample with supercritical carbon dioxide

[0002] [1] The invention relates to an apparatus for treating a liquid or solid sample with supercritical carbon dioxide and to a method thereof.

[0003] [2] The use of supercritical carbon dioxide is used in many applications. For example:

[0004] - to dye a textile,

[0005] - foam a polymer,

[0006] - impregnate or functionalize a material with a solute,

[0007] - clean or purify a room,

[0008] - sterilize a room.

[0009] [3] The result of such a treatment depends on several parameters, including the pressure and temperature of the supercritical carbon dioxide and the duration of exposure to the supercritical carbon dioxide. In order to optimize the choice of these parameters, depending on the desired application, it is necessary to carry out numerous experiments. For this, typically, the sample to be treated is placed inside a pressure-resistant cartridge equipped with a heating device. Then, the cartridge is fluidically connected, via an inlet valve and a pump, to a cylinder containing carbon dioxide in the liquid state. The inlet valve is then opened to introduce the carbon dioxide inside the cartridge until the pressure to be tested is obtained. In parallel, the heating device is also controlled to obtain the temperature to be tested of the carbon dioxide inside the cartridge.The tested pressure and temperature are higher, respectively, than the critical pressure and the critical temperature of carbon dioxide so that when the tested pressure and the tested temperature are reached inside the cartridge, the carbon dioxide is supercritical. Then, after a predefined time, a depressurization valve is opened in order to evacuate the carbon dioxide and return the pressure inside the cartridge to atmospheric pressure. At this point, the treated sample can be removed from the cartridge. Then, the same operations are repeated for different pressures, temperatures and / or exposure times until the pressure, temperature and exposure time to supercritical carbon dioxide are identified, which make it possible to obtain the desired result. An apparatus that can be used to carry out such treatment is, for example, disclosed in application WO2021237512A1 or application US2001014590A1.Other quite similar devices are disclosed in US10765968B2, US5785856A and US5866004A.

[0010] [4] This procedure is generally long and tedious and does not allow for testing short exposure times, i.e. exposure times of a few minutes or a few tens of minutes. Indeed, it typically takes a few tens of minutes before the pressure inside the cartridge reaches the pressure to be tested, i.e. a pressure for which the carbon dioxide is supercritical. Therefore, the total time of exposure to the carbon dioxide under pressure is necessarily greater than the time required to reach the pressure to be tested.

[0011] [5] The invention aims to remedy at least one of these drawbacks by proposing an apparatus which makes it possible to work at shorter exposure times.

[0012] [6] The invention is set forth in the attached set of claims.

[0013] [7] The invention will be better understood on reading the description which follows, given solely as a non-limiting example and made with reference to the drawings in which:

[0014] - Figure 1 is a schematic illustration of the architecture of a device for treating a sample with supercritical carbon dioxide,

[0015] - figure 2 is a schematic view, in vertical section, of a cartridge of the treatment apparatus of figure 1,

[0016] - Figure 3 is a flowchart of a treatment method using the apparatus of Figure 1.

[0017] [8] In this description, the terminology, conventions and definitions of the terms used in this text are introduced in a chapter I. Then, detailed examples of embodiments are described in a chapter II with reference to the figures. In a chapter III, variants of these embodiments are presented. Finally, the advantages of the different embodiments are specified in a chapter IV. [9] Chapter I: Definitions, terminologies and conventions:

[0018]

[0010] In the figures, the same references are used to designate the same elements.

[0019]

[0011] In the remainder of this description, the characteristics and functions well known to those skilled in the art are not described in detail.

[0020]

[0012] Figure 2 is oriented relative to an orthogonal coordinate system XZ, where the X direction is horizontal and the Z direction is vertical. Terms such as "above", "below", "top", "bottom", "upper", "lower" are defined relative to the Z direction.

[0021]

[0013] Supercritical carbon dioxide is obtained when carbon dioxide is subjected to a temperature above its critical temperature (31 °C) and to a pressure above its critical pressure (7.38 MPa). Supercritical carbon dioxide is neither in the gaseous nor in the liquid state, it has properties intermediate between those of liquids and those of gases.

[0022]

[0014] The symbol “CO2” denotes carbon dioxide.

[0023]

[0015] A "pure" component indicates that, if impurities are present in that component, then the mass of those impurities represents less than 1%, and typically less than 0.1% or less than 0.05%, of the total mass of the component.

[0024]

[0016] A thermal insulator is a material whose thermal conductivity, measured at 25°C, is less than or equal to 0.1 Wm^.K 1 and preferably less than 0.05 W.rrr 1 .K 1 .

[0025]

[0017] Chapter: Example of embodiment

[0026]

[0018] Figure 1 shows an apparatus 2 for treating samples with supercritical CO2.

[0027]

[0019] For this, the device 2 comprises:

[0028] - a 10-bottle containing pure CO2 in liquid state,

[0029] - a valve 12 fluidically connected to the bottle 10 via a pipe 14,

[0030] - a compression device 16 whose inlet is fluidically connected to the valve 12 via a pipe 18, - a reservoir 20 fluidically connected to an outlet of the compression device 16 via a pipe 22,

[0031] - an injector 24 capable of injecting a predetermined quantity of an additive inside the reservoir 20,

[0032] - an outlet valve 30 fluidly connected to the tank 20 by a pipe 32,

[0033] - a device 34 for heating the tank 20,

[0034] - a pressure sensor 36 which measures the pressure inside the tank 20,

[0035] - a temperature sensor 38 which measures the temperature inside the tank 20, and

[0036] - a valve 40 for depressurizing the tank 20.

[0037]

[0020] The reservoir 20 is capable of withstanding, without being damaged, the pressures usually encountered during sample treatments with supercritical CO2. Typically, these pressures usually encountered are between 8 MPa and 85 MPa and, most often between 8 MPa and 40 MPa or between 8 MPa and 30 MPa.

[0038]

[0021] The additive is for example a solvent miscible with supercritical CO2 or a solute which is dissolved by supercritical CO2.

[0039]

[0022] To inject a predetermined quantity of additive into the reservoir 20, the injector 24 comprises for example:

[0040] - a container 42 which contains the additive to be injected,

[0041] - a valve 44 fluidly connected to the container 42 by a pipe 46,

[0042] - a pump 48, one inlet of which is fluidically connected to the valve 44 by a pipe 51, and

[0043] - a pipe 53 which fluidly connects an outlet of the pump 48 to the reservoir 20.

[0044]

[0023] In this embodiment, the device 2 comprises several removable cartridges Ci, where the index i is the order number of the cartridge. In Figure 1, the device 2 is shown in the particular case where it comprises three cartridges Ci to C3.

[0045]

[0024] Each cartridge Ci is capable of containing a sample to be treated with supercritical CO2. Thus, each of the cartridges Ci is also capable of withstanding, without being damaged, the pressures usually encountered during sample treatments with supercritical CO2. For each cartridge Ci, the apparatus 2 comprises: - an inlet valve Vu, one inlet of which is permanently fluidically connected to the valve 30 via a pipe Tu and one outlet of which is fluidically connectable to the cartridge Ci,

[0046] - a Ru connection allowing the cartridge Ci to be mechanically and fluidically connected to the outlet of the valve Vu and, alternately, the cartridge Ci to be mechanically and fluidically disconnected from the valve Vu,

[0047] - a depressurization valve V2,i, one inlet of which is fluidically connectable to the cartridge Ci and one outlet of which opens into the open air,

[0048] - a connector R2,i allowing the cartridge Ci to be mechanically and fluidically connected to the inlet of the valve V2,i and, alternately, the cartridge Ci to be mechanically and fluidically disconnected from the valve V2.i,

[0049] - a DCi heating device capable of heating the supercritical CO2 contained inside the Ci cartridge,

[0050] - a CTi temperature sensor capable of measuring the temperature of the supercritical CO2 contained inside the Ci cartridge, and

[0051] - an agitator Ai capable of agitating the contents of the cartridge Ci.

[0052]

[0025] The u and R connections 2]i allow the cartridge Ci to be inserted into the device 2 and, alternately, the cartridge Ci to be removed from the device 2. When the cartridge Ci is inserted inside the device 2, the connections Ru and R 2]i mechanically and fluidically connect the cartridge Ci to the valves, respectively, Vu and V 2]i . When cartridge Ci is removed from device 2, this cartridge is mechanically separated and isolated from valves Vu and V 2]i . When the cartridge Ci is removed from the device 2, it can be freely moved and transported independently of the device 2.

[0053]

[0026] Here, all the valves of the apparatus 2 are movable between a closed position and an open position. In the closed position, each valve fluidly isolates its outlet from its inlet so that this valve cannot be crossed by carbon dioxide. Conversely, in the open position, the inlet and outlet of this valve are fluidically connected to each other, which allows carbon dioxide to freely pass through this valve. In addition, all the valves of the apparatus 2 are electrically controllable valves. More precisely, each of these valves switches from its closed position to its open position in response to receiving an electrical opening command. Conversely, in response to receiving an electrical closing command, the valve switches from its open position to its closed position. Thus, the valves of the apparatus 2 collectively form a set of controllable valves.

[0054]

[0027] The compression device 16, the injector 24, the heating device 34, the heating devices DCi and the agitators A are also each individually controllable.

[0055]

[0028] To control all these elements, the apparatus 2 comprises a control unit 50. The unit 50 comprises an electronic computer 52 and a human-machine interface 54. The computer 52 controls the various controllable elements of the apparatus 2. For this purpose, it is electrically connected to each of these controllable elements by cables. To simplify Figure 1, these cables have not been shown. In addition, each CT sensor is electrically connected to the unit 50 via an electrical connector which makes it possible to electrically connect the CT sensor to the unit 50 when the cartridge Ci is introduced inside the apparatus 2 and, alternately, to mechanically and electrically separate this CT sensor from the unit 50 when the cartridge Ci is removed from the apparatus 2.

[0056]

[0029] Typically, the computer 52 comprises a microprocessor 56 and a non-volatile memory 58. The memory 58 comprises the instructions and data necessary for the execution of the method of FIG. 3 when these instructions are executed by the microprocessor 56.

[0057]

[0030] The human-machine interface 54 makes it possible to acquire the instructions for the various treatments to be implemented by the device 2. For this purpose, here, the human-machine interface 54 comprises a screen 60 and a keyboard 62.

[0058]

[0031] Figure 2 shows the cartridge Ci in more detail. Here, for example, all the cartridges Ci are identical to each other.

[0059]

[0032] The cartridge Ci comprises an interior volume 70 capable of receiving a sample 72 to be treated. The interior volume 70 is at least ten times, and preferably one hundred times, smaller than the volume of the reservoir 20. Typically, the interior volume 70 is between 5 ml and 50 ml. Here, the cartridge Ci comprises a receptacle 74 which delimits the interior volume 72. This receptacle 74 is impermeable to supercritical CO2. The receptacle 74 comprises vertical walls 76 which surround the sample 72 and a horizontal bottom 78. The upper ends of the walls 76 delimit an opening 80 through which the sample 72 can be introduced inside the volume 70.

[0033] The sample 72 is a liquid or solid sample. Figure 2 is shown in the particular case where the sample 72 is a solid sample which rests on a horizontal grid 82 located above the bottom 78 and separated from the bottom 78 by a hollow.For example, sample 72 may be a piece of textile, a block of polymer, or a piece of metal.

[0060]

[0034] The cartridge Ci comprises an opening mechanism 90 movable between an open position and a closed position shown in Figure 2. In the open position, the sample 72 can be introduced into the volume 70 and, alternately, removed from the volume 70. In the closed position, the interior volume 70 is sealed against supercritical CO2. Here, this mechanism 90 comprises a threaded cover 92 and a thread 94 made in the periphery of the opening 80. In Figure 2, an empty space is shown between the cover 92 and the thread 94 to make the opening 80 more visible. However, in the closed position, this empty space does not exist and the cover 92 hermetically seals the interior volume 70. In its closed position, the mechanism 90 ensures a seal against compressed supercritical CO2 up to the pressures usually encountered during sample treatments with supercritical CO2.To achieve such a seal, the mechanism 90 comprises one or more seals not shown in FIG. 2.

[0061]

[0035] Here, the cover 92 is also crossed by an inlet pipe 100 and a depressurization pipe 102. Each of these pipes 100 and 102 has a lower end which opens directly into the interior of the volume 70 when the mechanism 90 is in its closed position. The upper end of the pipe 100 has a part Rm of the connection Ru which assembles with a fixed part of this connection Ru secured to the device 2 when the cartridge Ci is introduced into this device 2 to mechanically and fluidically connect the cartridge Ci to the outlet of the valve Vu. Similarly, the upper end of the pipe 102 has a part Rm 2|i of the R connection 2]i which is assembled with a fixed part of this fitting R 2]iintegral with the device 2 when the cartridge Ci is introduced into this device 2 to mechanically and fluidically connect the cartridge Ci to the inlet of the valve V 2]i .

[0062]

[0036] The cover 92 is also crossed by electrical conductors 104 which connect the sensor CTi, fixed on an inner face of the cover 92, to an electrical connector 106 fixed on an outer face of the cover 92. The connector 106 makes it possible to automatically electrically connect the sensor CT to the computer 52 when the cartridge Ci is introduced inside the device 2.

[0063]

[0037] An exemplary embodiment of the heating device DCi and the stirrer A are also shown in Figure 2.

[0064]

[0038] Here, the device DCi comprises an electrical heating resistor 110 and a controllable source 112 for supplying electricity to the resistor 110. For example, the resistor 110 is arranged opposite the vertical walls 76 when the cartridge Ci is introduced inside the device 2. The source 112 is controlled by the computer 52 in order to adjust the intensity of the current which passes through the resistor 110.

[0065]

[0039] In this embodiment, the stirrer A comprises a magnetic bar 120 and a magnetic field generator 122. Here, the bar 120 is housed inside the cartridge Ci between the grid 82 and the bottom 78. The generator 122 is integral with the apparatus 2 and is located under the bottom 78 when the cartridge Ci is introduced inside this apparatus 2. The generator 122 generates a rotating magnetic field which rotates the magnetic bar 120 around a vertical axis of rotation. For this purpose, the bottom 78 of the receptacle 74 is made of a material which does not obstruct the passage of the magnetic field generated by the generator 122. In the case where the bar 120 is magnetized, then the bottom 82 must not be made of a material, such as stainless steel, on which the bar 120 risks becoming fixed.

[0066]

[0040] The operation of the apparatus 2 will now be described with reference to the method of FIG. 3.

[0067]

[0041] Initially, during a step 150, the cartridges Ci each containing a sample are provided. For this purpose, during this step 150, a sample of the material to be treated with supercritical CO2 is introduced into each of the cartridges Ci. For this, typically, the cartridge Ci is first removed from the apparatus 2. Then, the mechanism 90 is moved into its open position and then the sample is introduced inside the volume 70 by passing through the opening 80. Once the sample is deposited on the grid 82, the mechanism 90 is moved to its closed position.

[0068]

[0042] During a step 152, each cartridge Ci containing a sample is introduced inside the device 2. The introduction of the cartridge Ci inside the device 2 causes the assembly of the parts Rmu and Rm 2li with the corresponding fixed parts of the fittings, respectively, Ru and R 2]iof device 2. At the same time, this also causes the electrical connection of the CT sensor to the computer 52.

[0069]

[0043] In parallel or before or after steps 150, 152, during a step 154, an operator enters, using the human-machine interface 54, for each cartridge Ci, the desired operating conditions. For this, here, for each cartridge Ci, the operator enters a pressure setpoint Pci, a temperature setpoint Tci, a duration Ao for the treatment, a depressurization speed setpoint Vdi and a concentration or quantity setpoint Ce of additive to be used. By way of illustration, here, the value of the setpoint Pe is chosen between 8 MPa and 40 MPa, the value of the setpoint Te is chosen between 31.1°C and 100°C or between 35°C and 100°C, the duration ci is chosen between 30 seconds and 10 hours, the setpoint Vdi is chosen between 0.01 MPa / min and 1 MPa / min. These operating conditions are then acquired by the computer 52.

[0070]

[0044] Once operating conditions have been acquired for each of the cartridges Ci introduced into the apparatus 2, the unit 50 executes one after the other each of the treatments defined by the acquired operating conditions, starting with the cartridge Ci.

[0071]

[0045] The processing of the sample contained in the cartridge Ci begins with a preparatory phase 160 followed by an automatic processing phase 162.

[0072]

[0046] During the preparatory phase 160, the computer 52 moves the valve 12 into its open position, the valve 30 into its closed position and each of the valves Vu, V2,i into their closed position. The valves which have been moved into the open and closed positions by the computer 52 are maintained in this position as long as the computer 52 does not command a modification of this position.

[0073]

[0047] Then, at regular intervals, during a step 170, the computer 52 acquires the pressure and temperature measurements from the sensors 36 and 38.

[0074]

[0048] In parallel, during a step 172, the computer 52 controls the compression or pumping device 16 to introduce carbon dioxide from the bottle 10 into the tank 20 until the pressure inside the tank 20 is equal to the Pci setpoint. Then, the computer 52 controls, as a function of the pressure measured by the sensor 36, the compression device 16 and, alternately, the valve 40 to control the pressure inside the tank 20 to the Pci setpoint. During step 172, when the computer 52 controls the opening of the valve 40, the carbon dioxide contained inside the tank 20 escapes, which reduces the pressure inside this tank. Conversely, when the computer 52 controls the compression device 16, an additional quantity of carbon dioxide is injected into the tank 20, which increases the pressure.

[0075]

[0049] In parallel with step 172, during a step 174, the computer 52 controls the heating device 34, as a function of the temperature measured by the sensor 38, to control the temperature inside the tank 20 to the setpoint Tci.

[0076]

[0050] Before or in parallel with step 172, during a step 176, the computer 52 controls the injector 24 to inject, inside the reservoir 20, a quantity of additive which makes it possible to reach the setpoint Cci. For example, for this, the computer 52 controls the valve 44 to move it into its open position then the pump 48. Once the desired quantity of additive has been introduced inside the reservoir 20, the computer 52 controls the valve 44 to move it into its closed position.

[0077]

[0051] Once the pressure and temperature of the carbon dioxide inside the tank 20 are equal, respectively, to the setpoints Pci and Tci, the carbon dioxide contained in the tank 20 is supercritical CO2. From the moment when the pressure and temperature of the supercritical CO2 are equal, respectively, to the setpoints Pci and Tci, during a step 180, the computer 52 checks that the time interval which has elapsed between the moment when the injector 24 has finished injecting the predetermined quantity of additive and the present moment is greater than a predetermined duration DS. If so, the computer 52 immediately triggers the execution of phase 162. If not, step 180 is repeated.The duration DS is sufficient to ensure that the mixture of the additive with the supercritical CO2 in the tank 20 is homogeneous or that the supercritical CO2 is saturated with additive or that the quantity of additive injected into the tank 20 has been completely dissolved by the supercritical CO2.

[0078]

[0052] At the start of phase 162, during a step 190, the computer 52 controls the valve 30 and the valve Vi.i to move them into their open position. In response, the supercritical CO2 fills the interior volume 70 of the cartridge Ci.

[0079]

[0053] Then, during a step 192, the computer 52 maintains the valves 30 and Vi.i in their open position for a predetermined time interval sufficient for the pressures inside the cartridge Ci and the reservoir 20 to balance.

[0080]

[0054] Here, since the volume 70 is much smaller than the volume of the reservoir 20, as soon as the supercritical CO2 is introduced inside the volume 70, its pressure, inside the cartridge Ci, is close to the set point Pci. Thus, the duration of the treatment applied to the sample 72 does not include the time necessary for the pressure of the carbon dioxide to reach the set point Pci. Therefore, the duration of the treatment can be very short and, for example, much less than one hour or 30 min.

[0081]

[0055] Furthermore, here, throughout the duration of step 192, step 172 of controlling the pressure inside the reservoir 20 to the setpoint Pci continues to be executed. This makes it possible to further reduce the difference between the pressure inside the cartridge Ci and the setpoint Pci.

[0082]

[0056] At the end of step 192, during a step 194, the computer 52 controls the movement of the valves 30 and Vu towards their closed position. Thus, from this moment and as long as the valve V2,i is not moved to the open position, the pressure inside the cartridge Ci remains constant.

[0083]

[0057] Then, during a step 196, as soon as the valve Vi.i is in the closed position, the computer 52 begins to count down the duration Aci.

[0084]

[0058] In parallel with step 196 and throughout the duration Aci, during a step 198, the computer 52 controls the heating device DCi, as a function of the temperature measured by the sensor CTi, to control the temperature inside the cartridge Ci to the setpoint Tci.

[0085]

[0059] Also in parallel with step 198 and throughout the duration Aci, during a step 200, the computer 52 controls the agitator Ai to agitate the supercritical CO2 contained inside the cartridge Ci throughout this duration Aci of the treatment.

[0086]

[0060] Once the computer 52 has finished counting down the duration Aci, it immediately triggers the execution of a step 210 of depressurization of the cartridge Ci. During this step, the computer 52 controls the valve V2,i to move it from its closed position to its open position while respecting the depressurization speed setpoint Vdi. For example, here, the computer 52 moves the valve V2,i from its closed position to its open position at a speed determined so that the depressurization speed of the supercritical CO2 contained inside the cartridge Ci is equal to the setpoint Vdi. The travel of the valve V2,i can be an angular travel or a linear travel.

[0087]

[0061] At the end of step 210, the processing of the sample 72 contained inside the cartridge Ci is finished.

[0062] During a step 212, the cartridge Ci is then removed from the apparatus 2 by disassembling the parts Rmi.i and Rm2,i of the connectors, respectively, Ri.i and R2,I and by disconnecting the connector CTi.

[0088]

[0063] Then, during a step 214, the sample contained inside the cartridge Ci is removed.

[0089]

[0064] As soon as the valves 30 and Vi.i have been moved into their closed position, i.e. as soon as step 194 is completed, the computer 52 begins to execute the preparatory phase 160 and then the processing phase 162 for the next cartridge. Thus, it is not necessary for the processing of the sample contained inside the previous cartridge to be completed to begin the execution of the preparatory phase 160 for the next cartridge. The preparatory phase 160 and the processing phase 162 executed for the next cartridge, i.e. here the cartridge C2, are identical to what was described in the particular case of the cartridge Ci except that the setpoints used are the setpoints Pc2, Tc2, Ac2, Vd2 and Cc2.

[0090]

[0065] Chapter III: Variants:

[0091]

[0066] Cartridge variants:

[0092]

[0067] The grid 82 can be replaced by a sintered basket. In the case of a liquid sample, the grid 82 can be replaced by a glass or stainless steel basket to facilitate their handling.

[0093]

[0068] Other embodiments of the opening mechanism 90 are possible. In particular, this mechanism 90 may also be identical to an opening mechanism of an autoclave known as one of those used in the field of chemistry.

[0094]

[0069] Alternatively, the tubes 100 and / or 102 may pass through one of the walls of the receptacle 74 instead of passing through the cover 92.

[0095]

[0070] Similarly, the conductors 104 may pass through one of the walls of the receptacle 74 instead of through the cover 92.

[0096]

[0071] In a simplified embodiment, the cartridges C are not removable. In this case, the connections Ru and R 2 iand connector 106 may be omitted. In such a case, conductors 104 are directly connected to the control unit 50.

[0097]

[0072] The cartridges Ci are not necessarily all identical to each other. For example, in a particular embodiment, the cartridges differ from each other by their internal volume. However, whatever the cartridge Ci, its internal volume is at least ten times, and preferably one hundred times, less than the volume of the reservoir 20.

[0098]

[0073] In a simplified variant, the device comprises a single cartridge Ci. In this case, the inlet and depressurization valves provided for other cartridges are omitted.

[0099]

[0074] Variants of the treatment apparatus:

[0100]

[0075] Alternatively, the treatment apparatus comprises only one copy of the fixed parts of the connectors Ri.i and R2,I and several cartridges Ci. The parts Rrrin and Rm 2li of connection of each cartridge Ci are identical and capable of being assembled with the fixed parts, respectively, of the connectors Ri.i and R2,I. In this embodiment, the cartridges Ci are introduced one after the other into the treatment apparatus, using for this each time the same fixed parts of the connectors R uand R2,I. Preferably, in such an embodiment, the treatment apparatus further comprises an automated carousel on which the different cartridges Ci are arranged. When this carousel is actuated, it automatically moves the next cartridge to be used and fluidly connects it to the fixed parts of the connectors Ri.i and R2,I. Then, the treatment with supercritical CO2 of the sample contained in this cartridge is carried out. Finally, the carousel is actuated again to automatically remove this cartridge and automatically introduce the next cartridge. In this case, for any i greater than one, the valves Vu, and V 2]i and the Ru, R connections 2 i are omitted.

[0101]

[0076] Other embodiments of the stirrer A are possible. For example, as a variant, the stirrer A comprises an actuator which makes it possible to shake the cartridge Ci when the supercritical CO2 is in contact with the sample inside this cartridge. For example, this actuator rotates the cartridge around an axis of rotation which intersects the longitudinal axis of the cartridge.

[0102]

[0077] In a simplified variant, the agitator A is omitted.

[0103]

[0078] Alternatively, the apparatus 2 comprises an additional agitator capable of agitating the mixture of carbon dioxide and the additive in the tank 20. Typically, this additional agitator is a magnetically driven agitator. For example, this additional agitator is made in a similar manner to the agitator A.

[0104]

[0079] Other embodiments of the device DCi for heating the cartridge Ci are possible. For example, as a variant, the heating device comprises heating resistors directly integrated in the wall 76 or in the bottom 78 of each cartridge Ci and connectors making it possible to electrically connect these heating resistors to a power source, controlled by the computer 52, when the cartridge is introduced into the device 2.

[0105]

[0080] In a simplified variant, the heating device DCi of the cartridge Ci can be omitted. This is particularly possible when the duration of the treatment is sufficiently short so that the temperature of the supercritical CO2 inside the cartridge does not have time to decrease substantially. For example, for this purpose, the walls of the cartridge Ci comprise a thermal insulator. When the heating device DCi is omitted, it is also possible to omit the temperature sensor CTi.

[0106]

[0081] The temperature sensor CTi can also be housed outside the cartridge Ci. For example, when the walls of the receptacle 74 are made of a good thermal conductor material, such as a metal, the sensor CTi measures the temperature of one of these walls to estimate the temperature of the supercritical CO2 contained inside this cartridge Ci. In this case, the sensor CTi can be permanently connected to the computer 52 and the connector 106 is omitted.

[0107]

[0082] In the particular case where it is not necessary to mix the supercritical carbon dioxide with an additive, the injector 24 can be omitted.

[0108]

[0083] In a simplified embodiment, valve 30 is omitted. Similarly, valves 12 and 44 may also be omitted.

[0109]

[0084] As a variant, the apparatus 2 further comprises a device for recycling supercritical carbon dioxide fluidically connected to the outlet of each depressurization valve V 2]i This recycling device liquefies the supercritical carbon dioxide before reintroducing it into the cylinder 10. Typically, the recycling device further comprises a filter for filtering the liquefied carbon dioxide before reintroducing it into the cylinder 10.

[0110]

[0085] The output of each depressurization valve V 2 i can also be fluidically connected to a cold trap or separator to precipitate or condense additives.

[0111]

[0086] Valve V 2 i can also be replaced by an automated pressure regulator which regulates the upstream pressure.

[0112]

[0087] Alternatively, some or all of the instructions Pc,, Te,, Ac,, Vd, and Ce, are pre-recorded in the memory 58 and the control unit 50 does not allow an operator to modify them. In the case where all of the instructions Pci, Te, Ac, Vdi and Ce are pre-recorded and cannot be modified, the apparatus 2 makes it possible to test the same treatment on different samples each contained in a respective cartridge Ci.

[0113]

[0088] Other additional setpoints can be acquired and used. For example, a setpoint Vp, for the pressurization speed of the cartridge C, can also be used to adjust the speed at which the valve Vu moves from its closed position to its open position.

[0114]

[0089] In a very simplified embodiment, the control unit 50 is omitted. In this case, for example, it is an operator who manually moves the valves 30, Vu and V2,i to implement the method of FIG. 3.

[0115]

[0090] Variants of the treatment method:

[0116]

[0091] In a simplified embodiment, as soon as the temperature and the pressure inside the tank 20 are equal to the setpoints, respectively, Te and Pc, the computer 52 immediately executes step 190. In this embodiment, step 180 is omitted. In addition, in this embodiment, one of the following two servocontrols can be omitted:

[0117] - the control of the temperature of the carbon dioxide contained in the tank 20 to the setpoint Te, and

[0118] - the control of the pressure of the carbon dioxide contained in the tank 20 to the setpoint Pc.

[0119]

[0092] Alternatively, the regulation of the pressure inside the tank 20 is interrupted when the valves 30 and Vu are moved into their open position.

[0120]

[0093] The execution of the preparatory phase 160 can begin while the cartridges Ci have not yet all been introduced inside the apparatus 2. In this case the steps 150, 152 are executed in parallel with the preparatory phase 160. On the other hand, the execution of the treatment phase 162 begins only after the cartridge which contains the sample to be treated has been introduced into the apparatus 10.

[0121]

[0094] In another variant, the setpoint Te varies during the duration Ac from an initial value, equal to the value of the setpoint Te at the start of the duration Ac, to a final value reached at the end of the duration Ac. The variation of the setpoint Te between its initial and final values ​​is, for example, linear or follows any other predefined law. The variation law of the setpoint Tci during the duration Aci of the processing is typically acquired during step 154.

[0122]

[0095] For some treatments, the depressurization speed can be arbitrary. In this case, it is not necessary to regulate the speed of movement of the valve V2,j. For example, in this case, the depressurization valve V2,i is moved from its closed position to its open position as quickly as possible.

[0123]

[0096] Several of the variants described above can be combined in the same embodiment.

[0124]

[0097] Chapter IV: Advantages of the described embodiments:

[0125]

[0098] The inlet valve Vu allows the introduction, inside the cartridge Ci, directly of the supercritical CO2. Thus, short treatment times become possible. Indeed, the sample is in contact only with the supercritical CO2 and is not in contact with the carbon dioxide during the time interval during which the pressure of the carbon dioxide is gradually increased until the carbon dioxide becomes supercritical CO2. The treatment time can therefore be reduced since it does not include the time interval during which the pressure of the carbon dioxide is gradually increased until supercritical CO2 is obtained. Moreover, since the volume of the cartridge Ci is much smaller, i.e. ten or one hundred times smaller, than the volume of the reservoir 20, when the cartridge Ci is filled with the supercritical CO2 contained in the reservoir 20, the pressure of the supercritical CO2 is practically not modified.Thus, while allowing reduced treatment times, the pressure and temperature conditions of this treatment are controlled and known since the pressure and temperature of the supercritical CO2 inside the cartridge Ci are substantially equal to the pressure and temperature of the supercritical CO2 inside the tank 20.

[0126]

[0099] Automatically controlling the set of valves makes it possible to automate the processing of a sample under predefined pressure, temperature and time conditions. This makes it possible to accelerate the experimental determination of the pressure, temperature and time conditions that are suitable for the processing of a sample with supercritical CO2. This also makes it possible to simplify the use of the apparatus 2 for people who are not specialists in pressure equipment.

[0100] Continuing to regulate the pressure and temperature of the tank 20 even when the inlet valve Vu is in the open position makes it possible to obtain a pressure and temperature of the supercritical CO2 introduced inside the cartridge that are even closer to the pressure and temperature setpoints.

[0127]

[0101] Controlling the device DCi for heating the cartridge Ci to control the temperature of the supercritical CO2 contained in this cartridge to the same temperature setpoint Te as that used to control the temperature of the supercritical CO2 contained in the reservoir 20 makes it possible to obtain an initial temperature inside the cartridge Ci as close as possible to the desired initial temperature. This allows a more reliable experimental determination of the pressure, temperature and duration conditions which are suitable for the treatment of a sample with supercritical CO2.

[0128]

[0102] Controlling the speed of movement of the depressurization valve V 2]i depending on the acquired depressurization speed Vdi setpoint, it allows the foaming of the sample contained inside the cartridge Ci to be adjusted.

[0129]

[0103] The fact of controlling the injection of additive into the reservoir 20 then waiting for the predetermined duration DS before triggering the execution of the automatic phase 162 of treatment of the sample makes it possible to systematically treat the sample with supercritical CO2 uniformly mixed with the additive or with supercritical CO2 saturated with additive.

[0130]

[0104] The fact that the apparatus comprises several cartridges Ci makes it possible to carry out several sample treatments in parallel. In addition, since there is one inlet valve Vu per cartridge, it is not necessary to provide for movement of the cartridges to connect them successively to the reservoir 20 via the same inlet valve.

[0131]

[0105] The fact of acquiring, for each cartridge Ci, at least the pressure setpoint PCi, the temperature setpoint TCi and the treatment duration Ci makes it possible to automatically and quickly test a large number of different pressure, temperature and treatment duration conditions.

[0132]

[0106] The fact that the volume of the reservoir 20 is greater than one hundred times the volume of the cartridge Ci makes it possible to obtain a pressure of the supercritical CO2 in the cartridge Ci practically immediately equal to the pressure of the supercritical CO2 stored inside the reservoir 20.

Claims

Claims 1. Apparatus for treating a liquid or solid sample with supercritical carbon dioxide, this apparatus comprising: - a reservoir (20) capable of containing supercritical carbon dioxide, - a compression or pumping device (16) capable of obtaining supercritical carbon dioxide inside the tank, - a device (34) for heating the tank capable of heating the carbon dioxide contained inside the tank until supercritical carbon dioxide is obtained, - at least one cartridge (Ci-C3, Ci) capable of containing the sample to be treated and supercritical carbon dioxide, this cartridge comprising an opening mechanism (90) movable between: - an open position in which the sample can be introduced into and, alternately, removed from the interior of the cartridge, and - a closed position in which the cartridge is sealed against supercritical carbon dioxide, - an inlet valve (Vi.i - Vi,3) fluidically connected between the reservoir (20) and the cartridge, this inlet valve being movable between: - a closed position in which it prevents the introduction, inside the cartridge, of supercritical carbon dioxide contained in the tank, and - an open position in which it allows the introduction into the cartridge of the supercritical carbon dioxide contained inside the tank, characterized in that the volume of the tank (20) is ten times greater than the internal volume (70) of the cartridge (Ci-C3, Ci).

2. Apparatus according to claim 1, wherein the apparatus comprises: - a set of controllable valves comprising the inlet valve (Vi.i - Vi,3) and a depressurization valve (V2,i - V 2]3) movable between: - a closed position in which this depressurization valve prevents the evacuation of supercritical carbon dioxide contained inside the cartridge, and - an open position in which this depressurization valve evacuates the supercritical carbon dioxide contained inside the cartridge while retaining the sample inside the cartridge, - a pressure sensor (36) capable of measuring the pressure inside the tank, - a first temperature sensor (38) capable of measuring the temperature inside the tank, - a control unit (50) configured to: - acquire a temperature setpoint, a pressure setpoint and a duration of treatment of the sample with supercritical carbon dioxide, then - acquiring the pressure measured by the pressure sensor and the temperature measured by the first temperature sensor when the compression device compresses the carbon dioxide inside the tank and when the tank heating device heats the carbon dioxide contained inside the tank, - when the pressure measured by the pressure sensor and the temperature measured by the first temperature sensor have reached, respectively, the acquired pressure setpoint and the acquired temperature setpoint, triggering the execution of an automatic treatment phase of the sample with the supercritical carbon dioxide contained in the tank, this automatic treatment phase comprising the automatic control, by the control unit, of the set of valves so as to introduce into the cartridge a portion of the supercritical carbon dioxide contained in the tank then to maintain this supercritical carbon dioxide in permanent contact with the sample for the acquired duration and, just at the end of the acquired duration, to evacuate the supercritical carbon dioxide contained inside the cartridge.

3. Apparatus according to claim 2, wherein the control unit (50) is also configured to control, as a function of the pressure measured by the pressure sensor and the temperature measured by the first temperature sensor, the compression device (16) and the heating device (34) of the tank so that the carbon dioxide inside the tank reaches a pressure and a temperature equal, respectively, to the acquired pressure and temperature setpoints, then to control the pressure and the temperature of the carbon dioxide inside the tank. tank (20) on, respectively, the pressure and temperature setpoints acquired including after the set of valves has been commanded to introduce part of the supercritical carbon dioxide inside the cartridge.

4. Apparatus according to claim 2 or 3, wherein the apparatus comprises: - a second temperature sensor (CTi - CT3, CT,) capable of measuring the temperature of the supercritical carbon dioxide contained inside the cartridge, - a device (DCi - DC3, DCi) for heating the cartridge capable of heating the supercritical carbon dioxide contained inside this cartridge, and - the control unit (50) is also configured to acquire the temperature measured by the second temperature sensor and to control, as a function of the temperature acquired by the second sensor, the cartridge heating device to control the temperature of the supercritical carbon dioxide contained in the cartridge to the acquired temperature setpoint.

5. Apparatus according to any one of claims 2 to 4, wherein the control unit (50) is capable of: - to acquire a cartridge depressurization speed setpoint, and - to control the speed of movement of the depressurization valve (V2,i - V 2]3 ) from its closed position to its open position depending on the acquired depressurization speed setpoint.

6. Apparatus according to any one of claims 2 to 5, wherein: - the device comprises a controllable injector (24) capable of injecting, inside the tank, a predetermined quantity of an additive other than carbon dioxide, and - the control unit (50) is configured to: - control the injector to inject the predetermined quantity of additive inside the tank, - then only when a predetermined time has elapsed since the predetermined quantity of the additive was injected inside the tank, trigger the execution of the automatic treatment phase.

7. Apparatus according to any one of claims 2 to 6, wherein the apparatus comprises: - several cartridges (Ci) each capable of containing a sample to be treated and supercritical carbon dioxide, each of these cartridges having an internal volume ten times smaller than the volume of the reservoir and each of these cartridges comprising an opening mechanism (90) movable between: - an open position in which the sample can be introduced into and, alternately, removed from the interior of the cartridge, and - a closed position in which the cartridge is sealed against supercritical carbon dioxide, - for each cartridge, an inlet valve (Vi.i - Vi,3) fluidically connected between the reservoir and this cartridge, this inlet valve being movable between: - a closed position in which it is capable of preventing the introduction, inside this cartridge, of the supercritical carbon dioxide contained in the tank, and - an open position in which it is capable of allowing the introduction into this cartridge of the supercritical carbon dioxide contained inside the tank.

8. Apparatus according to claim 7, wherein, for each of the cartridges, the control unit (50) is configured to: - acquire a temperature setpoint, a pressure setpoint and a treatment time of the sample with the supercritical carbon dioxide contained in this cartridge, then - when the pressure measured by the pressure sensor and the temperature measured by the first temperature sensor have reached, respectively, the pressure setpoint and the temperature setpoint acquired for this cartridge, trigger the execution of the automatic treatment phase of the sample contained in this cartridge with the supercritical carbon dioxide contained in the tank.

9. Apparatus according to any one of the preceding claims, wherein the volume of the reservoir (20) is one hundred times greater than the internal volume (70) of the cartridge.

10. Apparatus according to any one of the preceding claims, wherein the device comprises an agitator (Ai - A3, A) capable of agitating the supercritical carbon dioxide introduced inside the cartridge.

11. A method of treating a liquid or solid sample with supercritical carbon dioxide, this method comprising: - the supply (150) of at least one cartridge containing the sample to be treated, this cartridge comprising an opening mechanism movable between: - an open position in which the sample can be introduced into and, alternately, removed from the interior of the cartridge, and - a closed position in which the cartridge is sealed against supercritical carbon dioxide, - the command (172, 174), by a control unit: - a compression device for compressing the carbon dioxide contained inside a tank until a predetermined pressure setpoint is reached for which the carbon dioxide contained in the tank is supercritical carbon dioxide, and in parallel - a tank heating device for heating the carbon dioxide contained inside this tank until a predetermined temperature setpoint is reached for which the carbon dioxide contained in the tank is supercritical carbon dioxide, and - maintaining (170) an inlet valve, fluidically connected between the tank and the cartridge, in a closed position to prevent the introduction, inside the cartridge, of the carbon dioxide contained in the tank as long as this carbon dioxide is not supercritical carbon dioxide whose pressure is equal to the pressure setpoint and whose temperature is equal to the temperature setpoint, then - when the pressure and temperature of the supercritical carbon dioxide contained inside the tank are equal to the pressure and temperature setpoints, respectively, moving (190) the inlet valve to an open position to introduce, inside the cartridge, a portion of the supercritical carbon dioxide contained inside the tank, characterized in that: - the sample is introduced into the cartridge before the inlet valve is moved to its open position so that the sample is introduced into the cartridge before the introduction into the cartridge of the supercritical carbon dioxide contained inside the reservoir, and - the volume of the tank is at least ten times greater than the internal volume of the cartridge.

Images