Method for sorting contaminated catalysts or adsorbents

Abstract

A method and a device for separation of at least one catalyst and/or adsorbent from a homogeneous mixture of catalysts and/or adsorbents containing one or more metal, semi-metal or non-metal contaminant(s) deposited thereon, making it possible to separate catalysts or adsorbents according to the presence or absence of contaminant and also according to the contaminant content, starting from a sorting threshold that corresponds to a content and that is defined by the operator.

Claims

1. A method for separation of at least one catalyst and/or adsorbent from a homogeneous mixture of catalysts and/or adsorbents that are spent catalysts or adsorbents, with said catalysts or adsorbents containing one or more metal, semi-metal or non-metal contaminant(s) that is Fe, Hg, Ni, V, C, Cl, Na, S, N, Si, P, or As, with said contaminant(s) being deposited on said catalyst or adsorbent grains, said method comprising separating the catalyst or adsorbent grains according to a sorting threshold corresponding to a contaminant content and defined by the user, running catalyst grains of said mixture past an LIBS detection system that detects a wavelength that characterizes said contaminant, sending to an analyzing device associated with LIBS processes a signal from the detection system and analyzing the signal by comparing it to a set-point value that indicates the sorting threshold, sending by the analyzing device a signal ordering the evacuation of grains according to contaminant content, and obtaining at least 2 batchesat least one batch of catalysts or adsorbents that are loaded with said contaminant greater than the sorting threshold and at least one batch of catalysts or adsorbents that are loaded with said contaminant less than the sorting threshold, treating the catalysts that are loaded with contaminant less than the sorting threshold before being reused in an industrial method optionally by regeneration, rejuvenation, or lixiviation and catalysts that are loaded with contaminant greater than the sortie threshold are treated in final recycling to recover upgradable components.

2. The method according to claim 1, in which the sorting threshold is 0%.

3. The method according to claim 1, in which for Na as a contaminant, the sorting threshold is 0.3% by weight, with the grains containing less than 0.3% by weight being separated and being reused after treatment.

4. The method according to claim 1, in which for V as a contaminant, the sorting threshold is 12% by weight, with the catalyst grains containing 12% by weight or more being separated and being treated in final recycling to recover the upgradable elements.

5. The method according to claim 1, in which for V as a contaminant, the sorting threshold is 2% by weight, with the catalyst grains containing less than 2% by weight being separated and reused after an treatment optionally by regeneration, rejuvenation, or lixiviation.

6. The method according to claim 1, in which for S as a contaminant, the sorting threshold is 2% by weight, with the grains containing less than 2% by weight being separated and being reused after treatment optionally by regeneration, rejuvenation, or lixiviation.

7. The method according to claim 1, in which for As as a contaminant, the sorting threshold is 1% by weight, with the grains containing less than 1% by weight being separated and being reused after treatment optionally by regeneration, rejuvenation, or lixiviation.

8. The method according to claim 1, in which the catalysts or adsorbents come in the form of cylindrical extrudates, balls, trilobes, or multilobes.

9. The method according to claim 1, in having a dwell time of a grain in front of the LIBS detection system of less than 10 ms, and a number of detected/analyzed grains of at least 100 per second.

10. A device capable of separating and sorting at least one catalyst and/or adsorbent from a homogeneous mixture of catalysts and/or adsorbents, with said catalysts or adsorbents containing one or more metal, semi-metal or non-metal contaminant(s) deposited on grains of catalysts or adsorbents, with the device separating the catalysts or adsorbents according to a sorting threshold corresponding to a contaminant content defined by the user, with said device comprising: a chain transporting the mixture of catalysts, a monitor of the flow rate of grains transported, and monitor of speed, with said transport being adjusted in such a way that the dwell time of a grain in front of a LIBS detection means is less than 50 ms, and the number of sorted grains is at least 20 grains/s, an LIBS detection system comprising at least one laser past which the grains run, having a detection time less than 50 ms, and a wavelength that of the desired contaminant, said system detecting the grain that is loaded with said contaminant and measuring the intensity of the peak associated with said wavelength, at least one analyzing device (8) and at least one control (10), with said analyzing device processing the signal sent by the detector by comparing it to a set-point value that indicates the sorting threshold, at least one evacuation port for grains to be separated, with said port being actuated from said control according to the content of said desired contaminant.

11. The device according to claim 10, in which the transport is a crenelated belt, having a depth of gaps between 0.5 and 3 times characteristic largest dimension of the grains.

12. The method according to claim 1, wherein treatment of the catalyst with contaminant less than the sorting threshold is by regeneration, rejuvenation, or lixiviation.

13. The method according to claim 3, wherein treatment of grains containing less than 0.3% by weight is by regeneration, rejuvenation, or lixiviation.

14. The method according to claim 5, wherein treatment of grains containing less than 2% by weight is by regeneration, rejuvenation, or lixiviation.

15. The method according to claim 6, wherein treatment of grains containing less than 2% by weight is by regeneration, rejuvenation, or Lixiviation.

16. The method according to claim 7, wherein treatment of grains containing less than 1% by weight is by regeneration, rejuvenation, or lixiviation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts a preferred embodiment by way of illustration.

(2) FIG. 2 depicts a crenellated belt.

(3) FIG. 3 shows grain shapes.

(4) By way of illustration, FIG. 1 depicts an embodiment that is preferred but non-limiting of the method and the device that are the object of this invention.

(5) The unsorted mixture of catalyst or adsorbent grains (1) is brought on a means (2) that makes it possible to monitor the flow rate of grains on the rolling belt (5). The intake means of the mixture (3) can be manual (unloading of a bag, for example) or automatic (by controlled unloading of a silo, for example).

(6) The invention is described with a rolling belt as a transport means, but the description is entirely transposable with another transport means, such as, for example, the vibrating channel described above.

(7) The means that make it possible to monitor the flow rate are means that are well known to one skilled in the art, such as, for example, inclined vibrating plates, making possible the uniform spreading of the catalyst grain and the adjustment of the flow rate of the catalyst on the plate toward the rolling belt. One skilled in the art can thus adjust the distance between two grains on the transport chain and consequently adjust the detection frequencies or else, conversely, it is possible to adjust the distance depending on the detection frequencies.

(8) By way of example, in FIG. 1, we showed at (2) a vibrating plate in two orthogonal directions. With this type of equipment, it is possible to adjust the vibration frequencies for modulating the flow rate of solid (4) toward the rolling belt (5), to adjust the distribution between the grains over the passage section, and thus to monitor the spacing between the grains based on the travel speed of the belt.

(9) Preferably, in an optimal manner, the device will be adjusted so that the distance between the grains is at maximum equal to the mean length of the grains.

(10) Leaving the flow rate monitoring means (2), the catalyst grains fall on the rolling belt, which can be a simple flat conveyor belt, or a crenellated belt, as shown in FIG. 2.

(11) The crenellated belt of FIG. 2 has a manifest advantagewhen in particular extrudates are sortedin that it makes it possible, in an advantageous manner, to orient the grains in the direction of flow. The flow of the grains is thus more uniform and spaced, which promotes the detection and the separation, and improves the productivity of the installation. In a general way, regardless of the grain shape, the crenellated belt keeps the grain from moving under the action of the vibrations of the belt and/or pulses of the laser.

(12) In the case of a crenellated belt (20), a form of gap (21) that has the shape of an equilateral triangle as shown in FIG. 2 is advantageous; the depth of the gaps on the belt is then ideally between 0.7 times and 1.3 times the characteristic largest dimension of the grains, the diameter of the catalyst grains in the case of balls, the mean length in the case of cylindrical extrudates or trilobes or multilobes.

(13) The grains (22) are positioned on the belt (20). The travel speed of the belt is adjusted so as to optimize the production capacity, on the one hand, and the capacity of the system to detect the desired contaminant in the catalyst grains.

(14) An attempt will preferably be made to ensure that the dwell time of a grain is less than 50 ms, and is preferably less than 10 ms. More generally, the dwell time is the smallest possible, consistent with the response time of the detection system.

(15) Under these conditions, for example, for a cylindrical extrudate with a length that is equal to 5 mm, the speed is preferably between 0.1 and 5 m/s.

(16) The detection system comprises at least one laser (6), at least one spectrometer (or analyzing device) (8) and at least one means (10) for controlling the opening or not of at least one evacuation means.

(17) A laser (6) emits radiation focused on the surface of the sample (7). Following the pulse on the order of the femtosecond to the nanosecond between the laser and the sample, a plasma fed by the composition of the sample is generated and in several milliseconds sends wavelengths suitable to the composition of the sample (9).

(18) The emissions of the sample (9) are analyzed by a spectrometer (8) with specific wavelengths of the contaminant having to be detected. In an optional way, at least one optical fiber is used between the plasma and the spectrophotometer. It is possible to work with several wavelengths simultaneously by positioning on the light beam several spectrometers in parallel that work simultaneously with different wavelengths.

(19) For example, to measure the sodium content in the hydrocracking or hydrotreatment catalysts, the wavelength at 588.995 or 589.592 nm will be used owing to its high intensity. The lines at 818.326 nm or 819.482 nm can also be used. These four lines make it possible to detect the presence of sodium by minimizing the interference with Ni, Co, Mo, Al, W or Si.

(20) Depending on the requirements, it is possible to analyze all of the grains running past the detection system (6-7-8-9) on the rolling belt (5), overall or individually, by using several laser systems (6) in parallel in such a way as to cover the width of the belt and by adapting or decoupling also the laser and the spectrometer (8) analyzing the emissions (9).

(21) It is also possible to choose to operate statistically, by analyzing only a fraction of the flow, or to consider a movement over the width of the lasers (6) and the spectrometer(s) (8).

(22) The analyzing device (the spectrometer) (8) is connected to control means (10) that make it possible to convert the results of the analysis in action to act on said evacuation means (here, the valve 12).

(23) These means consist of, for example, a computer that makes it possible to initiate the opening of a valve (12).

(24) Thus, for example, when the analyzing device (8) detects that the grain has a larger content than the set-point value (for example, the contaminant sorting threshold), it sends a signal to the control means (10) that actuates the opening of the valve (12).

(25) The former is located on a duct of inert fluid (air, for example) under a pressure that is if possible greater than 5 bar (preferably air) to promote the creation of a jet of gas (air) that is sufficient to evacuate the grain.

(26) The valve (12) opens during a determined period DT1 and then closes again automatically. The opening of the valve makes it possible to generate a jet at the lower end of the duct (11). It acts with the duct as a gas (air) ejection nozzle. Advantageously, the duct (11) is positioned at the end of the conveyor belt at a distance of at most 10 cm from the end of the belt (based on the travel speed of the belt, the lower the unrolling speed of the belt, the closer the duct (11) approaches the end of the belt), at a level above the belt (5) preferably encompassed between 2 and 10 times the characteristic largest dimension of the catalyst grain (its length in the case of an extrudate).

(27) It is possible to position one or more ducts (11) in parallel depending on the width of the conveyor belt and the shape of the end of the duct.

(28) In the case of a spherical duct end fitting, the diameter of the end fitting of the duct is preferably less than or equal to the mean length of the grains.

(29) If the belt makes possible the simultaneous transition in the width of N particles simultaneously, it is possible to position up to N tubes (11) in parallel, each having their valve, the valves being controlled simultaneously or separately by the control means (10) depending on the number of analyzing devices used in parallel.

(30) It is also possible to work with a single duct (11) but whose rectangular section end could create a pencil gas jet, with the thickness of the jet then preferably being less than or equal to the mean length of the grains.

(31) So as to take into account the distance between the detection means and the evacuation means, the control system initiates the opening-closing cycles with a delay that is based on the distance to travel between these two points. For example, if the belt length between the focal position of the analyzing device on the belt (9) and the evacuation means (valve, air injection nozzle (12)) is 3 m and the travel speed on the belt is 3 m/s, a delay of one second is to be taken into account, optionally to correct, depending on the response time of the analyzing device (8), the control means (10) or the valve (12).

(32) For the requirements of the invention and to be selective, the opening-closing cycle of the valve is to be fast and cohesive with the dwell time of the grains in front of the detector. Preferably, the opening-closing cycle time will not exceed 1 and 5 times the dwell time of the grain in front of the detection means, preferably less than 3 times this mean dwell time.

(33) Thus, technologies of valves and actuators will be selected so as to have an opening-closing cycle of between 5 and 250 ms depending on the travel speed of the transport means (5).

(34) The gas jet (for example, air) created during this period has a speed that is at least equal to 5 times the terminal drop speed of the grain, preferably 10 times the terminal drop speed (in the case of a hydrotreatment extrudate, the terminal drop speed is in general close to 5 m/s and between 2 and 7 m/s).

(35) When the actuator initiates the opening of the valve, the gas jet diverts the path of the grain to a receptacle (14) that harvests all of the grains in which the contaminant content is greater than the sorting threshold defined by the operator.

(36) If the actuator is not triggered, then the path of the grain exiting from the conveyor belt describes a normal parabola depending on the unrolling speed of the belt and the terminal drop speed of the particles. The grain then falls into a receptacle (13) that harvests all of the grains to be eliminated that do not contain the undesirable element.

(37) Thus, the grains collected at (13) will constitute a new batch that has, for example, a contaminant content that is lower than the sorting threshold defined by the operator.

(38) In relation to the prior art, the invention makes possible a rapid sorting depending on the contaminant content of at least 20 to 100 objects (catalyst grains)/second, in general at least 50 and even 100 objects/second, or even beyond 100 objects/s, and its use allows up to 1,000 objects/second or more. The LIBS technique therefore allows itself alone a significant productivity.

(39) Another advantage of the invention is to be able to be implemented in air or any other atmosphere (not interacting with the detection or the grains).

Example 1

(40) Sorting of a Batch of a Mixture of Hydrotreatment Catalysts Containing Ni and Mo and an Na Contaminant:

(41) 120 grains of catalysts with a batch of catalysts were analyzed by LIBS from a batch of 3 g that initially was analyzed by X fluorescence (Panalytical PW2404, Rh tube). The mean contents of the elementary analysis by X fluorescence were provided in Table 1.

(42) TABLE-US-00001 TABLE 1 V Fe Na Ni Mo (% by (% by (% by (% by (% by Weight) Weight) Weight) Weight) Weight) 0.16 0.31 0.31 2.90 13.9

(43) An LIBS laboratory device (MobiLIBS III, IVEA) was used for this test; it consists of a laser (Brio, Quantel, Nd-YAG at 532 nm) and a spectrometer (Mechelle Andor, 200-900 nm). The device was used in single-laser-shot mode, and each catalyst grain was analyzed under the following conditions: 12 mJ/spot of 140 m/3-5 ns of pulse time.

(44) Starting from the number of hits measured on the spectrometer in the various lines of Na (lines at 588.995, 589.592, 818.326 and 819.482 nm), the 120 catalyst grains were sorted into three families: the catalyst grains having fewer than 60,000 hits, those between 60,000 and 120,000 hits, and those with a number of hits greater than 120,000.

(45) 0.57 g of grains having a signal with fewer than 60,000 hits was collected, while 0.53 g of grains having a signal of between 60,000 and 120,000 hits was recovered. 0.03 g of grains having a signal with a number of hits greater than 120,000 was observed.

(46) The batch of grains of 0.57 g and 0.53 g are sufficient to carry out an analysis of Na by atomic absorption spectrometry (Agilent SpectrAA 240 FS) after mineralization (0.2 g of sample+2 ml of HClO4 70%+4 ml of HF 40%) [sic]. The Na content measured in the batch of 0.57 g and having an LIBS signal with less than 60,000 hits was 0.14% Na while the batch of 0.53 g and having an LIBS signal of between 60,000 and 120,000 hits was 0.28% Na. This test confirms that sorting on individual grains is possible using the LIBS technique.

Example 2

(47) Sorting of a Batch of a Mixture of Hydrotreatment Residue Catalysts with a Threshold for Vanadium of 1%.

(48) In the same way as the preceding example, 50 grains of two families of catalysts (cat 1 and cat 2) having different vanadium contents were subjected to LIBS analysis. The characteristics of the catalysts in terms of chemical composition obtained by X fluorescence (Panalytical PW2404, Rh tube) are provided in Table 2:

(49) TABLE-US-00002 TABLE 2 V Fe Na Ni Co Mo (% by (% by (% by (% by (% by (% by Weight) Weight) Weight) Weight) Weight) Weight) Cat 1 0.45 0.14 0.15 0.79 2.22 11.0 Cat 3 1.73 0.24 0.35 1.13 2.17 11.3

(50) The LIBS system used is equipped with a laser (Quantel, Centurion, 1064 nm, 100 Hz) and two spectrometers with high acquisition frequency (HR2000+, grating at 1800 lines/mm, resolution of 0.11 nm for the 554-663 nm zone/HR2000+, grating at 2400 lines/mm, resolution of 0.09 nm for the 298-395 nm zone). The mean value of the LIBS signal, on the 50 grains of the Cat 1 family containing on average 0.45% of V, is 4,000 hits on the line at 609.022 nm versus 29,000 hits on the line at 309.311 nm. The same experiment conducted on the 50 grains of the Cat 3 family, containing on average 1.7% of V, provides mean values of 10,000 hits on the line at 609.022 nm versus 48,000 hits on the line at 309.311 nm. The signal measured on the line at 609.022 nm is on average 2.5 times higher over the 50 measured grains of the batch containing 1.73% of V in relation to the batch that contains only 0.45% of V. The same calculation performed on the line at 309.311 nm shows a mean signal that is 1.6 times higher for the batch that contains 1.73% of V in relation to the batch that contains only 0.45% of V. In the two cases, the LIBS technique therefore readily makes it possible to differentiate a batch of catalysts containing more or less than 1% of V of contaminant.

Example 3

(51) Sorting of a Batch of a Catalyst Mixture that is Used in a Guard Bed on the Reformer and is Contaminated with S at a Level of 2%:

(52) 50 grains of catalysts of a batch of catalysts in a guard bed were analyzed by LIBS to determine their S content and to decide whether these grains should be recycled or eliminated. The LIBS system used for these tests is equipped with a laser (Quantel, Centurion, 1064 nm, 100 Hz) and a spectrometer centered on the region 578 at 1011 nm (HR2000+, grating at 600 lines/mm). The lines of S with a wavelength of 921.287 or 922.809 nm are used for this detection of S, and a weak signal is detected on the analyzed catalyst grains. Starting from the number of hits measured on the line at 921.287 nm, sorting is carried out on the individual grains: the grains having a higher signal of more than 500 hits are ejected whereas the grains having a lower signal of less than 500 hits are retained.

(53) Of the 50 initial grains, 13 grains were ejected. Despite the small quantity of material, a semi-quantitative X-fluorescence analysis (Uniquant, Thermo Perform'X, Rh tube) by depositing the grains in a measurement cell (XRF sample cells, Fluxana SC-3340, 40 mm, 6 m polypropylene film) was made. The mean and semi-quantitative content measured on the ejected grains is 4.3% S, whereas an analysis carried out on the batch of the retained 37 grains shows a value of 1.2% of S. The sorting carried out on the basis of the detection of S at the wavelength of 921.287 nm is therefore effective for separating the catalyst grains in the guard bed that may or may not be contaminated by S at a level of 2%.