GAS CLEANING DEVICE FOR ONLINE ANALYSIS
Patent Information
- Application Number
- FR2017057131
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2017-07-27
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2037-07-27
AI Technical Summary
Existing methods for gas cleaning, particularly in syngas from biomass pyrolysis or gasification, struggle to efficiently remove tars, water, and solid particles while maintaining the integrity of compounds like HCl and H2S for online analysis, often leading to condensation and filter blockage, and are costly due to high heating requirements.
A gas cleaning device with filters comprising absorbent materials like cotton or nylon for tar removal, zeolite for water adsorption, and pH-controlled zeolite for acid gas handling, combined with heating and suction systems to maintain gas flow and prevent condensation, along with indicators for filter saturation.
Effectively removes tars and water from syngas, maintains compound integrity, and ensures continuous gas analysis by preventing condensation and filter blockage, while being cost-effective and efficient.
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Abstract
Description
ONLINE ANAL GAS CLEANING DEVICE The invention lies in the field of gas cleaning and relates to a device for cleaning a gas. The invention can be applied It works with all types of gas and finds a particularly interesting application. in gas cleaning (also called gas purification) for 'analysis in line of one or more compounds contained in the gas. Online analysis of the concentration of certain compounds in A gas such as synthesis gas can prove difficult when this gas contains tars. This is particularly the case with synthesis gas produced by a pyrolysis or gasification process of biomass, residues or waste. Tars are defined as organic compounds having a weight higher molecular weight than benzene, such as hydrocarbons polycyclic aromatics, aromatic amines or compounds inorganic. Tars condense at temperatures below 400°C. It is therefore necessary to remove them from the gas before andyzing the contents. certain compounds, such as HCl (hydrogen chloride) or HsS (sulfur) hydrogen or hydrogen sulfide), or NH3 (ammonia) in order to avoid its Condensation on the walls and mirrors in the analyzer cell. Other Condensable gases, such as water, as well as solid particles must also be eliminated from the gas before it is analyzed. In what follows, we will take the example of chloride analysis of hydrogen HCl in a synthesis gas. The invention can be applied to a other compounds, such as hydrogen sulfide or and also to any type of gas that may contain tars. There are methods for removing tar from the line Synthesis gas sampling based on the use of solvents organic compounds such as facetone or isopropanol. These methods present the disadvantage of capturing hydrogen chloride (HCl) in the line gas sampling. In addition, an accumulation of chloride Hydrogen HCl can occur in the empty space of the bubbler containing the organic solvent because hydrogen chloride is denser than the gas synthesis and gas flow rate in the sampling line is normally weak. There are also methods to prevent water condensation in the sampling line based on gas sampling by a probe and means of lowering the pressure of the gases taken from a pipeline. These means include a pressure relief nozzle arranged in the probe and a suction device. These anterior FART systems may also include heating methods to increase the pipe temperature above the water dew point in the gas sampled. These prior art methods are limited to gases containing of water and not tars. To avoid the condensation of tars in In this type of system, the pipe must be heated to increase the its temperature above the dew point of tars, i.e. approximately 400°C. The colt of such a line is relatively high, both in Colts terms of materials for piping and heating. Finally, there are also methods in the past for remove solid particles from the sampled gas. These methods use a filter. solid, for example in deactivated fused silica wool, in a probe of gas extraction. With a gas containing tars such as gas In summary, the risk of condensation on the filter in the probe due to Tars exist, which can clog the filter. The invention aims to overcome all or part of the problems mentioned above. high by proposing a tar removal device for a type of gas synthesis gas produced by a pyrolysis or gasification process biomass, residues or waste, suitable for eliminating fire and particles solids possibly present in the gas, suitable for online monitoring of the concentration of certain compounds contained in the gas. To this end, the invention relates to a cleaning device for a gases comprising a plurality of compounds, a first compound among the a plurality of compounds being tar, including a container with an inlet and an outlet, the gas flowing through the container from 'inlet to outlet', a first filter positioned between the inlet and outlet of the container, a through which the gas flows, designed to filter the tar, and the first filter comprising an absorbent material. Technical effect is to allow the tar to be absorbed, and therefore to remove the gas, without for it's best to capture the compounds that we want to leave in the gas. Advantageously, the absorbent material is a natural material. preferably cotton. Cotton is a particularly good material tar absorbent. According to another embodiment, the absorbent material is a synthetic material, preferably nylon. Nylon is a material particularly absorbent of tar Advantageously, a second compound among the plurality of Since the compounds are made of water, the device may include a second filter positioned between the inlet and outlet of the container, upstream or downstream of the first filter, through which the gas flows and designed to remove flame from the gas, and the second filter comprises a water-adsorbing material. The technical effect is to allow the water to be removed from the gas and to allow the compounds to pass through that we want to leave in the gas. Advantageously, a third compound among the plurality of Since the compounds are acidic gases, the water adsorbent material comprises a neutral or acidic particle surface. The resulting technical effect is to eliminate moisture from the gas without a chemical reaction occurring between certain compounds (e.g. HCl) and the Feau adsorbent material. Advantageously, the adsorbent material is a zeolite. The effect The technique involves using an adsorbent material with porosities of the structures all the same size. The resulting advantage is that the Zeolite adsorbs water and allows the desired compound(s) to pass through, such as the HCI. Advantageously, the container is a tube comprising two ends, one of the two ends being the entrance and one The second of the two ends is the exit. The advantage is to avoid the gas stagnation in the container. According to one embodiment, the tube has a cross-section substantially constant between the inlet and outlet. This results in a flow velocity of the constant gas in the container. According to another embodiment, the tube has a non-cross-section constant between input and output. The technical effect is to obtain a variation in the flow rate of the gas through the container. According to another embodiment, the device according to the invention may include a gas heating device positioned upstream of 'Inlet of the container. The technical effect is to heat the gas and the second filter. This results in maintaining the temperature of the second filter above— of the dew point of Feau, which avoids the phenomenon of condensation of water. According to another embodiment, the device according to the invention may include a cooling device for the first filter. The effect The technique is to increase the condensation of the tars and therefore more efficient tar removal. This results in an increase in tar filtration rate. Another technical effect is to prevent certain gas compounds, such as HCl, react with materials. Advantageously, the device according to the invention comprises a gas suction device positioned downstream of the container outlet. The technical effect is to conduct the gas from the 'inlet' to the outlet. Advantageously, the device according to IFinvention includes a indicator positioned downstream of the second filter and configured to indicate a water concentration in the gas downstream of the second filter beyond a A predefined threshold concentration is used. The technical effect is to show when the second filter is saturated. The resulting advantage is that it always to ensure good water disposal efficiency by changing or regenerating the adsorbent material when necessary. The invention will be better understood and there will be other advantages. will appear upon reading the detailed description of an embodiment given as an example, a description illustrated by the attached drawing in which Figure 1 schematically represents a first mode of implementation of a cleaning device with a first filter according to the invention, Figure 2 schematically represents a second mode of implementation of a cleaning device according to the invention, Figure 3 schematically represents another mode of Construction of a cleaning device with a tube of non-constant cross-section according to the invention, Figure 4 schematically represents another mode of implementation of a cleaning device according to the invention, Figure 5 schematically represents another mode of implementation of a cleaning device according to the invention, Figure 6 schematically represents another mode of implementation of a cleaning device with a second filter downstream of the first filter according to the invention, Figure 7 schematically represents another mode of implementation of a cleaning device with a second filter upstream of the first filter according to the invention Figure 8 schematically represents another mode of construction of a cleaning device with a heating device according to the invention, Figure 9 schematically represents another mode of construction of a cleaning device comprising several containers according to the invention, Figures 10A and 10B represent the infrared spectrum of 1000 ppm of HCl in the pure nitrogen matrix and the infrared spectrum of the gas containing the HCl produced by the pyrolysis at 750°C of pure PVC and a mixture of wood and 1% by mass of PVC, sampled using a conventional method, Figures 11A and 11B represent the infrared spectrum of 1000 ppm of HCl in the pure nitrogen matrix and the infrared spectrum of the gas containing the HCl produced by the pyrolysis at 750°C of pure PVC and a mixture of wood and 1% by mass of PVC, sampled with the device according to the invention. For the sake of clarity, the same elements will bear the same reference points in the different figures. Figure 1 schematically represents a first mode of construction of a cleaning device 10 with a first filter 11 according to the invention. The device 10 for cleaning a gas 12 comprising a plurality of compounds, a first compound among the plurality of compounds being tar, it includes a container 13 with an inlet 14 and an outlet 15, the gas 12 circulating through the container 13 from the inlet 14 towards the output 15. Device 10 includes the first filter 11 positioned between Window 14 and outlet 15 of container 13, through which the gas 12 flows, designed to filter tar. And the first filter 11 includes a material absorbent. Gas 12 comprises a plurality of elements and it is desirable to remove some of these elements, particularly the tar, but to retain others, for example HCl or HaS. The first filter 11 including an absorbent material allows it to absorb the tar, and therefore Removing gas 12, without capturing the elements we want leave in the gas for 12. Downstream of device 10 according to the invention, it is possible to connect a gas analyzer 16. Container 13 can be made of different materials, for example in glass or quartz. The absorbent material can be a natural material, Preferably cotton. Alternatively, the absorbent material can be a synthetic material, preferably nylon. Cotton and nylon are materials particularly absorbent of tar and it has been noted that they are particularly suitable as an absorbent material for first filter 11. Figure 2 schematically represents a second mode of Implementation of a cleaning device 20 according to the invention. All the The elements of Figure 2 are identical to those of Figure 1 except for the container. In Figure 2, the container is a bottle 23. The inlet 14 and the Outlet 15 of the container are represented at the upper end of the container but could be located, both or only one of them, on one face lateral, above the first filter 11 In Figure 1, container 13 is a tube comprising two ends, one of the two ends being Entry 14 and one The second of the two ends is outlet 15. Container 13 in The tube shape has the advantage of preventing the stagnation of certain elements of gas 12 in container 13. There is no dead zone in the container 13. Speed is an important parameter in the device according to the invention. to allow for good continuous analysis of gas 12. In Figure 1, tube 13 has a substantially constant cross-section. between Inlet 14 and outlet 15. The constant cross-section of tube 13 allows to ensure a constant flow rate of the gas through tube 13. Thus, the speed of the gas 12 through the tube 13 is known at all times. The tube can be of dimensions that allow control of the The gas inlet flow rate has a target velocity. For example, these dimensions They can be 120 mm long and have an internal diameter of 10 mm. fine geometry, that is to say a relationship between length and diameter of 10 a 15 is advantageous for controlling the inflow rate using means of drawing. Figure 3 schematically represents another mode of construction of a cleaning device 30 with a tube with a non-cross-section— constant according to the invention. All elements in Figure 3 are identical to those in Figure 1 except for the container referenced here 33. In the mode of In the construction of figure 3, the container 33 is a tube which has a cross-section not constant between input 14 and output 15. Due to the non-constant section of the tube, the flow velocity of gas 12 through the tube varies in relation with the cross-section of the tube. The larger the cross-section, the higher the speed The flow rate of gas 12 decreases, and the smaller the cross-section, the higher the velocity The flow rate of gas 12 increases, at the same temperature and pressure. By varying the tube's cross-section, it is possible to judiciously position the first filter 11 so that the flow velocity of the gas 12 at this point The tube is weaker. This results in a shorter residence time of the gas through the longer filter and therefore increased filtering of desired elements such as the tar. In Figure 3, only one variation in the cross-section of tube 33 is represented but the invention applies similarly to several successive variations in the cross-section of tube 33, increasing and / or decreasing. Figure 4 schematically represents another mode of implementation of a 40 cleaning device according to All the The elements of Figure 4 are identical to those of Figure 1. Device 40 includes several first filters 11 arranged successively in the tube. Adding several first filters 11 allows us to obtain a Better tar filtration in gas 12. Indeed, the tars not filtered by the first of the first filters, 11 must pass through the second, and possibly the third of the first 11 filters In Figure 4, the cleaning device 40 is shown with a tube, but the container could just as easily be a bottle. Figure 5 schematically represents another mode of Implementation of a cleaning device 50 according to the invention. All the The elements of Figure 5 are identical to those of Figure 1. The device 50 includes several first filters 11 arranged successively in the tube, for example here two, and one of the first filters is longer than Fautre. In other words, gas 12 has a longer transit time through the first filter. Besides the best filtration of tars in gas 12 obtained by implementing several initial filters, the fact of having a The first filter, 11, is longer along the axis along which the container extends, allowing further improve the tar removal capacity. Figure 6 schematically represents another mode of construction of a cleaning device 60 with a second filter 17 downstream of the first filter 11 according to the invention. A second compound among several The compounds to be eliminated in gas 12 are water. The device 60 of cleaning according to the invention includes the second filter 17 positioned between Inlet 14 and outlet 15 of container 13, upstream or downstream of the first filter 11 through which the gas 12 flows and is designed to be removed. Gas flame 12. The second filter 17 comprises a water adsorbent material. The juxtaposition of a first filter 11 and a second filter 17 in Container 13 allows for both a tar-absorbing material and a water-adsorbing material, which allows both, in the same container 13, to remove tars and water from gas 12. In Figure 6, and as is the case for each mode of The implementation represented in this application, the cleaning device 60, is depicted with a tube, but the container could just as easily be a bottle. Finally, the number of first filters is 11 and the number of second filters is 17. may vary, from a first filter 11 to several first filters 11 and / or from one second filter 17 has several second filters 17. Figure 7 schematically represents another mode of construction of a cleaning device 70 with a second filter 17 upstream of the first filter 11 according to the invention. All elements of Figure 7 are identical to those in Figure 6. The only difference lies in the positioning of the second filter 17 which is this time positioned upstream of the first filter 11 in container 13. The order in which the first and The second filters are positioned in the container and have no impact on their filtering capacity. In the case where a third compound among the plurality of compounds in gas 12 is an acidic gas such as HCl, the material Water adsorbent comprises a neutral or acidic particle surface. The surface pH of the adsorbent material is therefore less than or equal to 7.0. neutral or acidic particle surface of the water adsorbent material prevents any chemical or physical interaction of the compound to be analyzed, such than HCl, with the surface of the material. In the case where the third compound to be analyzed is in gas 12 is a basic gas, such as NH3, the water adsorbent material includes A neutral or basic particle surface. The surface pH of the material The adsorbent is therefore greater than or equal to 7.0. The surface area of the neutral particle or The basic nature of the Feau adsorbent material prevents any chemical interaction or physical properties of the compound to be analyzed, such as NHs, with the surface of the material. The adsorbent material can be a zeolite. The surface pH The effect of a zeolite can be controlled by contact with a solution acidic or basic. A zeolite can have only one type of porosity, meaning Good uniformity of pore size. By choosing judiciously The zeolite used in the second filter 17, the zeolite adsorbs water and leaves pass the desired element(s) such as HCI. Figure 8 schematically represents another mode of construction of an 80 cleaning device with a heating device according to the invention. All the elements of Figure 8 are identical to those of Figure 6. In this embodiment, the cleaning device 80 includes a gas heating device 19 12 positioned upstream of 'inlet 14 of container 13. Advantageously, the gas heating is The process is carried out upstream of the container and the second filter 17 is also heated. The temperature of gas 12 and the second filter 17 is important. In effect, the water must not condense. The heating device 19 allows for heat the gas 12 and the second filter 17 so as to maintain the temperature of the second filter 17—above the dew point of FTeau, which avoids the water condensation phenomenon. Furthermore, the device according to the invention may include a Cooling device 22 of the first filter 11. A first effect technique derived from the use of the cooling device 22 of the first Filter 11 is designed to increase tar condensation and therefore elimination more effective tars before the gas 12 exits through outlet 15. II y An increase in purification efficiency. A second technical effect resulting from the use of the cooling device 22 of the first filter 11 is that, in combination with synthetic materials, a decrease in Temperature prevents certain compounds, such as HCl, contained in the gas 12. to react with the materials. Note that the cooling device 22 of the first filter 11 is represented schematically in Figure 8. This device of Cooling is advantageous but not mandatory. It does not appear on the other figures but is of course combinable with the elements presented in figures 1 to 7 as well as in figure 9. The device according to the invention may also include a device 21 of the gas 12 suction positioned downstream of the outlet 15 of the container 13. The suction device 21 can be, for example, a pump, and allows to conduct the gas 12 from the inlet 14 to the outlet 15. Note that the same remark was made for the device of Cooling 22 of the first filter 11 applies to the suction device It is represented schematically in Figure 8. This device It is advantageous but not mandatory. It does not appear in the other figures. but is of course combinable with the elements shown in Figures 1 a 7 as well as figure 9. The device according to the invention may include an indicator 18 positioned downstream of the second filter 17 and configured to indicate a water concentration in gas 12 downstream of the second filter 17 beyond a A predefined threshold concentration. This could be, for example, a silica gel that changes color beyond a certain concentration of water. This indicator 18 shows that the second filter 17 is no longer efficient enough for elimination. The adsorbent material of the second filter 17 It absorbs water, and beyond a certain point of use, it needs to be changed or... regenerate. Figure 9 schematically represents another mode of Construction of a cleaning device comprising several containers According to all the elements in Figure 9, these are identical to those of Figure 8. The device 90 further comprises a second container 93, in parallel to container 13, in which there is a first filter 91 and a second filter 97 (upstream or downstream of the first filter 91, in figure 9 it is downstream) as well as an indicator 98. Device 90 includes a finger of bypass 94 upstream of containers 13, 93. In figure 9, the finger of Bypass 94 is positioned towards container 93, that is to say, it prevents the Gas 12 flows through container 93. All the gas 12 is therefore directed towards container 13 which it passes through to be cleaned. After a certain period of use, indicator 18 of the container 13 indicates a water concentration in gas 12 downstream of the second filter 17—beyond a predefined threshold concentration. II The adsorbent material of the second filter 17 must then be changed / regenerated. The bypass finger 94 is then tilted towards the container 13, that is to say that it prevents gas 12 from flowing through container 13. All the gas 12 is then directed towards container 93, which it passes through to be cleaned. The portion of With container 13 out of service, it is then easy to change and / or regenerate the adsorbent material of the second filter 17 At the same time, it is It is also possible to change the absorbent material of the first filter 11 for to ensure better filtration efficiency during the next use of the container 13. When 98 of container 93 indicates a concentration water in the gas 12 downstream of the second filter 17 beyond a concentration Once the threshold is predefined, the bypass finger 94 is then switched. towards container 93, that is to say, it prevents gas 12 from circulating through container 93. And it is then possible to perform the same maneuver as previously for the filters of container 13. Note that it is also possible to position the bypass finger 94 in neutral position, that is to say in a substantially horizontal position on the figure 9, so as to allow the flow of gas 12 in both containers 13 and 93. This allows for a greater inlet flow rate of gas 12, and therefore a greater gas cleaning capacity. This principle is also applicable to multiple containers. The tilting of the bypass finger 94 can also be controlled in a control loop with detection when Findicator 18 of a container indicates a concentration of water in the gas 12 downstream of the second filter 17—beyond a previously defined threshold concentration and tilting the bypass finger 94 towards said container to direct the gas into another container. Figures 10A and 10B represent the infrared spectrum containing 1000 ppm of HCl in the pure nitrogen matrix and the spectrum infrared radiation of the gas containing the HCl produced by the pyrolysis of PVC at 750°C pure and a mixture of wood and 1% by mass of PVC, sampled with a classic method, in this case using the solvent isopropanol. On In these figures, absorbance is plotted as a function of wavelength. It can be seen in figures 10A and 10B that there are no absorption peaks which correspond to HCl and therefore no HCl detection. We can conclude Therefore, the classical method of sampling HCI in the Syngas is not adequate. Figures 11A and 11B represent the infrared spectrum of 1000 ppm of HCl in the pure nitrogen matrix and the infrared spectrum of the gas containing the HCl produced by the pyrolysis at 750°C of pure PVC and a mixture of wood and 1% by mass of PVC, sampled with the device according to 'invention. On these figures, is drawn is a function of the wavelength. Figure 11A shows that using the device according to the invention for sampling HCl in a gas produced by the pyrolysis of With pure PVC, absorbance peaks can be observed, corresponding to the peaks of HCl in the 2600–2900 cm⁻¹ region of the spectrum. The same observation can be done on figure 11B for the gas produced by the pyrolysis of a a mixture of wood and 1% by mass of PVC. This time, the height of the spikes The absorbance is lower due to the lower concentration of HCl in the syngas. We can therefore conclude that the device according to the invention allows sampling of a gas containing even a low concentration initial of HCl.
Claims
Demands
1. Online analysis suite comprising: - a cleaning device (10, 20, 30, 40, 50, 60, 70, 80, 90) for a gas (12) comprising a plurality of compounds, a first compound among the plurality of compounds being tar and another compound being a gas to be analyzed chosen from hydrogen chloride, hydrogen sulfide and ammonia, and - a gas analyzer (16) connected downstream of the cleaning device (10) and arranged to analyze the gas to be analyzed; the cleaning device comprising: a container (13, 93) with an inlet (14) and an outlet (15), the gas (12) flowing through the container (13, 93) from the inlet (14) to the outlet (15), a first filter (11, 91) positioned between the inlet (14) and the outlet (15) of the container (13, 93), through which the gas (12) flows, intended to filter the tar, and in that the first filter (11.91) comprises a material that absorbs tar and allows the gas to be analyzed to pass through.
2. Online analysis set according to claim 1, characterized in The absorbent material is a natural material, preferably cotton.
3. Online analysis set according to claim 1, characterized in the absorbent material is a synthetic material, preferably nylon.
4. Online analysis set) according to any one of the claims 1 to 3, a second compound among the plurality of compounds being water, characterized in that it comprises a second filter (17, 97) positioned between the inlet (14) and the outlet (15) of the container (13, 93), upstream or downstream of the first filter (11, 91), through which the gas (12) flows and intended to remove water from the gas (12), and in that the second filter comprises a water adsorbent material.
5. Online analysis set according to claim 4, a third compound among the plurality of compounds being an acid gas, characterized in that the water adsorbing material comprises a neutral or acidic particle surface.
6. Online analysis assembly according to any one of claims 4 or 5, characterized in that the adsorbent material is a zeolite.
7. Online analysis assembly according to any one of claims 1 to 6, characterized in that the container (13, 93) is a tube comprising two ends, a first of the two ends being the inlet and a second of the two ends being the outlet.
8. Online analysis assembly according to claim 7, characterized in that the tube has a substantially constant cross-section between the inlet and outlet.
9. Online analysis assembly according to claim 7, characterized in that the tube has a non-constant cross-section between the inlet and outlet.
10. Online analysis assembly according to any one of claims 4 to 9, characterized in that it comprises a gas heating device (19) positioned upstream of the inlet (14) of the container (13, 93).
11. Online analysis assembly according to any one of claims 1 to 10, characterized in that it comprises a cooling device (22) for the first filter (11).
12. Online analysis assembly according to any one of claims 1 to 11, characterized in that it comprises a gas (12) suction device (21) positioned downstream of the outlet (15) of the container (13, 93).
13. Online analysis assembly according to any one of claims 4 to 12, characterized in that it comprises an indicator (18, 98) positioned downstream of the second filter (17, 97) and configured to indicate a water concentration in the gas (12) downstream of the second filter (17, 97) beyond a predefined threshold concentration.