TW201325701A - Catalytic filter system - Google Patents

Abstract

In order to provide a catalytic filter system which is easily adaptable to the various challenges of a catalytic gas phase reaction, a catalytic filter system is proposed, wherein the system comprises a filtration vessel having a fluid inlet and a fluid outlet, a separation wall provided in the interior of said filtration vessel and a plurality of filter candles, said separation wall dividing said interior into a raw gas chamber and a clean gas chamber; said separation wall comprising a plurality of openings designed to sealingly accommodate said plurality of filter candles; said fluid inlet being arranged in fluid communication with said raw gas chamber upstream of said plurality of filter candles; said fluid outlet being arranged in fluid communication with said clean gas chamber downstream of said plurality of filter candles; and said filter system comprising a first catalytic medium which is accommodated in said clean gas chamber downstream of said filter candles and upstream of said fluid outlet.

Description

Catalytic filter system

The present invention relates to a catalytic filter system comprising: a filtration vessel having a fluid inlet and a fluid outlet, a dividing wall disposed in the interior of the filtration vessel, and a plurality of filter candles. The dividing wall divides the interior of the container into an unpurified gas chamber and a purge gas chamber, and the partition wall includes a plurality of openings designed to sealingly receive the plurality of filter candles. The fluid inlet is in fluid communication with the raw gas chamber and is located upstream of the plurality of filter candles. The fluid outlet is in fluid communication with the purge gas chamber and is located downstream of the plurality of filter candles.

A filter system of this type is provided in US Pat. No. 6,863,868 B1 and the filter candle used is a catalytic filter candle such that the filter system can be used for hot gas filtration.

A filter system of different construction for purifying flue gas is known from EP 0 600 440 A2, wherein a barrier filter module is used with a separate catalytic module. The unpurified gas first passes through the barrier filter module and then through the catalytic module.

Both types of catalytic filter systems are useful in flue gas treatment because they provide both particle separation and catalytic gas phase reactions in one unit.

However, the problem of such a device for combining particle separation/catalytic gas phase reaction is that in the case where high catalytic conversion rate is required and high inlet concentration must be ensured, the surface velocity of the raw gas must be reduced in order to increase the gas. The residence time at which a catalytic reaction occurs in the catalytic element. This This leads to an increase in the number of filter elements in order to meet production capacity requirements and a corresponding increase in the size of the filter system.

In order to meet the need for particle loading (ie, filtration) of the raw gas, the size of such a filter system is generally unnecessarily increased.

It is an object of the present invention to provide a catalytic filter system in which the surface velocity can be determined by a filtration step and the filter system is readily adaptable to the various needs of the catalytic gas phase reaction stage.

This goal is met by a catalytic filter system having the features of claim 1.

The catalytic filter system of the present invention has a filtration vessel having a dividing wall therein, while the dividing wall separates the raw gas chamber from the purge gas chamber and is configured to accommodate a plurality of filter candles used.

Typically, the headspace downstream of the filter candle, which is necessary to handle the filter candle during installation and/or replacement, can be used to accommodate a first catalytic medium that is separate from the filter candle.

Thus, the surface velocity of the flue gas to be treated can be controlled by the filtration capacity of the filter candle, the number and size of which can be adapted to a particular filtration task. The catalytic level, ie the capacity of the first catalytic medium downstream of the filter candle, can be readily adapted to the need for flue gas contaminants to be removed or catalyzed in the catalytic gas phase reaction. Conversion.

In a more preferred catalytic system according to the invention, the filter candle comprises a catalyst and is used as a catalytic filter candle.

Thus, the catalytic gas phase reaction may have occurred in the filter candle and the first catalytic medium downstream of the filter candle is used to convert the residual pollutants of the purge gas to the desired level.

The filter candle used in the catalytic filter system of the present invention preferably includes an outer filter membrane upstream of the filter element.

The filter membrane can be more preferably selected as a fine filtration type. The fine filtration type membrane can retain particles having a size as small as less than about 1 μm, for example, about 0.5 μm.

The present invention provides an arrangement of catalytic media and filter candles in the same housing and still provides flexibility to adapt the filter system to a variety of filtration applications (eg, (in application) in flue gas filtration), and allows filtration stages Both the catalytic stage and the catalytic stage can be maintained at the same temperature without the need for a heating device, thereby improving the efficiency of the catalytic filter system.

Higher temperatures generally accelerate the rate of reaction of the catalytic gas phase reaction and are often desirable. According to the present invention, the gaseous fluid entering the catalytic filter system at elevated temperatures substantially maintains this temperature when the gaseous fluid is in contact with the first catalytic medium. Thus, heating systems are not required in many applications to ensure a satisfactory reaction rate.

In some embodiments of the catalytic filter system of the present invention, the filter system may also include a second catalytic medium downstream of the first catalytic medium or, even an additional catalytic medium downstream of the second catalytic medium.

More preferably, the first and/or second catalytic medium comprises a filter element having an average pore size approximately equal to or greater than the average pore size of the filter candle.

Another advantageous implementation of the catalytic filter system according to the invention For example, the backflow device is configured to be in fluid communication with the purge gas chamber.

More preferably, the dividing wall is level-aligned in the filter container such that the filter candle contained in the opening of the dividing wall is suspended from the same wall into the raw gas chamber. This arrangement makes it possible to vary the filtration capacity by inserting different numbers of filter candles and/or filter candles of different lengths, thereby allowing the screening surface area and filtration capacity of the system to be adjusted relative to the specific requirements for various applications.

In yet another embodiment of the invention, the catalytic filter system includes a first or second catalytic medium, the first or second catalytic medium being provided in the form of a fuse. Fuse catalytic elements typically have a deep filter structure and are used as a safety measure when the filter candle breaks. The fuse catalytic element then inhibits unfiltered, unpurified gas from entering the purge gas chamber. More preferably, a fuse catalytic element is provided for each filter candle.

The backflow device fluidly connected to the purge gas chamber is preferably connected to the purge gas chamber upstream of the first catalyst medium.

If the first catalytic medium should comprise a filter element or should take the form of a filter element, it is more preferred to have a backflow device arranged such that the backflow device is fluidly connected to the purge gas chamber downstream of the first catalytic medium.

By operating such a reverse flow device of a preferred catalytic filter system according to the present invention, it is possible to simultaneously regenerate not only the filter elements of the first catalytic medium but also the filter candles.

When the backflow gas is supplied to the filter system through the reverse flow device, the raw gas inlet upstream of the filter candle can be operated as an outlet for the reverse flow gas.

The filter system of the present invention typically includes a container that includes a separable portion from the container body container at a location downstream of the dividing wall. More preferably, the separable portion of the container is designed to accommodate the first and/or second catalytic medium.

If the filter system comprises a backflow device, the backflow device is better accommodated in the body of the container together with the dividing wall and the filter candle.

The filter candle may have a porous body (having a filter membrane on the upstream side). The porous body of the filter candle can be additionally impregnated with a catalyst. The filter candle is then used as a catalytic filter candle.

The non-catalytic filter candle and the catalytic filter candle are preferably hollow cylindrical. In some cases, the interior space of such a filter candle may be additionally partially or completely filled with a catalytic material (in particular in the form of foam, fibers or particulate particles), wherein the particulate particles may be provided in the form of a fixed bed.

The type of catalytic element used for the first, second or any other catalytic medium can be selected from catalytic fixed beds, fiber mats, foam structures, tubular elements, plates and/or honeycomb structures.

The catalytic element may comprise a porous body impregnated with a catalyst having an interior (forming a space for fluid flow). The space provided inside the component can additionally accommodate other catalyst materials. Thus, the porous body impregnated by the catalyst may have an internal space that is partially or completely filled with a material impregnated with the catalyst by foam, particulate particles or fibers. Typical examples are tubular elements or box-type elements.

In summary, the catalytic element forming part of the catalytic medium can be of a quite diverse structure, for example tubular, box, plate, block or Take the form of a fiber mat.

Typical examples of catalytic elements for the first, second and any other catalytic media are as follows:

a catalyst-impregnated fuse having a porous body made of sintered ceramic particle particles and/or fibers or foam and more preferably having an average pore size of from about 10 to about 500 μm, more preferably from about 50 to About 200 μm. Better to set a fuse for each filter candle.

a catalyst-impregnated porous body made of a ceramic foam of sintered particles of from about 10 to about 60 ppi (number of holes per inch), more preferably from about 30 to about 45 ppi, said sintered particles It has a particle size of from about 0.1 to about 100 μm, more preferably from about 0.3 to about 30 μm.

a catalyst-impregnated porous body made of ceramic fibers having an average fiber diameter of from about 1 to about 50 μm, more preferably from about 2 to about 10 μm. More preferably, the average fiber length is in the range of from about 1 to about 20 mm.

a fixed bed of catalytic particles having an average particle size of from about 10 [mu]m to about 30 mm, more preferably from about 100 [mu]m to about 10 mm.

The application of the catalytic filter system of the present invention covers various types of hot gas filtration applications in which particle removal can be combined with catalytic gas phase reactions. The invention can also be used in the following cases: hot gas purification in coal or biomass gasification, exhaust gas purification in a sinter plant or coke oven equipment, exhaust gas purification in power plants and incinerators, similar to FCC (fluid catalysis) The refining method of the cracking device is either in the chemical process, in the cement industry, or the like.

Catalytic ceramic filter candles are disclosed in WO 2006/037387 A1 and EP 2017003 A1, which are particularly useful for providing a plurality of filter candles housed in a dividing wall.

The advantages of the present invention are discussed in more detail in conjunction with the specific embodiments in accordance with the drawings and examples.

1 shows a schematic diagram of a catalytic filter system 10 of the present invention, the catalytic filter system 10 including a cylindrical vessel 12 having an interior partitioned by a dividing wall 14 into an unpurified gas chamber 16 and a purge gas chamber 18.

Typically, the dimensions of the cylindrical container include a diameter ranging from about 1 m to about 6 m or more and a height ranging from about 4 m to about 24 m or more.

In order to access the interior of the container 12 for maintenance or repair, the container can be divided into a lower fixed portion and an upper removable portion. However, very large containers are typically provided with a closable opening (not shown) on the wall of the container surrounding the purge gas chamber so that personnel can access the container.

The dividing wall 14 has a plurality of openings 20 that receive a plurality of filter candles 22. The filter candle 22 is received in the partition wall 14 by one end such that the body of the filter candle 22 is suspended substantially vertically from the partition wall into the raw gas chamber 16.

The raw gas inlet 24 is connected to the vessel 12 such that the raw gas inlet 24 is in direct communication with the raw gas chamber 16. Purification gas chamber 18 is in fluid communication with the purge gas outlet 26.

Downstream of the plurality of filter candles 22, i.e., above the filter candles within the purge gas chamber 18, a reverse flow device 28 is provided for generating a reverse fluid flow to intermittently regenerate the filter candles 22. A closable outlet 29 is provided at the bottom of the container 12 to permit intermittent removal of particulate matter from the container 12.

Further downstream, i.e. above the backflow device 28, a first catalytic medium 30 is provided in the purge gas chamber 18 for removing gaseous contaminants in the purge gas fluid.

The filter candle 22 can be selected from conventional non-catalytic or catalytic filter candles.

The surface speed can be increased to the maximum possible speed determined by the filtration capacity of the filter candle 22. The capacity of the catalytic medium 30 is adjusted according to the contaminant loading of the purge gas in a particular application, and/or a catalytic filter candle is used in place of the non-catalytic filter candle. Therefore, the desired conversion rate is ensured under all working conditions.

The catalytic medium 30 of Figure 1 can be selected from a wide range of catalytic media, which can include fuses, porous bodies of ceramic foam, porous bodies of sintered particles and/or fibrous particles, fixed bed catalysts, and the like.

2 illustrates another catalytic filter system 40 in accordance with the present invention that includes a cylindrical vessel 42 that is internally divided by a dividing wall 44 into an unpurified gas chamber 46 and a purge gas chamber. 48.

The dividing wall 44 has a plurality of openings 50 adapted to sealingly receive the filter candle 52, the filter candle 52 being suspended from the horizontally disposed dividing wall 44 Enter the raw gas chamber 46. An unpurified gas inlet 54 is disposed in the lower portion of the vessel 42 and is disposed in fluid communication with the raw gas chamber 46.

In the upper portion, the vessel 42 includes a purge gas outlet 56 that is in fluid communication with the purge gas chamber 48.

On the downstream side of the partition wall 44, i.e., the upper portion of the container 42, there is a separable portion 58 hereinafter referred to as a container, which portion 58 is designed to be separable from the body of the container 42. The separable portion 58 of the container typically houses the aforementioned purge gas outlet 56 and provides a space for containing the first catalytic medium (and any other catalytic medium, if applicable), the first catalytic medium according to the present invention being disposed downstream of the filter candle.

In the embodiment of the invention schematically illustrated in Figure 2, the first catalytic medium comprises three honeycomb catalytic elements 60, 61, 62, the honeycomb catalytic elements 60, 61, 62 being exchangeably secured to the container The upper portion of 42 is separable in portion 58.

Although FIG. 2 shows the catalytic elements 60, 61, 62 spaced apart from one another, the catalytic elements 60, 61, 62 may likewise be arranged in direct contact with one another in alternative embodiments.

Each of the honeycomb catalytic elements may be composed of a plurality of individual subunits, for example assembled in a common frame structure.

The purge gas exiting the filter candle 52 and entering the purge gas chamber 48 must pass through the honeycomb elements 60, 61 and 62 of the first catalytic medium before exiting the vessel 42 by means of the purge gas outlet 56.

The amount of honeycomb elements can be adjusted relative to the contamination (degree) of the raw gas so that the fluid gas can pass through the vessel 42 at once to achieve the desired conversion of NOx.

A typical example of a honeycomb structure that can be used as the catalytic elements 60, 61, and 62 is shown in FIGS. 3A and 3B. It is apparent from the comparison of Figures 3A and 3B that the honeycomb structure does not have to have a channel of a hexagonal structure, but may also have a different cross-sectional shape, for example, a square cross-sectional channel as shown in Figure 3B.

The purge gas entering the purge gas chamber 48 passes through a plurality of passages 66, 68 in the honeycomb elements 60', 61', 62' and 60", 61" 62" in intimate contact with the catalyst supported by the honeycomb structures.

As described in connection with the embodiment already shown in Figure 1, it is advantageous to have a backflow device 64 disposed on the downstream side of the filter candle 42 and still upstream of the honeycomb elements 60, 61 and 62 for passage of gas The reverse flow provides the possibility of intermittently regenerating the filter candle. More preferably, the backflow device 64 is located in the body of the container 42 and is not in the separable portion 58. At the bottom of the container 42, the container 42 includes a closable outlet 65 for intermittently removing particulate matter released from the filter candle during operation of the reverse flow device 64.

4 illustrates another embodiment of the present invention in the form of a catalytic filter system 80 that includes a vessel 82 that is divided into a raw gas chamber 86 and a purge gas chamber 88 by a horizontally oriented dividing wall 84. . The container 82 can be cylindrical or rectangular in shape.

The dividing wall 84 has a plurality of openings 90 that receive the filter candle 92 in a sealed manner such that the filter candle is suspended from the partition 84 and extends into the raw gas chamber 86. The raw gas inlet 94 is disposed at a lower portion of the vessel 82 and is in direct communication with the raw gas chamber 86.

In the upper portion of the container 82, the container 82 includes a purge gas outlet 96, The purge gas outlet 96 is in communication with the purge gas chamber 88.

As already described in connection with Figure 2, the container 82 is divided into two portions that are separable from each other, i.e., the upper separable portion 98 houses the first catalytic element and (below the position in which the first catalytic element 100 is received) Purified gas outlet 96. A reverse flow gas device 102 is disposed between the first catalytic element 100 and the partition wall 84. The reverse flow gas device 102 allows gas to flow back through the filter candle 92 into the raw gas chamber 86 to intermittently regenerate the filter candle 92.

Particles removed from the filter candle 92 by backflow are collected in the lowermost portion 104 of the container 82 and intermittently removed through the closed outlet 105.

The raw gas inlet 94 can be operated as an outlet for the reverse flow gas.

The first catalytic medium 100 is composed of a plurality of catalytic elements 106, which are more preferably hollow cylinders made of fibers, particles and/or foam. The structure of the hollow cylinder is more detailed in FIG. Shown. In the case where the catalytic element 106 is used as a fuse, the structure based on fibers and/or granular particles is more preferable. Catalytic element 106 is preferably housed in a cylindrical wall 108 that includes a plurality of openings 107 that contain a separate catalytic element 106 in a sealed manner. The cylindrical wall 108 is closed at its top 110 and open at its lower end, with the lower end of the cylindrical wall 108 being in direct fluid communication with the purge gas chamber 88.

Additionally, the lower end of the cylindrical wall 108 is sealingly coupled to the wall of the upper separable container portion 98 such that the purge gas exiting the filter element 92 and entering the purge gas chamber 88 is exiting through the purge gas outlet 96 Each of the catalytic elements 106 housed in the cylindrical wall 108 must be passed before the system 80 is opened. The cylindrical wall 108 thus divides the purge gas chamber 88 into compartments, one compartment upstream of the catalytic medium 100 and its catalytic element 106 and the other compartment downstream of the catalytic medium 100. The outer diameter of the cylindrical wall 108 is somewhat less than the inner diameter of the upper separable portion 98 of the container 82 so as not to impede the flow of fluid from the catalytic element 106 into the peripheral volume of the wall 108, the peripheral volume and purification of the wall 108. The gas outlet 96 is fluidly connected.

The container 82 can be rectangular in cross section. The wall 108 of the catalytic element 106 housing the first catalytic medium 100 is then also typically designed to enclose a rectangular space.

Catalytic element 106 can be a box-type structure having a flat porous wall of the lower and upper portions. While the side surface may be sealed against the purge gas in one embodiment, in other embodiments the sidewall may be made of the same material as the lower and upper walls. One side wall includes an opening that mates with an opening 107 in the wall 108.

FIG. 5 shows in detail one catalytic element 106 housed in wall 108. The catalytic element 106 has a cylindrical body 112 that is closed at one end thereof by a sealing bottom plate 114. The sealing bottom plate 114 of the cylindrical catalytic element 106 may be fluid impermeable or may be made of the same material as the cylindrical wall 112 to additionally contribute (contains still contained in the purge gas entering the catalytic element 106) Catalytic conversion.

The other end of the cylinder 112 is open and connected to the wall 108 such that a corresponding opening 107 in the wall 108 allows purge gas to exit the catalytic element 106 and exit the system through the purge gas outlet 96.

Yet another embodiment of the present invention is illustrated in Figure 6, in which the catalytic filter system 120 includes a vessel 122 that is substantially cylindrical in shape.

The container 122 is divided into an unpurified gas chamber 126 and a purge gas chamber 128 through a partition wall 124.

The dividing wall 124 includes a plurality of openings 130 that are designed to sealingly receive a cylindrical filter candle 132 that is inserted into the opening 130 and suspended from the dividing wall 124 into the raw gas chamber 126.

The vessel 122 also includes an unpurified gas inlet 134 that is in direct fluid communication with the raw gas chamber 126.

On the upper portion of the vessel, vessel 122 includes a purge gas outlet 136 that is in fluid communication with purge gas chamber 128.

The purge gas chamber houses a first catalytic medium 138 and an optional second catalytic medium 139.

Moreover, the vessel 122 is advantageously divided into a separable portion and a main portion, the upper separable portion 140 containing a purge gas outlet 136 and a first catalytic medium 138 and an optional second catalytic medium 139.

The first catalytic medium 138 can take the form of a fixed bed. Alternatively, it can be composed of a block-shaped ceramic foam element or a fiber mat.

For example, the second catalytic medium 139 may have a honeycomb structure impregnated with a catalyst. The catalyst can be different than the first catalytic medium 138 to help remove other contaminants from the purge gas.

After passing through the catalytic media 138 and 139, the purge gas exits the system 120 through the purge gas outlet 136.

In addition, the container 122 includes a reverse flow device 142 in its main portion. The reverse flow device 142 is used for the same purpose as the reverse flow device of the previously discussed embodiments of Figures 1, 2 and 4. The particulate matter can be removed intermittently from the bottom of the vessel 122 through the closed outlet 143.

The upper separable portion 140 of the container 122 is coupled to the main portion of the container 122 by radially outwardly extending flanges 144, 146 that allow the separable portion 140 to be sealingly mounted over the main portion of the container 122.

In all of the embodiments of the figures discussed above, the flue gas passes through the filter element from the unpurified gas chamber at a substantially constant temperature into the purge gas chamber and subsequently through the first catalytic medium.

For this reason, the temperature of the catalytic medium is heated to substantially the same temperature as the flue gas as it enters the vessel, without having to provide the heating means provided.

This provides high catalytic activity of the catalytic medium.

In order to additionally increase the catalytic conversion, the filter candle contained in the partition wall in any of the embodiments discussed above may be set as a catalytic filter candle, i.e., the filter candle has included a deposited catalyst in its filter element structure. .

Similarly, the first catalytic medium can be supplemented by a second catalytic medium or even more catalytic medium, as desired.

Since the container for locating the catalytic filter system in the vertical orientation of the main axis of the vessel of the catalytic filter system is advantageous in many respects, all of the embodiments described use this orientation. However, it should be noted that the filter system of the present invention can of course also operate in a levelwise orientation of the main axis of the container.

Reference example

In this reference example, a catalytic filter system as shown in Figure 1 is used in which the filter candle is a conventional DeNOx CatFil catalytic filter element and the DeNOx CatFil catalytic filter element is generally commercially available from Pall. Obtained by Filtersystems GMBH. However, the catalytic medium 30 is omitted. The dimensions of these filter elements are: an outer diameter of 60 mm and a length of approximately 1515 mm. The composition of the filter candle and the manufacturing process of the filter candle have been described in Example 1 of WO 2006/037387 A1, which is hereby incorporated by reference in its entirety.

These filter elements are used in typical DeNOx applications where the inlet concentration of NO amounts to approximately 300 ppmV and requires approximately 90% NO conversion.

The surface speed of the catalytic filter element must be limited to 60 m/h in order to achieve the required NO conversion. Roughly, 1500 catalytic filter elements of the above specifications must be used in a typical working environment at 300 ° C to ensure approximately 90% conversion of NO components over a three year period.

If the diameter of the vessel of the catalytic filter system has to be reduced, for example due to cost, the number of catalytic filter elements can be reduced to 1000. If the volume flow rate is kept constant, a surface speed of 90 m/h is caused. In this case, at a temperature of 300 ° C, only about 80% of NO conversion during the three-year period can be guaranteed.

Example 1

The catalytic filter system according to Example 1 of the present invention used the same DeNOx CatFil catalytic filter element as in the reference example. The number of catalytic filter elements is 1000 in order to reduce the cost of the container and the surface speed is Set to 90m/h.

In order to increase the NO conversion from about 80% to about 90% (can be guaranteed for 3 years), another 1000 tubular catalytic elements having a size of 60/44 x 1000 mm (outer diameter/inner diameter x length) are used. 106 is the first catalytic medium 100 downstream of the DeNOx CatFil filter candle 92, which may be installed as schematically illustrated in the embodiment of Figures 4 and 5.

For the preparation of the body of such a catalytic porous member 106, SiC particle particles having an average diameter of from about 550 μm to about 750 μm and SiO ₂ -Al ₂ O ₃ -based fibers having a size of 60/44×1000 mm were used ( It has a hollow cylindrical member made with a thickness of about 2 to about 3 μm and a length ranging from about 1 to about 5 mm, and the particle-to-fiber quality ratio is about 40:1 to about 50:1.

In order to sinter the mixture of particulate particles and fibers under atmospheric conditions, a sintering aid of 16.4% by weight is added to the mixture of particulate particles and fibers, depending on the mass of the mixture. A typical sintering aid is clay.

Catalytic activation of the sintered component body (having an average pore size of 150 ± 20 μm and a pore volume of 42 ± 5% by volume) using the incipient wetness technique by using (the composition is TiO ₂ -V ₂ O ₅ -WO ₃ (see The SCR (optional catalytic reduction) catalyst of Example 1) of WO 2006/037387 A1 is carried out. The weight percentage of TiO ₂ deposited in the first step was about 1.5 with respect to the sintered body of the element body obtained by using a suspension of TiO ₂ powder (having a BET surface of about 50 m ² ).

Suitable amounts of V ₂ O ₅ and WO ₃ deposited in a common subsequent step are about 0.3% by weight and about 2% by weight, respectively.

The volumetric flow rate corresponding to a surface velocity of 90 m/h of the raw gas causes the surface velocity of the purge gas to be 130 m/h when passing through the catalytic element of the first catalytic medium because the catalytic element is compared with the surface area of the filter candle 92 The surface area is small.

If the ratio of NH ₃ /NO is adjusted to 1 and the O ₂ content is adjusted to 3% by volume, when these catalytic elements are used as the first catalytic medium 100 (the temperature is 300 ° C and the surface speed is 130 m / h) The total amount of NO conversion provided by these catalytic elements is about 60%.

The combined conversion of catalytic filter element 92 and catalytic element 106 amounts to about 90% and is guaranteed over a period of about three years.

Example 2

Example 2 is based on the use of a catalytic filter system as described in the Reference Example, in which the number of catalytic filter elements has been limited to 1000 and the surface speed is set to 90 m/h.

In order to increase the NO conversion rate to 90% (to ensure a lapse of 3 years), a number of 4,300 tubular catalytic ceramic foam elements (which are 30 ppi (number of holes per inch) type and have a size of 40/10 x 500 mm As the first catalytic medium 100 downstream of the DeNOx CatFil element. Therefore, the surface velocity of the purge gas obtained when entering the first catalytic medium 100 is 90 m/h.

In order to prepare a suitable catalytic ceramic foam element having a size of 40/10×500 mm, a 30 ppi Al ₂ O ₃ -based tubular ceramic foam body is catalytically activated (using an SCR catalyst having a composition of TiO ₂ —V ₂ O ₅ —WO ₃ Wet impregnation technique after complete infrared drying). The wet impregnation technique is similar to the two-step impregnation method described in Example 1 of WO 2006/037387 A1, although the paraffin coating step is omitted. The amount of TiO ₂ deposited on the Al ₂ O ₃ based ceramic foam body by using a suspension of TiO ₂ powder (having a BET surface of 50 m ² ) relative to the blank of the ceramic foam body was 0.7% by weight. After the complete infrared drying of the program of Reference Example 1 referred to above, the heat treatment was continued at 300 ° C for 5 hours. The loadings of V ₂ O ₅ and WO ₃ were 0.7% and 1.2% by weight, respectively.

If the ratio of NH ₃ /NO supplied is 1 and the O ₂ content is 3% by volume, the tubular catalytic ceramic foam member used as the first catalytic medium 100 has a surface velocity of 300 ° C and 90 m / h. In the case of NO conversion, the total is 60%.

The combined conversion of the catalytic filter element and the first catalytic medium amounts to about 90% and is guaranteed for three years.

Due to the number of filter candles limited to 1000 and an additional 4300 catalytic elements, the size of the container of the filter system is reduced, and accordingly the cost of the system can be reduced. The higher the number of filter candles used, the larger the diameter required for the container, which greatly increases the cost of providing the filter container.

On the other hand, when the height of the filter container needs to be increased in order to increase the volume of the purge gas chamber to accommodate other catalytic media, the increase in cost is relatively low.

Example 3

Example 3 demonstrates the use of the catalytic filter system of the present invention in a tar reforming process. In the catalytic filter system of Figure 4, used A catalytic filter candle 92 combined with particle separation and catalytic tar reforming is used in place of the DeNOx CatFil filter candle.

Comprising 5g / Nm ³ naphthalene 3100Nm ³ / h volumetric flow model biomass gasification gas (model biomass gasification gas) as a model compound tar (tar model compound) at 850 deg.] C is fed into the system at atmospheric pressure.

In this case, the model biomass gasification gas contains 50 vol% of N ₂ , 12 vol% of CO, 10 vol% of H ₂ , 11 vol% of CO ₂ , 5 vol% of CH ₄ and 12 vol% of H ₂ O.

A 660 Al ₂ O ₃ based particle sintered tar reforming catalytic filter element (size 60/40 x 1500 mm, surface speed 72 m/h) achieved 60% conversion in the presence of 100 ppm V H ₂ S.

The catalytic filter element was prepared according to the teachings of Example 1 of US 2009/0019770 A1 with the following modifications:

The SiC particles are replaced by alumina particles of the same size.

The mullite film was replaced by a similar film of alumina.

In the first impregnation step, the MgO-Al ₂ O ₃ loading was reduced from 0.9% by weight to 0.8% by weight.

In the second impregnation step, a suitable nickel nitrate hexahydrate solution is used to produce a nickel oxide loading of 60% by weight relative to the MgO-Al ₂ O ₃ loaded blank.

US 2009/0019770 A1 is incorporated herein by reference in its entirety.

In order to increase the conversion of naphthalene from 60% to about 90% at 850 ° C under the above conditions, a 45 ppi tubular catalytic ceramic was taken (in accordance with the invention as the first catalytic medium 100 and having a size of 40/20 x 500 mm) A catalytic medium in the form of a foam element can be used downstream of the tar reforming catalytic filter candle 92, as shown in Figures 4 and 5.

The body of such a catalytic ceramic foam element was prepared by catalytic activation of a 45 ppi type Al ₂ O ₃ based ceramic foam body using a wet impregnation technique after full infrared drying (similar to that described in Example 1 of US 2009/0019770 A1). Method), although two solid paraffin coating steps are omitted. MgO-Al ₂ O ₃ and NiO were respectively deposited in two successive steps with respect to the weight percentage of the blank of the ceramic foam of 6.2 wt% and 3.7 wt%, respectively.

The use of a number of 1200 catalytic ceramic foam elements resulted in a surface speed of 170 m/h. For the catalytic medium downstream of the particulate sintered catalytic filter, 70% conversion of naphthalene was obtained at 850 °C.

Overall, 88% naphthalene conversion was achieved under these conditions and allowed higher syngas and hydrogen production in biomass gasification.

The present invention achieves a conversion of up to about 90% for the first time under the above conditions.

Further improvements can be obtained by partially or completely filling the interior space of the catalytic filter candle with additional catalyst material. This allows for even higher conversion rates.

Additionally or alternatively, the number of catalytic filter elements can be reduced, thereby allowing the diameter of the vessel of the catalytic filter system to be reduced. Because of the high operating temperature, very high cost savings are achieved by reducing the diameter of the vessel.

As a further alternative, the number of tubular catalytic ceramic foam elements can also be reduced.

10, 40, 80, 120‧‧‧ Catalytic filter system

12, 42‧‧‧ cylindrical containers

14, 44, 84, 124 ‧ ‧ partition wall

16, 46, 86, 126‧‧‧ Unpurified gas chamber

18, 48, 88, 128‧‧‧ purge gas chamber

20, 50, 90, 107, 130‧‧‧ openings

22, 52, 92, 132‧‧‧ filter candles

24, 54, 94, 134‧‧‧ raw gas inlet

26, 56, 964, 136‧‧ ‧ purified gas exports

28, 64, 142‧‧‧ Backflow device

29, 65, 105, 143 ‧ ‧ can close the exit

30, 100, 138‧‧‧ first catalytic medium

58, 98‧‧‧ separable parts of the container

60, 61, 62‧‧‧ Honeycomb catalytic elements

60', 61', 62'‧‧‧ honeycomb catalytic elements

60”, 61”, 62”‧‧‧ honeycomb catalytic elements

66, 68‧‧‧ channels

82, 122‧‧‧ containers

102‧‧‧Backflow gas installation

104‧‧‧Bottom part

106‧‧‧catalytic components

108‧‧‧ cylindrical wall

110‧‧‧ top

112‧‧‧Cylinder

114‧‧‧Seal backplane

139‧‧‧Secondary catalytic medium

140‧‧‧ separable parts

144, 146‧‧‧Flange

Figure 1 shows a schematic view of a first catalytic filter system according to the invention; Figure 2 shows a schematic view of a second catalytic filter system according to the invention; Figures 3A and 3B show the second catalytic in Figure 2 Details of the catalytic medium used in the filter system; Figure 4 shows a schematic view of a third catalytic filter system in accordance with the present invention; Figure 5 shows in more detail the use in the third filter system of Figure 4 Porous catalytic body member; Figure 6 shows a schematic of a fourth catalytic filter system.

10‧‧‧ Catalytic filter system

12‧‧‧ cylindrical container

14‧‧‧ partition wall

16‧‧‧Unpurified gas chamber

18‧‧‧Gas gas chamber

20‧‧‧ openings

22‧‧‧ Filter candle

24‧‧‧Unpurified gas inlet

26‧‧‧Clean gas export

28‧‧‧Backflow device

29‧‧‧ Exports that can be closed

30‧‧‧First Catalytic Medium

Claims (12)

A catalytic filter system comprising: a filter container having a fluid inlet and a fluid outlet; a partition wall disposed in an interior of the filter container; and a plurality of filter candles; wherein the partition wall The interior is divided into an unpurified gas chamber and a purge gas chamber; wherein the partition wall includes a plurality of openings designed to sealingly receive the plurality of filter candles; wherein the fluid inlet is disposed with the plurality of filter candles The upstream cleaned gas chamber is in fluid communication; wherein the fluid outlet is disposed in fluid communication with the purge gas chamber downstream of the plurality of filter candles; and wherein the catalytic filter system includes being contained in the purge A first catalytic medium in the gas chamber, the purge gas chamber being downstream of the filter candle and upstream of the fluid outlet. The catalytic filter system of claim 1, wherein the filter candle comprises a catalyst. The catalytic filter system of claim 1 or 2, wherein the filter candle comprises an outer filter membrane upstream of the filter element. The catalytic filter system of any one of claims 1 to 3, further comprising a second catalytic medium downstream of the first catalytic medium and upstream of the purge gas outlet. The catalytic filter system of any one of claims 1 to 4, wherein the first catalytic medium and/or the second catalytic medium comprises a filter element, the filter element having a large average pore size It is about equal to or greater than the average pore size of the filter candle. The catalytic filter system of any one of claims 1 to 5, wherein the plurality of filter candles are suspended from the partition wall and extend from the partition wall into the raw gas chamber. The catalytic filter system of any one of claims 1 to 6, wherein the first catalytic medium and/or the second catalytic medium are provided in the form of a fuse. The catalytic filter system of any one of claims 1 to 7 further comprising a backflow device housed in the purge gas chamber. The catalytic filter system of claim 8, wherein the reverse flow device is positioned in the purge gas chamber upstream of the first catalytic medium. The catalytic filter system of any one of claims 1 to 9 wherein the container comprises a separable upper housing portion, the separable upper housing portion being coupled to the filter container The lower main portion downstream of the partition wall. The catalytic filter system of claim 10, wherein the separable housing portion is designed to receive the first catalytic medium and/or the second catalytic medium. The catalytic filter system of any one of claims 1 to 11, wherein the first catalytic medium and the optional second catalytic medium and any other catalytic medium comprise a catalytic fixed bed, a fiber mat, Catalytic element in the form of a foam structure and/or a honeycomb structure.