TWI866651B - Washable catalyst materials and methods of preparing the same - Google Patents

Abstract

Disclosed is a washable catalyst material including a base and a composite material layer. The base includes an inorganic fiber selected from glass fibers, ceramic fibers, alumina fibers or combinations thereof. The composite materials layer formed on the base includes an inorganic filler, an inorganic glue material, a curing agent and a catalyst, the inorganic filler is selected from aluminum oxide, aluminum hydroxide, silica, titanium dioxide or combinations thereof; the inorganic glue material is selected from silica, titanium dioxide, alumina, phosphate, borate, water glass, silicate or combinations thereof; the curing agent is selected from epoxy resin, acrylic acid, polyurethane or combinations thereof; and the catalyst is selected from cerium dioxide, active carbon or combinations thereof. A method of preparing the washable catalyst material is additionally disclosed.

Description

Water-washable catalyst material and preparation method thereof

The present invention relates to a catalyst material, and in particular to a water-washable catalyst material for removing gaseous molecular pollutants and a preparation method thereof.

For industrial processes that require high cleanliness (e.g. semiconductors, liquid crystal panels, pharmaceuticals, biochemistry), airborne molecular contaminants (AMC) in the environment will affect production efficiency and product yield. The main technologies for removing AMC include: non-destructive condensation, adsorption, absorption, and destructive direct combustion, catalytic incineration, and biological methods. The absorption method uses wet scrubbing equipment to spray the gas with a scrubbing liquid (e.g. pure water) through a spray plate, so that the gas and the scrubbing liquid are fully in contact, and the gas molecular contaminants enter the liquid film through the gas phase film and are absorbed by the scrubbing liquid.

The washing effect of wet washing equipment is affected by factors such as liquid-gas ratio, pH value/conductivity/temperature/circulation volume of washing liquid, liquid-gas specific surface area, washing retention time, exhaust gas volume, wet factor, gas solubility, etc. The water spray plate of wet washing equipment can increase the contact area and contact time between gas and liquid to improve the removal rate of AMC. The configuration and material of the sprinkler plate affect the AMC removal effect and durability of the sprinkler plate. Previously, sprinkler plates were made of organic materials or paper. Such sprinkler plates have poor water resistance and are prone to outgassing pollution or bacterial growth after a period of use. There is also a technology that uses inorganic ceramic materials to make sprinkler plates. However, inorganic ceramic materials require high-temperature forging, which is not only time-consuming but also increases costs.

How to improve the AMC removal rate of wet washing equipment, extend the service life of the shower plate and reduce its manufacturing cost is the main purpose of developing the present invention.

To achieve the above-mentioned purpose, the present invention provides a water-washable catalyst material, comprising: a substrate and a composite material layer. The substrate comprises an inorganic fiber selected from glass fiber, ceramic fiber, alumina fiber or a combination thereof. The composite material layer is formed on the substrate, and comprises: an inorganic filler, an inorganic adhesive, a curing agent and a catalyst, wherein the inorganic filler is selected from alumina, aluminum hydroxide, silicon dioxide, titanium dioxide or a combination thereof; the inorganic adhesive is selected from silicon dioxide, titanium dioxide, alumina, phosphate, borate, water glass, silicate or a combination thereof; the curing agent is selected from epoxy resin, acrylic acid, polyurethane or a combination thereof; the catalyst is selected from barium dioxide, activated carbon or a combination thereof.

In one embodiment, the substrate has an oblique corrugated structure, the crest height of the oblique corrugated structure is between 3 mm and 8 mm, the distance between two adjacent crests of the oblique corrugated structure is between 5 mm and 15 mm, and the angle between the oblique corrugated structure and the center line of the geometric shape of the substrate is between 15° and 60°.

In one embodiment, the thickness of the composite material layer is between 0.2 mm and 1 mm.

In one embodiment, the particle size of the inorganic filler is between 0.01 microns and 10 microns.

In one embodiment, the particle size of the catalyst is between 0.1 micrometers and 50 micrometers.

To achieve the above-mentioned purpose, the present invention further provides a method for preparing a water-washable catalyst material, comprising: mixing an inorganic filler, an inorganic solvent, a curing agent and a catalyst to form a slurry, wherein the weight ratio of the catalyst to the slurry is between 1% and 10%; cutting an inorganic fiber sheet to form a substrate; soaking the substrate in the slurry to form a slurry-containing substrate; hot-pressing the slurry-containing substrate at 100° C. to 200° C. to produce a molded substrate; soaking the molded substrate in the slurry at least once again; and drying the slurry of the molded substrate at 100° C. to 200° C. so that the slurry forms a composite material layer, thereby completing a water-washable catalyst material.

In one embodiment, the inorganic filler is selected from alumina, aluminum hydroxide, silicon dioxide, titanium dioxide or a combination thereof; the inorganic sol is selected from silicon dioxide sol, titanium dioxide sol, alumina sol, phosphate sol, borate sol, water glass, silicate sol or a combination thereof; the curing agent is selected from epoxy resin, acrylic acid, polyurethane or a combination thereof; the catalyst is selected from barium dioxide, activated carbon or a combination thereof.

In one embodiment, the pH value of the slurry is between 3 and 5, and the viscosity of the slurry is between 450 cps and 2000 cps.

In one embodiment, the inorganic fiber sheet is selected from glass fiber, ceramic fiber, alumina fiber or a combination thereof, and the weight of the inorganic fiber sheet per square meter is between 20 grams and 65 grams.

In one embodiment, the time for hot pressing the slurry-containing substrate at 100° C. to 200° C. is between 10 minutes and 30 minutes; the time for drying the slurry of the molded substrate at 100° C. to 200° C. is between 10 minutes and 30 minutes.

The water-washable catalyst material of the present invention includes a curing agent and a catalyst. The curing agent can increase the chemical resistance and durability of the water-washable catalyst material as a whole, and greatly extend the service life of the water-washable catalyst plate. The catalyst is a porous material, which can increase the contact area between gas and liquid and enhance the filtering effect of AMC. The preparation method of the water-washable catalyst material of the present invention can be formed by hot pressing a slurry-containing substrate at 100°C to 200°C through the composition of slurry, and the formed substrate is soaked in slurry again, and the slurry is dried at 100°C to 200°C to solidify the slurry to complete the water-washable catalyst material, which greatly reduces the processing temperature and manufacturing cost.

The following is a more detailed description of the implementation of the present invention with reference to the drawings and component symbols, so that a person skilled in the art can implement the present invention after reading this description.

FIG. 1 is a flow chart of the steps of the method for preparing the water-washable catalyst material of the present invention. As shown in FIG. 1 , the preparation method of the water-washable catalyst material of the present invention comprises the following steps: step S11: mixing an inorganic filler, an inorganic solvent, a curing agent and a catalyst to form a slurry, wherein the weight ratio of the catalyst to the slurry is between 1% and 10%; step S12: cutting an inorganic fiber sheet to form a substrate; step S13: soaking the substrate in the slurry to form a slurry-containing substrate; step S14: hot-pressing the slurry-containing substrate at 100° C. to 200° C. to produce a molded substrate; step S15: soaking the molded substrate in the slurry at least once again; and step S16: drying the slurry of the molded substrate at 100° C. to 200° C. to form a composite material layer, thereby completing the water-washable catalyst material.

In step S11, the inorganic filler is selected from alumina, aluminum hydroxide, silicon dioxide, titanium dioxide or a combination thereof; the inorganic sol is selected from silicon dioxide sol, titanium dioxide sol, aluminum oxide sol, phosphate sol, borate sol, water glass, silicate sol or a combination thereof; the curing agent is selected from epoxy resin, acrylic acid, polyurethane or a combination thereof; the catalyst is selected from caesium dioxide (CeO ₂ ), activated carbon or a combination thereof. Based on the total weight of the slurry, the weight ratio of the inorganic filler is between 50% and 70%, the weight ratio of the inorganic sol is between 10% and 30%, and the weight ratio of the curing agent is between 3% and 5%. The pH value of the prepared slurry is between 3 and 5. The viscosity of the slurry increases with the increase of the catalyst addition ratio. Too high viscosity affects the hydrophilicity. Therefore, the catalyst addition ratio is set between 1% and 10%, so that the viscosity of the slurry is between 450cps and 2000cps.

In step S12, the inorganic fiber sheet is selected from glass fiber, ceramic fiber, alumina fiber or a combination thereof. The weight of the inorganic fiber sheet is between 20 grams and 65 grams per square meter. There are pores between the fibers of the inorganic fiber sheet for gas and liquid to pass through and contact. It is worth noting that there is no order between step S11 and step S12, and the slurry can be prepared first or the substrate can be cut.

In step S13, the amount of slurry attached to the slurry-containing substrate increases as the viscosity of the slurry increases; in step S14, the slurry-containing substrate is placed in a heated mold and hot-pressed at 100° C. to 200° C. for a time ranging from 10 minutes to 30 minutes to shape the slurry-containing substrate into a formed substrate, and the structure of the formed substrate is, for example, a geometric shape with an oblique wavy structure; in step S15, the formed substrate is immersed in the slurry once or several times to increase the slurry coverage of the formed substrate; in step S16, the formed substrate is dried at 100° C. to 200° C. for a time ranging from 10 minutes to 30 minutes to complete the preparation of the water-washable catalyst material.

In the preparation method of the water-washable catalyst material of the present invention, through the composition of the slurry, the slurry-containing substrate can be formed by hot pressing at 100°C to 200°C, and the formed substrate is soaked in the slurry again, and the slurry is dried at 100°C to 200°C to solidify the slurry to complete the water-washable catalyst material, which greatly reduces the processing temperature and manufacturing cost.

FIG. 2 is a schematic diagram of a top view and a side view of a water-washable catalyst material according to an embodiment of the present invention. As shown in FIG. 2 , the water-washable catalyst material 2 includes: a substrate 21 and a composite material layer 22 formed on the substrate, wherein the substrate 21 includes an inorganic fiber selected from glass fiber, ceramic fiber, alumina fiber or a combination thereof; the composite material layer 22 includes: an inorganic filler, an inorganic adhesive, a curing agent and a catalyst, wherein the inorganic filler is selected from alumina, aluminum hydroxide, silica, titanium dioxide or a combination thereof; the inorganic adhesive is selected from silica, titanium dioxide, alumina, phosphate, borate, water glass, silicate or a combination thereof; the curing agent is selected from epoxy, acrylic acid, polyurethane or a combination thereof; and the catalyst is selected from barium dioxide, activated carbon or a combination thereof.

The shape of the substrate 21 can be determined according to the use requirements, such as but not limited to: rectangular, square, circular, elliptical. In this embodiment, the shape of the substrate 21 is rectangular and has an oblique corrugated structure 211. The peak height h of the oblique corrugated structure 211 is between 3 mm and 8 mm, the distance d between two adjacent peaks of the oblique corrugated structure 211 is between 5 mm and 15 mm, and the angle α between the oblique corrugated structure 211 and the center line L (the symmetry line or the vertical line of the two opposite sides) of the geometric shape of the substrate 21 is between 15° and 60°. The oblique corrugated structure 211 can form a flow channel for gas and liquid, and increase the contact ratio between gas and liquid, thereby enhancing the filtering effect of AMC.

The thickness of the composite material layer 22 is between 0.2 mm and 1 mm, the particle size of the inorganic filler is between 0.01 μm and 10 μm, the inorganic adhesive is formed by drying the water of an inorganic sol selected from silicon dioxide sol, titanium dioxide sol, aluminum oxide sol, phosphate sol, borate sol, water glass, silicate sol or a combination thereof, and the particle size of the catalyst is between 0.1 μm and 50 μm.

In the water-washable catalyst material of the present invention, the curing agent can increase the chemical resistance and durability of the water-washable catalyst material as a whole, and greatly extend the service life of the water-spraying plate; the calcium dioxide or activated carbon or the calcium dioxide with activated carbon as a carrier as the catalyst are all porous materials, which can increase the contact area between the gas and the liquid and enhance the filtering effect of AMC. The calcium dioxide has the characteristics of Ce ³⁺ /Ce ⁴⁺ dual oxidation state, which can directly promote the redox reaction (Redox), help transport oxygen, increase oxygen storage capacity (Oxygen Storage Capacity, OSC) and supply more oxygen in the oxidation reaction, and the defects on crystalline CeO _{2 (defects on crystalline CeO 2} ) can also be used to improve the oxidation-reduction reaction of the catalyst. The catalytic activity of catalytic converters can further enhance the filtration effect of volatile organic compounds (VOCs).

Examples and Comparative Examples Alumina fiber sheets were cut as substrates, and slurries with different ratios were prepared to prepare examples and comparative examples of water-washable catalyst materials. The slurry ratios (weight ratios) and slurry properties of the examples and comparative examples are shown in Table 1. Table 1 Pulp Inorganic filler Inorganic Sol Curing agent Catalyst pH Viscosity value (cps) Comparative Example 1 70% 25% 5% 0% 4.5 350 Embodiment 1 69% 25% 5% 1% 4.7 470 Embodiment 2 67% 25% 5% 3% 4.67 1180 Embodiment 3 67% 25% 3% 5% 4.5 1460 Embodiment 4 59% 30% 3% 8% 4.2 1880 Embodiment 5 57% 30% 3% 10% 4.18 2120 From the data in Table 1, it can be seen that the proportion of catalyst has little effect on the acid-base value of the slurry, and the viscosity of the slurry increases with the increase of the proportion of catalyst.

The water-washed catalyst material of the embodiment and the water-spraying board material without catalyst of the comparative example were cut into 10 cm × 10 cm test pieces. The slurry coating weight of the test pieces and the time for the water to vertically climb 10 cm are shown in Table 2. Table 2 Test piece Slurry coating weight (g/10cm ² ) Moisture vertical climbing time (minutes: seconds) Comparative Example 1 2.594 02:16 Embodiment 1 2.752 02:15 Embodiment 2 2.824 02:00 Embodiment 3 3.024 03:20 Embodiment 4 3.577 03:52 Embodiment 5 4.126 04:36 From the data in Table 2, it can be seen that the coating weight of the slurry increases with the increase of the catalyst ratio. When the catalyst ratio is below 5%, it has no effect or even shortens the vertical climbing time of moisture. When the catalyst ratio is above 5%, the vertical climbing time of moisture increases, that is, the hydrophilicity of the water-washable catalyst material is reduced.

The results of the filtration of isopropyl alcohol (IPA) in the gas by using the water-washed catalyst material with different catalysts and the water-spraying plate material without catalyst (Comparative Example 2) are shown in Table 3. Table 3 Composition Substrate Catalyst IPA inlet concentration (ppb) IPA outlet concentration (ppb) Filter rate Comparative Example 2 Alumina fiber sheet without 6147 877 85.7% Embodiment Alumina fiber sheet Activated carbon 5003 467 90.7% Embodiment Alumina fiber sheet Calcium dioxide 6644 782 88.2% Embodiment Alumina fiber sheet Activated carbon and calcium dioxide 6998 329 95.3% From the data in Table 3, it can be seen that the catalyst of the water-washed catalyst material can effectively improve the removal rate of organic compounds in AMC.

The water-washable catalyst material of the embodiment and the existing water-spraying board material without curing agent and catalyst (Comparative Example 3) were immersed in acidic (pH=2), neutral (pH=7) and alkaline (pH=11) solutions respectively, and vibrated for 4 weeks with a shaker at a speed of 1000 rpm. The weight loss of the embodiment and comparative example 3 after 1 week, 2 weeks, 3 weeks and 4 weeks was measured based on the weight before the test as a tolerance test. Figure 3 is a tolerance test diagram of the water-washable catalyst material of the embodiment of the present invention and the existing water-spraying board material without curing agent and catalyst of the comparative example. As shown in FIG3 , the spray board material of comparative example 3 is not acid- and alkali-resistant, disintegrates after 2 weeks in an acidic solution, disintegrates after 3 weeks in a neutral solution (water), and loses more than 20% of its weight in an alkaline solution; the water-washable catalyst material of the embodiment loses no more than 3% of its weight after 4 weeks in an acidic solution and a neutral solution, and loses no more than 1% of its weight after 4 weeks in an alkaline solution. The tolerance test results show that the water-washable catalyst material of the present invention has excellent chemical resistance and durability, and can greatly extend the service life of the spray board.

FIG4 is a three-dimensional schematic diagram of a water-spraying plate using the water-washing catalyst material of the present invention. As shown in FIG4 , the water-spraying plate 4 includes a plurality of water-washing catalyst materials 2 stacked up and down, and the structure and material of the water-washing catalyst material 2 are as described in the above-mentioned embodiment. In this embodiment, the water-washing catalyst material 2 is rectangular in shape and has an oblique corrugated structure 211. The plurality of water-washing catalyst materials 2 are stacked in reverse order, so that the oblique corrugated structures 211 of two adjacent water-washing catalyst materials 2 have opposite inclination angles (as shown by the arrows in FIG4 ). The stacking thickness t of the plurality of water-washing catalyst materials 2 (i.e., the thickness of the water-spraying plate 4) is, for example but not limited to, 200 mm to 800 mm. The oblique corrugated structure 211 forms a flow channel for gas and liquid, which can increase the contact area and contact time between gas and liquid, and effectively improve the effect of filtering AMC.

In summary, the water-washable catalyst material of the present invention includes a curing agent and a catalyst. The curing agent can increase the chemical resistance and durability of the water-washable catalyst material as a whole, and greatly extend the service life of the water-washable catalyst plate. The catalyst is a porous material, which can increase the contact area between gas and liquid and enhance the filtering effect of AMC. The preparation method of the water-washable catalyst material of the present invention can be formed by hot pressing a slurry-containing substrate at 100°C to 200°C through the composition of the slurry. The formed substrate is soaked in the slurry again, and the slurry is dried at 100°C to 200°C to solidify the slurry to complete the water-washable catalyst material, which greatly reduces the processing temperature and manufacturing cost, thereby solving the problems of the existing technology and achieving the purpose of the present invention.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person skilled in the art may modify, combine and change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications, combinations or changes made by anyone with such professional knowledge in the relevant technical field without departing from the spirit and technical principles disclosed by the present invention shall still be covered by the scope of the patent application of the present invention.

2: Washable catalyst material 4: Sprinkling plate 21: Substrate 22: Composite material layer 211: Oblique corrugated structure d: Distance h: Height L: Centerline α: Angle t: Thickness S11, S12, S13, S14, S15, S16: Steps

FIG1 is a flow chart of the steps of the preparation method of the water-washable catalyst material of the present invention; FIG2 is a schematic diagram of the top view and side view of the water-washable catalyst material of an embodiment of the present invention; FIG3 is a tolerance test diagram of the embodiment of the present invention and the comparative example; and FIG4 is a three-dimensional schematic diagram of a water spraying plate using the water-washable catalyst material of the present invention.

2: Water-washable catalyst materials

21: Base material

22: Composite material layer

211: Oblique wave structure

d: distance

h: height

L: Centerline

α: Angle of intersection

Claims (9)

A water-washable catalyst material comprises: a substrate comprising an inorganic fiber selected from glass fiber, ceramic fiber, alumina fiber or a combination thereof, wherein the substrate has an oblique corrugated structure, the crest height of the oblique corrugated structure is between 3 mm and 8 mm, the distance between two adjacent crests of the oblique corrugated structure is between 5 mm and 15 mm, and the angle between the oblique corrugated structure and the center line of the geometric shape of the substrate is between 15° and 6°. 0°; and a composite material layer formed on the substrate, comprising: an inorganic filler selected from alumina, aluminum hydroxide, silicon dioxide, titanium dioxide or a combination thereof; an inorganic adhesive selected from silicon dioxide, titanium dioxide, alumina, phosphate, borate, water glass, silicate or a combination thereof; a curing agent selected from epoxy, acrylic acid, polyurethane or a combination thereof; and a catalyst selected from calcium dioxide, activated carbon or a combination thereof. The water-washable catalyst material as described in claim 1, wherein the thickness of the composite material layer is between 0.2 mm and 1 mm. The water-washable catalyst material as described in claim 1, wherein the particle size of the inorganic filler is between 0.01 microns and 10 microns. The water-washable catalyst material as described in claim 1, wherein the particle size of the catalyst is between 0.1 microns and 50 microns. A method for preparing a water-washable catalyst material comprises: mixing an inorganic filler, an inorganic sol, a curing agent and a catalyst to form a slurry, wherein the weight ratio of the catalyst to the slurry is between 1% and 10%; cutting an inorganic fiber sheet to form a substrate; soaking the substrate in the slurry to form a slurry-containing substrate; hot pressing the slurry-containing substrate at 100°C to 200°C to produce a molded substrate; soaking the molded substrate in the slurry at least once again; and drying the slurry of the molded substrate at 100°C to 200°C to form a composite material layer, thereby completing a water-washable catalyst material. The preparation method of the water-washable catalyst material as described in claim 5, wherein the inorganic filler is selected from alumina, aluminum hydroxide, silicon dioxide, titanium dioxide or a combination thereof; the inorganic sol is selected from silicon dioxide sol, titanium dioxide sol, aluminum oxide sol, phosphate sol, borate sol, water glass, silicate sol or a combination thereof; the curing agent is selected from epoxy resin, acrylic acid, polyurethane or a combination thereof; the catalyst is selected from barium dioxide, activated carbon or a combination thereof. A method for preparing a water-washable catalyst material as described in claim 5, wherein the pH value of the slurry is between 3 and 5, and the viscosity of the slurry is between 450 cps and 2000 cps. The method for preparing a water-washable catalyst material as described in claim 5, wherein the inorganic fiber sheet is selected from glass fiber, ceramic fiber, alumina fiber or a combination thereof, and the weight of the inorganic fiber sheet per square meter is between 20 grams and 65 grams. The preparation method of the water-washable catalyst material as described in claim 5, wherein the time of hot pressing the slurry-containing substrate at 100°C to 200°C is between 10 minutes and 30 minutes; the time of drying the slurry of the molded substrate at 100°C to 200°C is between 10 minutes and 30 minutes.