KR100903289B1 - Carbon Monoxide, Hydrocarbon and Particualte Matter Reduction Catalyst for High-Sulfur Fuel Engine - Google Patents

Abstract

The present invention relates to a complex catalyst which oxidizes and removes carbon monoxide and hydrocarbons, PM (Particulate Matter) and soot with carbon dioxide in an engine exhaust using high sulfur. The present invention is a silicon (si), titanium (Ti), platinum group metal (A) of at least one metal selected from platinum (Au), iridium (Ir), ruthenium (Ru) and palladium (Pd), and 6 cycles As a metal (B), a composite catalyst containing Si-Ti-AB with at least one metal selected from cesium (Cs) and barium (Ba) is prepared to form a porous foam made of metal such as Fe-Cr-Al alloy or stainless steel. When coated on a ceramic filter or the like and applied to an exhaust gas treatment device, it has excellent oxidation power of carbon monoxide and hydrocarbon even at low operating temperatures, and has an excellent oxidation effect of PM.

High sulfur, carbon monoxide, hydrocarbons, PM, carbon dioxide, catalysts

Description

Carbon Monoxide, Hydrocarbon and Particualte Matter Reduction Catalyst for High-Sulfur Fuel Engine}

  The present invention relates to a composite catalyst for exhaust gas treatment of a diesel engine which removes carbon monoxide and hydrocarbons with carbon dioxide and water at low temperature, and oxidizes and removes particulate matter (PM) and soot with carbon dioxide.

The prior art wash coats alumina, a refractory inorganic compound, and supports platinum on it to collect soot, and the smoke is oxidized at about 350 ° C or higher, so the amount of soot collected is rapidly increased. Oxidation is instantaneous, local overheating occurs, melting of ceramic filters, melting or breaking often occurs, and soot is discharged to the outside. On the other hand, when a fuel containing high sulfur content is used, performance is drastically reduced. In addition, carbon monoxide and hydrocarbons are not oxidized properly at low temperatures, and have a disadvantage in that they cannot achieve the original purpose of preventing air pollution.

The present invention eliminates the drawbacks of the prior art, oxidizes carbon monoxide and hydrocarbons at low temperatures, decomposes them into harmless carbon dioxide and water, and continuously oxidizes the collected soot from low temperatures, thereby collecting the soot trapping load on metal foam or ceramic filters. BPT (Balance Point Temperature), which balances the collected soot with the removed soot, can be used continuously without damage to the metal foam or ceramic filter, and the performance can be reduced even in a high sulfur atmosphere. It is to provide a composite catalyst that can remove soot and PM at low temperature without.

The present invention is a Si-Ti-AB composite catalyst, wherein A is a platinum group metal, and at least one metal of Pt, Ru, Ir, and Pd, and B is a 6-cycle metal, which is at least one of Cs, Ba, W, and Re. It provides a catalyst for removing carbon monoxide, PM and hydrocarbons.

As a method for preparing the catalyst, silicon alkoxide or silicon ethoxide or silicon ethyl hexanoisopropoxide is used as Si metal, and TiCl ₄ or titanium tetraisopropoxide and platinum group metal (A) are used as Ti metal. And a metal compound of at least one of ruthenium, iridium, and palladium metals, and at least one metal compound of cesium, barium, tungsten, or rhenium metal as a 6-cycle metal (B) at 60 ° C. to 150 ° C. in hydrochloric acid, sulfuric acid, or nitric acid solution. It provides a method for producing Si-Ti-AB catalyst for the removal of carbon monoxide, PM and hydrocarbon, characterized in that the mixture is prepared by stirring at 60 rpm or more for 3 hours or more. In addition, the Si-Ti-AB composite catalyst prepared above may be prepared by further mixing hexamethyldisilane or phenylmethylsilane or methyltrimethoxysilane with ethanol or isopropyl alcohol or propanol as alcohol and silane.

The Si-Ti-A-B composite catalyst used in the present invention has an excellent PM oxidation power at low temperature and an excellent oxidation effect of hydrocarbon and carbon monoxide in an engine using a sulfur-rich fuel. In addition, BPT takes place at low temperatures, which provides continuous removal of PEM and hydrocarbons at low temperatures. Therefore, it provides an excellent effect to apply to DPF (Diesel Particulate Filter), Partial Diesel Particulate Filter (DPF) or Diesel Oxidation Catalyst (DOC).

The catalyst for removing carbon monoxide, hydrocarbons and PMs used in the present invention uses silicon alkoxide or silicon ethoxide or silicon ethyl hexanoisopropoxide as Si metal, and TiCl ₄ or titanium tetraisopropoxide as Ti metal. A solution of hydrochloric acid, sulfuric acid, or nitric acid by mixing at least one metal compound among platinum, ruthenium, iridium, and palladium metal with platinum group metal (A) and at least one metal compound among cesium, barium, tungsten, and rhenium metal with 6-cycle metal (B). Si-Ti-AB composite catalyst was prepared by stirring at least 60 rpm at 60 ° C. to 150 ° C. for at least 3 hours, in which ethanol or isopropyl alcohol or propanol and silane were used as hexamethyldisilane or phenylmethylsilane or methyltri. A methoxysilane or glycidoxypropylmethoxysilane is mixed to form a catalyst coating solution.

The catalyst coating solution thus prepared is impregnated with a foam or filter made of Fe-Cr-Al material, stainless steel, metal, alloy, SiC, or ceramic, and dried at 110 ° C. for at least 6 hours, followed by drying at 300 ° C. to 600 ° C. Firing for at least time to obtain a Si-Ti-AB composite catalyst foam or Si-Ti-AB composite catalyst filter for reducing PM at low temperature. Where A represents a platinum group metal and is at least one of Pt, Ru, Ir, Pd. B is a 6-cycle metal (B) and is at least one of cesium, barium, tungsten and rhenium metals. (A) As a metal compound, platinum chloride or dinitrodiamineplatinate as a platinum metal compound, ruthenium chloride or ruthenium nitrate is used as a ruthenium metal compound, iridium chloride as a iridium metal compound, palladium chloride or nitrate as a palladium metal compound Palladium is used, and (B) as the metal compound, cesium nitrate as the cesium metal compound, barium nitrate or barium chloride as the barium metal compound, ammonium tungstate as the tungsten metal, and rhenium chloride as the rhenium metal. It is not concerned with specific metal compounds.

The ratio of the metal used in the Si-Ti-A-B composite catalyst is used by mixing the ratio of Ti metal to Si in a weight ratio of 100: 1 to 1: 100. And the ratio of metal B to metal A is used by mixing in a weight ratio of 100: 1 to 1: 100. The ratio of the sum of the weights of A and B metals to the sum of the weights of Si and Ti metals is used by mixing them in a weight ratio of 1,000: 1 to 10: 1. When the weight ratio between the metals is out of the reaction, the oxidation reaction force is reduced in the catalyst, so the effect of converting the smoke or PM into carbon dioxide is significantly reduced, or when exposed to the exhaust gas of the internal combustion engine using fuel containing high sulfur, the performance is sharply degraded.

An aqueous solution of hydrochloric acid, sulfuric acid, or nitric acid is used in a weight ratio of 100: 1 to 1: 1 based on the total weight of Si, Ti, (A) metal, and (B) metal. It is difficult to obtain the object of the present invention by inhibiting the formation of.

The amount of ethanol or isopropyl alcohol or propanol used as alcohol is mixed with silane methyl silane or phenylmethylsilane or methyltrimethoxysilane in a weight ratio of 50: 1 to 1:50, and Si-Ti- The amount of ethanol or isopropyl alcohol or propanol as an alcohol to the catalyst coating liquid consisting of an AB composite catalyst and an aqueous solution of hydrochloric acid or sulfuric acid or nitric acid, and hexamethyldisilane or phenylmethylsilane or methyltrimethoxysilane as silane is 50: 1. Mix by weight ratio up to 1:50. When the weight ratio is out of the above, the coating liquid of the composite catalyst is significantly reduced in adhesion to a Fe-Cr-Al material, or a stainless steel metal or alloy, SiC, or ceramic foam or filter, which causes problems in durability.

The present invention is explained in more detail by the following examples, which are not intended to limit the present invention.

Examples 1 to 5 were tested for the reduction efficiency of BPT, PM, hydrocarbon, and carbon monoxide by varying the composition of the Si-Ti-AB composite catalyst, Comparative Example 1 is a Si-Ti-A catalyst, Comparative Example 2 Si-Ti-B catalyst, Comparative Example 3 is a Ti-AB catalyst, Comparative Example 4 was tested for the reduction efficiency of BPT, PM, hydrocarbons, carbon monoxide using the AB catalyst.

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Example  One

To prepare a Si-Ti-AB composite catalyst, 50 g of silicon ethylhexanoisopropoxide as a Si metal and 50 g of TiCl ₄ as a Ti metal, ₅ g of chloroplatinic acid as a platinum group (A) metal, and a nitric acid as a 6 cycle metal (B) 5 g of cesium and 500 g of 10% aqueous hydrochloric acid were mixed and stirred for 3 hours at 90 ° C. at 60 rpm to form a Si-Ti-Pt-Cs composite catalyst, and 10 g of ethanol with alcohol and 10 g of hexamethyldisilane with silane were added thereto. Si-Ti-Pt-Cs composite catalyst coating solution was mixed to form a Fe-Cr-Al material with a diameter of 7 inches and a thickness of 1 inch, impregnated with two 30PPI and three 50PPI, and at 110 ° C. After drying for 6 hours and firing at 400 ° C. for 2 hours to obtain a low-temperature smoke reduction Si-Ti-Pt-Cs composite catalyst foam, the porosity was connected in series with two 30PPI foams and three 50PPI foams, and the sulfur content was 2,000 ppm. A diesel engine using a 3900cc engine as a fuel containing diesel BPT was measured after operating in Engelhard deterioration mode for 200 hours using a motor and PM, hydrocarbon and carbon monoxide removal rates were measured in ND-13 mode.

Example  2

     In order to prepare a Si-Ti-AB composite catalyst, 50 g of silicon ethoxide as a Si metal and 50 g of titanium triisopropoxide as a Ti metal were nitrated with 5 g of ruthenium chloride as a platinum group (A) metal and a 6 cycle metal (B). 5 g of barium and 500 g of 10% sulfuric acid aqueous solution were mixed and stirred for 3 hours at 90 ° C. at 60 rpm to form a Si-Ti-Ru-Ba composite catalyst, where 10 g of isopropyl alcohol as alcohol and phenylmethylsilane as silane were added. 10g was mixed to form a Si-Ti-Ru-Ba composite catalyst coating solution. A stainless steel foam having a diameter of 7 inches and a thickness of 1 inch was impregnated with two 30PPI and three 50PPI, and at 110 ° C for 6 hours. It was dried and calcined at 400 ° C. for 2 hours to obtain a Si-Ti-Ru- Ba composite catalyst foam for reducing PM at low temperature, and the porosity was connected in series with two 30PPI foams and three 50PPI foams, containing 2,000 ppm of sulfur. One diesel fuel, 3900 cc yen To the PM, hydrocarbons, carbon monoxide removal rate was measured by the engine operation to 200 hours after Engelhard degradation in Dynamometer measured BPT, and the operation mode used in ND-13.

Example  3

     To prepare a Si-Ti-AB composite catalyst, 50 g of silicon ethoxide as a Si metal and 50 g of titanium triisopropoxide as a Ti metal, 5 g of iridium chloride as a platinum group (A) metal and ammonium as a 6 cycle metal (B) 5 g of tungstate and 500 g of 10% nitric acid solution were mixed and stirred for 3 hours at 90 ° C. at 60 rpm to form a Si-Ti-Ir-W composite catalyst, wherein 10 g of propanol with alcohol and methyltrimethoxy with silane were added thereto. 10 g of silane was mixed to form a Si-Ti-Ir-W composite catalyst coating solution. A stainless steel foam having a diameter of 7 inches and a thickness of 1 inch was impregnated with 2 30PPI and 3 50PPI, and then heated at 110 ° C for 6 hours. And dried at 400 ° C. for 2 hours to obtain a low-temperature PM reduction Si-Ti-Ir-W composite catalyst foam having a porosity of 2,000 ppm by sulfur in series of two 30PPI foams and three 50PPI foams in series. 3900cc on one diesel fuel After 200 hours in operation Engelhard degradation in engine Dynamometer with binary measured BPT and, by operating with ND-13 mode to measure the PM, hydrocarbons, carbon monoxide removal rate.

Example  4

To prepare a Si-Ti-AB composite catalyst, 50 g of silicon ethoxide as Si metal and 50 g of titanium triisopropoxide as Ti metal were nitrated with 5 g of palladium chloride and 6 cycle metal (B) as platinum group (A) metal. 5 g of rhenium and 500 g of 10% nitric acid solution were mixed and stirred for 3 hours at 90 ° C. at 60 rpm to form a Si-Ti-Pd-Re complex catalyst, to which 10 g of propanol as alcohol and methyltrimethoxysilane as silane were added. 10g was mixed to form a Si-Ti-Pd-Re composite catalyst coating solution, impregnated with three honeycombs of stainless steel, 7 inches in diameter and 6 inches thick, dried at 110 ° C. for 6 hours and at 400 ° C. for 2 hours. It was calcined to obtain a Si-Ti-Pd-Re composite catalyst honeycomb for low temperature PM reduction, and three catalyst coated stainless honeycombs were connected in series, and the diesel fuel containing 2,000 ppm of sulfur was used as a fuel. Engine dynamo BPT was measured after operating in Engelhard deterioration mode for 200 hours, and the removal rate of PM, hydrocarbon and carbon monoxide were measured in ND-13 mode.

Example  5

     To prepare a Si-Ti-AB composite catalyst, 50 g of silicon ethoxide as Si metal, 50 g of titanium triisopropoxide as Ti metal, 3 g of dinitrodiamineplatinate as platinum group (A) metal, and 2 g of iridium chloride Si-Ti-Pt-Ir-Cs-W composite catalyst was mixed with 3 g of cesium nitrate and 2 g of ammonium tungstate, and 500 g of 10% aqueous nitric acid solution and stirred at 60 rpm at 90 ° C. for 3 hours. 10 g of propanol with alcohol and 10 g of methyltrimethoxysilane with silane were mixed to form a Si-Ti-Pt-Ir-Cs-W composite catalyst coating solution, having a diameter of 10.5 inches and a depth of 15 inches. Si-Ti-Pt-Ir-Cs-W composite SiC filter for PEM reduction at low temperature by impregnating a filter containing 30 mesh size SiC particles, drying at 110 ° C. for 6 hours and firing at 400 ° C. for 2 hours. Was prepared by using light oil containing 2,000 ppm sulfur as fuel. , And after 200 hours operation to Engelhard degradation in engine Dynamometer with 3900cc engine measured BPT, and the operation in ND-13 mode to measure the PM, hydrocarbons, carbon monoxide removal rate.

Comparative example  One

It was prepared in the same manner as in Example 1 except that 50 g of silicon ethylhexanoisopropoxide as the Si metal and 50 g of TiCl ₄ as the Ti metal were used with 5 g of chloroplatinic acid as the platinum group (A) metal and no B metal was used. Si-Ti-A composite catalyst without B metal was prepared.

Comparative example  2

  50 g of silicon ethoxide as a Si metal and 50 g of titanium triisopropoxide as a Ti metal were used in the same manner as in Example 2 except that 5 g of cesium nitrate was used as a 6-cycle metal (B) and no A metal was used. , A-metal-free Si-Ti-B composite catalyst was prepared.

Comparative example  3

      Same as Example 1 except that 100 g of titanium triisopropoxide was used as a platinum group (A) metal, 5 g of chloroplatinic acid, and 5 g of cesium nitrate as a 6-cycle metal (B), and nothing was used as Si metal. The Ti-AB composite catalyst without Si was prepared.

Comparative example  4

     A-B composite catalysts were prepared in the same manner as in Example 1, except that 5 g of chloroplatinic acid as the platinum group (A) metal and 5 g of cesium nitrate were used as the 6-cycle metal (B) and nothing was used as the Si and Ti metals.

Experimental Example

Table 1 shows the composition of Si-Ti-AB composite catalyst and BPT (Balance Point Temperature) after operating in Engelhard degradation mode for 200 hours with engine dynamometer using diesel fuel containing 2,000 ppm sulfur as fuel and using 3,900cc engine. ) And PM, hydrocarbon and carbon monoxide removal rates after operating in ND-13 mode.

The lower BPT (Balance Point Temperature) is, the lower the PM (PM) is, the lower the temperature is.

Table 1. BPT and PM, hydrocarbon and carbon monoxide removal rate according to each example

division Catalyst composition BPT (℃) % Removal PM hydrocarbon carbon monoxide Example 1 Si-Ti-Pt-Cs 260 71 88 97 Example 2 Si-Ti-Ru-Ba 260 71 88 97 Example 3 Si-Ti-Ir-W 265 70 86 96 Example 4 Si-Ti-Pd-Re 265 70 86 96 Example 5 Si-Ti-Pt-Ir-Cs-W 260 72 90 98 Comparative Example 1 Si-Ti-Pt 385 8 25 36 Comparative Example 2 Si-Ti-Cs 390 4 17 26 Comparative Example 3 Ti-Pt-Cs 390 6 22 31 Comparative Example 4 Pt-Cs 430 2 16 11

As shown in the results of Table 1, in the apparatus using the catalyst of the present invention, the BPT was lower by 100 ° C. or more than the comparative example, and the PM, hydrocarbon and carbon monoxide removal rates were also confirmed to be improved by at least 10 times compared to the comparative example.

Claims (2)

A composite catalyst comprising Si-Ti-AB, wherein A is a platinum group metal, at least one of Pt, Ru, Ir, and Pd, and B is a six-cycle metal, at least one of Cs and Ba, and in the composite catalyst The ratio of Ti metal to Si is mixed in a weight ratio of 100: 1 to 1: 100, and the ratio of B metal to A metal is mixed in a weight ratio of 100: 1 to 1: 100. Si-Ti-AB for carbon monoxide, PM and hydrocarbon removal is characterized in that the ratio of the weight sum of the A metal and the B metal to the sum of the weights of Ti and Ti is mixed at a weight ratio of 1,000: 1 to 10: 1. Complex catalyst containing. delete