Catalysts for NOX reduction employing h2 and a method of reducing NOX

a technology of nox reduction and catalyst, which is applied in the direction of physical/chemical process catalysts, metal/metal-oxide/metal-hydroxide catalysts, and separation processes, etc., can solve the problems of difficult construction of the supply network of hsub>2 /sub>, the use of ammonia to remove no/sub>x /sub>from diesel exhaust gas is very dangerous, and the urea-scr method is difficult to apply

Inactive Publication Date: 2011-06-23
HEESUNG CATALYSTS CORP
View PDF44 Cites 20 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0021]According to the present invention, oxides of A metals including Cu, Fe, Co and Ni and oxides of B metals including Cr, Mn, Mo and V are co-precipitated and mixed, thus preparing mixed oxide catalysts and ternary mixed oxide catalysts. These catalysts exhibit superior activity for production of ammonia through selective reaction between NO2 and H2 even in the presence of 5% or 10% O2, and simultaneously, manifest very high NO2 and NO storage performance. Thereby, the catalysts can exhibit superior NOx reduction perfor

Problems solved by technology

However, the use of ammonia to remove NOx from diesel exhaust gas is very dangerous because a diesel vehicle should be driven in a state of always being loaded with ammonia which is highly toxic.
Although the urea-SCR method is advantageous because NOx removal performance is high, it is problematic in that a tank for storing aqueous urea and a device for spraying such urea should be additionally mounted to a diesel vehicle.
As well, the urea-SCR method is difficult to apply to a diesel vehicle, due to problems including low solubili

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Catalysts for NOX reduction employing h2 and a method of reducing NOX
  • Catalysts for NOX reduction employing h2 and a method of reducing NOX
  • Catalysts for NOX reduction employing h2 and a method of reducing NOX

Examples

Experimental program
Comparison scheme
Effect test

example 1

Preparation of Mixed Oxide Catalysts

[0035]Mixed oxide catalysts were prepared from oxides of A metals (Cu, Fe, Co, Ni) and B metals (Cr, Mn, Mo, V) through co-precipitation and mixing. The weight ratio of A metal oxide to B metal oxide was adjusted to 2, 1 and 0.5. As a precipitating agent, ammonia water or aqueous sodium bicarbonate was used, and pH of the mixed solution was adjusted to 6.0˜8.0. Any one A metal was reacted with any one B metal, thus preparing binary mixed oxide catalysts, and also, multicomponent mixed oxide catalysts were prepared using two or more kinds of these metals. The method of preparing some catalysts which are regarded as important is described below.

[0036]a) Cu—Cr Mixed Oxide Catalyst

[0037]A solution of 15.2 g of copper nitrate and 1.60 g of barium nitrate in 152 g of water was mixed with a solution of 15.4 g of potassium dichromate in 154 g of water, thus preparing a mixed solution. For sufficient mixing, the mixed solution was stirred for 30 min and th...

example 2

Preparation of Pt- or Pd-supported Mixed Oxide Catalyst

[0049]To evaluate NO2 reduction performance by a H2 reducing agent, Pt was supported in an amount of 0.1, 0.2, 1.0 and 2.0% by weight on the mixed oxide catalyst of Example 1. As a Pt precursor, hexachloroplatinic acid was dissolved in an amount of each of 0.1, 0.2, 1.1 and 2.1 g in 35 g of water, thus preparing a Pt solution, which was then added to 50 g of the mixed oxide catalyst. The catalyst reached equilibrium after 24 hours, and then dried in an oven at 80° C. and thus dewatered. The solution was burned in an electric furnace at 400° C. for 2 hours, placed in a quartz tube and then subjected to reduction treatment using a gas mixture containing N2 and H2 mixed at an equal ratio. The Pt-supported Cu—Cr catalysts and Fe—Mn catalysts were represented by Pt(0.1)-Cu—Cr, Pt(0.2)-Cu—Cr, Pt(1.0)-Cu—Cr, Pt(2.0)-Cu—Cr, Pt(0.1)-Fe—Mn, Pt(0.2)-Fe—Mn, Pt(1.0)-Fe—Mn, and Pt(2.0)-Fe—Mn.

[0050]On the other hand, Pd-supported mixed oxide c...

example 3

X-ray Diffraction Pattern of A-B Mixed Oxide Catalyst

[0051]Among the A-B mixed oxide catalysts prepared in Example 1, the catalysts in which the B metal was Cr and the A metal was Fe, Co, Ni and Cu were burned, after which X-ray diffraction patterns thereof were measured. The results are shown in FIG. 1. The diffraction pattern of the mixed oxide catalyst was very complicated because the diffraction peaks of metal oxides alone and in combinations thereof coexisted. In the Cu—Cr catalyst, the diffraction peaks of CuO, CuCr2O4 and BaCrO4 were shown. In any catalyst, the diffraction peak of BaCrO4 added to improve structural stability of the catalyst was distinctly observed. In the Cu—Cr and Fe—Cr catalysts, the diffraction peak of CuO or Fe2O3 was strongly observed. In the Fe—Cr and Co—Cr catalysts, the diffraction peaks difficult to confirm were present, and thus the mixed oxide catalysts were seen to have a complicated structure.

[0052]FIG. 2 shows the X-ray diffraction patterns of t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Temperatureaaaaaaaaaa
Volumeaaaaaaaaaa
Ratioaaaaaaaaaa
Login to view more

Abstract

Disclosed is a catalyst composition for reducing NOx through two steps including reacting NOx with H2 thus producing ammonia which is then reacted with NOx, instead of direct NOx reduction by H2, and a method of reducing NOx using the catalyst composition.

Description

TECHNICAL FIELD[0001]As a system for reducing NOx from diesel exhaust gas, selective catalytic reduction (SCR) and NOx storage reduction (NSR) are known. In the SCR method, a reducing agent is continuously sprayed into exhaust gas and selectively reacted with NOx in a catalyst bed so that NOx is converted into N2. This method is classified into NH3-SCR, Urea-SCR, HC-SCR and H2-SCR depending on the type of reducing agent such as ammonia, urea, hydrocarbon and H2. On the other hand, in the NSR method, NOx is stored in an oxidation atmosphere and then desorbed in a reduction atmosphere formed through spray of fuel, thus reducing NOx.BACKGROUND ART[0002]Generally, NOx emitted from large-scale boilers or nitric acid plants can be effectively removed through NH3-SCR which supplies ammonia as a reducing agent to a catalyst bed composed of titania-supported vanadia or iron-containing zeolite. Ammonia is highly reactive and selective and is thus very effective for removing NOx from the exhau...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): B01J23/86B01J23/889B01J23/34B01J29/072B01J37/03B01J37/08B01J37/18C01B21/02
CPCB01D53/9418B01D53/9427B01D2255/1021B01D2255/1023B01D2255/20723B01D2255/2073B01D2255/20738B01D2255/20746B01D2255/20753B01D2255/20761B01D2255/20769B01D2255/91B01J23/002B01J23/34B01J23/6562B01J23/8472B01J23/862B01J23/868B01J23/8892B01J23/898B01J23/8986B01J23/8993B01J29/7615B01J35/002B01J37/0201B01J37/033B01J37/08B01J37/18B01J2523/00B01D2251/202B01J2523/17B01J2523/25B01J2523/67B01J2523/842B01J2523/72Y02C20/10B01D53/56B01J23/84B01J23/888B01J37/03
Inventor HAN, HYUN-SIKKIM, EUN-SEOKSEO, GONPARK, SE-MINLEE, YUN-JE
Owner HEESUNG CATALYSTS CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap