Method for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles

A nitrogen oxide, selective technology used in chemical instruments and methods, separation methods, exhaust devices, etc., to achieve the effect of reducing the risk of corrosion

Inactive Publication Date: 2009-10-28
ALZCHEM AG
View PDF2 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Disadvantageously, at the same time very corrosive formic acid is released and possible reverse formation of ammonium formate on the surface of the SCR-catalyst at exhaust gas temperatures below 250 °C

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
  • Method for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles
  • Method for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles
  • Method for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] corresponding to the basis figure 1 Description of the use of 40% by weight guanidine formate in automatic ammonia generators Aqueous solution, (GF) (Fp

[0043] Car engine 1 produces 200Nm 3 / h exhaust gas flow, which is led through the intermediate pipe 2 to the exhaust gas intermediate pipe 6 via the platinum oxidation catalyst 3 and the particle filter 4 . The composition of exhaust gas measured with FTIR-gas analyzer 5 in intermediate pipe 6: nitrogen oxide (NO) of 150ppm; nitrogen dioxide (NO2) of 150ppm 2 ); 7% of carbon dioxide (CO 2 ); 8% of water vapor, 10ppm of carbon monoxide (CO).

[0044] In the storage tank 7 there is the GF-solution 8 , which is sprayed into the reactor 11 by means of the metering pump 9 via the delivery pipe 10 and the nozzle 12 . The reactor 11 consists of a vertically arranged tube of an inner diameter of 51 mm made of austenitic stainless steel heated to 250° C. and provided with a heating jacket 15 . In reactor 11 there ar...

Embodiment 2

[0049] Similar to embodiment 1 operation, but titanium dioxide catalyst 14 is replaced by palladium oxide-titania catalyst, wherein titanium dioxide is replaced with Pd(NO 3 ) 2 The aqueous solution impregnated such that after drying and calcination (5 hours at 500° C.) a catalyst containing 1% by weight of PdO (= about 0.9% by weight of Pd) was produced and which resulted in partial oxidation of carbon monoxide. On the FTIR gas analyzer 17 no increase in the CO concentration can be detected.

Embodiment 3

[0051] The procedure was carried out analogously to Example 1, but instead of the 40% by weight guanidine formate solution a 15% by weight guanidine dicarbonate solution was used. Reactor 11 was also heated at 250° C., catalysts 13 and 14 were the same as those of Example 1.

[0052] No by-products (2 Elevation as expected; NO and NO detectable in gas analyzer 19 2 The concentration was reduced by about 92% to 25 ppm.

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
diameteraaaaaaaaaa
lengthaaaaaaaaaa
Login to view more

Abstract

The invention relates to the use of aqueous guanidinium formiate solutions, optionally combined with urea and/or ammonia and/or ammonium salts, for the selective catalytic reduction of nitrogen oxides using ammonia in exhaust gases of vehicles. The inventive guanidinium formiate solutions enable a reduction of the nitrogen oxides by appoximately 90 %. Furthermore, said guanidinium formiate solutions can enable an increase in the ammonia forming potential from 0.2 kg, corresponding to prior art, up to 0.4 kg ammonia per litre of guanidinium formiate, along with freezing resistance (freezing point below -25 DEG C). The risk of corrosion of the inventive guanidinium formiate solutions is also significantly reduced compared to that of solutions containing ammonium formiate.

Description

technical field [0001] The invention relates to a method for the selective catalytic reduction of nitrogen oxides in vehicle exhaust gases by means of a guanidinium salt solution, wherein ammonia is produced from the corresponding guanidinium salt by evaporation and catalytic decomposition and is used as reducing agent for the subsequent selection of nitrogen oxides sexual catalytic reduction. Background technique [0002] According to prior art, ammonia (NH 3 ) as reducing agent in the selective catalytic reduction of nitrogen oxides in oxygen-containing vehicle exhaust gases upstream of a special SCR-catalyst or upstream of a group of SCR-catalyst modules integrated in a muffler which can flow through in parallel It is introduced into the exhaust tract of combustion plants and internal combustion engines, in particular of vehicles, and initiates the reduction of nitrogen oxides contained in the exhaust gas in the SCR catalyst. SCR means nitrogen oxides (NO x ) selective...

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
Patent Type & Authority Applications(China)
IPC IPC(8): B01D53/94B01D53/90F01N3/20F01N3/10
CPCB01D2257/404B01D2255/20707F01N3/2066F01N2240/25Y02T10/24B01D53/9477B01D2255/1023B01D2251/206B01D2251/106B01D53/9418B01D2255/106F01N2610/02Y02A50/20B01D53/90B01D53/94F01N3/20F01N3/10Y02T10/12
Inventor B·哈默H-P·克里默B·舒尔茨E·雅各布
Owner ALZCHEM AG
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