A Review of Solid Materials as Alternative Ammonia Sources for Lean NOx Reduction with SCR

Fulks, Gary C.; Fisher, Galen B.; Rahmoeller, Ken M.; Wu, Ming‐Cheng; D'Herde, Eric; Tan, Julian

doi:10.4271/2009-01-0907

Cited by 56 publications

(49 citation statements)

References 9 publications

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“…For instance, the applications in forward osmosis of desalination [25][26][27]. Gary et al [28] and Gokel [29] studied ammonium bicarbonate decomposition in solution over the temperature range between 30°C and 85°C. Complete decomposition into ammonia, carbon dioxide and water was observed above 60°C [30].…”

Section: Thermal Decomposition Of Ammonium Bicarbonate (Nh 4 Hco 3 ) mentioning

confidence: 99%

Novel Applications of Non Hofmeister Ion Specificity in Bubble Interactions

Xue

Pashley

Ninham

2016

Current Opinion in Colloid & Interface Science

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Section: Thermal Decomposition Of Ammonium Bicarbonate (Nh 4 Hco 3 ) mentioning

confidence: 99%

Novel Applications of Non Hofmeister Ion Specificity in Bubble Interactions

Xue

Pashley

Ninham

2016

Current Opinion in Colloid & Interface Science

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“…Then the urea solution in the storage device is sucked by the supply pump and injected into the exhaust pipe in front of the catalysts through the nozzle of urea supply system. The urea reduces into reductant NH 3 by heating, as shown in formula (1). On the surface of the SCR catalyst, the NO X is reduced to N 2 by NH 3 , its main formula of reaction as shown in (2) (3) In high-temperature environment (higher than 300 ℃), NO X in the exhaust gas can quickly react with ammonia (NH 3 ) to form N 2 and H 2 O under the action of the catalyst.…”

Section: Structure Of System and Chemical Reaction Of Scrmentioning

confidence: 99%

“…So Urea tank has the low temperature heating device. In addition, there are a lot of alternatives of urea solution, including the solid urea, ammonium salts (such as ammonium carbamate), chloride salts (such as magnesium chloride) storage technologies of ammonia [1][2]. Part of the solution can make the freezing point of urea solution to -30 ℃.…”

Section: Present Status Of Urea-scr Technologymentioning

confidence: 99%

Research status and development trend of Urea-SCR technology

Qi¹,

Li²,

Guo³

et al. 2015

Proceedings of the 4th International Conference on Mechatronics, Materials, Chemistry and Computer Engineering 2015

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Abstract.Stringent emissions regulations require further reducing NOx emissions, selective catalytic reduction (SCR) technology is the mainstream technology to remove NOx at euro V and euro VI stage. First This article introduces the chemical reaction mechanism of Urea-SCR technology that could reduce NOx emissions from diesel engine. Then it points out research actuality of Urea-SCR from the urea storage device, urea supply system, catalystic converter and control unit separately. Finally it analyzed development trend of SCR technology based on research that we have today.

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“…Ammonium carbamate is the ammonium salt of the instable carbamic acid, and it can be transformed to urea by a condensation of the salt [86]. Another compound which can be decomposed to yield NH 3 without a catalyst is ammonium carbonate [87]. However, ammonium carbonate stores less NH 3 per mass and volume, because it contains an additional molecule of water with respect to ammonium carbamate.…”

Section: 21)mentioning

confidence: 99%

“…The decomposition of ammonium carbonate is considered to proceed via the stable ammonium bicarbonate intermediate [87].…”

Section: 21)mentioning

confidence: 99%

Ammonia Storage and Release in SCR Systems for Mobile Applications

Peitz

Bernhard

Kröcher

2014

Urea-SCR Technology for deNOx After Treatment of Diesel Exhausts

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The SCR reaction requires ammonia for the reduction of nitrogen oxides. While compressed or liquefied ammonia is used for the supply of ammonia in stationary applications, the odorous ammonia gas had to be replaced in mobile SCR applications by an ammonia precursor compound for the safe storage and reliable release of ammonia in the right quantities and right dynamics. Thus, significant innovation was needed before mobile SCR systems could be realized, even though commercial operation of ammonia SCR systems in coal power plants ([250 MW) started already around 1980 [1]. After the invention of HC-SCR for mobile NO x sources, to avoid handling NH 3 [2], and the discovery of cyanuric acid as a safe NH 3 storage compound, [3] urea was proposed as a storage material for NH 3 in 1988 [4]. By then, urea was already known to work as an NH 3 precursor for SCR in stationary applications for 3 years [5]. First results on mobile urea-based SCR were publically presented in 1990, already showing NO x conversions above 90 % from 250°C at gas hourly space velocities (GHSV) of 12,900 h -1 [6]. The first patented mobile applications of urea solutions for SCR were registered in 1990 [7].Due to the large-scale production of urea as a bulk commodity, it is readily available in large quantities. Since the involved reactants CO 2 and NH 3 needed for urea synthesis are bulk chemicals that are produced directly from air and natural gas, using the well-known industrial Haber-Bosch process, urea can be produced at a low price [8]. Also, urea is nontoxic, noncorrosive and can easily be handled as aqueous solutions, such as a 32.5 wt % solution with the trade name AdBlue

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A Review of Solid Materials as Alternative Ammonia Sources for Lean NOx Reduction with SCR

Cited by 56 publications

References 9 publications

Novel Applications of Non Hofmeister Ion Specificity in Bubble Interactions

Novel Applications of Non Hofmeister Ion Specificity in Bubble Interactions

Research status and development trend of Urea-SCR technology

Ammonia Storage and Release in SCR Systems for Mobile Applications

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