Reduction of Nitric Oxide in Diesel Exhaust With the Addition of Methylamine

1999 ◽  
Vol 121 (3) ◽  
pp. 563-568 ◽  
Author(s):  
Y. Nakanishi ◽  
Y. Yoshihara ◽  
K. Nishiwaki ◽  
T. Tanaka
Keyword(s):  
Nitric Oxide ◽  
Gas Phase ◽  
Diesel Exhaust ◽  
No Reduction ◽  
Nox Reduction ◽  
Molar Ratio ◽  
Exhaust Gas ◽  
Engine Exhaust ◽  
Temperature Range ◽  
Reactor Temperature

A Chemical gas-phase process capable to reduce the nitric oxide in diesel engine exhaust was studied. In this process, monomethylamine (CH3NH2) was added to the exhaust gas in a molar ration to NO varying between 1:1 and 4:1, Experiments were conducted in electrically heated quartz, reactors in a temperature range of 200°C to 600°C. Diesel exhaust gas and simulated exhaust gas were used in this experiment. The results showed thorough mixing of methylamine into the exhaust effectively breaks NO down into nitrogen and water, enabling more than 80 percent NO reduction in a reactor temperature range of 400°C to 540°C and at a molar ratio of 1. On the other hand, imperfect mixing between methylamine and exhaust gases results in excess ammonia and reduced NO decomposition. Consequently, it is suggested that the mixing is a very important factor in this technique. The results also show that the coexisting gases such as carbon monoxide, carbon dioxide, hydrocarbons, and water vapor in the diesel exhaust have no effect on NO reduction by methylamine. However, the presence of oxygen in excess of 10 percent in the exhaust is needed for an 80 percent NOx reduction. Furthermore, the mechanisms of the methylamine process were discussed.

Purification of Diesel Exhaust Gas Using Reducing Catalysers

1997 ◽  
Vol 2 (2) ◽  
Author(s):  
Katsuharu Kinoshita ◽  
Shigeo Watanabe, ◽  
Niichi Hayash ◽  
Yoshiyuki Uchida ◽  
David Dykes ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Exhaust ◽  
Nox Reduction ◽  
Exhaust Gas ◽  
Gas Purification ◽  
Photochemical Smog ◽  
Engine Exhaust ◽  
Suitable Temperature ◽  
Series Of Experiments ◽  
Outstanding Result

AbstractDiesel engine exhaust gas is known to be one cause of photochemical smog, which is so damaging to city environments. However, because of its high thermal efficiency and economic advantages, the diesel engine is not easily dispensable. The authors have previously conducted a series of experiments to assess the purifying effects of a diesel gas purification device employing an electric trap. It has been confirmed that an extraction rate of 60∼75 % for black smoke can be achieved using this apparatus. But the extraction effect for nitrogen oxides (NOx) is insufficient if the electro-trap device is used on its own. To improve its performance, experiments have now been undertaken using the same device in combination with various types of attached catalysers to oxidise and remove the nitrogen in the exhaust gas. Utilising a commercial 3-way catalyser, it proved difficult to maintain the gas at a suitable temperature, so that no outstanding result could be obtained. Nor was any significant result observ­ed from the use of an ozoniser. However, with a zeolyte catalyser, it was possible to achieve a NOx reduction of 20∼30 %. This latter experiment is reported in the present paper.

Reduction of Nitrogen Oxides in Engine Exhaust Gases by the Addition of Cyanuric Acid

1989 ◽  
Vol 111 (3) ◽  
pp. 387-393 ◽  
Author(s):  
J. A. Caton ◽  
D. L. Siebers
Keyword(s):  
Nitric Oxide ◽  
Equivalence Ratio ◽  
Flow Reactor ◽  
Cyanuric Acid ◽  
Exhaust Gas ◽  
Oxide Reduction ◽  
Temperature Range ◽  
Nitric Oxide Concentration ◽  
Nitric Oxide Reduction ◽  
Reactor Temperature

Nitric oxide concentrations in a portion of the exhaust of a diesel engine operated with equivalence ratios between 0.25 and 0.75 were reduced by up to 98 percent by the addition of cyanuric acid. The cyanuric acid was combined with the exhaust gas in an electrically heated quartz flow reactor. The effects of the key process parameters (temperature, exhaust gas composition and residence time, and the overall engine equivalence ratio) on NO reduction by cyanuric acid were investigated. Nitric oxide reduction was evident at flow reactor temperatures above 700 K. The maximum nitric oxide reduction varied from 80 percent for a reactor temperature of 1180 K and an engine equivalence ratio of 0.25 to 98 percent for a temperature of 1120 K and an equivalence ratio of 0.75. The temperature range over which 60 percent or greater nitric oxide reduction was obtained was 1100 to 1340 K. Increasing the exhaust gas carbon monoxide concentration lowered the required reactor temperature and increased the temperature range for significant nitric oxide reduction. Increasing the exhaust gas nitric oxide concentration lowered the ratio of cyanuric acid to nitric oxide required for maximum nitric oxide reduction.

scholarly journals Testing and Correlation of 8mm Pitch Honeycomb & Plate Type Module Performance in a 20 Litres SCR Test Facility

2020 ◽  
Vol 9 (3) ◽  
pp. 3540-3547
Keyword(s):  
Nox Reduction ◽  
Space Velocity ◽  
Test Facility ◽  
Molar Ratio ◽  
Maximum Efficiency ◽  
Exhaust Gas ◽  
Performance Parameters ◽  
Nox Conversion ◽  
Ammonia Slip ◽  
Plate Type

The main aim of this experiment is to reduce the concentration of NOx in the exhaust gas below 100ppm with the most effective technique named selective catalytic reduction (SCR) with ammonia over to evaluate the performance of honeycomb and plate type catalyst in NOx reduction by varying the performance parameters such as flue gas temperature, space velocity, NH3 /NO molar ratio, etc., and to find the optimum values of the above parameters under which we get the maximum efficiency of NOx conversion at which air is not polluted and we have the sustained and eco-friendly environment. The effect of various performance parameters on the SCR process is also evaluated and the optimum values of performance parameters are also found to get the maximum efficiency of NOx conversion. SCR performance is substantially under the effects of reactant (ammonia) concentration and operating temperature, so that the concentration of untreated ammonia emitted from reactor discharge (ammonia slip) increases significantly at NH3 /NO ratios of more than 1.14 and operating temperatures less than 360 ºC and 300 ºC, respectively, in the catalytic filter medium and honeycomb reactor. low level of ammonia slip can be achieved at the NH3 /NO ratio of 1 and temperature range of 300–350 ºC in both reactors.The temperature of SCR is varied between 300OC to 350OC ,with a fixed space velocity of exhaust gas and a fixed value of NH3/NO ratio of 1.

scholarly journals A low temperature investigation of the gas-phase N(2D) + NO reaction. Towards a viable source of N(2D) atoms for kinetic studies in astrochemistry

2018 ◽  
Vol 20 (25) ◽  
pp. 17442-17447 ◽  
Author(s):  
Dianailys Nuñez-Reyes ◽  
Kevin M. Hickson
Keyword(s):  
Nitric Oxide ◽  
Supersonic Flow ◽  
Low Temperature ◽  
Gas Phase ◽  
Flow Reactor ◽  
Kinetic Studies ◽  
Phase Reaction ◽  
Atomic Nitrogen ◽  
Gas Phase Reaction ◽  
Temperature Range

The gas-phase reaction of metastable atomic nitrogen N(2D) with nitric oxide has been investigated over the 296–50 K temperature range using a supersonic flow reactor.

scholarly journals Chemical Kinetics Computations of Fuel Decomposition to Aldehydes for NOx Reduction in Engine Exhaust Gas

2016 ◽  
Vol 7 (4) ◽  
pp. 244-248
Author(s):  
Shigeto Yahata ◽  
◽  
Hayato Okuda ◽  
Norihiko Yoshikawa ◽  
Nozomu Kanno ◽  
...  
Keyword(s):  
Chemical Kinetics ◽  
Nox Reduction ◽  
Exhaust Gas ◽  
Engine Exhaust

scholarly journals Nitric Oxide Reduction of Heavy-Duty Diesel Exhaust Gas by NH3-SCR Upstream of the Turbocharger (Pre-Turbo SCR)

2014 ◽  
Vol 86 (9) ◽  
pp. 1611-1612 ◽  
Author(s):  
T. Rammelt ◽  
C. Hauck ◽  
J. Böhm ◽  
O. Deutschmann ◽  
R. Gläser
Keyword(s):  
Nitric Oxide ◽  
Diesel Exhaust ◽  
Exhaust Gas ◽  
Oxide Reduction ◽  
Heavy Duty ◽  
Nh3 Scr ◽  
Nitric Oxide Reduction ◽  
Heavy Duty Diesel

scholarly journals Signal filtering method of the fast-varying diesel exhaust gas temperature

2018 ◽  
Vol 175 (4) ◽  
pp. 48-52
Author(s):  
Patrycja PUZDROWSKA
Keyword(s):  
Diesel Exhaust ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Engine Exhaust ◽  
Temperature Changes ◽  
Filtering Method ◽  
Significant Parameter ◽  
Mathematical Processing ◽  
Exhaust Gas Temperature ◽  
The Impact

The paper presents the problem of the impact of external distortions originating on laboratory test stands on the results of measurements of fast-varying diesel exhaust gas temperature. It has been stressed how significant the aspect of the test stand adaptation is during an experiment to ensure the smallest possible impact. This paper, however, focuses on the methods of mathematical processing of a signal recorded during experimental research of a real object. The most significant parameter requiring filtering is the fast-varying exhaust gas temperature in the engine exhaust channel. Methods of mathematical processing adequate to this type of distorted signal have been presented, particularly those that can be used in the Matlab environment and consisting in averaging of the obtained curves of temperature changes. The results of the application of these methods have also been presented on actual curves recorded during laboratory tests and their evaluation has been made.

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