scholarly journals The Use of Photocatalysis and Titanium Dioxide on Diesel Exhaust Fumes for NOx Reduction

2018 ◽  
Vol 10 (11) ◽  
pp. 4031
Author(s):  
Beatrice A. Atzl ◽  
Maximilian Pupp ◽  
Marco Rupprich
Keyword(s):  
Titanium Dioxide ◽  
Diesel Engine ◽  
Relative Humidity ◽  
Nitrogen Oxides ◽  
Diesel Exhaust ◽  
Photocatalytic Oxidation ◽  
Catalytic Reduction ◽  
Nox Reduction ◽  
Conversion Rates ◽  
Exhaust Fumes

Nitrogen oxides are emitted in large quantities by vehicles, and solutions to the problem are sought after. Efforts towards abatement include Selective Catalytic Reduction, catalytic converters, and redesigning engines to make them more efficient. This article focuses on the photocatalytic oxidation, which involves the use of titanium dioxide and ultraviolet radiation to oxidise nitrogen oxides to nitrates. To test this, the interior of a serpentine reactor was coated with titanium dioxide and irradiated with various intensities of ultraviolet light, and the photocatalytic abatement was monitored for the exhaust fumes from a standalone 4-stroke test diesel engine. The conversion rates were calculated using the entering concentration and the concentration after a certain time increment. The rates varied between 13.7% and 37.3% and depended strongly on the relative humidity, as a higher relative humidity directly correlated with a better conversion. The irradiance was also varied, and a decline in the conversion rate occurred when the irradiance was increased.

scholarly journals Investigation of Urea Uniformity with Different Types of Urea Injectors in an SCR System

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1269
Author(s):  
Muhammad Khristamto Aditya Wardana ◽  
Kwangchul Oh ◽  
Ocktaeck Lim
Keyword(s):  
Diesel Engine ◽  
Catalytic Reduction ◽  
Nox Reduction ◽  
Heavy Duty ◽  
Ammonia Gas ◽  
Experimental Parameters ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Scr System

Heavy-duty diesel engines in highway use account for more than 40% of total particulate and nitrogen oxide (NOx) emissions around the world. Selective catalytic reduction (SCR) is a method with effective results to reduce this problem. This research deals with problems in the urea evaporation process and ammonia gas distribution in an SCR system. The studied system used two types of urea injectors to elucidate the quality of ammonia uniformity in the SCR system, and a 12,000-cc heavy-duty diesel engine was used for experimentation to reduce NOx in the system. The uniformity of the generated quantities of ammonia was sampled at the catalyst inlet using a gas sensor. The ammonia samples from the two types of urea injectors were compared in experimental and simulation results, where the simulation conditions were based on experimental parameters and were performed using the commercial CFD (computational fluid dynamics) code of STAR-CCM+. This study produces temperatures of 371 to 374 °C to assist the vaporization phenomena of two injectors, the gas pattern informs the distributions of ammonia in the system, and the high ammonia quantity from the I-type urea injector and high quality of ammonia uniformity from the L-type urea injector can produce different results for NOx reduction efficiency quality after the catalyst process. The investigations showed the performance of two types of injectors and catalysts in the SCR system in a heavy-duty diesel engine.

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.

scholarly journals A comparative analysis of platinum and oxide-based catalytic converters in terms of NOx reduction with ammonia

2012 ◽  
Vol 150 (3) ◽  
pp. 55-62
Author(s):  
Wojciech KAMELA ◽  
Stanisław KRUCZYŃSKI
Keyword(s):  
Comparative Analysis ◽  
Diesel Engine ◽  
Catalytic Properties ◽  
Nox Reduction ◽  
Active Surface ◽  
Catalytic Converters ◽  
Nitric Oxides ◽  
Exhaust Gases ◽  
Conversion Rates ◽  
Physical And Chemical

The paper presents a comparison of the catalytic properties of two types of catalytic converters (containing platinum and oxide active coatings) in the aspect of a reduction of nitric oxides with ammonia. The tests were performed for three concentrations of ammonia in the exhaust gases of a diesel engine. The work contains images of the topography of the active surface of the catalytic converters and the results of its physical and chemical analysis. The changes of the conversion rates of the nitric oxides have also been presented in the converter temperature range from 150 to 550 °C along with the results of calculations of the shares of NO2 in NOx for all analyzed concentrations of ammonia in the exhaust gases.

Reduction of NOx Emission From Diesel Engines Using Cu-ZSM-5 Catalyst

2001 ◽  
Author(s):  
Yoshiyuki Aoyagi ◽  
Masahiro Kaneda ◽  
Keisuke Numahata ◽  
Koji Korematsu ◽  
Junya Tanaka
Keyword(s):  
Diesel Engine ◽  
Nitrogen Oxides ◽  
Conversion Rate ◽  
Nox Reduction ◽  
Diesel Oil ◽  
Exhaust Pipe ◽  
Exhaust Gas ◽  
Nox Conversion ◽  
Catalyst Temperature ◽  
Reduction Of Nox

Abstract In this paper effect of on reduction a Cu-ZSM-5 catalyst of nitrogen oxides is investigated in a diesel engine. This research focuses to solve a problem that there is not enough THC to reduce nitrogen oxides in exhaust gas from a diesel engine. When diesel oil is directly supplied into the exhaust gas, the THC concentration sharply rises and the NOx conversion rate increases. The maximum NOx conversion rate reaches to 63% when the flow rate of diesel oil is 30 ml/min at a catalyst temperature 450 °C. The NOx reduction with less sacrifice of the specific fuel consumption is possible when the fuel is supplied into the exhaust pipe.

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