Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engine

The oxides of nitrogen (NOx) emitted from diesel engines are perilous pollutants, contributing to environmental and health hazards. Selective Catalytic Reduction (SCR) using urea is a proven technology for reducing NOx emissions, while air preheating has been utilized to enhance NOx reduction effici...

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Main Authors: Mohammad Shahed H.K. Tushar, Musa Ibne Mannan, Afra Azmain
Format: Article
Language:English
Published: Elsevier 2025-02-01
Series:Heliyon
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Online Access:http://www.sciencedirect.com/science/article/pii/S2405844025007790
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author Mohammad Shahed H.K. Tushar
Musa Ibne Mannan
Afra Azmain
author_facet Mohammad Shahed H.K. Tushar
Musa Ibne Mannan
Afra Azmain
author_sort Mohammad Shahed H.K. Tushar
collection DOAJ
description The oxides of nitrogen (NOx) emitted from diesel engines are perilous pollutants, contributing to environmental and health hazards. Selective Catalytic Reduction (SCR) using urea is a proven technology for reducing NOx emissions, while air preheating has been utilized to enhance NOx reduction efficiency. From the studies, a sole focus on urea-SCR with air preheating remains noticeably unexplored. This study presents an integrated approach using urea-SCR and air preheating in a four-stroke, single-cylinder, water-cooled diesel engine for a comparative study in decreasing NOx emissions. The experimental setup involved a mechanical urea injection system, a platinum-rhodium catalyst, and an air-preheating mechanism utilizing exhaust gas heat. Tests were conducted at varying engine speeds and loads to evaluate the combined system's performance. Results indicate that the combined air preheating and urea-SCR system achieved a NOx reduction of up to 55 % under low engine load conditions, with a corresponding CO emission reduction of 19 % for preheated set-up. The system enhanced brake thermal efficiency (BTE) and reduced brake-specific fuel consumption (BSFC) compared to baseline configurations, with no significant backpressure observed. A significant noise level reduction (21–27 %) was also achieved, highlighting the dual benefits of emissions and noise control. The findings demonstrate that combining urea-SCR with air preheating is an effective strategy for reducing NOx emissions while maintaining or improving engine performance. This approach offers a promising pathway for enhancing diesel engine emission control systems. Further studies are recommended to explore the scalability of this method for larger engines and to assess long-term system stability.
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spelling doaj-art-722d6a27b8a7465fa70e1a8e725d70c52025-02-05T04:32:20ZengElsevierHeliyon2405-84402025-02-01113e42399Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engineMohammad Shahed H.K. Tushar0Musa Ibne Mannan1Afra Azmain2Corresponding author.; Department of Mechanical Engineering, Rajshahi University of Engineering & Technology, Rajshahi, BangladeshDepartment of Mechanical Engineering, Rajshahi University of Engineering & Technology, Rajshahi, BangladeshDepartment of Mechanical Engineering, Rajshahi University of Engineering & Technology, Rajshahi, BangladeshThe oxides of nitrogen (NOx) emitted from diesel engines are perilous pollutants, contributing to environmental and health hazards. Selective Catalytic Reduction (SCR) using urea is a proven technology for reducing NOx emissions, while air preheating has been utilized to enhance NOx reduction efficiency. From the studies, a sole focus on urea-SCR with air preheating remains noticeably unexplored. This study presents an integrated approach using urea-SCR and air preheating in a four-stroke, single-cylinder, water-cooled diesel engine for a comparative study in decreasing NOx emissions. The experimental setup involved a mechanical urea injection system, a platinum-rhodium catalyst, and an air-preheating mechanism utilizing exhaust gas heat. Tests were conducted at varying engine speeds and loads to evaluate the combined system's performance. Results indicate that the combined air preheating and urea-SCR system achieved a NOx reduction of up to 55 % under low engine load conditions, with a corresponding CO emission reduction of 19 % for preheated set-up. The system enhanced brake thermal efficiency (BTE) and reduced brake-specific fuel consumption (BSFC) compared to baseline configurations, with no significant backpressure observed. A significant noise level reduction (21–27 %) was also achieved, highlighting the dual benefits of emissions and noise control. The findings demonstrate that combining urea-SCR with air preheating is an effective strategy for reducing NOx emissions while maintaining or improving engine performance. This approach offers a promising pathway for enhancing diesel engine emission control systems. Further studies are recommended to explore the scalability of this method for larger engines and to assess long-term system stability.http://www.sciencedirect.com/science/article/pii/S2405844025007790Diesel engineNOx emissionAir preheatingSelective catalytic reduction (SCR)Urea-SCR
spellingShingle Mohammad Shahed H.K. Tushar
Musa Ibne Mannan
Afra Azmain
Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engine
Heliyon
Diesel engine
NOx emission
Air preheating
Selective catalytic reduction (SCR)
Urea-SCR
title Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engine
title_full Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engine
title_fullStr Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engine
title_full_unstemmed Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engine
title_short Exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce NOx in diesel engine
title_sort exhaust gas after treatment using air preheating and selective catalytic reduction by urea to reduce nox in diesel engine
topic Diesel engine
NOx emission
Air preheating
Selective catalytic reduction (SCR)
Urea-SCR
url http://www.sciencedirect.com/science/article/pii/S2405844025007790
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AT musaibnemannan exhaustgasaftertreatmentusingairpreheatingandselectivecatalyticreductionbyureatoreducenoxindieselengine
AT afraazmain exhaustgasaftertreatmentusingairpreheatingandselectivecatalyticreductionbyureatoreducenoxindieselengine