Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel Engines

Ammonia, as a hydrogen carrier and an ideal zero-carbon fuel, can be liquefied and stored under ambient temperature and pressure. Its application in internal combustion engines holds significant potential for promoting low-carbon emissions. However, due to its unique physicochemical properties, ammo...

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Main Authors: Zhongcheng Wang, Ruhong Li, Jie Zhu, Zhenqiang Fu
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Energies
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Online Access:https://www.mdpi.com/1996-1073/18/3/565
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author Zhongcheng Wang
Ruhong Li
Jie Zhu
Zhenqiang Fu
author_facet Zhongcheng Wang
Ruhong Li
Jie Zhu
Zhenqiang Fu
author_sort Zhongcheng Wang
collection DOAJ
description Ammonia, as a hydrogen carrier and an ideal zero-carbon fuel, can be liquefied and stored under ambient temperature and pressure. Its application in internal combustion engines holds significant potential for promoting low-carbon emissions. However, due to its unique physicochemical properties, ammonia faces challenges in achieving ignition and combustion when used as a single fuel. Additionally, the presence of nitrogen atoms in ammonia results in increased NOx emissions in the exhaust. High-temperature selective non-catalytic reduction (SNCR) is an effective method for controlling flue gas emissions in engineering applications. By injecting ammonia as a NOx-reducing agent into exhaust gases at specific temperatures, NOx can be reduced to N<sub>2</sub>, thereby directly lowering NOx concentrations within the cylinder. Based on this principle, a numerical simulation study was conducted to investigate two high-pressure injection strategies for sequential diesel/ammonia dual-fuel injection. By varying fuel spray orientations and injection durations, and adjusting the energy ratio between diesel and ammonia under different operating conditions, the combustion and emission characteristics of the engine were numerically analyzed. The results indicate that using in-cylinder high-pressure direct injection can maintain a constant total energy output while significantly reducing NOx emissions under high ammonia substitution ratios. This reduction is primarily attributed to the role of ammonia in forming NH<sub>2</sub>, NH, and N radicals, which effectively reduce the dominant NO species in NOx. As the ammonia substitution ratio increases, CO<sub>2</sub> emissions are further reduced due to the absence of carbon atoms in ammonia. By adjusting the timing and duration of diesel and ammonia injection, tailpipe emissions can be effectively controlled, providing valuable insights into the development of diesel substitution fuels and exhaust emission control strategies.
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spelling doaj-art-c76c7a799ed24c6db574de28cad293cb2025-08-20T02:48:09ZengMDPI AGEnergies1996-10732025-01-0118356510.3390/en18030565Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel EnginesZhongcheng Wang0Ruhong Li1Jie Zhu2Zhenqiang Fu3Merchat Marine College, Shanghai Maritime University, Shanghai 201306, ChinaMerchat Marine College, Shanghai Maritime University, Shanghai 201306, ChinaMerchat Marine College, Shanghai Maritime University, Shanghai 201306, ChinaMerchat Marine College, Shanghai Maritime University, Shanghai 201306, ChinaAmmonia, as a hydrogen carrier and an ideal zero-carbon fuel, can be liquefied and stored under ambient temperature and pressure. Its application in internal combustion engines holds significant potential for promoting low-carbon emissions. However, due to its unique physicochemical properties, ammonia faces challenges in achieving ignition and combustion when used as a single fuel. Additionally, the presence of nitrogen atoms in ammonia results in increased NOx emissions in the exhaust. High-temperature selective non-catalytic reduction (SNCR) is an effective method for controlling flue gas emissions in engineering applications. By injecting ammonia as a NOx-reducing agent into exhaust gases at specific temperatures, NOx can be reduced to N<sub>2</sub>, thereby directly lowering NOx concentrations within the cylinder. Based on this principle, a numerical simulation study was conducted to investigate two high-pressure injection strategies for sequential diesel/ammonia dual-fuel injection. By varying fuel spray orientations and injection durations, and adjusting the energy ratio between diesel and ammonia under different operating conditions, the combustion and emission characteristics of the engine were numerically analyzed. The results indicate that using in-cylinder high-pressure direct injection can maintain a constant total energy output while significantly reducing NOx emissions under high ammonia substitution ratios. This reduction is primarily attributed to the role of ammonia in forming NH<sub>2</sub>, NH, and N radicals, which effectively reduce the dominant NO species in NOx. As the ammonia substitution ratio increases, CO<sub>2</sub> emissions are further reduced due to the absence of carbon atoms in ammonia. By adjusting the timing and duration of diesel and ammonia injection, tailpipe emissions can be effectively controlled, providing valuable insights into the development of diesel substitution fuels and exhaust emission control strategies.https://www.mdpi.com/1996-1073/18/3/565zero-carbon fuelhigh temperature selective non-catalytic reductiondiesel ignitionengine emission characteristics
spellingShingle Zhongcheng Wang
Ruhong Li
Jie Zhu
Zhenqiang Fu
Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel Engines
Energies
zero-carbon fuel
high temperature selective non-catalytic reduction
diesel ignition
engine emission characteristics
title Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel Engines
title_full Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel Engines
title_fullStr Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel Engines
title_full_unstemmed Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel Engines
title_short Effect of Selective Non-Catalytic Reduction Reaction on the Combustion and Emission Performance of In-Cylinder Direct Injection Diesel/Ammonia Dual Fuel Engines
title_sort effect of selective non catalytic reduction reaction on the combustion and emission performance of in cylinder direct injection diesel ammonia dual fuel engines
topic zero-carbon fuel
high temperature selective non-catalytic reduction
diesel ignition
engine emission characteristics
url https://www.mdpi.com/1996-1073/18/3/565
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