SCR versus EGR: What's the right choice for the rail industry?

Today, there are two core technologies to reduce emissions within the rail industry: Selective Catalytic Reduction (SCR) and Exhaust Gas Recirculation (EGR). But how do you know which is the right technology for your customers?

A quick internet search for “SCR vs. EGR” will return more than two million results from various sources, but what does it all mean? For decades, people have been debating the merits of each technology, arguing over which is better. We’d argue, however, that the question you should be asking is this: Which technology is right for your customers?

In this article, we’ll provide a clear and practical explanation for SCR and EGR technology in the rail industry.

First, a little background on the SCR vs. EGR technology debate.

EGR or SCR for the rail industry
A mix of technologies - from electronics and controls to aftertreatment sytems - are used in the race towards near-zero NOx engine emissions. 

Emission regulations for engines used in heavy-duty applications - from on-road vehicles to locomotives - started in the 1990s and became more stringent in the 2000s. Locomotive manufacturers were able to meet these emission regulations without the use of exhaust gas aftertreatment technologies in most applications. On the other hand, heavy-duty on-road engine manufacturers had to meet more stringent regulations compared to railway locomotives. 

In the 2010s, as emission regulations got more stringent, several heavy-duty on-road engine manufacturers needed to use a combination of SCR and EGR technologies to achieve the required emission levels. For the rail industry, where most applications require the use of larger engines, several engine manufacturers had to choose between SCR or EGR to meet the new emission regulations. This was the beginning of the debate between SCR and EGR technologies. 

A Better Question: What is the right emission reduction technology for your customers? 

From rail operators to locomotive manufacturers, rail industry players have needs unique to their business models and markets served. Instead of making the technology choice the starting point, we have outlined three use cases and the right aftertreatment technology.   

When running hours and fuel consumption makes the engine efficiency an important parameter

Challenge: As regulations require pollutant emissions deceased, engine manufacturers could adjust engine parameters to partially lower the emission of pollutants.

Combustion temperature is one of these parameters, however, a lower combustion temperature reduces NOx emission yet increases fuel consumption. For rail operators focusing on improving fleet utilization, increased fuel consumption could negatively impact their financials and worsen their environmental impact. 

Opportunity: Rail operators can optimize engine combustion for higher fuel efficiency and choose to reduce NOx separately through SCR, since SCR is a solution external to the engine. Given the high proportion of fuel costs in rail operators’ overall running costs, rail operators would likely offset the additional cost of diesel exhaust fluid (DEF) over time through the fuel consumption savings.

When reliability matters, and you want to build upon an already reliable engine

Challenge: Engine manufacturers have the option to introduce varying levels of engine design changes to meet the more stringent emission regulations. For locomotive manufacturers, any extensive change in engine design raises the question of engine reliability. This concern is further amplified for engines, such as the Cummins QSK50 and QSK60, which have proven their reliability over many applications and millions of hours of usage.

Opportunity: Locomotive manufacturers could lower the risk of adversely impacting engine reliability by choosing engines that didn’t go through significant architectural design changes and new part introductions from an engineering perspective. SCR technology helps the engine meet emission regulations with limited architectural design changes in an engine’s combustion chamber.   

When a high degree of commonality helps you create a financial edge through operational savings

Challenge: As emission regulations vary across regions, locomotive manufacturers and rail operators face a dual challenge: offering products that are fit for local needs, while increasing their financial performance. 

Opportunity: Use of SCR technology would likely allow locomotive manufacturers to have higher commonality across variations within a given engine platform. This offers financial and operational benefits. For instance, rail operators managing a fleet with higher engine commonality will benefit from common service methodologies while managing fewer parts. 

“We expect the locomotive manufacturers and rail operators using engines with SCR technology today to be better positioned in the near future when the emission regulations get more stringent. Today’s SCR technology is well suited to meet future emission regulations with less interventions, positioning users of SCR technology a step ahead of users with other emissions technologies,” says Miranda Cross, Global Rail Account Manager of Cummins Power Systems.

Bottom line, it is important to evaluate your customers’ key needs and use cases before making the technology decisions. For customers with the above three use cases, SCR offers a combination of financial and environmental benefits, including greenhouse gas reduction, while also helping locomotive manufacturers and rail operators meet unique local needs.   

To learn more about trends and technologies in rail industry follow Cummins  on Facebook and LinkedIn. To learn more about rail power solutions Cummins offers, visit our webpage. 

您认为您的朋友和同事会喜欢此内容吗?在 LinkedIn 和 Facebook 上分享。

Aytek Yuksel-康明斯公司

Aytek Yuksel

Aytek Yuksel 是康明斯公司的内容营销领导者,专注于电力系统市场。Aytek 于2008加入了该公司。从那时起,他曾担任过多个营销角色,现在为您带来从工业到住宅市场等主要市场的经验教训。Aytek 住在明尼苏达州明尼阿波利斯,与他的妻子和两个孩子一起生活。

本月最佳机器: Oxbo 9240 台咖啡收割机

Oxbo 9240 咖啡收割机

Worldwide, more than 2.25 billion cups of coffee are consumed daily. On average it takes around 70 beans to brew each cup. Each bean starts its life as a coffee cherry that must go through a process which includes harvesting, processing, drying, milling, tasting, exporting, roasting, and grinding to become what you would recognize as coffee.   

从手工采摘到机械措施,有多种方法来收获含有咖啡豆的樱桃。近两年来,Oxbo 一直是生产高品质的咖啡收割机的领导者,可机械地摘下樱桃。下一代这些收割机是 Oxbo 9240。

Oxbo 9240 咖啡收割机

Oxbo 9240 的设计旨在在崎岖的地形上收割,具有广泛的车轮底座和3轮设计,可提高机动性。该机器是为南美市场制造的,采用低安装的康明斯 QSF2.8 3 级发动机,额定功率为72马力(hp)。发动机位置可帮助收割机保持较低的重心,从而实现更高的稳定性。





Cummins is a global power leader that designs, manufactures, sells and services diesel and alternative fuel engines from 2.8 to 95 liters, diesel and alternative-fueled electrical generator sets from 2.5 to 3,500 kW, as well as related components and technology. Cummins serves its customers through its network of 600 company-owned and independent distributor facilities and more than 7,200 dealer locations in over 190 countries and territories.



一个零售中心、一家运输公司、一艘游艇改装店和一家发动机制造商走进一家酒吧.....。哦,等等这意味着他们开始在长岛的 COVID-19 上使用一艘同类的可持续混合动力船舶在当地采购产品,在大流行期间为商品提供无害环境的准入。


鲍勃. 安德鲁·库恩克尔曾在康涅狄格州的诺沃克居住了27年。一个有着独特背景的男人喜欢在水上消磨时间,而且还在厨房里。这两种激情使他与一家致力于在东北海岸销售优质食品和海上公路计划的食品市场结婚。

港口收获混合动力首先,这是什么混合动力船舶?安德鲁·库恩克尔是替代船用技术的总裁,专门从事常规推进历史或船舶设计以外的项目。在与 BAE 系统(一家先进技术公司)的联系下,这两个组织认为将 BAE 的电动车总线系统转换为海事项目。在与最初的发动机制造商合作后,安德鲁·库恩克尔和 BAE 发现康明斯公司的全集成船用系统成为他们百万美元的最后一项理念。使用两台 QSB6.7 混合动力发动机和一个显示套件来监控发动机、混合部件和储能系统,柴油电动双体船诞生了。


从可持续发展的角度来看,效益是显而易见的。在大约一个小时内,从康涅狄格州的诺沃克到亨廷顿,从6-12 小时到纽约的卡车运输车都能完成港口丰收的行程。但公路上的排放并非港口收获中唯一能挽救的东西;他们还在提高当地农民的效率。家庭农场不需要倾倒牛奶或丢弃他们的产品,因为他们无法成功上市。港口的收成为他们的食物提供了一条可靠而有利可图的餐桌路线。

在 COVID-19 大流行期间,以诺瓦克为基础的组织蓬勃发展。虽然由于餐馆和零售业的需求减少,这艘船每周仅运行一到两天,但它们肯定不会耗尽基本物品。

港口收获1st 地点

安德鲁·库恩克尔表示: "大型肉类加工厂在关闭方面存在问题.""我们直接前往农场和定制屠宰场,因此我们没有任何供应肉类、鱼类和其他产品的问题."他接着说,当地的供应商可以更好地应对当地的紧急情况,称这加剧了 "购买当地居民" 和 "支持当地" 的真正意义。


安德鲁·库恩克尔总结道: "我认为我们与改变世界的距离相当接近,但其意图却是一种不经意的语气,但却是最认真的."






介绍我们的 "未来" 系列文章的 "现场",我们将着眼于将塑造建筑业未来的趋势。











在您的社交平台上与 #Cummins 进行对话,或访问 ,了解有关我们当前和未来产品解决方案的更多信息。我们还让世界各地的康明斯专家高兴地回答您的问题。通过访问 或致电 1-800-康明斯,查找离您最近的康明斯专业人士。



Cummins is a global power leader that designs, manufactures, sells and services diesel and alternative fuel engines from 2.8 to 95 liters, diesel and alternative-fueled electrical generator sets from 2.5 to 3,500 kW, as well as related components and technology. Cummins serves its customers through its network of 600 company-owned and independent distributor facilities and more than 7,200 dealer locations in over 190 countries and territories.





"在康明斯,我们的日常生活围绕安全而旋转," 在康明斯海事公司工作的珍妮弗. McQuilken 表示,同时也是美国海岸警卫队的授权船长。"在将产品安装到应用中时,从佩戴适当的保护设备到采取适当的预防措施,确保我们的团队成员和客户的安全是最重要的。这就是为什么我们在康明斯海事公司的所有人都想在您第一次进入水中之前提醒您几件轻松的事情. "

如果没有进一步的 ado,下面是五条划船安全提示,以便在您为航行做好准备时记住。


据美国海岸警卫队称,每台 boater 都有佩戴救生衣的建议。



确保您的船上有适当的安全设备。有很多项目需要检查的任何船舶,其中一些到期。有效的注册、运行指示灯、耀斑和批准的灭火器是在水中进行安全旅行所需的一些因素之一。不要忘记防晒霜、水和元素的适当衣物。不确定您是否拥有所需的内容?在您击中水之前,请与您当地的美国海岸警卫队辅助人员或美国动力中队安排一次免费的 船舶安全检查


向您信任的人通报您的浮动计划,其中包括有关行程、船只、人员、拖车、通信设备和紧急联系人的详细信息。如果您不按预期返回或签入,浮动计划将确保某人拥有所需的信息,以帮助他们。在 中查找更多。




规则和法律可根据州 、地区或国家的不同而有所不同。违规行为可能导致售票、罚款或入狱时间。最低的操作员年龄、拖车限制和划船执照和保险各不相同。在碰到水之前,确保在您当地的指导方针中办理登机手续。

McQuilken 上尉表示: "在水中使用是一种有趣的方式,可以与您的朋友和家人建立联系."


无论您是经验丰富的 boater,还是只是脚湿,都有可用的资源来帮助您、家人或朋友了解有关在水中安全的更多信息。请考虑 乘坐安全的划船课程 ,无论是面对面还是在线。