Standing Strong During Turbulent Times

Röchling continues to support diesel technology – and is optimizing it with increasingly innovative SCR tank systems

Swimming against the tide: diesel vehicles have fallen into disrepute due to their pollutant emissions. In light of this, it takes strong convictions, resolve, and courage to not blindly follow the same path as everyone else. Röchling Automotive is objectively evaluating the advantages and disadvantages of diesel and is striving to make it even better.

The fundamentally bad reputation of diesel-powered vehicles at the moment is hardly surprising given the fraud scandals, driving restrictions, and unexplained financial compensation for drivers. One thing is definite: the current emission levels, mainly from nitrogen oxide, are primarily due to the old stock of diesel vehicles from the Euro 5 standard and earlier standards. Modern diesels that have been on the roads since 2016/2017 are superior to any gasoline engine when it comes to exhaust emissions. If you look at the overall impact on the environment, they even beat electric cars that run on batteries.

Diesel vehicles can therefore certainly be trusted to keep air clean in inner cities. This is also the opinion of Prof. Thomas Koch from the Institute of Piston Engines at the Karlsruhe Institute of Technology, Germany: “If only state-of-the-art diesel vehicles were on the roads, the contribution of diesel to nitrogen oxide emissions would only be three micrograms per cubic meter,” says Koch. As a comparison, the current EU limit value is 40 micrograms.

“We see diesel as indispensable in the longer term too, mainly due to its low consumption and comparably low carbon dioxide emissions.”

Walter Kral, Director Product Area Propulsion

Röchling as a Pioneer of SCR Technology
“We see diesel as indispensable in the longer term too, mainly due to its low consumption and comparably low carbon dioxide emissions,” emphasizes Walter Kral, Director Product Area Propulsion at Röchling Automotive in Laives, Italy. The company is one of the pioneers of SCR technology (selective catalytic reduction), which transforms the diesel engine into an efficient and clean drive unit for cars. Röchling Automotive has been developing SCR tanks since 2011. Back then, the only tanks available on the market were blow-molded. “Our injection molding technique means that we can achieve significantly thinner wall thicknesses and other components and functions can be integrated into the tank,” explains Christoph Ganthaler, Head of Product Line Fluid Solutions. At the time, Röchling Automotive’s extensive experience in manufacturing compensation tanks helped them to develop their SCR tank. “We knew that we could do it right from the outset,” says Kral. “It” meant developing and producing 25 to 30 liter tanks, and then integrating a wide range of other components into them. And those who want to establish themselves as pioneers need all the courage they can muster.

In 2013, the first SCR tank from Röchling Automotive went into series production at a car manufacturer. A number of other manufacturers followed suit. They were particularly impressed by the fact that Röchling Automotive constructed its own welding and manufacturing facilities and produced the devices in-house. “That’s a real advantage. The customer sees that we have experience of the process from A to Z,” explains Kral assuredly. The in-house plant construction coupled with a vast openness to new ideas also mean that Röchling Automotive can work particularly fast, for example in the development of a prototype. In addition to this, they maintain open, transparent, and honest communication. “Our customers generally want a partner who is willing to weigh in – and who doesn’t make promises they can’t keep,” says tank specialist Kral with confidence.

“Our customers generally want a partner who is willing to weigh in – and who doesn’t make promises they can’t keep.”

Walter Kral, Director Product Area Propulsion

System Expertise in Tank Design
Röchling Automotive has now developed extensive system expertise in SCR tanks and is working tirelessly on further optimizations. For example, the vent valve and a bubble section have been integrated in the filling head to save valuable installation space in “odorless” filling systems. Parts of the vent line are also integrated into the tank shell. The tank design has been optimized so that frozen AdBlue can be better distributed in the tank in very low minus temperatures and to prevent tank deformations. The aqueous urea solution AdBlue is indispensable in SCR technology. A full-surface heater is used to defrost frozen AdBlue. It is activated via an electronic control unit and heats the entire tank bottom to ensure that enough liquid AdBlue is available. Röchling Automotive prevents the AdBlue from making distracting sloshing noises by using injection molding during the manufacture of the SCR tanks to create anti-slosh baffles.

The engineers from Röchling Automotive are currently applying their expertise and experience in tank design to a different field. It isn’t just diesel vehicles that have to contend with increasingly stringent emissions limits, as gasoline engines also have to comply with every tightened standard. “The demand for clean, efficient vehicles with gasoline engines will increase in the future,” predicts Kral. Röchling wants to be at the forefront of this and is therefore intensively looking into the field of water injection – an interesting way to reduce pollutants and carbon dioxide emissions.

The Idea

Conventional gasoline engines use gasoline to cool the engine during high-load operation – and the environment pays the price. Water injection replaces the “additional” gasoline with water. “This enables significant fuel savings while reducing CO2 emissions at the same time,” explains Kral. Röchling Automotive is currently working on an end-to-end water injection system. At the heart of the solution is the extremely important water tank. The shape and capacity of the tank are individually adapted to the manufacturer’s requirements. This makes optimal use of the available installation space, ensuring that the water has to be refilled as infrequently as possible. The developers are also tackling a well-known winter problem with a newly developed water tank heating system with a high defrosting performance. Prevention of “biofilm” is another typical requirement for water tanks. Thanks to an integrated bio-decontamination function developed by Röchling, this unwanted byproduct can be prevented efficiently, in an environmentally friendly manner, and without any additional energy expenditure. The market launch for the water injection system is planned for 2020/2021.