Testing times: The role of Linde’s gases in reducing emissions

With the legislative belt tightening around all sources of air pollutant emissions, Linde’s specialty gases are playing an increasingly important role in ensuring compliance.

Strict regulations for emissions in the automotive sector and beyond spell opportunity for Linde

Air pollution; we may not always see it, but we all too often see its effects. The World Health Organisation (WHO) cites polluted air as the single largest environmental health risk in Europe and a major cause of premature death and disease. The pollutants that enter ambient air via tailpipes, chimney stacks and countless other sources also disrupt delicate terrestrial and aquatic ecosystems, contribute to climate change and literally corrode cultural history.

Thankfully, in recent years, international organisations, national and local governments and NGOs the world over have taken measures to reduce air pollutant emissions. At a European level, several pieces of legislation now set strict emissions standards across various sectors. As a result, the scope for testing emissions is ever-widening. For a company that provides the specialty gases required for testing, that spells opportunity. 

The legislative landscape

Compliance with this legislation relies on accurate measurement during emissions tests. It goes without saying that to measure anything accurately, there must be a reference standard: and that’s what Linde’s HiQ® brand provides. Known as calibration gases, these specialty gases are the certified reference standards used to calibrate the emissions testing instrumentation. 

“The legislative landscape for emissions testing is evolving and changing,” explains Roberto Parola, Global Product Manager for Linde’s HiQ® Specialty Gases & Equipment. “Whether that’s a volume increase due to a wider testing scope or new product requirements due to changing specifications, each change represents a business opportunity for us.” 

Much of that business has come directly from the transport sector. Since fuel combustion is the main source of many primary pollutants such as Nitrogen Oxides (NOx), Sulphur Oxides (SOx), Hydrocarbons (HC), Particulate Matter (PM) and Carbon Monoxide (CO), this is where the finger of blame has been pointing for some time. 

Diesel car engines for example, while they emit less carbon dioxide than their petrol counterparts, release more NOx and PM into the air that we breathe. To combat this, the European Union has set strict emission standards for road transport vehicles. Euro 6, for example, introduced Real Driving Emission (RDE) testing. Effective as of 2019, this regulation may be the latest iteration, but is unlikely to be the last.

Calibration is key

Building on its expertise in automotive emissions testing, Linde has developed a new, dedicated range of HiQ® Euro 6 specialty gases and equipment to meet testing and analysis needs under this new legislation. That includes calibration and instrumentation gases.

“When testing for levels of pollutants from an engine, you need two types of calibration mixtures: zero gas and a span gas,” explains Parola. Zero gases (usually purified nitrogen or synthetic air) contain zero parts of the pollutants being measured and span gases contain a specified amount of the pollutant being measured (e.g. 80ppm CO in purified nitrogen). By using the instrument with these gases, the measurement range can be set and reliable results can be read.

Such accuracy is fundamental to a system where test results determine legislative compliance. Euro 6 requires the automotive industry to adapt to ever more rigorous and stringent quality control systems, which in turn calls for the highest quality gases. While 100% purity can never be achieved due to manufacturing processes, Linde prides itself on the very high levels of purity it can offer customers. The extensive range of Linde HiQ® gases and mixtures come with Certificates of Analysis, directly traceable to Linde’s industry-leading internal standards.

The scope widens

The buck doesn’t stop at the automotive sector however. Legislative rigour is now affecting areas that have long been of only minor interest: most recently, non-road mobile machinery (NRMM) was cast under the spotlight. From hedge clippers to bulldozers to generators, NRMM is responsible for around 15% of total NOx emissions and 5% of total PM emissions in the EU: something that NRMM Stage V legislation (2016) aims to reduce. Again, Linde can support customers by offering the calibration and instrumentation gases they need in the purity and accuracy levels mandated by this particular legislation.







Linde HiQ gases and the Euro 6 regulation






How Linde caters for emissions testing of non-road mobile machinery.

Specific regulations cover static emissions (e.g. from industrial processes and power generation) and even marine-based sources (the Sulphur Directive). Each piece of legislation doesn’t only bring opportunity for Linde but also challenges. Linde too must adapt and come up with innovative, flexible solutions that meet both the latest regulatory requirements but also cater for a widening range of testing scenarios.

Getting ahead through innovation

“If you measure your pollutants in a lab setting, it’s quite straightforward,” says Parola, “But once you leave and test in the field, things get much more complex.” Indeed, in-service monitoring requires Portable Emissions Measurement Systems (PEMS). Euro 6 for example calls for Real Driving Emissions (RDE) tests: roller tracks in a lab are no longer enough, the car must be on the roads. Another example use case might be calibrating monitoring emissions systems at the top of a chimney stack. Here, carrying a 40 litre cylinder of calibration gases plus the required specialty equipment like pressure regulators is a tall order for any engineer.





“This was the reason we came up with the ECOCYL,” explains Parola, “It’s a signature product in our innovative range of portable solutions – and it’s eco-friendly.” The 1 litre or 2 litre ECOCYL cylinders are equipped with an integral valve and flow regulation device, creating an all-in-one handheld solution. In keeping with the idea of environmental awareness, the ECOCYL is made from sustainable packaging and is refillable; thus, negating the need for more traditional disposable cylinders. 

Besides the specialty gases and equipment, Linde’s advisers also possess the specialty expertise to guide customers from whichever sector across this legislative landscape. Linde hopes that the quality it ensures in its gases goes some way to reaching a better air quality for us all.

An engineer equipped with Linde’s portable ECOCYL solution.