From fertiliser to fuel: Ammonia's growing role in green energy | Engineer Live

Ammonia, commonly known for its role in fertilisers, might not seem like a green energy solution at first glance. Yet ammonia holds the potential to become exactly that as it emerges as an effective hydrogen carrier.

Right now, transporting and storing pure hydrogen presents significant challenges. Its tiny atomic size allows it to easily escape through pipes and tanks, and at normal temperatures, hydrogen occupies a vast amount of space, making long-distance transportation impractical. To move hydrogen efficiently, it must either be compressed or liquefied, which requires cooling it to an ultra-low temperature of -253°C, just above absolute zero.

With ammonia, transportation and storage is less challenging. It can be stored and transported as a liquid at normal pressure and a more manageable temperature of -35°C. In addition, it is less flammable than hydrogen, having a higher ignition temperature and requiring more energy to ignite. This makes it ideal for transporting hydrogen around the world by ship or for long-term storage. Once at its destination, the ammonia is subjected to a heat-intensive cracking process to break it down into its original components of nitrogen and hydrogen. The mixture is purified, releasing the nitrogen back into the atmosphere without carbon dioxide and leaving the hydrogen ready for use.

Although ammonia has potential as a hydrogen carrier, it poses specific risks to workers and facilities due to its toxic and corrosive nature. However, with the right selection of high-quality materials and safety equipment, it can be managed.

To understand how this is best achieved, it is important to take a closer look at ammonia’s properties. If people are exposed to it, irritation and damage to the eyes, nose, throat and lungs can occur. At higher concentrations, ammonia can even be deadly. If it comes in contact with the skin, it can also cause chemical burns. And while ammonia is less flammable than hydrogen, it is still a safety concern: The chemical can be ignited at concentrations between 14 to 32.5 Vol.% and ignites spontaneously in the presence of sufficient oxygen at 630°C.

Dräger offers a robust suite of safety solutions, encompassing the holistic approach needed for handling ammonia, including portable and fixed fire and gas detection systems as well as appropriate personal protective equipment (PPE).

A first line of defence for ammonia gas leaks includes ultrasonic monitors like the Dräger Polytron 8900 Ultrasonic Gas Detector. These early warning area monitors detect high-pressure gas leaks in outdoor industrial process environments. Thanks to their acoustic sensor, they respond earlier than conventional gas detectors because they register the ultrasound frequencies emitted by leaking gas instead of measuring the concentration of accumulated gas clouds. As gas escapes, leaks are immediately detected in the surrounding area, regardless of wind direction.

Another option is catalytic point gas detectors. The Dräger Polytron 8200 CAT, for example, is used for lower explosive limit (LEL) monitoring and measures combustible gases such as ammonia within a few seconds. Because the Polytron 8200 is made of high-quality materials, it shows long endurance under the influence of poisonous substances and is approved for temperatures of up to 302°F/150°C, detecting gas concentrations in a range of 0-10% LEL.

Should a fire break out, proper flame detection is another line of defence. The Dräger Flame 1750 H2 is specifically designed to detect hydrogen fires, but can also detect fires associated with ammonia at shorter ranges. The flame detector utilises innovative IR3 sensor technology, providing rapid response with a low false alarm rate.

A fixed detection system alone, however, is not sufficient for comprehensive safety. For inspection and maintenance work, it is recommended to use mobile gas detection technologies for personal air monitoring or clearance measurement to detect any hazardous concentrations near personnel. One such detector is the Dräger X-am 8000. It allows workers to measure up to seven gases, which detects flammable gases as well as vapours and oxygen all at once.

To round out employee safety, PPE is another necessary layer to protect employees during operational and maintenance work. Work in confined spaces may require independent air supply units. For routine operations where there is sufficient ambient oxygen, filtering face masks or powered air-purifying respirators provide necessary respiratory protection. Protective clothing, such as chemical protective suits, is required in areas where there is any risk of skin contact. The expected concentrations of this hazardous substance must be assessed before selecting the appropriate protective equipment.

Ammonia's role as a fuel carrier holds significant promise for reducing greenhouse gas emissions and advancing sustainable energy practices. Due to its toxicity and potential fire hazard, choosing the right precautions, including detection and protection solutions, is key to working smart and safe with ammonia. This is all possible with proper consultation and consideration alongside safety experts like Dräger. The improvement in gas leak and fire detection as well as PPE marks a crucial step forward in managing this compound as an energy carrier, offering a clear path for multiple industries.

This article is contributed by Dräger Safety AG & Co. KGaA