ASDS is a system for ammonia storage and delivery that is used to activate the SCR catalysts used on diesel vehicles to remove NOx from the engine exhaust. The system can be used on commercial vehicles such as buses, medium-duty/heavy-duty trucks and light-duty trucks including pick-up trucks as well as passenger diesel vehicles (cars and SUV) and non-road mobile machinery (NRMM).

Amminex’ ASDS technology was created on the basis of two key achievements:

• The invention of AdAmmine; a chemical way to store large quantities of ammonia in a compact solid-form salt material. This material can absorb large amounts of ammonia just like a sponge and carry it safely onboard vehicles in cartridges. A 100-gram cube of the material can fit into the palm of a hand yet contain up to 50 grams of solid ammonia—the equivalent of 60 litres of ammonia gas.

• The development of a complete system, ASDS, consisting of standard components and an intelligent software package that can be tailored and configured to meet specific customer needs and allows the release of stored ammonia on-demand and optimally feeding it to the SCR-catalyst.

Conventional dosing technology is based on spraying an aqueous urea solution (diesel exhaust fluid, DEF) into the exhaust stream. This works well on motorways, but has limitations in city driving. At low exhaust temperatures—e.g. when vehicles move slowly due to congestion, inner city speed limits or the weather is cold—the injection of liquid is not active unless extra fuel is consumed to heat up the exhaust line. This adds cost and increases CO₂ emissions.

ASDS is an always-on technology that also has other benefits. For example, the density of ammonia in the solid material is twice as high as in the liquid based ammonia solution, extending the driving range between refills. Further, since ammonia is released as a gas, no deposits occur in the exhaust system. This represent a major advantage because it translates into less maintenance and vehicle down-time.

Testing earlier this year at the University of Graz in Austria found that ASDS has an excellent performance on homologation cycles, achieving NO_x conformity factors down to 0.5. This means that the engine emitted 50% below the current legal NO_x emission limits and is fully compliant to Euro VI. This performance boost is partly achieved from the effective dosing of gaseous ammonia and removal of NO_x in the low exhaust temperature range from 140-180°C.

Due to the reduced effort in reaching the engine emission compliance, ASDS could also be used to significantly optimize the fuel consumption. Preliminary results are showing in the range of 2% fuel consumption reduction, while still being compliant with the Euro VI emission legislation.

The tests at Graz were performed in the framework of the Horizon2020-funded project CARVE.

Faurecia is also investigating closely other applications of ASDS, such as for off-road vehicles and high horsepower (HHP) engines used on ships and vessels. The remaining shares are held by the Danish Foundation Nordea-fonden.

Both Annika Isaksson, Amminex CEO and Tue Johannsen, Chief Technology Officer, who invented the technology and founded Amminex, will remain in their positions to accompany the technology in this new stage of its development.