Germany-based Eberspächer has developed a system to reduce visible steam emissions from mobile fuel cell applications, aiming to address potential road safety concerns linked to exhaust plumes.
Fuel cells generate electricity through the reaction of hydrogen and oxygen, producing water vapour as a byproduct. In vehicle applications, this can result in noticeable steam emissions at the tailpipe, particularly in colder conditions.
Eberspächer’s De-Hydrator system is designed to minimise this effect through a multi-stage process.
“The moisture-laden air generated as a byproduct of the chemical process is mixed with cooled air – a heat exchange takes place and the water condenses,” the company stated.
The condensed water is then separated, while reheated air is fed back into the cooled, unsaturated exhaust stream to further reduce visible emissions.
“This procedure significantly reduces the amount of water in the tailpipe.”
Eberspächer’s De-Hydrator technology ©Eberspächer
This is important for fuel cell vehicles because their exhaust is essentially warm, moist air which can form dense visible plumes of steam when it hits colder ambient air.
A concentrated plume from the tailpipe can obscure the view of vehicles behind, especially at low speeds or in stop-start traffic.
Drivers may also mistake the plume for engine smoke or a fire, prompting sudden braking or evasive manoeuvres.
Emissions testing programmes led by organisations such as the US National Renewable Energy Laboratory, Transport Canada, and Environment and Climate Change Canada are increasingly examining the composition and behaviour of fuel cell exhaust streams.
While primarily focused on environmental performance, this work also supports regulatory understanding of how these emissions behave in real-world conditions.
While tested in prototype and demonstration settings, Eberspächer’s technology has yet to reach full-scale commercial deployment.
