How PEM Hydrogen Injection Works

1. Electrolysis on demand

Direct current from the vehicle's 12 or 24 V system passes through a proton-exchange-membrane stack. The membrane is a solid polymer — there is no potassium hydroxide bath, no caustic liquid on the vehicle, and nothing to mix or dispose of.

Gas is produced only while the engine runs. A vibration sensor starts and stops the unit with the engine, so there is no hydrogen storage vessel anywhere in the installation.

2. Delivery into the intake

The mixed H₂/O₂ stream leaves the unit through an 8 mm line and is introduced downstream of the mass-airflow sensor, upstream of the turbocharger or throttle body depending on platform. Flow rates are small — 450 to 1,800 ml/min depending on the unit — relative to engine air consumption.

• ▸No modification to the fuel system, injectors or ECU
• ▸Compatible with DPF, SCR, EGR and urea after-treatment
• ▸Fully reversible, non-destructive installation

3. What happens in the cylinder

Hydrogen has a far higher laminar flame speed and a much wider flammability range than diesel or gasoline. Introduced as a minor fraction of the charge, it acts as a combustion promoter: ignition initiates across more of the charge, flame propagation is faster, and a greater proportion of the fuel burns within the useful part of the expansion stroke.

The practical consequences reported in the peer-reviewed literature are more complete combustion, reduced unburned hydrocarbons and reduced particulate/smoke opacity, with a NOₓ trade-off that depends on load and timing.

4. What it does not do

• ▸It does not replace diesel or gasoline
• ▸It does not store hydrogen onboard
• ▸It does not reprogram or override the engine ECU
• ▸It does not repair a worn, poorly maintained or mis-tuned engine