The Hydrogen Internal Combustion Engine (H₂-ICE) Consortium launched by the U.S. Southwest Research Institute (SwRI) in 2022 has engineered a hydrogen-fueled Class-8 demonstration vehicle. The technology is intended to offer a zero-greenhouse gas emissions option to help decarbonize the long-haul trucking sector.

SwRI researchers converted an X15N natural gas engine provided by H₂-ICE Consortium member Cummins to operate on port-injected hydrogen using components supplied by other project participants. An aftertreatment system was adapted to the hydrogen exhaust environment. When paired with the H₂-ICE’s already low engine emissions, the addition of this system reduces nitrogen oxides (NO_x) emissions to 0.008 g/hp-hr with aged catalysts, well below the 2027 U.S. Environmental Protection Agency limit of 0.035 g/hp-hr and an industry first.

Source: SwRI

The 370-hp engine produces 2,025 Newton-meters (nm) of torque, which is considered ideal for most heavy-duty trucking applications. The engine efficiency exceeds 40% and peaks at 43%. Trace amounts of carbon emissions have been measured in the exhaust, totaling about 1.5 g/hp-hr of carbon dioxide.

According to SwRI engineer Chris Sharp, “The NO_x emissions produced by the H₂-ICE platform are already at or below the best numbers achieved in our previous diesel low-NO_x programs. We anticipate the H₂-ICE reaching near-zero tailpipe NO_x emissions, with single digit mg/hp-hr levels under nearly all operating conditions.”