World's First Heavy-Duty Commercial Vehicle High-Pressure Direct-Injection Pure Ammonia Engine Successfully Ignites

On April 26, the mid-term review meeting of the National Key R&D Program project titled "Key Technology Development and Application of Ammonia-Fueled Internal Combustion Engines Dedicated for Heavy-Duty Commercial Hybrid Vehicles" was held in Changshu, Jiangsu Province. At the meeting, the project team successfully ignited and stably operated the world’s first large-displacement, high-pressure direct-injection pure-ammonia internal combustion engine specifically designed for hybrid applications. This engine runs exclusively on ammonia fuel and integrates several core technologies, including a pent-roof combustion chamber, an active pre-chamber ignition system, high-pressure direct liquid ammonia injection into the cylinder, a low-temperature, high-efficiency multi-nitrogen-based aftertreatment system, and intelligent control of multi-hydrogen-fuel co-injection. The engine achieves thermal efficiency comparable to the current highest levels of heavy-duty diesel engines and has demonstrated successful integration with a high-pressure ammonia-to-hydrogen system, validating the feasibility of pre-chamber jet ignition for high-pressure direct-injected liquid ammonia. The accompanying ammonia-to-hydrogen system employs a catalytic cracking route for high-pressure hydrogen production, featuring a novel low-temperature ruthenium-based catalyst that efficiently converts ammonia to hydrogen at temperatures between 400°C and 450°C. This breakthrough overcomes the technical bottleneck of efficient catalytic conversion of ammonia to hydrogen under low-temperature, high-pressure conditions, significantly reducing both energy consumption and thermal losses associated with hydrogen production. This achievement provides a zero-carbon powertrain solution for long-haul heavy-duty commercial vehicles that balances lifecycle costs with low-carbon emission requirements.