Hydrogen Compression Ignition Engines

Abstract

The compression ignition (CI) engine has been the workhorse of the global economy for several decades. However, owing to the need to combat global climate change, the long-term survival of the CI engine depends on its ability to operate with alternative carbon-neutral fuels. Hydrogen has excellent combustion characteristics, making it suitable for application in CI engines. However, it has a high auto-ignition temperature, which limits its operation as a secondary fuel in a dual-fuel engine, unless an ignition source, such as a glow plug, is present. Hydrogen dual-fuel CI engines exhibit diesel-like combustion characteristics and are less prone to the loss of combustion control at high loads or the occurrence of abnormal combustion events, which often occur in hydrogen spark-ignition engines. The biggest challenge associated with the implementation of hydrogen dual-fuel engines is the high combustion temperature, which results in the production of high nitrogen oxide (NOx) emissions that must be addressed using aftertreatment technologies. Nevertheless, hydrogen dual-fuel CI engines are a low-cost and mature technology that can significantly reduce carbon emissions. Over the past few decades, significant research has been conducted on the adaptation of this technology as a medium-term decarbonization solution.