Exhaust Emissions and Aftertreatments of Hydrogen Internal Combustion Engines: A Review

• Published in: International journal of automotive technology Vol. 24; no. 6; pp. 1681 - 1690
• Main Author: Kim, Junghwan
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Society of Automotive Engineers 01.12.2023; Springer Nature B.V; 한국자동차공학회
• Subjects: Automobile industry; Automotive Engineering; Chemical reduction; Engineering; Fuel injection; Hydrogen combustion; Internal combustion engines; Invited Review; Mixers; Nitric oxide; Selective catalytic reduction; Vehicle emissions; 자동차공학; Selective catalytic reduction (SCR); Combustion engine; Hydrocarbon; CO; Hydrogen; NOx
• ISSN: 1229-9138; 1976-3832
• DOI: 10.1007/s12239-023-0136-0

Adopting carbon-neutral fuels is paramount to aligning internal combustion engines with global efforts to mitigate the impact of global warming. Hydrogen offers distinct advantages over other renewable fuels owing to its superior combustion properties. This comprehensive review explores three fuel injection systems suitable for using hydrogen as a fuel: mixers, port injections, and direct injections. Subsequently, we examined the emission characteristics of hydrogen internal combustion engines (HICE). Although nitric oxides (NOx) is the major emission from HICE, small quantities of hydrocarbon, CO, and CO 2 should be expected due to engine oil burn. Moreover, we provide a concise overview of aftertreatment options, including urea-based selective catalytic reduction (SCR) and hydrogen-assisted SCR (H 2 -SCR).