Hydrogen addition to ethanol-fuelled engine in lean operation to improve fuel conversion efficiency and emissions

Sami massalami mohammed elmassalami Ayad, Carlos rodrigues pereira Belchior, José ricardo Sodré*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


This work applies computer simulation to investigate the combined approach of hydrogen (H2) addition with lean operation to enhance the potential of ethanol as a clean engine fuel for low-carbon transportation. To this end, this research evaluates how this operation regime impacts brake power, fuel conversion efficiency, and exhaust emissions. A dedicated software was used to perform a parametric study with varying amount of hydrogen addition and excess air ratio. The software combustion and performance parameters were calibrated against available experimental data and optimised for engine operation at the tested conditions. The results show that hydrogen addition does not produce noticeable effects on brake power and fuel conversion efficiency for lean operation with up to 20% air excess. However, for operation with 40% air excess, 6% H2 addition is necessary to keep the power at the same level of the engine baseline condition while simultaneously improving fuel conversion efficiency. Operation in the range of air excess between 10% and 30% together with hydrogen addition up to 2% can simultaneously produce noticeable improvements of fuel conversion efficiency, carbon monoxide (CO) and hydrocarbon (HC) emissions, without compromising brake power and oxides of nitrogen (NOX) emissions.
Original languageEnglish
Pages (from-to)744-752
JournalInternational Journal of Hydrogen Energy
Early online date21 Sept 2023
Publication statusPublished - 2 Jan 2024

Bibliographical note

copyright © 2023 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY
license (http://creativecommons.org/licenses/by/4.0/).

Funding: The authors thank the Human Resources Programme of the Brazilian National Agency of Oil, Natural Gas and Biofuels – PRH-ANP – and the research funding agencies CAPES, CNPq and FINEP, for the financial support to this research.


  • Emissions
  • Ethanol
  • Fuel conversion efficiency
  • Hydrogen
  • Internal combustion engines
  • Modelling and simulation


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