Impact of produced oxyhydrogen gas (HHO) from dry cell electrolyzer on spark ignition engine characteristics

Gad M., El-Shafay A., Ağbulut Ü., Panchal H.

International Journal of Hydrogen Energy, vol.49, pp.553-563, 2024 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 49
  • Publication Date: 2024
  • Doi Number: 10.1016/j.ijhydene.2023.08.210
  • Journal Name: International Journal of Hydrogen Energy
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Artic & Antarctic Regions, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Environment Index, INSPEC
  • Page Numbers: pp.553-563
  • Keywords: Combustion characteristics, Emissions, HHO, Performance, SI engine
  • Yıldız Technical University Affiliated: No


In the current study, an onboard dry cell electrolyzer was built to produce an oxyhydrogen (HHO) flow rate of 0.5 L/min by water electrolysis. The objective is to show the impact of oxyhydrogen introduction on engine exhaust gases, combustion characteristics, and engine performance related to gasoline. The experiments were carried out in a petrol engine at a fixed engine speed of 3000 rpm and variable engine loading. When comparing HHO gasoline dual fuel to standard gasoline fuel, the maximum improvements in volumetric efficiency, thermal efficiency and air-fuel ratio were determined as 7.5%, 8% and 11%, respectively. In the case of HHO addition, the highest reductions in specific fuel consumption and exhaust gas temperature were 9% and 6.5%, respectively, compared with conventional gasoline fuel. The highest reduction in CO, HC, NOx, and CO2 concentrations was observed as 18%, 9%, 15%, and 11%, respectively, for HHO-gasoline dual-fuel mode compared to gasoline fuel. The peak cylinder pressure and HRR improvements were 1.5% and 4.5%, respectively, at 100% engine load. Oxyhydrogen gas is highly recommended as a substitute fuel since it significantly enhances engine performance and combustion characteristics as well as reducing exhaust pollutants.