Investigating the effect of electrolyzer operating variables to increase the efficiency in hydroxy gas production with regard to thermal and electrical processes

Shahraki Shahdabadi, Reza; Behbahani Nia, Seyed Ali; Hosseini Kahsari, Seyed Mohammad Javad

doi:10.22034/jrenew.2026.230280

Investigating the effect of electrolyzer operating variables to increase the efficiency in hydroxy gas production with regard to thermal and electrical processes

Document Type : Original Article

Authors

reza shahraki shahdabadi ¹

seyed ali behbahani nia ²

seyed mohammad javad hosseini kahsari ³

¹ PhD Student, Energy Systems Engineering, K.N.Toosi University of Technology, Tehran, Iran

² Associate Professor, Energy Systems Engineering, K.N.Toosi University of Technology, Tehran, Iran

³ Associate Professor, Energy Conversion Engineering, Golestan University, Gorgan, Iran

https://doi.org/10.22034/jrenew.2026.230280

Abstract

Water electrolysis is considered an efficient method for producing hydroxy gas as a clean fuel. This study investigates the effect of electrolyte type and concentration (distilled water, tap water, potassium hydroxide, sodium hydroxide), temperature, and current intensity in a custom-designed, multi-cell dry electrolyzer. Experiments were conducted with electrolyte concentrations ranging from 5 to 20 wt% and temperatures from 23 to 70 °C. The research employed precise measurement systems and a three-repetition experimental design to ensure data validity, accuracy, and a systematic approach. The results indicated that a potassium hydroxide solution with a concentration of 15-20 wt%, at a temperature of 70 °C and a current intensity of 10-15 A, provided the maximum gas production (up to 156 L/hr) with optimal energy consumption (1.3-2 Wh/L). Furthermore, increasing the potassium hydroxide concentration up to 20% significantly reduced the solution’s resistance and increased electrical conductivity; however, values exceeding this range were practically associated with excessive energy consumption and corrosion risk. Additionally, the ohmic resistance of the electrolyzer was dependent on the type of electrolyte and water hardness, and increasing the temperature improved the efficiency of the process.

Keywords

Electrolyzer

hydroxy gas production

various electrolytes

KOH

NaOH

Subjects

Renewable and New Energy

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