MODELING STUDIES ON PRODUCTION OF HYDROGEN FROM ALKALINE W ATER ELECTROLYSIS

Abstract

The primary use of hydrogen at the present time is as an industrial chemically commodity .The chemical and petroleum industries use the majority of hydrogen to produce ammonia, the backbone o f the fertilizer industiy, and for methanol production. Hydrogen will be a central fuel in the future as an energy carrier liquid H2 has significantly higher amounts o f energy per unit weight than any hydrocarbon fuel and has been used for space applications. When relatively small quantities of hydrogen are required, on site electrolysis of water may be more economical than other methods. Production o f hydrogen by this method is a simple process with no moving parts and can be designed as a potable unit. This technique is very clean, reliable and produces more than 99.989% purity o f hydrogen gas for most commercial technology. Alkaline electrolyte is most commonly used in water electrolysis, avoiding the huge corrosion loss caused by acid electrolytes. Nickel is a electrode material due to its high activity and availability as well as low cost. In order to increase efficiency, the voltage should be reduced by lowering the overvoltage experience (at the cathode and anode) and the interelectrode resistance from the electrolyte, the membrane, and the bubbles. In the present study a mathematical modeling for bubble growth on electrode and electrode kinetic has been studies, in these study we get information about affect of gas bubble at electrode from bubble growth model, an electrode kinetic analysis reveals the hydrogen evolution reaction overpotential in KOH and NaOH used as electrolyte in alkaline water electrolysis for hydrogen production. The analysis that current density uptolKA/m2 bubble coverage on electrode is negligible after that increasing with current density in both case of (KOH and NaOH) as electrolyte, also increasing ohmic resistance with current density due to bubble coverage. The model solved with the help o f available data in literature by using Matlab 7..