Optimization of alkaline electrolysis system for hydrogen production: A simulation study

Abstract. Global economic development and population growth have increased the energy demand, necessitating a reduction in the dependence on non-renewable sources. Rising energy demand necessitates a shift from fossil fuels to renewable hydrogen production. While nickel-based electrodes are common in alkaline electrolysis, their performance can be further enhanced. Previous studies indicate Ni/TiO2 electrodes as promising electrode materials; however, these findings are based on experimental studies and a preliminary simulation study is needed to further be utilised in industrial-scale applications. This study aims to develop and validate a simulation model to predict the performance of an alkaline electrolyser using the new Ni/TiO2 coated electrode system. The base case model of the alkaline electrolysis system was developed using Aspen Plus and validated by comparing the simulation result with the reference data, with the maximum acceptable overall percentage difference of 5%. Based on the result obtained, changing electrode material from conventional Ni to Ni/TiO2 coated electrode reduces the activation overpotential by 4.13% and it improves the hydrogen production rate by 4.3% due to its enhanced electrocatalytic properties. TiO2 coating enhanced the electrocatalyst efficiency, leading to higher hydrogen evolution rates which is mainly attributed to the increased active surface area and improved charge transfer which has eventually increased the amount of hydrogen produced.