Alkaline electrolyser

Electrolysis uses electricity to split water into its basic components (H2 and O2). Alkaline electrolysers are a type of electrolyser that uses nickel-based electrodes and a concentrated alkaline solution (25-35 wt% KOH) to enable the splitting of water. Alkaline electrolysers have been applied on 10+ MW scale for over hundred years, where they were traditionally used to produce hydrogen for ammonia plants based on hydropower until gas reforming became the cheapest technology. These electrolysers were traditionally operated in a baseload manner. Both atmospheric and pressurized versions (15-30 bara) do exist. The electrolysis products from anodes via water splitting may not only be O2. For example, the product is Cl2 from the chlor-alkali process, which is today the largest market for alkaline electrolysers. The selectivity of the products is dependent on the electrolytes and catalysts.