Alkaline water electrolysis: enabling large-scale production of green hydrogen

Decarbonization is an essential and urgent task to mitigate the adverse effects of climate change. In fact, moving societies from the use of coal and other fossil fuels to alternative energy sources to power industries, transportation, and the hard-to-abate sectors is one of the challenges of our time. To execute the energy transition fully, we need new and innovative solutions, as well as a shift in personal behaviors, and legislative changes.

Green hydrogen is emerging as a pivotal solution in the quest for decarbonization. Unlike traditional hydrogen production methods, which rely on fossil fuels and result in significant CO₂ emissions, green hydrogen is produced through water electrolysis using renewable energy sources such as wind, solar, or hydroelectric power. This process (1) splits water (H₂O) into hydrogen (H₂) and oxygen (O₂) without emitting CO₂, making it a truly clean energy carrier.

H2O + electricity → H2 + O2 (1)

DeNora solutions harness the power of the so-called advanced alkaline water electrolysis, a type of electrolysis that occurs in an alkaline environment; a consolidated and mature technology, ready to be commercialized and brought to market for the production of green hydrogen. This cutting-edge, clean tech builds its foundation and the centennial knowledge of traditional alkaline water electrolysis, with the difference being the utilization of coated electrodes, a zero-gap configuration, and the use of a thinner diaphragm.

The electrolyzer is the technology that enables the production of green hydrogen using electricity directly from renewables. The core of an electrolyzer system is constituted by the stack—a series of anodes and cathodes separated by a diaphragm—which splits water upon the passage of the electric current (1).

More precisely, water is split into its constituting elements – oxygen and hydrogen – according to the following equations:

2OH- → H2O + 1/2O2 + 2e- (2)

2H2O + 2e- → H2 + 2OH- (3)

At the anode side (2) the hydroxyl ion (OH-) is converted into molecular oxygen (O2) whilst water (H2O) is converted into hydrogen and hydroxyl ions are also produced at the cathode side (3). The role of the diaphragm is both to separate the anode and cathode side, hence the gasses produced, and to shuttle the OH- from the cathode to the anode, thus sustaining the functionality of the electrochemical process.

By leveraging the potential of the advanced alkaline water electrolysis, De Nora, with its proprietary electrodes became a key player in the field of green hydrogen production, enabling higher hydrogen production rates at any specific energy consumption, positioning itself as a top enabler of the energy transition. In this field, De Nora brought recently to market a new Dragonfly® system, an electrolyzer that enables the decentralized production of green hydrogen through alkaline water electrolysis.

In addition to bringing to market a new Dragonfly® system that serves the mid-size electrolyzer market, De Nora is in the process of constructing a Gigafactory in Italy for the production of parts and components, electrodes for water electrolysis, and containerized systems to produce green hydrogen.

Additionally, the HyNCREASE project, with the main objective of upscaling the production capacity for innovative clean-tech equipment, will provide comprehensive and integrated support to the hydrogen sector, enabling a significant cost reduction of electrolyzers and hydrogen.

In conclusions, green hydrogen stands out as a versatile and clean energy carrier that can play a crucial role in achieving deep decarbonization across multiple sectors. Based on its ESG roadmap and with 100+ years of electrochemistry knowledge, De Nora is contributing to the energy transition with continuous research in the field of alkaline water electrolysis to upscale the production of green hydrogen so that we can comply with climate agendas and respond promptly to repower the world with cleaner and more sustainable energy solutions.