Chapter 4 - Electrochemical hydrogen production

Abstract

Electrochemical hydrogen production has received significant attention as an environment-friendly and sustainable approach to producing hydrogen, which is a promising energy carrier. This chapter provides a comprehensive overview of three major types of electrochemical hydrogen production systems: alkaline water electrolyzers (AWE), proton exchange membrane (PEM) electrolyzers, and solid oxide steam electrolyzers (SOSEs). This chapter introduces the basic principles and reaction equations for each type of system, followed by a detailed discussion of their thermodynamics equations, including cell voltage, energy efficiency, and exergy efficiency. This chapter also highlights the advantages and disadvantages of each system and provides a critical analysis of their performance based on the latest research findings. The AWE is the most commonly used system for hydrogen production due to its low cost and high efficiency. This chapter provides an in-depth discussion of its performance and the factors affecting its efficiency, including the electrode material, electrolyte concentration, and temperature. The PEM electrolyzer is another promising system that uses a solid polymer electrolyte to facilitate proton transport. This chapter explains the advantages of the PEM system, such as its high-purity hydrogen production and rapid response to load changes. This chapter also discusses the challenges associated with the PEM system, including its high cost and the need for proper water management. Finally, this chapter introduces the SOSE system, which uses a solid oxide electrolyte to produce hydrogen at high temperatures. This chapter discusses the unique features of the SOSE system, such as its high efficiency and the potential for cogeneration of electricity and heat. This chapter also highlights the challenges associated with the SOSE system, such as its high operating temperature and the need for specialized materials.