Alkaline Water Electrolysis Hydrogen Production Equipment — A Complete Technology Guide

Introduction

Alkaline water electrolysis (AWE) remains the most mature and widely deployed technology for industrial-scale hydrogen production. Using a potassium hydroxide (KOH) aqueous solution as electrolyte, the process splits water molecules into hydrogen and oxygen under direct current. With decades of operational track record, alkaline electrolyzers deliver proven reliability, scalable capacity, and competitive levelized cost of hydrogen (LCOH) — making them the preferred choice for large-scale green hydrogen projects worldwide.

How Alkaline Water Electrolysis Works

The core of an alkaline electrolysis system is the electrolyzer cell, which contains a cathode, an anode, and a diaphragm separator immersed in KOH solution. When DC power is applied, the following electrochemical reactions take place:

Cathode (reduction):  2H₂O + 2e⁻ → H₂↑ + 2OH⁻

Anode (oxidation):  4OH⁻ → O₂↑ + 2H₂O + 4e⁻

Overall reaction:  2H₂O → 2H₂↑ + O₂↑

Hydrogen gas is generated at the cathode side and oxygen at the anode side. The diaphragm prevents gas crossover while allowing hydroxide ions to pass through. The raw hydrogen then passes through gas-liquid separators, cooling units, washing towers, and drying/purification modules to achieve the required purity.

Key Technical Features of Alkaline Hydrogen Production Equipment

1. Bipolar Pressure Filter Electrolyzer Design

Modern alkaline electrolyzers adopt a bipolar pressure filter structure with high-reliability insulating sealing gaskets. This design ensures excellent sealing performance under high differential pressure (1.5–2.5 MPa) and maintains long-term operational stability without gas leakage.

2. Silicon Rectification Power Supply

Replacing traditional thyristor rectification, silicon rectifier systems significantly reduce harmonic pollution to the power grid and lower reactive power losses. This grid-friendly feature is particularly important for renewable energy-coupled hydrogen projects where power quality matters.

3. Modular Gas-Liquid Processing

The gas-liquid processing unit uses a modular frame-combined structure with clear process flow layout. This simplifies on-site installation, daily operation, and maintenance, effectively reducing O&M costs and downtime.

4. Intelligent Control System

A fully automatic microcomputer monitoring platform supports both local touch-screen operation and remote centralized management. Multi-level permission management, real-time data logging, and traceability ensure safe and reliable unattended operation.

Three Installation Types for Different Application Scales

Alkaline water electrolysis hydrogen production equipment is available in three installation configurations, each serving different capacity ranges and deployment scenarios. The core electrolysis principle and key components remain identical across all types — the difference lies in how the subsystems are packaged and installed.

Split-Installation Type (CDQ Series: 20–3000 Nm³/h)

The CDQ series is designed for large-scale hydrogen stations. The electrolyzer, gas-liquid processing frame, hydrogen drying/purification unit, rectifier power supply, and control system are arranged independently and connected by piping. This layout suits fixed hydrogen station construction and facilitates maintenance and capacity expansion of individual subsystems. The CDQ series covers 15 models from CDQ-20 to CDQ-2000, with hydrogen purity reaching 99.999% after purification and DC power consumption as low as 4.5 kW·h/Nm³H₂.

Integrated Type (CNDQ Series: 5–10 Nm³/h)

The CNDQ series integrates the electrolyzer, gas-liquid separator, and hydrogen drying device onto a single base platform. This compact design is tailored for small-to-medium distributed hydrogen supply scenarios. The unit is pre-assembled and factory-tested, requiring only water, electricity, and gas connections on-site. It supports DCS integration for unattended operation and features low noise levels suitable for indoor installation.

Containerized Type (KCDQ Series: up to 100 Nm³/h per unit)

The KCDQ series encapsulates the complete alkaline electrolysis process — including electrolyzer, gas-liquid processor, triple-tower PSA purification, rectifier cabinet, transformer, and PLC control — within a standard 40-foot ISO container. This plug-and-play design eliminates civil engineering work, enabling deployment in remote areas, temporary projects, and overseas installations. Multiple containers can be paralleled for capacity expansion.

Technical Parameters Overview

Standard alkaline water electrolysis hydrogen production equipment delivers the following performance specifications:

Industrial Applications

Alkaline hydrogen production equipment serves a broad spectrum of industries:

▸ Renewable energy coupling: Large-scale green hydrogen production paired with wind and solar power, serving chemical feedstock and metallurgical reduction markets.

▸ Petroleum refining: Hydrodesulfurization, hydrocracking, and ammonia synthesis feedstock supply.

▸ Electronics & semiconductors: High-purity hydrogen for chip manufacturing, solar cell production, and LED fabrication.

▸ Power system peak shaving: Off-peak electricity storage as hydrogen for fuel cell power generation during peak demand.

▸ Metallurgy: Reducing hydrogen for steel smelting and non-ferrous metal extraction, supporting low-carbon transition.

▸ Float glass: Hydrogen-nitrogen protective atmosphere for tin bath operations.

Conclusion

Alkaline water electrolysis hydrogen production equipment offers a proven, scalable, and cost-effective path to industrial hydrogen supply. With three installation types — split-installation CDQ for large-scale stations, integrated CNDQ for distributed applications, and containerized KCDQ for mobile deployment — the technology adapts to project requirements ranging from 5 to 3,000 Nm³/h. As green hydrogen demand accelerates globally, alkaline electrolyzers will continue to play a foundational role in the hydrogen economy.