In the wave of global energy transition and rapid development of the hydrogen industry, hydrogen, as a clean and efficient energy carrier and key industrial raw material, its purity and safety directly determine process efficiency and system stability. Moisture, as one of the most common impurities in hydrogen, if not effectively removed, will cause a series of problems such as equipment corrosion, catalyst poisoning, and hydrogen embrittlement failure. This article focuses on the core technology of hydrogen drying, deeply analyzing the principles, characteristics, and selection logic of refrigerated and adsorption drying solutions, providing professional reference for the efficient utilization of hydrogen energy.

Hydrogen Drying: Why Is It a Must?

Hydrogen has high activity and easy diffusion characteristics, and its moisture content (usually expressed as dew point) affects application scenarios far beyond imagination:

• Equipment Corrosion Risk: Moisture combines with trace impurities in hydrogen to form an acidic environment, continuously corroding the inner walls of pipelines, valves, and storage tanks, shortening equipment lifespan and increasing maintenance costs.

• Process Efficiency Decline: In chemical hydrogenation reactions, moisture poisons precious metal catalysts, leading to reduced reaction conversion rates and increased by-products, directly affecting product quality.

• Prominent Safety Hazards: Liquid water in high-pressure hydrogen systems may cause hydrogen embrittlement of materials, resulting in reduced strength of pipelines or containers, posing risks of leakage or even explosion.

• Purity Grade Requirements: Electronic-grade hydrogen (such as semiconductor manufacturing) requires strict dew point control (≤ -70°C); excess moisture will significantly reduce chip yield; hydrogen for fuel cells also requires ultra-low dew points to ensure stack performance.

Therefore, the core goal of hydrogen drying is to precisely control the dew point between -40°C and -70°C (or even lower) according to scenario requirements, building a solid safety and efficiency barrier for subsequent applications.

Refrigerated vs Adsorption Dryers

(1) Refrigerated Hydrogen Dryer: The Choice for Efficient Pretreatment

Working Principle

Relying on refrigeration cycles to achieve moisture condensation and separation, the core process includes:

1. Pre-cooling Stage: Wet hydrogen enters the heat exchanger to exchange heat with dry hydrogen, initially cooling and dehydrating;

2. Deep Cooling: Hydrogen is cooled to 1~10°C through an evaporator (commonly using environmentally friendly refrigerants like R134a), causing moisture to condense into liquid;

3. Gas-Liquid Separation: Condensed water is discharged through an automatic drain valve to avoid secondary carryover;

4. Reheating Output: Dry hydrogen is reheated after recovering cold energy through the heat exchanger, reducing energy loss.

Technical Features

• Dew Point Range: 1°C~10°C, meeting general industrial hydrogen pretreatment needs;

• Energy Consumption Advantage: Only relies on electric power to drive the refrigeration system, no adsorbent consumption, low operating cost;

• Applicable Scenarios: Large flow hydrogen treatment (such as petrochemical industry), scenarios with non-stringent dew point requirements (such as metal heat treatment, conventional chemical gas use).

Limitations

Cannot achieve ultra-low dew points (< -40°C); requires anti-freeze devices in low-temperature environments to prevent condensed water from freezing and blocking the system; economically not recommended for subzero dew point demand scenarios.

(2) Adsorption Hydrogen Dryer: Ultra-High Purity Guarantee Solution

Working Principle

Utilizes the microporous structure of adsorbents (molecular sieves, activated alumina, etc.) to selectively adsorb moisture, achieving continuous operation through regeneration processes. Main regeneration methods include:

• Pressure Swing Adsorption (PSA): Suitable for small flow equipment, uses part of the dry hydrogen or external gas to backflush the adsorption tower, desorbing moisture through pressure changes; discharge gas must comply with high-altitude emission regulations;

• Temperature Swing Adsorption (TSA): Heats the adsorption tower with hot air at 140~200°C to desorb moisture, achieving higher regeneration efficiency, suitable for medium to high flow scenarios.

The core process is a "Adsorption - Regeneration - Cooling" cycle: moisture is captured when wet hydrogen passes through the adsorption tower; after regeneration, the tower cools and stands by, ensuring continuous dry output.

Technical Features

• Dew Point Accuracy: Can stably reach -40°C to -70°C, with special customized models achieving even lower dew points;

• Selectivity Advantage: Molecular sieves have extremely strong selective adsorption for water molecules, capable of deeply removing trace moisture;

• Applicable Scenarios: High-end scenarios such as drying at the back end of electrolytic hydrogen production (including alkaline water electrolysis, PEM electrolysis, AEM electrolysis, etc.), semiconductor electronic-grade hydrogen, and hydrogen for fuel cells.

Limitations

Adsorbents need to be replaced regularly (cycle about 3~5 years, depending on feed gas humidity and operating load), involving certain maintenance costs.

Efficient Utilization of Hydrogen Energy

• Composite Drying System: Refrigerated pretreatment + adsorption deep drying in series, reducing adsorbent load while ensuring ultra-low dew points, achieving both energy efficiency and accuracy.

• Intelligent Control Technology: Equipped with dew point online monitoring sensors and adaptive regeneration strategies, it adjusts the regeneration frequency in real time to reduce ineffective energy consumption.

• Green regeneration solution: Uses industrial waste heat and photovoltaic power to drive TSA regeneration, reducing fossil energy consumption and aligning with dual carbon goals.

The selection of hydrogen drying equipment must be based on actual operating conditions, comprehensively considering dew point requirements, processing flow, energy consumption costs, and long-term operation and maintenance needs. As a technical service provider specializing in gas drying and purification, we offer full-chain solutions from standard models to customized systems, covering the entire lifecycle services from process design, equipment manufacturing to operation and maintenance support.

If you need targeted technical consultation or solution design, feel free to contact our engineering team and let professional technology safeguard the safe and efficient application of hydrogen energy!

 

Phone: 0571-88684007/0571-86016039

Official website: www.hzlinuo.com

Email: linuo@hzlinuo.com