Packaging, Inerting and Blanketing

Inerting, also known as blanketing, is the process of replacing the atmospheric air around a substance or material with a non-reactive gas, such as nitrogen or argon, to ensure it stays in a passive or unreactive state.

Nitrogen is typically used due to its inertness and friendly environmental profile making it suitable for a host of applications. Since it does not react with most materials, nitrogen is an excellent inerting, blanketing and purging gas that can be used to protect valuable chemical products from harmful contaminants. One of its most important uses is to eliminate flammability risks in reactor vessels and storage tanks.

Other gases such as carbon dioxide and argon can also be used in some cases for inerting purposes.

We can help you choose the optimum method to meet your needs, while also keeping gas usage to a minimum.

Liquid nitrogen cryogenic tank and vaporizers

The Benefits of Nitrogen Blanketing/Inerting

Safety: Protects sensitive materials from fire and explosions with the minimum gas volume
Controlled critical oxygen concentration (COC) levels: Proprietary software to perform calculations ranging from mixture flammability and COC
Quality: Increase shelf-life and prevent air and other contaminants from infiltrating and causing degradation
Range of purity and supply mode options: Your application requirements for purity, usage pattern, volume, and footprint will allow us to recommend the most efficient method of supply

Nitrogen Blanketing System

Continuous purge blanketing

A continuous flow of nitrogen (or other inert gas) is used to maintain safe oxygen concentrations within a tank headspace.

Pressure control blanketing

Nitrogen is introduced into the tank headspace to maintain a set pressure. Pressurization with nitrogen minimizes air in-bleed and can reduce nitrogen usage compared to continuous purging.

Concentration control blanketing

An oxygen monitoring system controls the flow of nitrogen into the headspace of the tank. A concentration control system can help enable precise operation and reduce gas usage compared to continuous purging.

Nitrogen purging systems

This method is commonly used when the vessel being purged only has one opening or in batch operations like purging ethylene oxide sterilizers. Nitrogen is used to pressurize a vessel or line, it mixes with and dilutes the contents and then the diluted mixture is vented to emission control units. This process is repeated until the vessel is sufficiently purged.

Dilution purging and drying

Nitrogen can continuously enter the vessel, dilute the mixture and exhaust through an exit preferably opposite the entrance. The geometry of the vessel and orientation of entry and exit points are important factors in the effectiveness of dilution purging. Drying follows a similar process but allows for removal of residual materials.

Displacement purging and pigging

Nitrogen can be used to purge out a pipe run. A “pig,” a bullet shaped object, can also be pushed through the line using nitrogen gas pressure in order to purge the contents.

Pressure transfer of liquids

A vessel’s headspace can be pressurized with nitrogen to transfer liquids without the use of a pump. This can be advantageous when pumping the material is difficult due to space constraints or when the material, such as corrosives, can cause pump issues.

Are you interested in using nitrogen for inerting?

We can help you choose the optimum method to meet your needs while also keeping gas usage to a minimum.

Ask the Expert

Jon Trembley

Technology Manager - Cryogenic Applications

“How much nitrogen do I need to keep my flammable liquid tanks safe?”

There are many factors that must be considered when designing a nitrogen blanketing system. Understanding the material being stored and type of vessel will help to design an optimized system for your operation. Watch our short video on nitrogen blanketing. (2:45)

Ask a Question

Gases

Argon

Compressed argon gas and liquid argon in a variety of purities and in various modes of supply around the world thanks to our network of storage and transfill facilities.

Carbon Dioxide

Our experienced applications teams across the globe can use their industry and application knowledge to provide you with a compressed or liquid carbon dioxide supply and technology solution to meet your unique needs.

Nitrogen

Useful as a gas, for its inert properties, and as a liquid for cooling and freezing. Virtually any industry can benefit from its unique properties to improve yields, optimize performance and make operations safer.

Bulk Supply

Delivered by truck and stored on your site either as a liquid in cryogenic tanks or as a gas in high-pressure tubes based on your volume, desired pressure, purity level, flow rate, and operating pattern.

On-site Gas Generation

On-site gas generation helps sustainability-minded customers lower their carbon footprint, boost energy efficiency, increase throughput, enhance end product quality, and improve environmental performance.

Pipeline Supply

Located in major industrial locations around the world, pipelines offer customers with large product demands a range of benefits, including reliable, safe and flexible supply in a cost-effective way.

Modeling Services for Inerting Applications

Air Products’ Computational Modeling Center utilizes applied mathematical and computational techniques to solve research, engineering and business problems. We leverage over 20 years of experience in computational chemistry, computational fluid dynamics (CFD), process modeling and optimization and other skills to improve decision making in business and technology areas.