With the continuous upgrading of automation and packaging technology in the food industry

With the continuous upgrading of automation and packaging technology in the food industry, nitrogen is being used more and more widely in food processing, storage, transportation, and packaging. Especially in industries such as nuts, puffed foods, dairy products, coffee, tea, meat products, aquatic products, and frozen foods, food nitrogen generators have become one of the core auxiliary equipment.

Food nitrogen generator

The food industry's need for nitrogen essentially stems from its ability to "isolate oxygen."

Oxygen will cause:

• Food oxidation and spoilage
• rancidity of oils
• Color changes
• Microbial reproduction
• Aroma loss
• Shortened shelf life

Traditional liquid nitrogen supply methods suffer from high transportation costs, complex tank maintenance, and high safety risks. As a result, more and more companies are starting to adopt on-site nitrogen generation systems.

Common pain points in the current food industry include:

1. Nitrogen purity is unstable.

Many food companies have found in actual production that:

• Oxygen content exceeded the standard after packaging
• Nitrogen purity fluctuation
• Poor preservation effect
• Product dampness

The root cause usually comes from:

• Nitrogen generator design is unreasonable
• Air compressor with excessive oil and water content
• Carbon molecular sieve aging
• Pipeline leak
• Insufficient buffer tank capacity

2. Excessive energy consumption

The food industry often operates 24 hours a day.

if:

• Low efficiency of compressed air systems
• Air compressor mismatch
• Nitrogen waste is serious

This will lead to a significant increase in energy consumption per ton of product.

3. Strict food safety requirements

Food-grade nitrogen is not simply "containing nitrogen".

Also involved:

• cleanliness
• Oil-free
• Aseptic
• Dew point control
• Pipe Material
• Food contact safety

Many common industrial nitrogen generation systems are not suitable for the food industry.

4. The packaging machine is incompatible with the nitrogen generation system.

In actual situations, the following often occur:

• Insufficient nitrogen flow
• Large fluctuations in instantaneous gas consumption during packaging
• Pressure decreases when multiple packaging machines work simultaneously

This leads to unstable packaging quality.

What is a food-grade nitrogen generator?

A food nitrogen generator is an on-site nitrogen generation device used in the food processing and packaging industry.

Its core function is:

Nitrogen is separated from the air and continuously outputs high-purity nitrogen that meets the requirements of the food industry.

The current mainstream technology is:

• PSA pressure swing adsorption nitrogen production
• Membrane separation for nitrogen production

The PSA food nitrogen generator is the most widely used in the food industry.

Nitrogen generators for food processing are typically used for:

• food packaging
• Food preservation
• Food storage tank protection
• Antioxidant of cooking oil
• Powder conveying protection
• Coffee aroma preservation
• Dairy products to prevent spoilage

Working principle of food nitrogen generator

PSA pressure swing adsorption nitrogen generation principle

Most food nitrogen generators use PSA (Pressure Swing Adsorption) technology.

The core principle is:

Air separation is achieved by utilizing the different diffusion rates of oxygen and nitrogen through carbon molecular sieves.

Main components of air:

• Nitrogen: approximately 78%
• Oxygen content: approximately 21%
• Other gases account for approximately 1%.

After compressed air enters the adsorption tower:

Carbon molecular sieves preferentially adsorb impurities such as oxygen, moisture, and carbon dioxide.

Nitrogen gas is then passed through the molecular sieve and output.

When the molecular sieve adsorption is saturated:

The system rapidly depressurizes and regenerates.

The two towers alternate in a cycle to achieve continuous nitrogen supply.

PSA nitrogen production core process

Pressure adsorption stage

Compressed air enters the adsorption tower.

Oxygen is adsorbed:

• Nitrogen output
• Nitrogen purity gradually increases

equalization phase

Pressure balance is achieved between the two towers.

Reduce compressed air loss.

Pressure reduction regeneration stage

The adsorption tower was rapidly depressurized.

Oxygen is released from the molecular sieve.

Purging and regeneration stage

Partial nitrogen backflushing.

Further restore the adsorption capacity of molecular sieves.

Food nitrogen generator system composition

air compressor system

effect:

Provides a stable supply of compressed air.

The food industry typically requires:

• Oil-free air
• Stable pressure
• Continuous operation

Common configurations:

• screw air compressor
• oil-free air compressor
• Variable frequency air compressor

Refrigerated dryer or desiccant dryer

effect:

Remove moisture from the air.

If the compressed air has too high a moisture content:

This will result in:

• Molecular sieve poisoning
• Nitrogen purity decreased
• Valve malfunction

Common requirements in the food industry:

• Pressure dew point ≤ -40℃
• High-end scenarios ≤ -60℃

Precision filtration system

Typically includes:

• Pre-filter
• Oil removal filter
• Activated carbon filter

Main function:

• Remove oil mist
• Remove particles
• Remove odor

PSA nitrogen generator

Core equipment.

Mainly composed of:

• Adsorption tower
• carbon molecular sieve
• pneumatic valve
• PLC control system

composition.

Nitrogen buffer tank

effect:

• Voltage Regulator
• Buffering flow fluctuations
• Maintain packaging stability

Food packaging machines typically have a high instantaneous flow rate requirement.

Therefore, the buffer tank is very critical.

Nitrogen purity detector

For real-time detection:

• Oxygen content
• Nitrogen purity

Some systems support:

• Online alarm
• Automatic drain
• Remote monitoring

Nitrogen generator process flow diagram

Core technical parameters of food nitrogen generator

Nitrogen purity

Common in the food industry:

Nitrogen flow rate

Common range:

• 5Nm³/h
• 10Nm³/h
• 50 Nm³/h
• 100Nm³/h
• 500Nm³/h

Large-scale food factories can reach:

Above 1000 Nm³/h.

Export pressure

generally:

• 0.5~0.8MPa

Some high-voltage scenarios:

A booster system is required.

Dew point

General requirements in the food industry:

-40℃ or below.

High-end packaging requirements:

-60℃ or below.

Oxygen content

The food industry often focuses on:

Residual oxygen content in packaging.

Common requirements:

• ≤2%
• ≤1%
• ≤0.5%

Application scenarios of food nitrogen generator

Nitrogen-filled food packaging

The most typical application.

include:

• potato chips
• nut
• biscuit
• pastry
• fast food

The role of nitrogen:

• Antioxidant
• Prevent crushing
• Extend shelf life

coffee industry

Coffee oxidizes very easily.

Nitrogen can:

• Prevent aroma from evaporating
• Extend flavor stability

Many specialty coffee companies:

Nitrogen purity of 99.9% or higher is required.

Edible oil industry

Nitrogen sealing can reduce:

• Oil oxidation
• Acid value increases

Commonly used in:

• Tank protection
• Filling protection

Meat products industry

Nitrogen can:

• Inhibit bacterial growth
• Maintain color stability

Commonly used in:

• Ham
• Delicatessen
• chilled meat

dairy industry

Used for:

• Milk powder packaging
• Aseptic delivery
• Tank protection

It requires extremely high cleanliness.

Tea and Chinese medicinal materials industry

Tea leaves are highly susceptible to moisture absorption and oxidation.

Nitrogen generators for food processing can:

• Preserve aroma
• Extend storage time

Case Study of Nitrogen Generator Industry in Food Processing

Case 1: Nut Packaging Production Line

A nut factory:

Originally, bottled nitrogen was used.

exist:

• Frequent bottle changes
• Nitrogen is expensive
• Unstable gas supply

After switching to a PSA food nitrogen generation system:

• Nitrogen costs decreased by approximately 50%.
• The oxygen content in the packaging remains stable below 1%.
• Shelf life extended by approximately 30%.

Case Study 2: Coffee Roasting Company

A specialty coffee factory:

The nitrogen purity requirement is 99.9%.

System Configuration:

• oil-free air compressor
• Adsorption dryer
• High-purity PSA nitrogen generator

accomplish:

• The coffee aroma remains stable
• Improved packaging consistency

Common problems with food nitrogen generators

Why does the purity of nitrogen generators used in food processing decrease?

Common causes:

Oil-containing air compressor

After the oil enters the molecular sieve:

It will cause permanent pollution.

Drying system malfunction

High air moisture content:

The adsorption performance of molecular sieves decreases.

Molecular sieve aging

Normal lifespan:

Approximately 5 to 8 years.

pneumatic valve malfunction

Untimely switching:

This can cause gas leakage.

Gas consumption exceeded design value

Packaging machine instantaneous flow rate is too high:

This leads to fluctuations in purity.

How to select a nitrogen generator for food processing

Select based on nitrogen purity

The higher the purity:

• The lower the nitrogen production
• The higher the energy consumption

Therefore, one should not blindly pursue high purity.

Choose based on packaging speed

Packaging machine speed determines:

Instantaneous gas consumption.

Calculations must be made:

• Peak traffic
• Average flow

Choose according to food type

Different foods:

The requirements for residual oxygen levels differ.

For example:

• Potato chips: 95%~99%
• Coffee: 99.9%
• Milk powder: 99.99%

Select based on production method

Continuous manufacturing enterprises:

suggestion:

• Dual-machine backup
• Automatic switching
• Remote monitoring

Energy consumption analysis of food nitrogen generator

In food nitrogen production systems:

The largest energy source is not the nitrogen generator.

Instead:

Air compressor.

generally:

Compressed air energy consumption accounts for more than 80% of the entire system.

Factors affecting energy consumption

Nitrogen purity

The higher the purity:

The greater the air consumption.

air compressor efficiency

Inefficient air compressors:

This will significantly increase operating costs.

Leakage rate

Many factories:

Pipeline leakage exceeds 20%.

Pressure setting

Excessive stress:

It will increase compression power consumption.

Energy-saving measures

Use a variable frequency air compressor

Reduce energy consumption under partial load.

Optimize pipeline design

Reduce pressure drop.

Add gas storage tank

Reduce the frequency of loading.

Regular leak checks

Reduce nitrogen waste.

Food nitrogen generator maintenance

Routine inspection

include:

• pressure
• flow
• purity
• Dew point

Replace the filter regularly

A clogged filter can cause:

• Increased pressure drop
• Increased energy consumption

Check valves

Pneumatic valves are high-frequency operating components.

It wears out easily.

Check the molecular sieve condition

if:

• Purity declines over a long period
• Increased air consumption

The molecular sieve may need to be replaced.

Drainage system maintenance

Automatic drain malfunction:

This will cause a large amount of water to enter the system.

Food nitrogen generator industry standard

The food industry has high requirements for nitrogen systems.

Commonly involved:

Food safety standards

For example:

• HACCP
• GMP
• FDA food contact requirements

Compressed air standards

Frequently referenced:

ISO 8573 Compressed Air Quality Standard.

Key areas of control:

• oil content
• Moisture content
• Particle size

Pressure Vessel Specifications

Gas storage tanks and pressure vessels:

It must comply with relevant safety regulations.

Food nitrogen generator market development trend

High purity

With increasing requirements for food preservation:

Demand is gradually increasing at a rate of over 99.99%.

Intelligent

Future systems will adopt more of the following:

• PLC intelligent control
• Remote monitoring
• IoT
• AI predicts maintenance

Energy saving

Reduce compressed air energy consumption:

It has become a key focus of the industry.

Modular

More and more companies are adopting:

Skid-mounted integrated system.

convenient:

• Quick installation
• Expansion and Upgrade

Oil-free

The food industry is gradually phasing out conventional oil-injected air compressors.

The demand for oil-free air systems is growing rapidly.

Future Technological Directions for Food Nitrogen Generators

Future development of nitrogen generation technology for food will focus on:

• Low-energy carbon molecular sieves
• High-efficiency airflow control
• AI-powered intelligent purity adjustment
• Remote fault diagnosis
• Ultra-low dew point air treatment
• Integrated intelligent gas supply system

at the same time:

The food industry for:

• Purification
• automation
• stability
• Food safety

The requirements will become increasingly higher.

Nitrogen generators for food processing have gradually evolved from traditional auxiliary equipment into an important basic system in the modern food industry.

For food companies:

A stable, safe, and low-energy nitrogen supply system is not only related to the food preservation effect, but also directly affects:

• Product Quality
• Production efficiency
• Energy costs
• Food safety
• Enterprise competitiveness

In the future, with the upgrading of food packaging and the development of intelligent manufacturing, food nitrogen generators will be used in:

• Food preservation
• Aseptic packaging
• Smart Factory