How to make nitrogen? Learn more

How to make nitrogen? Learn more

nitrogen (N₂) is a colorless, odorless, and odorless inert gas that makes up 78% of Earth's atmosphere. Due to its wide range of industrial applications, such as food preservation, chemical synthesis, electronic manufacturing and other fields, the demand for nitrogen has increased year by year. How to manufacture nitrogen? This article will introduce the manufacturing method of nitrogen in detail, and discuss its application in industry.

1. Sources of nitrogen

nitrogen is mainly derived from air separation and chemical synthesis. The concentration of nitrogen in the air is as high as 78%, so the separation of nitrogen from the air is currently the most commonly used production method. Chemical synthesis methods (such as the Harper method) can also produce nitrogen, but this method is mainly used for industrial-scale ammonia production, which is relatively expensive, so it is not common in commercial nitrogen production.

2. Cryogenic separation method: extraction of nitrogen from air

cryogenic separation is a traditional nitrogen manufacturing method, which is widely used in large-scale industrial production. This method liquefies the oxygen and nitrogen in the air separately by cooling the air to a very low temperature (about -196°C). The liquefied oxygen and nitrogen can be separated by distillation to obtain high purity nitrogen.

The steps are as follows:

• compressed air: Compress air to a high pressure state, usually 10-20 times atmospheric pressure.
• Cooling air: Cool the compressed air to close to room temperature to remove moisture and other impurities.
• Further cooling: Send the cooled air into the heat exchanger, and use liquid nitrogen or liquid oxygen for cryogenic treatment to liquefy the oxygen and nitrogen in the air.
• Separation of liquefied gas: Through distillation or fractionation technology, liquid oxygen and liquid nitrogen are separated to obtain high-purity liquid nitrogen.

Advantages:

• large scale of production, suitable for industrial needs.
• Oxygen and nitrogen can be produced simultaneously.

Disadvantages:

• the equipment is complex and the initial investment is high.
• Operating costs are high and require a lot of energy.

3. Pressure swing adsorption (PSA): another efficient method of nitrogen production

pressure swing adsorption (PSA) is a relatively modern nitrogen manufacturing technology, especially suitable for small and medium-scale nitrogen demand. The method uses the adsorption characteristics of adsorbents (such as carbon molecular sieves) for different gas molecules to separate nitrogen and oxygen through pressure changes.

The steps are as follows:

• compressed air compress the air to about 6-8 bar.
• Filtration of impurities: Remove moisture, oil and carbon dioxide from compressed air.
• adsorption separation: The purified air is sent to the adsorption tower equipped with carbon molecular sieve. Under high pressure, the carbon molecular sieve preferentially adsorbs oxygen molecules, while nitrogen passes through the adsorption column.
• Reduced Pressure Release: When the pressure in the adsorption tower decreases, the adsorbed oxygen will be released, and the carbon molecular sieve will restore its adsorption capacity and be recycled.

Advantages:

• compact equipment and flexible operation.
• Low energy consumption and low operating costs.
• High purity nitrogen (up to 99.999 percent) can be produced.

Disadvantages:

• suitable for small and medium-scale production, not suitable for large-scale demand.
• There are certain requirements for the performance and life of the adsorbent.

4. Membrane separation method: simple and efficient nitrogen separation technology

membrane separation is a new nitrogen manufacturing technology, which uses the special hollow fiber membrane to separate nitrogen and oxygen. This method is simple and efficient, and is particularly suitable for scenarios that require low purity nitrogen.

The steps are as follows:

• compressed air compressed air to about 2-4 bar.
• Filtration of impurities: Remove moisture and other impurities from compressed air.
• membrane separation: The purified air is passed through the hollow fiber membrane. Since the nitrogen molecules are larger, the oxygen molecules pass through the membrane more easily, thereby achieving the separation of nitrogen and oxygen.
• Nitrogen collection: The nitrogen that does not pass through the membrane is collected as the required nitrogen product.

Advantages:

• the equipment is simple and easy to install.
• Low energy consumption and low operating costs.
• High purity nitrogen (up to 99.9 percent) can be produced.

Disadvantages:

• suitable for small-scale production, not suitable for large-scale demand.
• There are certain requirements for the performance of membrane materials.

5. Summary: Select the appropriate nitrogen manufacturing method

there are various manufacturing methods for nitrogen, and each method has its applicable scenarios and advantages and disadvantages. The cryogenic separation method is suitable for large-scale industrial production, and the pressure swing adsorption method and membrane separation method are more suitable for small-scale and small-scale needs. With the advancement of technology, the efficiency and cost of nitrogen manufacturing will be further optimized to meet the needs of different industries.

To learn more, you can choose a manufacturing method that suits your needs, or consult a professional gas manufacturing company for more detailed solutions. As an important part of modern industry, the continuous progress of its manufacturing technology will bring more possibilities for various industries.