Nitrogen, as an important industrial gas is widely used in many industries such as food, medicine, chemical industry, electronics, and metal processing.
There are two ways to obtain nitrogen: On-site gas production by nitrogen generator: nitrogen is separated from the air through pressure swing adsorption (PSA) separation or cryogenic technology. Liquid nitrogen purchase: liquid nitrogen is purchased from the gas product supplier, stored in a cryogenic liquid tank, and then vaporized when used.
PSA Nitrogen plant: https://www.hznuzhuo.com/nuzhuo-nitrogen-gas-making-generator-cheap-price-nitrogen-generating-machine-small-nitrogen-plant-product/
Cryogenic nitrogen plant: https://www.hznuzhuo.com/nuzhuo-cryogenic-liquid-oxigen-plant-air-separation-unit-plant-for-producing-liquid-oxygen-nitrogen-argon-product/
Here we will conduct an in-depth cost comparison between install nitrogen generators and purchase liquid nitrogen from multiple dimensions such as equipment investment, operating costs, supply stability, flexibility, and safety, and combine actual cases to provide a reference for enterprises to choose a suitable solution.
Equipment investment cost
Nitrogen Generator: The initial investment cost of a nitrogen generator depends mainly on the following factors:
1) Nitrogen production requirements: The higher of production, the larger of equipment and the higher of cost. Small PSA nitrogen generator (5-50 Nm³/h): Investment cost is about RMB 100,000-300,000; Medium-sized PSA nitrogen generator (50-200 Nm³/h): Investment cost is about RMB 300,000-1,000,000; Large PSA nitrogen generator (＞200 Nm³/h): Investment cost exceeds RMB 1,000,000;
2) Nitrogen purity requirements: The higher of purity, the higher of equipment cost. For example, a nitrogen generator with 99.999% purity costs more than a nitrogen generator with 99.9% purity.
Liquid nitrogen storage system: The investment cost of a liquid nitrogen storage system depends mainly on storage capacity. The larger of capacity, the higher of cost. Small storage tank (1-5 tons): Investment cost is about RMB 50,000-150,000; Medium storage tank (5-20 tons): Investment cost is about RMB 150,000-500,000; Large storage tank (>20 tons): Investment cost exceeds RMB 500,000; Additional equipment: such as vaporizer, booster pump, etc., the cost depends on demand.
Comparative analysis: For small nitrogen demand (<50 Nm³/h), the initial investment cost of nitrogen generator and liquid nitrogen storage system may not be much different, and liquid nitrogen storage system may even be cheaper. For medium and large nitrogen demand, the initial investment cost of nitrogen generator is usually higher than that of liquid nitrogen storage system.
Operating costs
Nitrogen generator: The operating costs of nitrogen generator mainly include:
1) Electricity-The main source of energy consumption for nitrogen generator. The energy consumption of PSA nitrogen generator is about 0.2-0.4 kWh/Nm³
2) Maintenance costs: Including regular replacement of filter elements, valves, compressor lubricating oil, etc., the cost is about 3-5%/year of equipment investment.
3) Personnel costs: Professional personnel are required to operate and maintain the equipment.
Liquid nitrogen: The operating costs of liquid nitrogen mainly include:
1) Liquid nitrogen procurement costs: According to market price fluctuations, the price of liquid nitrogen is about 1000-2000 yuan/ton (equivalent to 1.4-2.8 yuan/Nm³).
2) Transportation costs: The costs will vary depending on the transportation distance and frequency.
3) Vaporization costs: If an external vaporizer is used, the cost needs to be calculated separately. Storage loss: Liquid nitrogen storage tanks have natural evaporation losses of about 0.1-0.5%/day, depending on the insulation performance of the tank and the ambient temperature.
Comparative analysis: In the long run, the operating cost of a nitrogen generator is usually lower than the purchase cost of liquid nitrogen. Assuming that the energy consumption of the nitrogen generator is 0.3 kWh/Nm³ and the electricity price is 0.7 yuan/kWh, the cost of nitrogen production is about 0.21 yuan/Nm³. The purchase cost of liquid nitrogen is calculated at 1.5 yuan/Nm³, plus transportation and storage losses, the actual cost of liquid nitrogen is about 1.7-2.0 yuan/Nm³. However, it should be noted that the maintenance cost of the nitrogen generator will increase with the increase of the service life of the equipment, and the price of liquid nitrogen may also fluctuate.
Supply Stability
Nitrogen generator:
1) Advantages: It can achieve self-sufficiency in nitrogen and is not affected by external factors. The equipment is highly reliable and can operate continuously.
2) Disadvantages: Equipment failure may cause nitrogen supply interruption, requiring backup equipment or emergency plans. It is highly dependent on electricity supply, and power outages will affect nitrogen production.
Liquid nitrogen:
1) Advantages: Suppliers usually provide stable supply guarantees. Liquid nitrogen storage tanks can be used as buffers to store a certain amount of liquid nitrogen to deal with emergencies.
2) Disadvantages: There are uncertainties in the transportation link, such as traffic jams and bad weather, which may affect supply. The supplier’s operating conditions, production capacity changes, etc. will also affect the stability of supply.
Comparative analysis: In terms of supply stability, liquid nitrogen is slightly better than nitrogen generators, but nitrogen generators can improve supply reliability by equipping them with backup equipment and a complete emergency plan.
Nitrogen generator:
1) Advantages: Nitrogen production and purity can be adjusted according to actual needs, with high flexibility. Suitable for occasions with large fluctuations in nitrogen demand.
2) Disadvantages: Equipment startup and shutdown take a certain amount of time, and the response speed is relatively slow.
Liquid nitrogen:
1) Advantages: Liquid nitrogen can be purchased at any time, and nitrogen supply can be replenished quickly, with good flexibility.
2) Disadvantages: Nitrogen purity is fixed and difficult to adjust according to demand. Storage capacity is limited, and it is difficult to cope with large demand fluctuations in a short period of time.
Comparative analysis: Liquid nitrogen has more advantages in responding to emergency needs and short-term demand fluctuations, while nitrogen generators perform better in long-term operation and meeting diversified needs.
Security
Nitrogen generator:
1) Advantages: The safety risk of equipment operation is relatively low. No need to store large amounts of hazardous gases.
2) Disadvantages: Improper equipment maintenance may pose a safety hazard. The compressed air system needs to be checked regularly to prevent pressure leaks.
Liquid nitrogen: Advantages: Suppliers usually provide professional safety guidance and services. Disadvantages: Liquid nitrogen is a cryogenic liquid and poses safety risks such as frostbite and suffocation. Liquid nitrogen storage tanks need to be checked regularly to prevent leakage and explosion.
Comparative analysis: Overall, nitrogen generators are safer than liquid nitrogen, but the safety risks of liquid nitrogen can be reduced through strengthened management and training.
Example Analysis
Assuming that a company’s nitrogen demand is 100 Nm³/h, the purity requirement is 99.9%, and the annual operating time is 8,000 hours.
Nitrogen generator solution: Equipment investment: about RMB 500,000; Annual operating cost (electricity + maintenance): about RMB 200,000; Total cost in 10 years: about RMB 2.5 million;
Liquid nitrogen solution: Storage tank investment: about RMB 300,000; Annual liquid nitrogen procurement cost: about RMB 1 million (calculated at 1.5 yuan/Nm³); Annual transportation and storage loss cost: about RMB 50,000; Total cost in 10 years: about RMB 10.5 million
Conclusion: In the long run, the nitrogen generator solution is more economical.
To sum up the above, choosing install the nitrogen generator or purchase liquid nitrogen, the following factors need to be considered comprehensively:
1) Nitrogen demand: The greater the demand, the more obvious the advantages of the nitrogen generator. Frequency of use and stability requirements: For long-term stable use, a nitrogen generator is more suitable; for short-term or intermittent use, liquid nitrogen may be more flexible.
2) Budget constraints: The initial investment budget is limited, so liquid nitrogen can be considered; if the long-term operating cost is more critical, a nitrogen generator is more cost-effective.
3) Safety considerations: For extremely high safety requirements, a nitrogen generator may be more suitable. Ultimately, companies should conduct a comprehensive assessment based on their actual situation and choose the most suitable nitrogen supply solution.
If you want to know more information, please contact us freely:
Contact: Lyan.Ji
Tel: 008618069835230
Mail: Lyan.ji@hznuzhuo.com
Whatsapp: 008618069835230
WeChat: 008618069835230
Post time: Apr-17-2025