When selecting a nitrogen supply method for high-purity applications (e.g., 30 Nm³/h flow rate with 99.999% nitrogen purity), it’s essential to evaluate the overall operating and usage costs of three common options: nitrogen cylinders, liquid nitrogen, and on-site nitrogen generation. The following analysis presents a comprehensive cost comparison of these three approaches.
1. Operating Cost Analysis
A. Nitrogen Cylinders
Nitrogen cylinders with 99.999% purity are typically priced at around RMB ¥50 per cylinder. Each cylinder, pressurized to 12 MPa, provides approximately 5 cubic meters of usable nitrogen gas. This translates to a cost of roughly ¥10 per Nm³. Due to high unit costs and logistical limitations, this method is only suitable for users with very low nitrogen consumption.
B. Liquid Nitrogen
Liquid nitrogen with 99.999% purity is generally sold at approximately RMB ¥1,500 per metric ton. One ton of liquid nitrogen yields about 600 cubic meters of gaseous nitrogen after vaporization. Thus, the average cost is around ¥2.5 per Nm³. However, this excludes upfront investment in cryogenic tanks, vaporizers, pipelines, and operator labor.
C. On-Site Nitrogen Generation (30 Nm³/h System)
The operating cost of an on-site nitrogen generation system includes four main components:
1. Power Consumption
- Air Compressor: Rated at 15 kW, actual consumption ≈9 kW
- Refrigerated Dryer: ≈0.58 kW
- Nitrogen Generator (instrument use): ≈0.6 kW
- Purification System: ≈6 kW
➡️ Total Power Consumption: ~17 kW
➡️ Electricity Rate: ¥0.7/kWh
➡️ Hourly Power Cost: 17 × 0.7 = ¥11.9
➡️ Cost per Nm³: ¥11.9 / 30 = ¥0.4 per Nm³
2. Labor Cost
As the system runs automatically and only requires periodic inspection, labor costs are minimal. Estimated at ¥20/day, or ¥7,200/year.
3. Maintenance & Consumables
| Component | Frequency | Unit Price (RMB) |
|---|---|---|
| Air filter cartridge | Every 4,000 hours | ¥445 |
| Oil-gas separator | Every 8,000 hours | ¥480 |
| Oil filter | Every 2,000 hours | ¥346 |
| Lubricating oil | Every 2,000 hours | ¥350 |
| Compressed air filters (C/T/A) | Every 4,000 hours | ¥600 (set of 3) |
| Oxygen analyzer sensor | Every 2 years | ¥580 |
➡️ Annual Maintenance Estimate: ¥2,830/year
4. Equipment Depreciation
Based on a 10-year depreciation period, and a total system investment of ¥172,400, the annual depreciation cost is ¥18,000/year.
2. Annual Usage Cost Summary
| Supply Method | Unit Cost (¥/Nm³) | Hourly Cost (30Nm³/h) | Annual Cost (8000h) |
|---|---|---|---|
| Cylinder Nitrogen | 10.0 | ¥300 | ¥2,400,000 |
| Liquid Nitrogen | 2.5 | ¥75 | ¥600,000 |
| On-Site Generation | 0.4 | ¥12 | ¥124,000 |
✅ On-site nitrogen generation saves over 90% annually compared to cylinder nitrogen and nearly 80% compared to liquid nitrogen.
3. Market Price Fluctuation Reminder
Please note that nitrogen prices may vary depending on global energy costs, raw material fluctuations, and local supply-demand dynamics. The cost figures provided in this comparison are based on standard market averages and should be used for reference only. Actual pricing may differ based on region and vendor contracts. We recommend consulting your gas supplier for up-to-date quotations.
4. Final Conclusion
For industrial users requiring consistent, high-purity nitrogen at medium to high volumes, on-site nitrogen generation provides the most cost-effective and sustainable solution. Although initial investment is required, the significantly lower long-term operating costs ensure rapid ROI and reliable gas supply without dependence on external logistics.
About Jinhong Gas
Jinhong Gas is a leading industrial gas supplier in China, specializing in high-purity nitrogen, oxygen, helium, hydrogen, carbon dioxide, and specialty gases. With decades of experience, we provide tailored gas solutions to industries such as electronics, metallurgy, aerospace, glass processing, and pharmaceuticals.
Our nitrogen generation systems are engineered for high efficiency, safety, and environmental performance. Whether you need bulk nitrogen delivery, on-site gas generation, or custom purity levels, Jinhong Gas offers expert support and reliable service.
👉 Contact Jinhong Gas today to optimize your gas supply and reduce operating costs with a smarter, cleaner nitrogen solution.
