The energy costs of on-site nitrogen production for Modified Atmosphere Packaging (MAP) are primarily determined by the electricity consumption of the nitrogen generator and the required compressor. These costs typically vary between €0.10 and €0.30 per cubic meter of nitrogen, depending on the purity level, production volume, and local energy rates. For many companies that regularly use nitrogen for food packaging, on-site production results in lower operational costs compared to traditional delivery methods, with a typical payback period of 1-3 years.
What exactly does on-site nitrogen production for MAP involve?
On-site nitrogen production for Modified Atmosphere Packaging (MAP) is a technology where companies produce nitrogen gas at their own location, rather than depending on external suppliers. Using nitrogen generators, nitrogen is extracted directly from ambient air through pressure swing adsorption (PSA) or membrane technology.
In these processes, air is first filtered and compressed, after which oxygen, water vapor, and other gases are removed, leaving only pure nitrogen. The purity level can be adjusted depending on the specific requirements of your MAP application, typically between 95% and 99.999%.
MAP is a packaging technique where the air in food packaging is replaced by a controlled atmosphere, often consisting primarily of nitrogen. This slows down spoilage by preventing oxidation and inhibiting the growth of aerobic microorganisms, significantly extending the shelf life of products such as meat, fish, ready meals, cheese, vegetables, and fruit.
Companies choose on-site nitrogen production for multiple benefits:
- Continuous availability without delivery interruptions
- Cost savings with regular use
- Reduced dependence on external suppliers
- No need to store large quantities of gas
- More sustainable solution with a lower CO2 footprint
How are the energy costs of nitrogen production calculated?
The energy costs of on-site nitrogen production are mainly calculated based on the electricity consumption of the system. The total costs per cubic meter of nitrogen are determined by multiplying the energy consumption (kWh) by the local electricity price (€/kWh).
The main factors in this calculation are:
- Electricity consumption of the compressor (kWh)
- Electricity consumption of the nitrogen generator itself
- Local electricity rate (including network costs and taxes)
- Efficiency of the system (SCFM nitrogen per kW of energy consumed)
- Maintenance costs and depreciation of the equipment
A typical formula for calculating the energy costs per cubic meter of nitrogen is:
Cost per m³ N₂ = (Total energy consumption in kWh per m³) × (Electricity rate in €/kWh)
The total energy consumption per cubic meter of nitrogen typically varies between 0.25 and 0.70 kWh, depending on the purity level and the efficiency of the system. At an electricity price of €0.20 per kWh, this would amount to approximately €0.05 to €0.14 per cubic meter of nitrogen, excluding maintenance costs and depreciation.
Which factors influence energy consumption in nitrogen production?
The energy consumption in on-site nitrogen production is influenced by various factors, with the purity level having the most significant impact. The higher the desired purity, the more energy is required to achieve it.
The main influencing factors are:
- Purity level: For every additional 0.1% purity above 99%, energy consumption can increase by 5-15%. For MAP applications, 99.5% purity is usually sufficient, offering a good balance between quality and energy consumption.
- Production volume: Larger systems are often more efficient per cubic meter of nitrogen produced. A system operating at 80-90% of its capacity usually achieves optimal efficiency.
- Operational pressure: Higher pressure requires more compression energy. For MAP, a lower pressure (5-8 bar) is usually sufficient compared to other industrial applications.
- Ambient temperature: Higher temperatures reduce compressor efficiency. Good ventilation or cooling of the compressor room can reduce energy consumption by 3-7%.
- Equipment quality and maintenance: Regular maintenance and the use of high-quality filters can reduce energy consumption by 10-15% by limiting pressure losses.
The chosen technology also has an influence. PSA technology (Pressure Swing Adsorption) is often more energy-efficient at higher purity levels, while membrane technology is simpler to use and maintain but may consume slightly more energy at very high purity levels.
How do energy costs compare to traditional nitrogen delivery?
The energy costs of on-site nitrogen production are typically a fraction of the total costs associated with traditional delivery methods. While on-site production operational costs primarily consist of electricity consumption, traditional methods include transport, handling, rental of cylinders or tanks, and higher safety measures.
A comparison between the methods:
- On-site production: €0.10-0.30 per m³ (primarily energy costs)
- Cryogenic nitrogen (bulk): €0.40-0.80 per m³ (including delivery costs)
- Cylinders: €2.00-5.00 per m³ (depending on volume and delivery frequency)
The break-even point is usually reached after 1-3 years, depending on consumption volume. For companies that regularly use nitrogen for MAP applications, the energy costs of on-site production are almost always more advantageous in the long term.
Besides the direct cost benefits, on-site production also offers less visible advantages such as supply security, flexibility in production volumes, and reduced administrative burdens for managing supplier relationships. These factors contribute to the overall cost efficiency, even when the pure energy costs would be comparable.
What are effective ways to reduce energy costs in nitrogen production?
There are various strategies to reduce energy consumption and thus the costs of on-site nitrogen production. The most effective measures focus on optimizing the production process and improving the energy efficiency of the entire system.
Practical strategies to reduce energy costs:
- Optimize purity level: Precisely determine what purity is truly needed for your MAP application. Reducing from 99.9% to 99.5% can already save 10-20% energy without affecting product quality.
- Implement heat recovery: The heat released during compression can be reused for space heating or process water, improving the overall energy balance.
- Ensure regular maintenance: Timely replacement of filters, checking for leaks, and optimization of pressure losses can lead to 15% energy savings.
- Apply variable speed drives: Compressors with frequency control adjust their power to demand, which is more efficient than on/off cycles in traditional systems.
- Install a nitrogen buffer: A buffer tank can absorb peaks in demand, allowing the system to operate more stably and efficiently.
- Choose energy-efficient components: Modern energy-efficient compressors and generators can reduce consumption by 20-30% compared to older models.
- Implement smart control systems: Automatic monitoring and control can optimize the system for different production levels and conditions.
By applying a combination of these measures, you can significantly reduce the energy costs of your nitrogen production, sometimes by up to 40% compared to non-optimized systems.
Key insights on energy costs of on-site nitrogen production
On-site nitrogen production for MAP offers significant benefits in terms of costs, flexibility, and supply security. The key insights about energy costs can help you make an informed decision for your business.
In summary, these are the core points:
- Energy costs form the largest part of operational costs in on-site production, typically between €0.10 and €0.30 per cubic meter of nitrogen
- The purity level has the greatest impact on energy consumption – therefore, precisely determine what purity your MAP application truly needs
- Modern systems offer significantly better energy efficiency than older installations, shortening the payback period
- Regular maintenance and system optimization can reduce energy consumption by 15-40%
- On-site production usually becomes cost-effective with regular use, with a payback period of 1-3 years compared to traditional delivery methods
At Presscon, we understand that every MAP application has unique requirements. We offer customized solutions specifically designed to minimize energy costs without compromising on quality and reliability. Through our years of experience in various sectors, including the food industry and packaging solutions, we can advise you on the most energy-efficient solution for your specific needs.
Would you like to know more about how you can optimize the energy costs of your nitrogen production for MAP? We are happy to provide personalized advice that takes into account your specific situation and objectives. Contact our nitrogen production specialists for a detailed consultation.