Nitrogen Generators Prove Up to 3× More Cost Effective than Cylinders - Full TCO Analysis

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• A 10-year total cost of ownership (TCO) analysis shows that an on-site NITRO-GEN+ nitrogen generator is up to 65% cheaper than cylinders.
• Labs can save nearly $63,000 over the same 10-year period by switching away from cylinders.
• For high-capacity evaporation, that makes on-site nitrogen generation almost three times more affordable than relying on cylinders.

Introduction

When laboratories scale up their sample evaporation workflows, nitrogen gas quickly becomes a critical, yet costly resource. Two primary options exist for supplying that nitrogen:

- High-pressure cylinders delivered by a gas supplier
- An on-site nitrogen generator that continuously produces gas from compressed air

Both methods can power Organomation’s popular evaporators, but they differ significantly in long-term economics and day-to-day management. With rising gas prices and increasing demand for operational efficiency, labs frequently ask: Which option is more cost-effective over the life of the equipment?

This analysis compares the five-year and ten-year total cost of ownership (TCO) for two of Organomation’s most popular systems—a 24-position N-EVAP and a 48-position MULTIVAP—when supplied by either nitrogen cylinders or a NITRO-GEN+ generator. By looking at purchase price, operating expenses, and maintenance, we can highlight the break-even point and show where a generator begins to outperform cylinders financially, while still noting situations where cylinders remain a practical choice.

Key Assumptions

- Operating schedule: 40 minutes/day, 250 workdays/year
  (40 minutes is the average time it takes to evaporate 10 mL samples of methanol)
- Gas flow per sample position: 0.33 L/min
- Cylinder size & price: 300 ft³ (~8,495 L) at $400 per cylinder
- Cylinder fees: $20 monthly rental + $30 delivery per tank
- Generator cost & maintenance: $15,000 purchase, compressor replacement $1,800 every 18 months
- Evaporator cost: $6,200 for the 24 position N-EVAP and $6,700 for the 48 position MULTIVAP
- Electricity: $0.13/kWh (≈$25/year for cylinders, ≈$39/year for generator)

24 Position N-EVAP Nitrogen Evaporator

Nitrogen Demand

- Total flow when fully loaded: 8 L/min
- Daily consumption: 8 L/min × 40 min = 320 L/day
- Annual consumption: 320 L/day × 250 days = 80,000 L/year

Option A – Cylinder Supply

- Capital (evaporator): $6,200
- Annual cylinders required: 80,000 L ÷ 8,495 L ≈ 10 cylinders/year
- Annual cylinder purchase cost: 10 × $400 = $4,000
- Annual cylinder rental: 10 x $20 rental = $200
- Annual cylinder delivery: 10 x $30 rental = $300
- Annual energy cost (evaporator): ~ $25

* 5 year TCO: $6,200 + ($4,000 x 5) + ($200 x 5) + ($300 x 5) + ($25 x 5) = $28,825
* 10 year TCO: $6,200 + ($4,000 x 10) + ($200 x 10) + ($300 x 10) + ($25 x 10) = $51,450

Option B – NITRO-GEN+ Generator

- Capital (evaporator + generator): $21,200
- Maintenance: 

- Compressor replacement: every 18 months @ $1,800 → ~$6,000 over 5 years → ~$12,000 over 10 years

- Annual energy cost (evaporator + generator): ~ $39

* 5 year TCO: $21,200 + $6,000 + ($39 x 5) = $27,395
* 10 year TCO: $21,200 + $12,000 + ($39 x 10) = $33,590

5 Year TCO Comparison

10 Year TCO Comparison

At a moderate daily workload, the NITRO-GEN+ generator is already ~5% more cost-effective than cylinders over five years for the 24-position N-EVAP, and nearly 35% cheaper over ten years, saving the lab almost $18,000. In other words, over a decade, a lab using a generator spends about 1.5 times less than if relying on cylinders.

Beyond cost, the generator eliminates the need for frequent cylinder deliveries and storage, reducing logistical complexity and improving workflow reliability.

48 Position MULTIVAP Nitrogen Evaporator

Nitrogen Demand

- Total flow when fully loaded: 16 L/min
- Daily consumption: 16 L/min × 40 min = 640 L/day
- Annual consumption: 640 L/day × 250 days = 160,000 L/year

Option A – Cylinder Supply

- Capital (evaporator): $6,700
- Annual cylinders required: 160,000 L ÷ 8,495 L ≈ 20 cylinders/year
- Annual cylinder purchase cost: 20 × $400 = $8,000
- Annual cylinder rental: 20 x $20 rental = $400
- Annual cylinder delivery: 20 x $30 rental = $600
- Annual energy cost (evaporator): ~ $30

* 5 year TCO: $6,700 + ($8,000 x 5) + ($400 x 5) + ($600 x 5) + ($30 x 5) = $51,850
* 10 year TCO: $6,700 + ($8,000 x 10) + ($400 x 10) + ($600 x 10) + ($30 x 10) = $97,000

Option B – NITRO-GEN+ Generator

- Capital (evaporator + generator): $21,700
- Maintenance: 

- Compressor replacement: every 18 months @ $1,800 → ~$6,000 over 5 years → ~$12,000 over 10 years

- Annual energy cost (evaporator + generator): ~ $39

* 5 year TCO: $21,700 + $6,000 + ($39 x 5) = $27,895
* 10 year TCO: $21,700 + $12,000 + ($39 x 10) = $34,090

5 Year TCO Comparison

10 Year TCO Comparison

For the 48-position MULTIVAP, the NITRO-GEN+ generator delivers even more striking savings. Over five years, it is ~46% cheaper than cylinders, and over ten years it is ~65% cheaper, saving nearly $63,000. Put differently, using a generator makes nitrogen supply almost 3 times more affordable than relying on cylinders over a decade.

Beyond the financial advantage, the generator removes the need for roughly 20 cylinder deliveries per year, reduces storage requirements, and ensures a continuous, reliable nitrogen supply for high-throughput workflows.

What the Numbers Show

The financial edge of on-site generation becomes unmistakable as capacity and time increase.

- 24 Position N-EVAP: At moderate daily use, a NITRO-GEN+ generator is about 5% cheaper than cylinders over five years and roughly 35% cheaper over ten years, saving nearly $18k. Over a decade, that’s about 1.5x lower total cost for nitrogen supply.

- 48 Position MULTIVAP: Higher throughput magnifies the gap: the generator is around 46% cheaper at five years and about 65% cheaper at ten years, trimming almost $63k from total costs. In other words, on-site generation is nearly 3x more affordable than cylinders across a ten-year period.

These numbers underscore a clear pattern: the more samples a lab processes—and the longer the planning horizon—the stronger the case for investing in a nitrogen generator.

Takeaway

For laboratories running daily evaporations, on-site nitrogen generation delivers long-term savings and operational freedom:

- Financially superior: Even at moderate capacity, the generator edges out cylinders within five years. At higher capacity, it slashes decade-long costs by tens of thousands of dollars.

- Scalable and reliable: Continuous nitrogen output eliminates delivery scheduling, storage headaches, and the risk of running out of gas mid-analysis.

- Strategic investment: Over a ten-year horizon, the NITRO-GEN+ enables labs to spend up to 65% less on nitrogen supply and reinvest those savings into research or instrumentation.

Cylinders can remain practical for very low-usage operations, but once nitrogen demand reaches moderate to high levels, an on-site generator is the clear, cost-effective choice for supplying nitrogen blowdown evaporators. 

See how much a nitrogen generator could save your lab: