Analysis of Trace Carbon Monoxide (CO) in Hydrogen Fuel Using Jetanizer™

Significance of the Topic

Hydrogen fuel is gaining traction in applications ranging from fuel cell vehicles to residential power systems. However, trace impurities such as carbon monoxide (CO) can significantly impair fuel cell performance and longevity. Accurate, sensitive detection of CO at sub‐ppm levels is essential to comply with international standards (ISO 14687‐2) and ensure the reliability of hydrogen fuel systems.

Objectives and Study Overview

This study demonstrates a streamlined gas chromatographic method for quantifying trace CO in hydrogen fuel. By integrating the Jetanizer™ nozzle‐type methanizer into an FID detector and employing a compact Brevis™ GC-2050 system with N₂ carrier gas, the method aims to:

• Detect CO at the 0.2 ppm level or lower.
• Maintain excellent linearity and repeatability across a calibration range of 0.1–5 ppm.
• Avoid reliance on helium or alternative costly carrier gases.

Methodology and Instrumentation

A compact Brevis GC-2050 chromatograph was used, featuring a minimal installation footprint. Key analytical components included:

• Carrier gas: Nitrogen in constant linear velocity mode (40 cm/s).
• Column: SH-Msieve 5A (30 m × 0.53 mm I.D., 50 µm), with 2.5 m particle trap; preconditioned periodically at 300 °C to remove adsorbed moisture.
• Detector: Flame ionization detector equipped with the Jetanizer™ methanizer nozzle (45 mm insertion depth), operating at 400 °C.
• Makeup gas: N₂ (24 mL/min); H₂ flow: 32 mL/min; Air flow: 250 mL/min.
• Sampling: Shimadzu MGS-2030 gas sampler with 1 mL loop; split ratio 1:1; injection port at 100 °C.
• Oven program: Initial hold at 40 °C for 2.5 min, ramp to 200 °C, then to 270 °C at controlled rates.

Main Results and Discussion

A four‐point calibration using CO standards (0.1, 0.5, 1, 5 ppm in H₂) yielded an R2 ≥ 0.9999, confirming excellent linearity. The limit of detection (S/N = 3) was determined as 0.04 ppm CO.

Repeatability tests at 0.2 ppm CO (n = 5) showed:

• Quantified concentrations: 0.200–0.207 ppm CO.
• Area %RSD: 1.6 %.

The results demonstrate that the Jetanizer enables sensitive, reproducible CO analysis using N₂ as the carrier gas, simplifying system requirements and reducing operational costs compared to helium‐based detectors.

Benefits and Practical Applications

The proposed method offers:

• High sensitivity for trace CO detection meeting ISO 14687‐2 requirements.
• Use of readily available N₂ carrier gas, alleviating helium supply constraints.
• A compact, space‐efficient GC platform suitable for laboratory and on‐site monitoring.
• Robust repeatability critical for quality control in hydrogen production and distribution.

Future Trends and Opportunities

Advancements may include:

• Integration of multi‐channel methanizer arrays for simultaneous CO, CO₂, and CH₄ analysis.
• On‐line monitoring solutions with automated sampling for continuous fuel quality surveillance.
• Further miniaturization of GC systems for field‐deployable hydrogen purity analyzers.

Conclusion

This work validates a high‐performance GC method using the Jetanizer and Brevis GC-2050 for trace CO analysis in hydrogen fuel. Achieving sub‐ppm detection sensitivity, excellent linearity, and repeatability with N₂ carrier gas, the approach addresses key challenges in fuel quality assurance and supports broader adoption of hydrogen energy technologies.

Reference

• Application News No.01-00599. Assessment of Jetanizer™ and Quantitative Analysis of CO₂ and CH₄ in the Atmosphere.