Assessment of Jetanizer and Quantitative Analysis of CO2 and CH4 in the Atmosphere

Significance of the Topic

The drive towards carbon neutrality and high‐purity hydrogen production requires sensitive, reliable quantification of trace gases including CO, CO₂, and CH₄.
Conventional detectors (TCD, BID) face limitations in sensitivity and carrier gas requirements.
The integration of a methanizer (Jetanizer™) with GC‐FID offers a simplified, oxygen‐tolerant solution for these analyses.

Study Objectives and Overview

This study assesses the performance of the Jetanizer™ coupled to a Shimadzu Nexis GC‐2030 FID system for the quantitative determination of CO, CO₂, and CH₄.
Key goals include evaluation of conversion efficiency, linearity, repeatability, detection limits, and oxygen durability.

Methodology and Instrumentation

• Instrumentation: Nexis GC‐2030 with MGS‐2030 gas sampling valve (1 mL loop), Jetanizer™ integrated in the FID nozzle.
• Columns: SH‐Q‐BOND PLOT capillary (30 m × 0.53 mm) & Porapak‐Q packed (2 m × 2 mm) for fundamental performance; MICROPACKED‐ST column for ambient air analysis.
• Carrier and makeup gas: Nitrogen (constant flow or linear velocity); hydrogen for FID flame and in situ reduction; air flow at 250 mL/min.
• Temperatures: Injector 150–250 °C; column 40 °C isothermal or programmed; FID + Jetanizer nozzle at 400 °C.
• Analytical conditions: Split injection (1:5 or 1:3), column flows ~40 cm/s or 10 mL/min, hydrogen 32 mL/min.
• Standard gases: CO, CO₂, CH₄ mixtures in N₂ spanning 1 ppm–25 % for calibration.

Key Results and Discussion

• Conversion Efficiency: >97 % for CO and CO₂ across 1 ppm–1 % on capillary column; slight efficiency drop (68.7 %) at 25 % CO in packed column due to catalyst overloading.
• Linearity and Repeatability: Calibration curves with R² >0.999 (capillary) and >0.9988 (packed); area repeatability RSD <2.5 % for all analytes.
• Detection Limits: LODs of 0.27–0.37 ppm on capillary, improved to 0.08–0.17 ppm on packed column.
• Oxygen Durability: No sensitivity loss after >3500 sequential air injections (total ~3.5 L) demonstrating catalyst stability.
• Ambient Air Analysis: Successful separation of O₂, CH₄, CO₂ with ambient CH₄ quantified at 2.1 ppm (RSD 0.49 %) and CO₂ at 419 ppm (RSD 0.51 %).

Benefits and Practical Applications

• Simplified hardware: no external methanizer heater or gas lines; exchange of FID nozzle only.
• Low operational cost by using nitrogen as carrier gas.
• Oxygen‐tolerant catalyst allows direct analysis of air samples without strict oxygen exclusion.
• Applicable to environmental monitoring, process control, and high‐purity gas quality assessment.

Future Trends and Potential Applications

• Integration with automated sampling systems for real‐time monitoring of greenhouse gases.
• Development of portable GC‐FID units with Jetanizer for field analysis.
• Expansion to other trace gas analyses through catalyst design enhancements.
• Application in carbon capture verification and industrial emission control strategies.

Conclusion

The Jetanizer™ integrated GC‐FID system on the Nexis GC‐2030 delivers high conversion efficiency, excellent linearity, low detection limits, and robust oxygen tolerance, offering a streamlined and cost‐effective solution for trace analysis of CO, CO₂, and CH₄.