Real-Time Gas Chromatography System for Ultrasensitive Monitoring of Odorants in Natural Gas Infrastructure

Natural gas (NG), primarily composed of methane, is colorless and odorless, thus necessitating odorization to enable leak detection and accident prevention. Precise monitoring of odorants is critical to meet safety standards while preventing excessive dosing. This study introduces a real-time gas chromatography system integrating gas chromatography and photoionization detection for the real-time, online odorant analysis in gas pipelines. This system effectively isolates tetrahydrothiophene (THT) and sulfur-free odorants from NG, enabling accurate concentration quantification. It achieves THT detection within 2∼150 mg/m³, with a relative standard deviation (RSD) of less than 1.5% and maximum deviation of less than 3 mg/m³. Additionally, this system exhibits good field applicability. When combined with a cloud-based warning platform, it can achieve monitoring, warning, and self-optimization of odorant concentration. This study demonstrates the reliability of this system for NG odorant monitoring, providing a robust solution for pipeline safety management and regulatory compliance, while offering a new approach for NG safety testing.