Design and Use of a Full Flow Sampling System (FFS) for the Quantification of Methane Emissions

Area of Science:

• Environmental Science and Engineering
• Atmospheric Chemistry
• Energy Systems

Background:

• Growing natural gas production, especially from shale, intensifies scrutiny over methane emissions due to methane's high global warming potential.
• Existing methods for measuring methane emissions from natural gas infrastructure have limitations in accuracy and flexibility.
• A single commercial system for component-level emissions quantification has known weaknesses.

Purpose of the Study:

• To design, develop, and implement a novel full flow sampling system (FFS) for accurate quantification of methane and greenhouse gas emissions.
• To improve the accuracy and flexibility of methane emission measurements across the natural gas supply chain.
• To provide a portable and adaptable solution for diverse measurement applications.

Main Methods:

• Developed a modular full flow sampling system (FFS) incorporating an explosive-proof blower, mass airflow sensor (MAF), thermocouple, sample probe, constant volume sampling pump, laser-based greenhouse gas sensor, and data acquisition hardware/software.
• Utilized laser-based sensors to mitigate interference from higher hydrocarbons (C2+) and co-measured water vapor for humidity correction.
• Configured the system for portability, enabling applications from handheld use to vehicle mounting, with flow rates from 40 to 1,500 SCFM.

Main Results:

• The FFS successfully quantified methane emission rates with a relative uncertainty of ± 4.4%.
• The system demonstrated real-world operational capability in both conventional and remote natural gas facilities.
• Laser-based sensing effectively handled complex gas mixtures and allowed for necessary environmental corrections.

Conclusions:

• The novel full flow sampling system (FFS) provides a significant advancement in the accurate and flexible quantification of methane emissions.
• The FFS is a versatile and portable tool suitable for a wide range of natural gas industry applications, addressing current measurement gaps.
• This technology contributes to better environmental monitoring and management of greenhouse gas emissions within the energy sector.