Introduction
The document discusses the challenges and solutions related to measuring biogas flow in a municipal wastewater treatment utility's digester system. The utility sought to improve its existing flow metering technology to better manage biogas, which consists of methane, CO2, and trace gases, to prevent hazards and optimize energy generation.

Problem Statement
The existing Vortex technology-based flow meters were prone to clogging in the dirty biogas environment, leading to potential safety and environmental issues. Accurate measurement was critical for efficient co-generation power engine operation and to minimize maintenance costs.

Specifications and Requirements
The flow meters needed to handle a wide flow range from 1.64 to 1640 SFPS (0.5 to 500 NMPS) and pressures from 0.8 to 17.6 psig (0.05 to 1.21 bar). The technology had to be robust and low-maintenance, suitable for wet gas with particulates.

Solution
Fluid Components International (FCI) recommended the GF90 Series thermal mass flow meter and a Vortab® meter run flow conditioner. The thermal mass flow meter, with its no-moving parts design, is ideal for dirty gases. It features a smart transmitter with three calibration groups for varying gas compositions, enhancing accuracy and efficiency.

Installation Considerations
The piping layout was suboptimal for accurate measurement due to elbows near the meter. A Vortab® flow conditioner was installed to correct flow profile issues, eliminating the need for costly re-piping.

Results
The new system improved process control, compliance with environmental regulations, and co-gen engine efficiency. Maintenance costs were significantly reduced due to the non-fouling design of the thermal mass flow meter.

Conclusion
The implementation of the GF90 Series thermal mass flow meter and Vortab® flow conditioner has enhanced the operational efficiency and safety of the digester gas system, providing a reliable solution for biogas flow measurement.