Mass flowmeter for biofuel, methane capture

This flowmeter is designed to deal with the challenges of gas flow measurement barriers presented by the wet, dirty nature of biogas.
By Plant Engineering Staff August 12, 2008

Mass flowmeter

The model ST51 mass flowmeter is designed for owners, operators and manufacturers of biogas production and methane capture and recovery systems. The explosion-proof flowmeter features a no-moving parts design that’s non-clogging and operates over a wide flow range with low-flow sensitivity. The calibration is matched to the user’s actual gas composition and installation conditions. Dual 4-20 mA analog outputs are user assignable to flow rate and/or temperature, and there is a 0-1-kHz pulse output for totalized flow. The transmitter’s digital communications include an RS-232C port, and with units that have the digital display option there is a wireless IR link for PDA use.

In anaerobic digester produced biogas, gas flow measurement is challenged by the wet, dirty nature of biogas. The biogas produced is a potentially dangerous mixed composition of primarily methane and carbon dioxide, with smaller percentages of hydrogen sulfide and other gases. The wetness, hydrogen sulfide and other particulates in the gas create a corrosive condensate that deposits itself on the pipe wall and instruments in the pipe. The gas flow varies widely too, based on fluctuating plant process demands and seasonal variations in temperature and humidity.

Fluid Components International