Landfill Gas Measurement and Recovery

Landfills produce a mixture of methane and carbon dioxide with traces of nitrogen, oxygen and other gases. These gases are extracted from multiple wellheads and collected through a network of pipes to a common header pipe. Typical systems also involve blowers, pumps, knock-out pots and a flare or oxidizer. The collected "greenhouse gas" may be disposed of or recovered as a fuel source for a co-generation engine to produce electric power.

An accurate measurement of the landfill gas flow through the system provides operators with information on the amount of gas being extracted for optimizing effectiveness, for reporting to environmental agencies and for carbon credit programs.

Accurate flow measurement requires performance under challenging application conditions such as:
  • Mixed composition gases
  • Wet and/or dirty gas
  • Potentially explosive installation environment
  • Wide variations in flow rates
  • Large swings in gas and ambient temperatures
  • Large pipe sizes
Landfill Gas Measurement

Key Criteria For Flow Meter Selection

  • Accurate and calibrated for mixed methane, landfill gas composition
  • Temperature compensation
  • No moving parts to clog or foul in the presence of wet, dirty gas
  • Lowest cost and easiest to install in larger line sizes
  • Wide turndown for accurate, repeatable measurement over wide flow range
  • Excellent low flow sensitivity
  • Agency approved for use in Division 2 [Zone 2] and often Division 1 [Zone 1] hazardous environments
  • Multi-function – flow rate, totalized flow and temperature display outputs

FCI thermal dispersion flow meters, in both insertion and in-line styles are the landfill recovery industry's most often selected solution and the preferred choice of the leading landfill gas collection and flare system manufacturers. With robust designs and a broad selection of product solutions that meet all of the criteria above it is easy to understand why FCI is the preferred solution.

For line sizes larger than 2.5" [63 mm]
For line sizes 2.0" [51 mm] and smaller
* FCI Model FLT93 switches provide level detection for Knock-Out Pot (KOP) applications.