APPLICATION NOTE
Reliable Landfill Wellhead Tuning using Micro GC Fusion®
OVERVIEWThis application note describes the advantages ofusing Micro GC Fusion Gas Analyzer to analyze landfill
gas. With its accurate result and simple operation,
Micro GC Fusion supports efficient wellhead tuning tooptimize landfill gas quality.

INTRODUCTION
Landfill gas is mostly generated through the natural
decaying process of organic waste in a landfill, which iscomposed of methane, carbon dioxide, nitrogen,oxygen and other gases. With the high methane
concentration in landfill gas, typically ranging 45–60%1,
landfill gas is a major contributor to global climatechange when allowed to vent freely2. Methane is also
known for its high energy content. Capturing landfill
gas for energy generation and consumption purposes,
therefore, is beneficial for both environmental andcommercial purposes.
The United States Environmental Protection Agency(USEPA) Landfill Methane Outreach Program (LMOP)
encourages effective use of biogas recovered fromlandfill emission. Usages may include electricity
generation, heating for local communities, and with an
upgrade to renewable natural gas (RNG) landfill gas
can be used for pipeline injection or vehicle
consumption. The United States government facilitates
renewable energy adoption by providing regulatory
incentives to the energy industry. An example of this is
the Renewable Identification Number (RIN)3, a serial
number assigned to a batch of biofuel. Compressed orliquefied natural gas produced from RNG generates
RINs, which can be purchased by producers andimporters of gasoline and diesel to fulfill their
Renewable Fuel Standard (RFS) compliance. RIN is
therefore a tradable instrument that is highly desirable
by petrochemical companies.
A landfill can benefit from outputting high quality landfill
gas and selling the gas along with the associated
RINS.

Efficiency of anaerobic bacterial decomposition oforganic waste in a landfill is correlated to the oxygen
level in the landfill. To maintain high quality gas output,operators “tune” the landfill by regulating air intake at
the landfill wellheads. An important indication of how
the wellhead should be tuned is provided by the landfill
gas composition at the wellhead. Micro GC Fusion
empowers operators with highly accurate andcomprehensive gas composition measurement tooptimize landfill gas output.

EXPERIMENT
A landfill gas calibration standard (MESA SpecialtyGas) was analyzed on a 2-module Micro GC Fusion:Module A: Rt-Molsieve 5A, 10m temperature
programmable column with a backflush injector
and thermal conductivity detector (TCD)

Module B: Rt-U-Bond, 12m temperature
programmable column with a large variable volumeinjector and TCD

Two sets of fifteen runs were performed, one set withhelium carrier gas and another set with argon carriergas. The last ten of each fifteen runs were used for thepeak area and retention time (RT) repeatability
calculation.
An additional run was conducted mixing moisture into
the landfill gas calibration standard to simulatecomposition close to a real landfill gas sample.

REFERENCE
1. “Landfill Gas Primer - An Overview for Environmental HealthProfessionals.” Centers for Disease Control and Prevention.
November 01, 2001. Accessed August 03, 2018.
https://www.atsdr.cdc.gov/HAC/landfill/html/ch2.html
2. “Benefits of Landfill Gas Energy Projects.” EPA. May 24, 2018.
Accessed July 20, 2018.
https://www.epa.gov/lmop/benefits-landfill-gas-energy-projects.
3. “Renewable Identification Numbers (RINs) under the
Renewable Fuel Standard Program.” EPA. March 20, 2017.
Accessed July 20, 2018.
https://www.epa.gov/renewable-fuel-standard-program/renewabl
e-identification-numbers-rins-under-renewable-fuel-standard.

1 of 4RESULTS
Six gas components in the landfill calibration standard were analyzed in 90 seconds. See Figure 1, Figure 2 andFigure 3. Relative standard deviation of the last ten consecutive runs were checked. All compounds of interest had
peak area %RSD of <1% and a retention time % RSD of <0.1%. The concentrations of the components in thecalibration standard, carrier gas used, component retention time, %RSD for peak area and retention time areshown in Table 1.
Table 1 Analytical Performance on Landfill Gas Components
ModuleComponent

Mole%Carrier Gas

Retention Time (s)Area %RSD

RT %RSDA

hydrogen

5.14

argon

50.08

0.07

0.03

A

oxygen1.03

helium

44.60

0.36

0.05

A

nitrogen

2.19

helium

48.840.280.03

Amethane49.61

helium

54.36

0.61

0.04

A

carbon monoxide

0.10helium

64.12

0.96

0.04

B

carbon dioxide

41.93

helium

22.96

0.57

<0.01

Figure 1 Chromatogram of Module A (Helium)

Column: Rt-Molsieve 5A, 10m; Column Temperature: 110°C;
Column Head Pressure: 30 psi; Carrier Gas: Helium

Reliable Landfill Wellhead Tuning using Micro GC Fusion®

2 of 4

Figure 2 Chromatogram of Module B (Helium)

Column: Rt-U-Bond, 12 m; Column Temperature: 70°C;
Column Head Pressure: 30 psi; Carrier Gas: Helium

Figure 3 Chromatogram of Module A (Argon)

Column: Rt-Molsieve 5A, 10m; Column Temperature:110°C; Column Head Pressure: 30 psi; Carrier Gas: Argon

Reliable Landfill Wellhead Tuning using Micro GC Fusion®

3 of 4

Reliable Landfill Wellhead Tuning using Micro GC Fusion®

4 of 4Figure 4 Chromatogram of Module B with Water in Sample (Helium)

Column: Rt-U-Bond, 12m; Column Temperature:
70°C (hold 40 s) to 160°C at 1°C/s (hold 10 s);
Column Head Pressure: 30 psi; Carrier Gas: Helium

DISCUSSION
In this experiment hydrogen was detected using argon as the carrier gas. The large difference in thermal
conductivity between hydrogen and argon provides the best analytical performance on a TCD. If helium is used asa carrier gas, the hydrogen peak intensity as detected by the TCD will be significantly reduced, due to the small
thermal conductivity difference between helium and hydrogen.
Landfill gas usually contains moisture, which elutes on a Rt-U-Bond column after the carbon dioxide peak. The
water peak may appear as a ghost peak in the next run if the current run is stopped before water elutes. Starting atemperature ramp after the carbon dioxide peak elutes speeds up the water peak elution. This effectively elimatesghost peak interference in the next run. See Figure 4.
A backflush injector is recommended to avoid Molsieve column performance degradation caused by the carbon
dioxide and moisture present in landfill gas.

CONCLUSION
Micro GC Fusion offers an accurate and simple gas measurement solution for methane, carbon dioxide, nitrogen,oxygen, carbon monoxide and hydrogen. This supports landfill tuning and optimizes landfill gas output quality. With
its small size and fast analysis, Micro GC Fusion is the ideal analyzer for both container office or field vehicle setup.

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