Products

Solutions

Services

Real-time quality
measurements inbiogas and biomethane

Benefits at a glance• High quality, repeatable andfast measurements• Low maintenance• Reliable in harsh environments• Accurate and real-timemeasurements• NIST traceable calibrations

Summary: Biogas is on its way tobecoming a staple in the movement toreduce our carbon footprint on theplanet. Biogas is a renewable source ofenergy that comes from a variety ofsources. Once biogas is formed within
the anaerobic digester, it is processed
to remove unwanted contaminants
such as H2O, CO2, and H2S. In nature,biogas is formed when organic matteris broken down by bacteria through anatural biochemical process. With theutilization of anaerobic digesters, thisnatural process is now being replicatedby large and small biogas producers.
Challenge: post processing —meeting gas quality requirements
After biogas is processed, theconcentration of methane is 97–99%,
earning the name biomethane. Oncethe gas is processed to biomethane, it

J22 and JT33 TDLAS gas analyzers

Typical composition of biogas pre- and post-processing:
ChemicalBefore processingAfter processing

MethaneCH450–80%

97–99%

Carbon dioxide

CO220–50%

1–3%

NitrogenN2

10–20%

0–2%

Oxygen020–2%<1000 ppmv

Hydrogen sulfide

H 2S

0–0.3%<4 ppmv

Water

H 2O

0–90% (RH)

<10 0 ppmv

2

Real-time quality measurements in biogas and biomethane

is injected into an interconnect pipeline where it issubjected to a custody transfer measurement. During thismeasurement, the biomethane must meet industry
standards and local and regional regulations.
These standards specify the minimum levels ofcontaminants (H2O, CO2, H2S and O2) allowed in biogas to
be injected and mixed into natural gas pipelines. Current
industry standards for injection into the pipeline gas byutilities companies are aligned with the regulatory

requirements for natural gas pipelines. If the biomethanemeets industry standards, it is then transferred to atransmission pipeline for distribution.
The industry standards and governmental regulations areset to keep the public safe and sustain the integrity of thepipeline infrastructure. High levels of contaminants H2O,
CO2, H2S and O2 cause corrosion in pipelines and cannegatively affect combustion in generators.

Basic flow of biogas products
The process map shows a simple diagram that exemplifies a basic biogas system. The most common sources ofmethane are dairy farms and livestock, landfills, and wastewater.

Anaerobic digester: AX1
H2O: SS500*

J22

CO2: SS2100a/i H2S: JT33, SS2100 O2: OXY5500

Post-gas processing: AX2
H2O: J22

CO2: SS2100a/i H2S: JT33, SS2100 O2: OXY5500

Multi-component*
SS2100 2-Pack (H2S & H2O or H2S & CO2)
SS2100 2-Pack + OXY5500 (H2S, H2O, O2)
SS2100 3-Pack (H2S, H2O, CO2)
SS2100 3-Pack + OXY5500 (H2S, H2O, CO2, O2)*These products available with CSA Class I Div 2 certifications only.

Real-time quality measurements in biogas and biomethane

Our Solution: Our analyzers employ tunable diode laser
spectroscopy (TDLAS) that detects and measures theconcentration of molecular compounds (H2O, H2S, CO2) ingas streams. The rugged nature of our laser-based
analyzers has allowed them to be used in natural gas
pipelines with very little maintenance, no interference, andwith no detrimental effects from glycol, methanol, amine,
H2S and moisture. Since its inception, this technology has
demonstrated its reliability in thousands of installations
worldwide.

Our TDLAS-based analyzers require no calibration in thefield and the calibration is stable for the life of the analyzer;
however, validation of H2O, H2S, and CO2 concentration issimple to perform.
For performance specifications, please see application notes
below:• H2O in natural gas production, storage and transportation(AI01215C)• H2S in natural gas production, storage and transportation(AI01217C)• CO2 in natural gas production, storage and transportation(AI01216C)• O2 in natural gas production, storage and transportation(AI01218C)
Get more details for a specific measurement bydownloading the application note.
Simply enter the title in the “Find Products, Downloads, and more...”search field at www.endress.com.

SS500 TDLAS analyzer for H2O measurement

J22 TDLAS analyzer for H2O measurement and JT33 TDLAS analyzer
for H2S measurement

SS2100 TDLAS series analyzers for H2O, H2S, and CO2 measurement

OXY5500 QF analyzer for O2 measurement

3PU01455C/66/EN/02.23

www.addresses.endress.com