CBG Gas Train
A complete gas train that takes raw biogas through scrubbing, drying, upgrading and compression to 250 bar for CBG cascades.
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One gas train from raw biogas to 250 bar
CRA supplies the complete CBG gas train as one engineered package: H₂S scrubbing, gas conditioning, membrane upgrading, compression to 250 bar and metering. Every stage is sized from the same gas data and engineered by one team, so the plant has one supplier responsible for gas quality from the digester to the cascade.
Compression
Up to 250 bar
Product gas
IS 16087:2025
Methane slip
Below 1%
Scope
Raw biogas to cascade
What is a CBG gas train?
A CBG gas train is the set of process stages between a biogas plant's digester and its CBG cascade. It cleans and dries the raw biogas, separates the carbon dioxide to make biomethane, and compresses the gas for storage and sale. Each stage depends on the one before it, so the train works best when it is designed as one system.
How it works
Raw biogas passes through five stages, with a flare for excess and off-spec gas.
A chemical scrubber with biological regeneration removes the H₂S, with polishing where needed.
Dehumidification and moisture removal protect the membranes and compressors.
Multi-stage membranes separate the carbon dioxide and recover the methane.
Compressors take the biomethane up to 250 bar for the cascades.
The CBG is metered for sale, and a flare takes excess and off-spec gas.
Key Benefits
Scrubbing, drying, upgrading, compression and metering come from one supplier with one design basis.
Bulk H₂S removal and polishing protect the membranes and compressors downstream.
Membrane upgrading produces gas with more than 98% methane for CBG.
The whole train runs under a single control system with one operator interface.
Stages are built as skids, which shortens site installation and commissioning.
The CRA Edge
CRA has more than 30 years of experience in gas handling and flare engineering.
Design, R&D and manufacturing are carried out under one roof.
ISO 9001 certified through TÜV NORD, with designs aligned with ASME, API and CE.
Designs are customised to the process needs and the regulations that apply at site.
Applications
Built to help you specify.
Sizing tools, decision guides, and technical references. Use them before, during, and after your evaluation.
Frequently Asked Questions
What does the CBG gas train include?
It includes H₂S scrubbing, gas drying, membrane upgrading, compression to 250 bar and metering, engineered together as one package.
Why buy the train from one supplier?
Each stage depends on the one before it. A single supplier gives one design basis, one control system and one point of responsibility for gas quality.
Can CRA supply part of the train?
Yes. CRA supplies each stage on its own as well, and can match it to equipment already at site.
What data does CRA need for an offer?
CRA needs the raw biogas flow range, its composition including H₂S, the required CBG output and the site conditions.
Does the train suit seasonal feedstocks?
Yes. CRA designs the train for the plant's flow range, including the low flows at the start and end of a season.