6 TPD biomethane, modular to 24 TPD
CBG plants
Straw in. CNG-grade gas, and fertiliser, out.
A CBG plant is a sealed biological train, not a single machine. Rice straw and other organics are screened, wetted to a slurry and held in bolted-steel digesters — no air, gently stirred, kept in the mesophilic band. Bacteria turn the carbon into raw biogas: methane plus carbon dioxide, with water and a little hydrogen sulphide.
Raw gas cannot go to vehicles or a grid as-is. It is dried, desulphurised, compressed and passed through membranes that keep the methane and reject most of the CO₂. What leaves the skid is biomethane — a renewable stand-in for CNG. The leftover digestate is split into a stackable solid fertiliser and a liquid that can be recycled as inoculum or applied on farms.
Tanks are modular so a site can add another unit later. Pumps and blowers sit duty-plus-standby so one motor failure does not stop the gas. A Siemens panel runs levels, mixers and alarms; surplus or off-spec gas goes to an enclosed flare instead of being vented raw.
- Capacity
- 6 TPD biomethane, modular to 24 TPD
- Lead time
- 8–14 months
- Power
- Parasitic load sized in FEED
Yield
More straw. More gas.
A 6 tonne-per-day biomethane line takes about 90–100 tonnes of rice straw and organics a day. Raise the feedstock and the same process scales — up to 24 tonnes of biomethane a day.
Slide the duty — 6, 12, 18 or 24 TPD
- Rice straw / organics in
- 90–100 t/day
- Raw biogas
- 13,600 m³/day
- Biomethane out
- 6 t/day
- Solid fertiliser
- 32 t/day
- Liquid fertiliser
- 447 t/day
Figures follow a rice-straw duty and move with moisture, C/N ratio and how well the tanks are run. Liquid slurry includes a recycle stream used as inoculum.
Process flow
Rice straw and organics to CBG.
The 6 tonne-per-day line, from feedstock prep through digestion, gas upgrade, fertiliser split and flare. Larger duties add the same modules.
Process
- 01Receive and screen rice straw and organics
- 02Mix and wet to a pumpable slurry
- 03Anaerobic digestion in sealed tanks — warm, stirred, no air
- 04Collect raw biogas in double-membrane holders
- 05Dry, desulphurise and filter the gas
- 06Compress and membrane-upgrade to biomethane
- 07Split digestate into solid cake and liquid fertiliser
Equipment
- Mechanical grille, paddle and submersible mixers
- Bolted modular digester tanks with double-membrane holders
- In-tank stirrers and heating coils
- Desulphuriser, dryer and duty/standby biogas blowers
- Compressor and hollow-fibre membrane upgrade skid
- Solid–liquid separator
- Siemens PLC / HMI, flare and gas analyser
Standards
- IS 16087 biogas
- SATAT offtake alignment
- EN gas-grid practice
Feedstock / product
Rice straw · Agri-straw · Cattle dung · Press mud · Food waste · Municipal organics
Brochure
Get the CBG pack as a PDF.
Process, mixing, offtake projects and the full biomethane line — click to download.
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