Why paddy straw CBG plants matter
Every year, large quantities of paddy straw (parali) are burned across north India, which contributes to air pollution and loses a valuable resource. A paddy straw CBG plant converts this residue into Compressed Biogas for transport and industry, and returns organic manure to the soil. Farmers also earn from selling straw.
Paddy straw: from bale to CBG
- Paddy straw bale
- Bale shredder
- Hammer mill
- Twin-screw shearing
- Pretreatment / hydrolysis
- Digester
- Biogas
- Purification
- CBG
- Bale shreddingOpens compact round/square bales and separates entangled fibres
- Hammer millingConverts shredded straw into consistent coarse material
- Twin-screw shearingIntensive shearing, compression and fibre opening with controlled moisture
- Pretreatment / hydrolysisConditions the biomass for the selected digestion technology
- Anaerobic digestionMicrobes convert organic matter into raw biogas
- Upgrading & compressionCleaning, CO₂ removal and compression to CBG
Engineering challenges we design for
| Challenge | Biovardhan approach |
|---|---|
| Short harvest window | Bale aggregation planning, storage shed sizing, fire safety for stored biomass |
| Tough, long fibres | Shredder, hammer mill and twin-screw shearing line before the digester |
| Floating / scum layers | Fibre opening, slurry preparation and agitator design |
| Slow hydrolysis | Feedstock-specific retention time and organic loading, with co-digestion where useful |
| Digestate volume | FOM/LFOM processing for sale back to agriculture |
Where paddy straw CBG makes sense
Paddy-growing belts in Punjab, Haryana, Uttar Pradesh and Madhya Pradesh, and in Rajasthan's canal-irrigated districts including the Kota–Bundi region, have ample straw within an economic collection radius. Mustard straw, wheat straw and other residues can diversify supply. See CBG plants in Rajasthan.
Biomass aggregation machinery support may be available for eligible projects under the prevailing government guidelines. Check the GOBARdhan scheme.
Related: Biomass pretreatment · Napier grass CBG plant · CBG plant cost
Frequently asked questions
Yes. Paddy straw is a lignocellulosic residue with good biogas potential, but its tough, silica-rich fibre must be shredded, size-reduced and mechanically pretreated (for example by twin-screw shearing) and digested under suitable conditions. Co-digestion with cattle dung is common.
Feedstock logistics and preparation. Paddy straw is harvested over a short season, so it must be baled, transported and stored for year-round operation. Its fibre must then be opened up to avoid floating layers and poor digestion.
It depends on the plant capacity, straw quality and the digestion process. The DPR calculates the annual straw requirement, the collection radius and the storage area from feedstock lab tests.
It can be processed into Fermented Organic Manure (FOM) and LFOM, returning organic carbon to the same fields that supplied the straw.