Truck carrying paddy straw towards a compressed biogas plant

Crop-residue feedstock profile

Paddy Straw for CBG Plants: Procurement, Quality and Storage Guide

Paddy straw can anchor a large crop-residue programme in rice-growing belts, but the commercial result depends on a short collection window, dry handling, preprocessing and disciplined fire-safe storage.

Overview

Paddy straw: a valuable bioenergy feedstock

Paddy straw is an abundant agricultural residue with useful bioenergy potential. When collected, processed and stored properly, it can serve as a dependable CBG feedstock while reducing stubble burning and creating rural income. Commercial decisions must still be based on recoverable surplus, representative testing and verified local operations.

Abundant availability

Reduced field burning

Farmer income

CBG feedstock

Key facts

~10 t

Indicative straw per tonne of CBG

250-300 Nm3/t

Indicative raw biogas range

45-55%

Typical methane share in raw biogas

84-88%

Typical total solids on dry basis

Round paddy straw bale in a harvested field

Feedstock value chain

From field to CBG plant

A managed supply chain protects quality, lowers losses and makes production planning traceable.

Paddy straw collection, transport, storage and CBG plant feeding stages
  1. 1Harvest & collection
  2. 2Baling & transport
  3. 3Storage & preprocessing
  4. 4Feeding to CBG plant

Feedstock specifications

Typical paddy straw properties

Indicative ranges vary by variety, region and season.

ParameterTypical range
Total solids (TS)84-88%
Volatile solids (VS)70-80% of TS
Moisture12-16%
C:N ratio60-100:1
Ash content12-18% of TS
Lignin15-22% of TS
Silica5-10% of TS
Bulk density, baled100-180 kg/m3

Quality standards

Receiving controls

Contract limits must match plant design and trial results.

ParameterPlanning recommendation
Moisture at receiptContract-specific; commonly <=15-20%
Foreign matterTarget <=2%
Chopped particle sizeTypically 10-30 mm
Bale densityTarget >=120 kg/m3
Visible mould or rotReject
Sand and gritTarget <=2%
Storage durationPrefer <=6-9 months with controls
Fire riskHigh if unmanaged; controls mandatory

Methane potential

Indicative conversion ranges

Actual yield depends on feedstock quality, preparation and digester design.

ParameterTypical range
Raw biogas yield250-300 Nm3/t
Methane in raw biogas45-55%
Indicative methane yield110-165 Nm3 CH4/t
Energy equivalent2.0-3.0 GJ/t
Theoretical CBG90-140 Nm3/t
Paddy straw per tonne CBGApproximately 8-12 t
Validate representative samples and controlled plant trials before contracting gas output.

Procurement & collection

Control the short harvest window

Field plans, lot identity and machinery capacity determine dependable volume.

  • Work through mapped farmer groups and accountable local aggregators.
  • Pre-book balers, loaders and trucks before the short harvest window.
  • Prioritize field-cured straw and record moisture at source and receipt.
  • Reject soil, stones, plastic, burnt residue and visibly mouldy bales.
  • Link every load to field cluster, harvest date, bale count and weighbridge ticket.
Paddy straw baler collecting residue in the field

Storage & handling

Preserve quality and prevent fire

Dry covered storage, stack monitoring and engineered fire controls are essential.

  • Use raised, drained platforms with covered or engineered weather protection.
  • Keep breathable stack covers, safe aisles and fire breaks between blocks.
  • Monitor internal temperature, moisture ingress and inventory age.
  • Keep ignition sources away and maintain water access and response equipment.
  • Apply first-in, first-out dispatch and investigate every damaged stack.
Paddy straw bales stacked inside a covered storage shed

Availability & seasonality

Major rice belts and a concentrated collection season

Treat this as planning context; build commitments from district field evidence and recoverable surplus.

Indicative biomass service map of India

Major rice-producing states

  1. 1Punjab
  2. 2Haryana
  3. 3Uttar Pradesh
  4. 4Bihar
  5. 5West Bengal
  6. 6Madhya Pradesh
  7. 7Chhattisgarh
  8. 8Andhra Pradesh
  9. 9Telangana
  10. 10Tamil Nadu

Typical monthly availability

LowMediumHigh
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Economics

Indicative delivered-cost stack

Model by region, season, density and route.

ParameterTypical range
Farm-gate priceINR 1,500-2,500/t
Collection & balingINR 300-700/t
Short/medium transportINR 300-800/t
ProcessingINR 200-600/t
Indicative delivered costINR 2,300-4,600/t

Planning ranges are not supplier quotes. Recalculate using current district evidence, fuel prices, loading time and accepted net weight.

Processing & pretreatment

Improve handling and digestibility

Select the least-complex process that meets verified plant performance and safety requirements.

Chopping

  • 10-30 mm planning range
  • Improves handling
  • Reduces floating

Grinding / milling

  • Faster hydrolysis
  • Higher energy use
  • Confirm equipment wear

Ensiling / co-feed

  • Can preserve mixed feed
  • Useful for wet co-feed
  • Needs recipe validation

Advanced pretreatment

  • Alkaline, thermal or enzymatic
  • May improve biodegradability
  • Validate cost and safety

Related resources

Evidence for the decision file

Official and sector references supporting this planning guide.

Plan your paddy straw supply chain

Model field availability, collection capacity, storage buffer and delivered cost for your plant location.

Open feedstock planner

All quantities, ranges and costs on this page are indicative planning inputs. They are not a plant guarantee, engineering specification or supplier commitment. Validate local recoverable surplus, representative laboratory samples, fire and environmental controls, and controlled plant trials with qualified professionals.