---
title: "Straw / agricultural-residue firing"
description: "Straw and agricultural-residue firing — wheat straw, rice straw, corn stover, palm fronds — is a regionally important biomass-energy practice, dominant in Denmark, parts of Germany, China, India and Spain. Crops are baled or pelletised and burned in dedicated boilers, typically BFB or CFB designs that tolerate the difficult ash chemistry."
canonical_url: "https://sylio.co/glossary/straw-agricultural-residue-firing"
last_updated: "2026-06-28T02:29:41.824Z"
---

**Straw and agricultural-residue firing** — wheat straw, rice straw, corn stover, palm fronds — is a regionally important biomass-energy practice, dominant in Denmark, parts of Germany, China, India and Spain. Crops are baled or pelletised and burned in dedicated boilers, typically [BFB](/glossary/bfb-boiler) or [CFB](/glossary/cfb-boiler) designs that tolerate the difficult ash chemistry.

## Why straw is hard to burn

- **Very high potassium content** — K₂O often 10–25% of ash; far above wood
- **High chlorine content** — particularly rice and wheat straw; drives [chloride corrosion](/glossary/chloride-induced-corrosion)
- **Low ash-melting temperature** — KCl-rich ash melts at 700–800 °C and bonds to tubes as [low-melt sticky ash](/glossary/low-melt-sticky-ash)
- **Silica content** — abrasive on grates and bed materials

The combination defeats steady-state operation on conventional designs and accelerates [tube wastage](/glossary/tube-erosion-tube-wastage) faster than any fossil-fuel-only boiler would experience.

## Cleaning

Straw-fired boilers are challenging acoustic-cleaning targets but also where the technology earns the most operational value. [Sonic horns](/glossary/sonic-horn) on the superheater, [generating bank](/glossary/generating-bank) and economiser keep deposits from consolidating into the unrecoverable bonded slag that would otherwise force frequent water-washing.

## Related terms

- [Alkali metals in ash](/glossary/alkali-metals-in-ash)
- [Chloride-induced corrosion](/glossary/chloride-induced-corrosion)
- [Low-melt sticky ash](/glossary/low-melt-sticky-ash)
- [Boiler](/glossary/boiler)