Biomass fuel, primarily made from agricultural and forestry waste (such as straw, sawdust, bagasse, and rice husks), undergoes processes such as crushing, pulverizing, and drying, and is then processed by a biomass pellet machine into various pellets for direct combustion. So, what are some key considerations when using biomass fuel in a furnace?

1. Storage: Moisture-Proof, Fire-Proof, and Spontaneous Combustion Prevention

Biomass pellet fuel (especially wood and straw pellets) is highly hygroscopic. If stored in a high humidity environment (relative humidity >60%), it can easily absorb moisture, clump, and mold, reducing combustion efficiency (calorific value decreases by approximately 1% for every 1% increase in moisture content). It can also harbor microorganisms and produce odors.

Moisture-Proof: Store in a sealed warehouse or on moisture-proof pallets, maintain ventilation and dryness, and avoid direct contact with the ground (optionally elevated). Bags of pellets should be used promptly after opening. Fire and Spontaneous Combustion Prevention: Dry pellets are flammable and should be kept away from open flames and heat sources (such as boiler flues). When stacking, maintain a controlled height (generally ≤ 3 meters) to avoid over-compaction. During storage, pellets may release heat due to microbial respiration or slow oxidation. If heat is not dissipated properly during stacking, the temperature may rise to the point of spontaneous combustion (especially with straw pellets, which have a higher oxygen content, increasing the risk).

2. Compatibility of Combustion Equipment: Avoiding "Inappropriate Material for the Equipment"

Biomass pellets made from different raw materials (such as wood, straw, and peanut shell pellets) vary significantly in composition: Wood pellets have a high calorific value (approximately 4200-4800 kcal/kg), a low ash content (<1%), and minimal charring. Straw pellets have a lower calorific value (approximately 3000-3800 kcal/kg), a high ash content (3%-8%), and contain alkali metals such as potassium and sodium, making them prone to charring. If the equipment isn't designed for the pellet characteristics (for example, using a conventional wood pellet stove with straw pellets), the following may occur: ① Incomplete combustion (black smoke and ash); ② Coking and blockage of the grate and flue (alkali metals melt at high temperatures); ③ Rapid ash accumulation, affecting heat transfer efficiency and even damaging the equipment (such as corrosion of boiler tubes).

Specialized equipment should be selected based on the pellet type (for example, straw pellets require a decoking device and a high-temperature resistant grate), and the air supply ratio should be adjusted regularly to ensure adequate air-fuel mixing.

3. Environmental Compliance: Not "Zero Emissions," Pollutant Control Requires

Although biomass pellets are a "carbon-neutral" energy source, the combustion process may still produce pollutants:

Particulate matter (PM2.5): Incomplete combustion produces a large amount of smoke and dust, requiring purification equipment such as bag filters.

Nitrogen oxides (NOx): The combustion of pellets with high nitrogen content, such as straw, may release NOx, requiring low-NOx combustion techniques (such as staged ventilation).

Dioxins: If the combustion temperature is below 850°C (especially in small equipment), incomplete combustion may produce dioxins, requiring furnace temperature compliance.

Compliance with local environmental standards (such as the "Boiler Air Pollutant Emission Standards") is essential to avoid the risk of "environmentally friendly fuels that are not environmentally friendly."

4. Safety Precautions: Preventing Carbon Monoxide Poisoning and Fire

Carbon Monoxide (CO): Combustion in the absence of oxygen (such as in enclosed spaces or with blocked flues) produces highly toxic CO. Household or small equipment should install CO alarms and maintain ventilation. Industrial boilers require regular inspection of flue seals to prevent leaks. Operational Safety: During pellet conveying (e.g., screw feeders), prevent blockage and mechanical injuries. When cleaning hot ash, cool it down before use to avoid igniting combustible materials.

5. Fuel Quality Control: Reject "low-quality pellets"

Some pellets on the market contain adulteration (dirt, rocks, waste plastic), excessive moisture (>15%), and high ash content. These issues can lead to:

Equipment wear (impurities damage grates and fan blades);

A sharp drop in combustion efficiency (excessive moisture requires heat to evaporate);

Increased ash cleaning frequency, leading to hidden costs.

Key indicators should be tested during procurement: moisture (ideally <10%), ash content (<5%), calorific value, and impurity content. Prioritize qualified manufacturers. 6. Equipment Maintenance: Regular Ash Cleaning and Anti-Coking

Ash Cleaning: Ash accumulation reduces boiler heat exchange efficiency (each 1mm increase in ash layer increases heat loss by approximately 5%). Daily grate cleaning and weekly flue cleaning are required.

De-coking: Combustion of pellets such as straw easily forms coke in the furnace and flue. These must be removed regularly using mechanical or chemical methods (such as high-temperature steam purging) to prevent flue blockage and explosion risks.

Component Inspection: Consumable parts such as fans and feeders require regular inspection and maintenance to prevent malfunctions that could lead to combustion interruptions or fuel accumulation.

In summary, the use of biomass pellet fuel requires multi-dimensional management, including storage, equipment, environmental protection, safety, and cost, to fully realize its clean energy value and avoid potential risks.