Shredding and recycling wooden pallets into alternative fuels

Wood pallets are processed through shredding, sorting, and other processes to produce RDF (Refuse Derived Fuel) or SRF (Solid Recovered Fuel), a highly efficient way to utilize resources. Wooden pallets are primarily composed of wood, which inherently has a high calorific value (approximately 16–20 MJ/kg), making them an ideal fuel ingredient. We are an equipment manufacturer with a complete bulky waste sorting and recycling line. We can also customize production line equipment based on customer schedules.

Summary Process Schematic (Wood Pallets → RDF/SRF)
Waste Pallets
↓
Pretreatment (impurity sorting, metal removal, plastic removal, etc.)
↓
Coarse shredding (large pieces, 10–20 cm)
↓
Fine shredding (small pieces/wood chips, 2–10 cm)
↓
Sorting (magnetic separation, air separation, impurity removal)
↓
(Optional) Drying (moisture reduction)
↓
Crushing/Pressing (Optional, Pellets/Blocks)
↓
Making RDF or SRF
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For Energy Utilization in Cement Kilns, Power Plants, Boilers, etc.

I. Applicable Materials:

1. Sources of Pallets

• Pallets that have been discarded or damaged by industries such as logistics, warehousing, manufacturing, and retail.
• May include:
• New pallets (unused but not meeting specifications)
• Old pallets (worn, broken, or deformed)
• Damaged pallets (contaminated with chemicals, oil, etc., requiring evaluation for fuel conversion)

II. Pallet Shredding Processing

1. Primary Shredding

• A heavy-duty, dual-shaft shredder is used to break the entire pallet into larger pieces (typically 10–20 cm).
• Purpose: To reduce size for subsequent handling and transportation.

1. Fine Shredding

• The wood pieces are further broken down into smaller pieces or chips (typically 2–10 cm, or even finer, depending on RDF/SRF requirements) using a fine shredder or hammer mill. • The final material form may be:
• Wood chips
• Wood fiber/wood pellets (similar to biomass fuel)

III. Sorting and Purification (Key Step)
Although wooden pallets are primarily wood, sorting is still required to improve fuel quality, especially if they are intended to produce SRF (high-quality solid recovered fuel) that meets standards.

1. Magnetic Separation

• Removes residual metal objects (such as screws, nails, and metal brackets).

1. Air Classification/Trommel

• Removes light impurities (such as plastic film, labels, and paper) or heavy impurities (such as rocks and sand).
• If the wooden pallets were previously strapped with plastic, this step can effectively remove any remaining plastic.

IV. Drying (depending on the situation)

• The moisture content of raw pallets is generally between 20% and 50%. Excessive moisture content reduces calorific value, increases transportation costs, and makes combustion more difficult. • If subsequently used as high-quality SRF or fed into dedicated combustion equipment, mechanical drying or hot air drying is often required to reduce the moisture content to 10%-20%.
• Drying Methods:
• Belt Dryer
• Rotary Drum Dryer
• Hot Air Circulation System
  Note: If used directly in facilities with a high moisture tolerance, such as cement kilns and fluidized bed boilers, the drying step can be omitted.

V. Applications of RDF/SRF
The resulting pallet-based RDF/SRF has the following characteristics:

• High calorific value: 16–20 MJ/kg, approaching or even exceeding that of coal (approximately 24 MJ/kg)
• Low carbon emissions: Compared to fossil fuels, biomass fuel is CO₂ neutral
• Applications:
• Alternative fuel for cement kilns (widely used worldwide, wood pallets are a high-quality raw material)
• Auxiliary fuel for power plants
• Fuel for industrial boilers
• Biomass heating systems
• Dedicated RDF incineration systems