Gasifier and BiocharFuels and Feedstocks

Selection

• Wood/bamboo– Chips– Sticks– Sawdust

• Shells/pods/nuts/seeds• Citrus peels

Processing

• Chopping, chipping, breaking, grinding• Sifting/sorting/sizing• pelletizing

Drying

• Sun drying• Solar drying• Flue gas drying• Hot air drying

Sun/Air drying

• Direct drying on surfaces in direct sunlight– Disadvantages• Slower• Prone to rain and dew rewetting unless covered• More labor intensive

– Advantages• Cheap

Solar drying

Drying with sun in enclosed/covered apparatusAdvantages

fasterless laborprotection from rewetting

Disadvantages more expensivemore complicated

Simple solar tent dryer2x6 frame, ½ hardware cloth bottom,

2x3, 2x4 frame greenhouse plastic tent top

Flue gas dryer

• Pass the hot combustion gasses directly through the wet fuel– Advantages• Simpler than indirect• Cheaper than indirect

– Disadvantages• Requires high heat materials• Risk of ignition

Flue gas dryers

• Rotary drum of expanded/perforated steel• Trays/drawers in frame• Multi level “fountain” in steel drum

Indirect (heat exchanger) dryers

• Counterflow air heater • Shell and tube air heater

blow hot air into:stacked traysRotary drum

Storage

• Dry• Ventilated• Protected from rain• Containers off the ground