Off Grid Power in Liberia 

Appropriate Fuels


Download Feedstock Handbook

For your gasifier to operate properly, you must use the correct biomass fuels which have been properly prepared and sifted.
Feedstock fuel must be dry, of the correct shape and size to flow through the reactor, and free of dust, sand and contaminants:

  • Particle size: 1 cm – 4 cm (0.5 in. – 1.5 in.)
  • Moisture content (% by dry weight): 5% – 30%
  • Ash content <5%

The following Table of Feedstocks shows the most common ones that have been tested and are known to work, which ones are known to be unusable, and which ones need more testing. For more information on fuel preparation, contact APL For more information on fuel preparation, contact APL.

Download printable version of this chart

GreenKnown to work with standard operations and maintenance effort
YellowKnown to work with increased operations and maintenance effort
GrayNot enough testing to approve at this time. Use voids warranty
RedKnown to not work. Use voids warranty
Wood Chips
e.g: Oak, Rubber, Pine
Use only chips; chunks or long shards can bind auger or bridge in the reactor
Nut Shells
e.g: Coconut, Walnut, Hazelnut
Not all shells will work, please contact us to discuss your particular feedstock
Corn CobsMust be broken to size and must not include husks. Increased chance of slagging
Palm Kernel ShellsRisk of high temperatures. May need to be blended or other steps taken to lower temperatures
Macadamia Nut ShellsExcellent shape, not enough testing
Cashew Nut ShellsKnown toxicity, not enough testing
Wood PelletsMay work depending on size & makeup, pellets prone to decompose
Coffee GroundsToo fine, not physically compatible, pelletization may allow use
Saw DustToo fine, not physically compatible, pelletization may allow use
Corn stoverHigh ash content; silica content leads to slag
Rice HuskHigh silica content leads to slagging
BambooDifficult to prepare to correct size and shape
Grasses: Switchgrass, Miscanthus, etc.High silica and low bulk density.
Paper, Sugarcane Bagasse, Coconut HuskShapes not physically compatible
Municipal Solid Waste / TrashSlag risk; heavy metals; plastic content not suitable
CoalBurns too hot, releases sulfur and heavy metals
PlasticsMelts and fouls auger/reactor
Manure - Cow, Pig, Chicken, etcHigh slag, low energy density
TiresNot chemically compatible