Biomass

Question 1

Extraction Methods

Answer 1

1. Direct combustion of raw biomass
2. Combustion after limited physical processing (drying, chopping, compressing)
3. Thermochemical processing (upgrading into biofuels)
4. Biological processing (fermentation)

Question 2

Gasification

Answer 2

The process of reacting steam and air or oxygen with a solid fuel to produce a gaseous fule

Question 3

Pyrolysis

Answer 3

Heat treat the biomass in the absence of air to drive off volatile components leaving a residue. Eg charcoal has twice the energy of wood

Question 4

Anaerobic Digestion

Answer 4

Similar to pyrolysis but the conversion process is achieved at low temperatures by bacterial action

Question 5

Fermentation

Answer 5

Anaerobic biological process of converting sugars into alcohol by micro-organisms (yeast). The resulting alcohol (ethanol) can be mixed with gasoline to produce an effective fuel

Question 6

Low conversion efficiency because

Answer 6

Not all solar flux falls during growing times
Not all falls on leaves
Some is reflected
Half remaining energy is correct wavelength
Not all converted to stored energy
Stored energy used by plant

0.5% original incident solar energy converted to stored biomass energy