has never been attempted on a large scale, in part because the large-scale cultivation
operations have focused on other, more economical uses of algae. Drying is not
difficult, and several methods have been standardized, including sun-drying, drum
drying, vacuum drying, and freeze-drying. These methods are capable of reducing
the moisture content to *2%. Because it is not possible to burn biomass directly in
an internal combustion engine, the technology for power generation could be a
Rankine engine using a forced convection industrial boiler. A system with this
configuration would require an area of *20 Â 20 m and a continuous power
output of a kilowatt, at a cost of roughly USD 0.95 kWh, which is approximately
four times the cost of current diesel generation in off-grid areas. Furthermore, the
practical aspects of pumping algae from a separator to a dryer and handling and
feeding algal solids into a combustor have not been standardized or automated for
any commercial power generation scheme as of yet, so while this configuration
appears quasi-attractive from a thermal efficiency, land footprint, and cost perspective, it would still require significant engineering input to be realized (Orosz
and Forney 2008).
Fig. 2 Thermochemical and biochemical processing in a microalgae biorefinery for production of
biofuels and value-added compounds (adapted from Toledo-Cervantes and Morales 2014). Brown
dotted lines mean the incorporation of residual biomass to produce biofuels, blue dotted lines
indicate water recycling, and red dotted lines are CO 2 gas stream generated during microalgae
biofuel processing and reincorporated for biomass growth
110
P.-L. Gorry et al.
operations have focused on other, more economical uses of algae. Drying is not
difficult, and several methods have been standardized, including sun-drying, drum
drying, vacuum drying, and freeze-drying. These methods are capable of reducing
the moisture content to *2%. Because it is not possible to burn biomass directly in
an internal combustion engine, the technology for power generation could be a
Rankine engine using a forced convection industrial boiler. A system with this
configuration would require an area of *20 Â 20 m and a continuous power
output of a kilowatt, at a cost of roughly USD 0.95 kWh, which is approximately
four times the cost of current diesel generation in off-grid areas. Furthermore, the
practical aspects of pumping algae from a separator to a dryer and handling and
feeding algal solids into a combustor have not been standardized or automated for
any commercial power generation scheme as of yet, so while this configuration
appears quasi-attractive from a thermal efficiency, land footprint, and cost perspective, it would still require significant engineering input to be realized (Orosz
and Forney 2008).
Fig. 2 Thermochemical and biochemical processing in a microalgae biorefinery for production of
biofuels and value-added compounds (adapted from Toledo-Cervantes and Morales 2014). Brown
dotted lines mean the incorporation of residual biomass to produce biofuels, blue dotted lines
indicate water recycling, and red dotted lines are CO 2 gas stream generated during microalgae
biofuel processing and reincorporated for biomass growth
110
P.-L. Gorry et al.