Table 2
(continued)
Technology
Function
Advantages
Difficulties
Emerging
technologies
Ultrasound
Ultrasound is used to exploit dielectric
properties of microalgae cells by forcing them
to move to the nodules of the standing waves,
flocculate, and sediment
High efficiency
Potential for multipurpose
use as: cell lysing with
lower frequencies and
higher pressures
High energy cost compared
to other technologies
including
filtration and
centrifugation
Magnetophoretic (Japar
et al. 2017)
Use of magnetophoretic properties of
microalgae by adding a magnetic nanoparticle
which will link microalgae cells into
flocculates and be removed
Easily remove from broth
High efficiency of
recovering biomass
High efficiency of
recycling magnetic
particle and can be reused
Energy intensive due to
need for agitation and use
of compressors and shear
mills
High efficiency can be
maintained only for low
flow rates (<0.6 L/h)
Polymers absorbing water
(Japar et al. 2017)
Super-absorbent polymers which will
immobilize biomass
Fast
High concentration factor
Separation of biomass for
polymers still unclear
Algal predators (bacteria)
(Sathe and Durand 2015)
Flocculating agent
Potent
flocculating agent
Inexpensive
Eco-friendly
More investigation
necessary
Attached microalgal
growth
High velocity culture in PBR have a support
inside the culture medium where microalgae
can
fix itself
Easy recovery
Depend on the microalgae
ability to form
film
Pelletizations with
filamentous fungi (Gultom
et al. 2014; Tan et al.
2014, Xia et al. 2011)
Fungi will trap microalgae cell in their
filamentous and make pellets of high weight
which make them sediment
Low cost of culture
(wastewater, sucrose)
(Zhou et al. 2013)
2 days to sediment
Need to be further
filtrated
5 Microalgae Biorefineries for Energy …
101
(continued)
Technology
Function
Advantages
Difficulties
Emerging
technologies
Ultrasound
Ultrasound is used to exploit dielectric
properties of microalgae cells by forcing them
to move to the nodules of the standing waves,
flocculate, and sediment
High efficiency
Potential for multipurpose
use as: cell lysing with
lower frequencies and
higher pressures
High energy cost compared
to other technologies
including
filtration and
centrifugation
Magnetophoretic (Japar
et al. 2017)
Use of magnetophoretic properties of
microalgae by adding a magnetic nanoparticle
which will link microalgae cells into
flocculates and be removed
Easily remove from broth
High efficiency of
recovering biomass
High efficiency of
recycling magnetic
particle and can be reused
Energy intensive due to
need for agitation and use
of compressors and shear
mills
High efficiency can be
maintained only for low
flow rates (<0.6 L/h)
Polymers absorbing water
(Japar et al. 2017)
Super-absorbent polymers which will
immobilize biomass
Fast
High concentration factor
Separation of biomass for
polymers still unclear
Algal predators (bacteria)
(Sathe and Durand 2015)
Flocculating agent
Potent
flocculating agent
Inexpensive
Eco-friendly
More investigation
necessary
Attached microalgal
growth
High velocity culture in PBR have a support
inside the culture medium where microalgae
can
fix itself
Easy recovery
Depend on the microalgae
ability to form
film
Pelletizations with
filamentous fungi (Gultom
et al. 2014; Tan et al.
2014, Xia et al. 2011)
Fungi will trap microalgae cell in their
filamentous and make pellets of high weight
which make them sediment
Low cost of culture
(wastewater, sucrose)
(Zhou et al. 2013)
2 days to sediment
Need to be further
filtrated
5 Microalgae Biorefineries for Energy …
101