amongst the potential solutions to overcome these bottlenecks.
Additionally alternative open cultivation systems, like thin layer
flow lanes or algae turf scrubbers (Table 1), can be applied to
achieve high productivity or easier harvesting. Despite all negative
aspects, the majority of commercial production of microalgae takes
place in open ponds due to the relatively low production costs.
3 Closed Cultivation Systems
There are several types of closed cultivation systems, or photobioreactors (Figs. 2 and 3). Most of the deviation between different
systems is related to the design of the cultivation compartment,
which can be tubular reactors, laminar (or flat panel) reactors,
hanging plastic sleeves, or fermenter-like tank reactors [10]. They
may or may not be artificially illuminated depending on location
and product being made. The development of commercial scale
photo-bioreactors has made good progress in the past decade and
designs with relatively high efficiencies have been constructed [14].
However, due to much higher cost for building and operating
closed systems compared with open systems, all the large-scale,
closed systems operating at present produce algal biomass for
high-value products such as cosmetics and neutraceuticals.
Fig. 2 An example of a closed tubular photobioreactor. Water is pumped through the glass tube from a gas
exchange unit and the algae collects light in the tube. Picture: IGV Biotech, Wikipedia, CC BY-SA 3.0
4
Jacqueline Jerney and Kristian Spilling
Additionally alternative open cultivation systems, like thin layer
flow lanes or algae turf scrubbers (Table 1), can be applied to
achieve high productivity or easier harvesting. Despite all negative
aspects, the majority of commercial production of microalgae takes
place in open ponds due to the relatively low production costs.
3 Closed Cultivation Systems
There are several types of closed cultivation systems, or photobioreactors (Figs. 2 and 3). Most of the deviation between different
systems is related to the design of the cultivation compartment,
which can be tubular reactors, laminar (or flat panel) reactors,
hanging plastic sleeves, or fermenter-like tank reactors [10]. They
may or may not be artificially illuminated depending on location
and product being made. The development of commercial scale
photo-bioreactors has made good progress in the past decade and
designs with relatively high efficiencies have been constructed [14].
However, due to much higher cost for building and operating
closed systems compared with open systems, all the large-scale,
closed systems operating at present produce algal biomass for
high-value products such as cosmetics and neutraceuticals.
Fig. 2 An example of a closed tubular photobioreactor. Water is pumped through the glass tube from a gas
exchange unit and the algae collects light in the tube. Picture: IGV Biotech, Wikipedia, CC BY-SA 3.0
4
Jacqueline Jerney and Kristian Spilling