4 Biorefinery Strategies and Current Concepts
Fluctuations in fossil fuels prices, diminution of oil reserves, and COP21 agreements
to reduce the GHG emissions encourage the biomass-biofuel industry and enhance
the microalgae biofuel research (Pires 2017). Microalgae can play a dual role: They
capture CO 2 , and the resulting biomass can be used to produce a wide range of
materials. It is important to mention that some chemicals derived from microalgae
biomass cannot be synthesized from fossil fuels. Some of them are high-value
products and can be used directly after separation or with slight structural adjustments. For these reasons, microalgae are of great interest for research and development of industrial processes to make viable their use in a biorefinery concept. As
was mentioned previously, in the biorefinery concept, it is necessary to valorize most
of the constituents of the microalgal biomass. Figure 3 shows options for valorization of the algae biomass that include its use as: (1) intact algae cells, (2) the
disrupted whole cell content, or (3) fractionation of the biomass into different biochemical groups or specific compounds (Bastiaens et al. 2017). In the first alternative, the microalgae biomass is mostly commercialized as dry powder for feed, food,
or aquaculture and the volume market is constantly increasing (IEA 2017; Vigani
et al. 2015). Manufacturing commercial products derived from whole cells does not
generate residual biomass, and extraction or fractioning of biomass is not necessary.
On the contrary, the other two options allow the application of the biorefinery
concept. The following sections present the main strategies to cultivate/process/
valorize the microalgae biomass, and they are globally classified into four categories:
(i) biofuels production only (low-value compounds), (ii) high-value-added products
Fig. 3 Biorefinery strategies for microalgae biomass valorization
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P.-L. Gorry et al.
Fluctuations in fossil fuels prices, diminution of oil reserves, and COP21 agreements
to reduce the GHG emissions encourage the biomass-biofuel industry and enhance
the microalgae biofuel research (Pires 2017). Microalgae can play a dual role: They
capture CO 2 , and the resulting biomass can be used to produce a wide range of
materials. It is important to mention that some chemicals derived from microalgae
biomass cannot be synthesized from fossil fuels. Some of them are high-value
products and can be used directly after separation or with slight structural adjustments. For these reasons, microalgae are of great interest for research and development of industrial processes to make viable their use in a biorefinery concept. As
was mentioned previously, in the biorefinery concept, it is necessary to valorize most
of the constituents of the microalgal biomass. Figure 3 shows options for valorization of the algae biomass that include its use as: (1) intact algae cells, (2) the
disrupted whole cell content, or (3) fractionation of the biomass into different biochemical groups or specific compounds (Bastiaens et al. 2017). In the first alternative, the microalgae biomass is mostly commercialized as dry powder for feed, food,
or aquaculture and the volume market is constantly increasing (IEA 2017; Vigani
et al. 2015). Manufacturing commercial products derived from whole cells does not
generate residual biomass, and extraction or fractioning of biomass is not necessary.
On the contrary, the other two options allow the application of the biorefinery
concept. The following sections present the main strategies to cultivate/process/
valorize the microalgae biomass, and they are globally classified into four categories:
(i) biofuels production only (low-value compounds), (ii) high-value-added products
Fig. 3 Biorefinery strategies for microalgae biomass valorization
114
P.-L. Gorry et al.