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20 Application of Sustainable Micro-Algal Species in the Production of Bioenergy

Table 20.1

Cultivation and processing of microalgae.

1

Cultivation

Species selection

Cyanaobateria

Unicellular microalgae

Multicellular microalgae

Cultivation system

Open terrestrial

Closed terrestrial

Open offshore

Closed offshore

Water

Fresh water

Salt water

Growth mode

Phototrophic

Mixotrophic

2

Harvesting

Intermediate constituents

Hydrocarbons and

alcohols

Lipids

Carbohydrates

Proteins

Consolidated biomass

3

Processing

Conversion processes

Biochemical conversion

Thermochemical

conversion

Direct synthesis

Anaerobic digestion

4

Products

Fuels/products

Alcohols and chemicals

Esterified biodiesel,

biogas/hydrogen

Animal feed and other

products

different methods can be compared based on techno-economic feasibilities. There

are yet other methodologies in which species are grown at a maximum carbon fixa-

tion rate that retains large fractions of the fixed carbon in their final products. A few

such technologies are as follows:

●Algal biomass fermentation to yield hydrocarbons or alcohols;

●Conventional catalysis process;

●Synthesis gas fermentation;

●Hydrous pyrolysis;

●Gasification and syngas translation to alkanes, aromatics, and alcohols;

●Anaerobic digestion to methane.

The above-mentioned pathways are not generally used but can be placed into

practice. The feedstocks should not contain high water content. The central of