Category Archives: BIOFUELS FROM ALGAE

Proteins

The proteins, peptides, and amino acids vary with the algal species as well as the habitat and the season (Arasaki and Arasaki,1983). In general, the protein content is relatively low in brown algae but is higher in green and red algae. Proteins may indeed represent 35-45% of dry matter in macroalgae (Holdt and Kraan, 2011) and even 60%-70% in microalgae […]

Read more

Harvesting and Conditioning of the Biomass

It is widely acknowledged that one of the major bottlenecks of bioenergy production from microalgae lies in the concentration step. The selected studies assess a large variety of tech­nologies to achieve concentration, dewatering, and sometimes drying of the algal biomass. The final dry-matter content (DM) before biofuel production depends also on the transforma­tion process. For instance, anaerobic digestion of bulk […]

Read more

Flotation

Flotation is a separation process in which air or gas bubbles are directed at the solid par­ticles and then drive these particles to the liquid surface. Flotation is more beneficial and efficient for removing cells than sedimentation. Flotation can capture particles smaller than 500 pm in diameter (Chen et al., 2011).

Read more

Dissolved-Air Flotation

In the dissolved-air flotation system, a liquid stream saturated with pressurized air is added to the dissolved-air flotation unit, where it is mixed with the incoming feed. As the pressure returns to atmosphere, the dissolved air comes out of the liquid, forming fine bubbles that bring fine particles with them as they rise to the surface, where they are removed […]

Read more

Glucose Accumulation Inside the Cell

Accumulation of energy-rich compounds is the primary step for microalgal lipid biosynthesis. However, this carbon accumulation varies with both autotrophic and hetero­trophic organisms. Autotrophs synthesize their own carbon (photosynthates) through photosynthesis, whereas heterotrophic organisms assimilate it from outside the cell. In photoautotrophs, the chloroplast is the site of photosynthesis where, light reaction takes place at the thylakoid followed by CO2 […]

Read more

ALGAL FUEL PROPERTIES

The characterization of the algal oil derived after transesterification showed the possibility of using it as biodiesel. The properties of the microalgae oil are mostly dependent on the feed­stock and the conversion method used. Key aspects to evaluate the properties of microalgae oil are acid number, iodine number, specific gravity, density, kinematic viscosity, flash point, pour point, heating value, and […]

Read more

Halogenated Derivatives

Besides iodine, compounds derived from halogens are produced by red and brown macroalgae (Butler and Carter-Franklin, 2004). Halogenated compounds appear as several classes of primary and secondary metabolites, including indoles, terpenes, acetogenins, phenols, fatty acids, polyhalogenated monoterpenes, and volatile halogenated hydrocarbons (e. g., bromoform, chloroform, and dibromomethane) (Dembitsky and Rozentsvet, 1990; Butler and Carter-Franklin, 2004). In many cases, they possess […]

Read more

Closed Photobioreactors

To overcome the limitations of the open pond system in algae cultivation, closed photobioreactors are designed to ensure that algal cells are always grown under optimal con­ditions with high consistency in biomass productivity. Since the conditions in a closed photobioreactor system are strictly controlled, the contamination level in the cultivation me­dium is minimized. This permits the cultivating of single algal […]

Read more
1 2 3 4 5 52