Category Archives: BIOFUELS FROM ALGAE

CHALLENGES AND PROSPECTS

Biofuel derived from algae is currently a hotly debated topic because its production is one of the more costly processes, which can dictate the sustainability of algae-based biofuel products. There are two major energy and cost constraints to bulk production of microalgae for biofuels: expensive culture systems with high capital costs and high energy requirements for mixing and gas exchange, […]

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MICROALGAE CULTIVATION

Cultivation of microalgae influences both biomass growth and lipid productivity. Cultur­ing of algae requires the input of light as an energy source for photosynthesis with a sufficient supply of macronutrients (nitrogen and phosphate) and micronutrients (sulphur, potassium, magnesium) in dissolved form (Mata et al., 2010). The main options for algae cultivation on a commercial scale are open-ponds or closed systems […]

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MACROALGAE

Seaweeds or macroalgae belong to the lower plants, meaning that they do not have roots, stems, and leaves. Instead they are composed of a thallus (leaf-like structure) and sometimes a stem and a foot. Macroalgae represent a diverse group of eukaryotic, photosynthetic marine organisms. Unlike microalgae, which are unicellular, the macroalgal species are multicellular and possess plant-like characteristics. They are […]

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Insight into the Economic Breakdown of Algal Biofuels

Algal biofuel technology is currently still in an early stage of development and therefore economically unfavorable for scaling-up purposes. Thus, analyzing the detailed economic breakdown of the multistage processing of algal biofuels will certainly open up a new direc­tion in identifying, evaluating, and verifying the actual problems that result in the high pro­duction cost of algal biofuels. A detailed discussion […]

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LIGHT REGIME

The light spectrum and intensity are factors that directly affect the performance of phototrophic microalgal growth, both indoors and outdoors. In outdoor cultures, sunlight is the major energy source, whereas innovations in artificial lighting, such as light-emitting diodes (LED) and optical fiber, are interesting for indoor cultivation systems. In indoor cul­tures, the biggest challenge is the high cost of artificial […]

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Raceway Ponds

Raceway ponds are a modified version of the open pond system that has a different flow pattern compared to that of the simple pond. In raceways, the water flow direction is con­trolled by the rotation speed of paddlewheels, in contrast to only coaxial mixing in conven­tional open ponds. Therefore, in the raceway systems, the microalgae, water, and nutrients are continuously […]

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Microstraining

Microstrainers consist of a rotary drum covered by a straining fabric, stainless steel or poly­ester. The partially submerged drum rotates slowly in a trough of suspended algal particles. The screen is fine mesh that captures only fairly large particles such as algae. As the mesh moves to the top, water spray dislodges the drained particles. When a microstrainer is used […]

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POSSIBLE IMPROVEMENTS OF ECONOMICS IN HETEROTROPHIC ALGAL OILS

Although heterotrophy of algae shows its potential for oil production, the overall produc­tion cost of heterotrophic oils remains relatively high, restricting the commercialization of heterotrophic algal oils. From an estimation of Yan et al. (2011) using heterotrophic C. protothecoides for oil production, the unit production cost of algal oils was still much higher than that of plant oils. Glucose represents […]

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Bead-Beating Method

The bead-beating method involves the application of beads for the disruption of the algal cell wall. Continuous exposure of biomass to beads leads to cell-wall rupture, resulting in the release of intracellular contents into the solvent medium. Similar to expeller pressing, this method can also be applied for both disruption and extraction. The influence of bead beating on cell-wall disruption […]

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