Category Archives: biofuel
You may be wondering exactly how this slimy green stuff can be turned into a fuel for cars and airplanes, and even for the heaters that warm our homes and schools. Let’s find out more about what makes biodiesel from algae so exciting.
Algae have been traditionally regarded as simple plants, and some are closely related to the higher plants.
Forms of Algae
The main branches/lines of algae are:
* Chromista – this line includes the brown algae, golden brown algae, and diatoms.
* The Red Line – this is an early branch of marine algae containing just
Chlorophyll A. Red algae can often be seen coating wave washed rocks. A characteristic of red algae is that their plastids contain only one type of chlorophyll — chlorophyll a. This is different from green algae and plants which have both chlorophyll a and b.
* Dinoflagellates – these evolved on a separate line that includes, surprisingly,the ciliated protists. (see: Introduction to the Dinoflagellata from UMCP, Berkeley,Dinoflagellate Information – from MBARI, Dinoflagellate – from Wikipedia)
* The Euglenids – this independent line of single celled organisms that include both photosynthetic and non-photosynthetic species (see: Euglenid – from Wikipedia)
* The Green Line, is related to plants. Plants and green algae have chlophylls A and B. ( see also: Introduction to Green Algae)
The three most prominent lines of algae are the brown algae (Chromista), the red algae,and the green algae, of which some of the most complex forms are founds among the greenalgae. This lineage eventually led to the higher land plants. The point where thesenon-algal plants begin and algae stop is usually taken to be the presence of reproductive organs with protective cell layers, a characteristic not found in the other alga groups
Where do algae grow?
Algae are some of the most robust organisms on earth, able to grow in a wide range of conditions.
Algae are usually found in damp places or bodies of water and thus are common in terrestrial as well as aquatic environments. However, terrestrial algae are usually rather inconspicuous and far more common in moist, tropical regions than dry ones,because algae lack vascular tissues and other adaptions to live on land As mentioned above, algae grow in almost every habitat in every part of the world. The following are examples of non-marine (loosely termed ‘freshwater’ here) habitats.
Animals: Reported substrates include turtles, snails, rotifers, worms, crustacea and many other animals
Aquatic plants: Algae grow on and inside water plants (including other algae)
Artificial substrates: Wooden posts and fences, cans and bottles etc. all provide algal habitats.
Billa bongs & lagoons: Rich micro algal habitats, particularly for desmids.
- Bogs, marshes & swamps
- Farm Dams
- Hot springs
- Mud and sand
- Ponds (ephemeral), puddles, roadside ditches and rock pools
- Rock (internal & surface)
- Saline Lagoons
- Saline Lakes & Marshes
- Salt marshes and salt lakes
How are algae cultivated for bio diesel?
Like plants, algae require primarily two components to grow: sunlight and carbon-di-oxide. Like plants again, they use the sunlight for the process of photosynthesis. Photosynthesis is an important biochemical process in which plants,algae, and some bacteria convert the energy of sunlight to chemical energy. This chemical energy is used to drive chemical reactions such as the formation of sugars or the fixation of nitrogen into amino acids, the building blocks for protein synthesis.
Since algae need for their growth sunlight, carbon-di-oxide and water, they can cultivated in open ponds. However, the unassisted growth in open ponds is slow, owing to the lower concentration of carbon-di-oxide; where carbon-di-oxide concentrations are increased artificially, higher growth rates can be achieved in open ponds as well.
Alternatively, algae could be grown in closed structures called photobioreactors, where the environment is better controlled than in open ponds. While the costs of setting up and operating a photobioreactor would be higher than for those for open ponds, the efficiency and higher oil yields from these photobioreactors could be significantlyhigher as well, thus offsetting the initial cost disadvantage in the medium and long run.
Finding algae strains to grow isn’t too difficult. Cultivating specific strains of algae for biodiesel could be however a bit more difficult, as they can require high maintenance and could get easily contaminated by undesirable species.