Microalgae A Source Of Alternative Energy

Microalgae are the most efficient plants in capturing and utilizing solar energy and CO2 for photosynthesis. In addition, the CO2 used to increase productivity. There are four groups of microalgae are so far known in the world of diatoms (Bacillariophyceae), green algae (Chlorophyceae), golden algae (Chrysophyceae), and blue algae (Cyanophyceae). The four groups of microalgae can be bioenergy used as raw materials. In Indonesia itself can be found hundreds of types of microalgae. On the other hand, the ecological function of microalgae is very helpful in the prevention of global warming.

Some studies claim that microalgae can produce fatty acids that can become the engine fuel (biodiesel) or fuel. This opens the birth of new alternative fuel sources to overcome the energy crisis. Chlorella for example, has a fatty acid content of 14-22% of the weight of cells in the normal planting conditions. By manipulating the environment (lighting) and growth media, the physiological condition of their life cycle can change from a heterotrophic Autotroph drastically so green microalgae can increase fat content to 60%. In another research note microalgae that crude oil (crude algae oil) appeared to contain isochrysis galbana (20-35%) and Nannochloropsis oculata (31-68%). Due to the high content of the compound will increase the amount of fatty acids that can be converted into hydrocarbon compounds.

Microalgae easily found in waters rich with nitrogen and phosphate, both in brackish waters and sea water. Microalgae can be cultured only by using simple technology. Success factors in pengkulturan in sea water depends on the medium high nitrogen content, pH 6-8, the light setting, stirring evenly, and harvesting through the process of separation.

The process of making biofuel microalgae becomes quite easy. The first step is the identification and isolation of microalgae and microalgae cultivation (cultivated), for 7 to 10 days. After that microalgae can be harvested later in the process of microalgae was filtered, dried, extracted (separation) using the solvent hexane or diethyl ether. Extraction methods can also be selected according to need and want the products obtained. The next stage is purification (Decolorize and deodorisasi) and esterified to break down fats into hydrocarbons.

Global Development of microalgae as a biofuel source material with a nickname or Blue Third Generation Biofuel Energy is rampant and the scheme has been approaching commercial production. Now comes a new trend of utilizing microalgae as liquid pollution control, especially heavy metals and air pollution, especially greenhouse gas CO2. The two-way activities can be related in an effort to increase the production of microalgae. Waste biofuel microalgae can be used among others to feed. While microalgae mass byproduct CO2 gas emission control can be used for broader purposes including biofuels. At the present stage, preferring microalgae production activities in the photobioreactor cultivation system.

Photobioreactor is a bioreactor coupled with a specific light source for the intake of light energy into a reactor. Energy from sunlight necessary for photosynthesis process. CO2 gas is absorbed in the chlorophyll processed into carbohydrates and oxygen that plants need be released into the air. Basically, a pool open for the maintenance of microalgae is equivalent to the photobioreactor. The difference, photobioreactor is a closed system that is more easily controlled and adjusted the design to the installation location, more able to prevent contamination, prevent evaporation of water and CO2, and does not require large areas.

(LIPI)