TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The microalgae cultured in a reactor comprise Chlorella sorokiniana, Chlorella vulgaris, Scenedesmus dimorphus, Scenedesmus obliquus, Microcystis aeruginosa and Euglena gracilis. Preferred Method: The biofuel production in the step (e) comprises harvesting biomass by automatically collecting microalgae by the microalgae collector when the concentration of micro algae in culture medium reaches target concentration.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The reactor comprises an light-emitting diode lamp and a reflective mirror facing each other to increase the proliferative effect of high density microalgae in right or left or both sides; and a miniature reactor provided with relatively small baffle in the longitudinal direction in inside, where the miniature reactor is provided with a culture blocking gate to block the flow of culture medium on both sides, and at least one miniature paddle for circulating the culture medium at a constant speed and is driven automatically or manually such that the speed of circulation be controlled according to the growth rate of the microalgae. The circulation rate of culture medium controlled depending on growth rate of the algae is adjusted upwardly from the time when microalgae in culture medium are 50% of the exponential phase maximum concentration. The bottom surface of the reaction vessel is provided with a diffusing pipe to generate fine bubbles at regular intervals to induce mass proliferation of micro algae while preventing entanglement or aggregation phenomena of microalgae. The top opening of the reactor is provided with sliding switchgear to block the influx of contaminants from the outside while minimizing damage according to the rapid temperature drop or rainfall and snowfall. The reactor comprises a hot wire for controlling internal temperature. The reactor is connected to carbon dioxide injection device to culture high density micro-algae. The carbon dioxide injecting device collects carbon dioxide emitted from power plant or plant and then introduces into the reactor. The biomass production unit comprises a microalgae collector for collecting microalgae reaching target concentration of microalgae biomass, where the collector is provided with a culture water circulator for re-circulating the culture water generated in the microalgae collection through the collector.