The effect of carbon dioxide concentration and the dimension of photobioreactor on the growth of microalgae Nannochloropsis sp.

Abstract

Microalgae is one of the organisms that can be considered ideal and potential for raw materials for bioenergy production because the lipid content in microalgae is relatively high. Microalgae are aquatic organisms that produce complex organic compounds from inorganic molecules using carbon dioxide as a source of carbon, and sunlight for energy supply. Fixation of microalgae-CO 2 has a potential advantage compared to other carbon capture and storage approaches, such as wide distribution, high photosynthesis rates, good environmental adaptability, and ease of operation. The rate of growth and capture of CO 2 from microalgae is influenced by gas flow velocity and CO 2 concentration. This study quantitatively investigated the effect of inside diameter (ID) of photobioreactor and CO 2 concentration on the growing rates of Nannochloropsis sp. microalgae cultivated in photo-bioreactors. Photobioreactor ID effects to the value of the Reynolds number. The high value of Reynold's number makes the microalgae damaged and dead. The optimal CO 2 concentration for Nannochloropsis sp. growth is 10%.