Method and apparatus for the synthesis of alga biopolymer

Abstract

This specification discloses a method and apparatus for the synthesis of alga biopolymer. The method is comprised of two stages and involves subjecting an aqueous culture containing alga cells and nutrients required for the growth of the alga cells to a first stage of artificial illumination for a period of time such that growth of the alga and synthesis of biopolymer begins followed by a second stage of natural illumination provided by successive cycles of diurnal solar radiation and darkness. During the cycles of diurnal solar radiation and darkness in the second stage, the aqueous culture is continuously contacted with a mixture of carbon dioxide and air. Furthermore, during these cycles of diurnal solar radiation and darkness, the temperature of the aqueous culture is maintained at a level conducive to the growth of the alga cells. The apparatus is employed in the second stage and contains a lower chamber adapted to contain an aqueous thickening culture from a stage-one reactor. Means are provided for passing continually into the chamber and into contact with the aqueous culture a mixture of carbon dioxide and air. Means are also provided for maintaining the temperature of the aqueous culture at a level conducive to growth of the alga cells. There is also provided an upper chamber enclosed at the top portion thereof with a hemispherical radiant energy receiver capable of receiving incident solar radiation and being substantially transparent to the solar radiation. Conduit means are provided to transfer the aqueous culture from the lower chamber to the upper chamber. Means for impinging the aqueous culture upon the underside of the hemispherical radiant energy receiver are also provided. There are also provided means for returning the aqueous culture to the lower chamber from the upper chamber after impinging upon the underside of the hemispherical radiant energy receiver.