Method and Unit for Producing Microalgae

Patent metadata

Field	Value
Publication number	US-2016152933-A1
Application number	US-201414905469-A
Country	US
Kind code	A1
Filing date	Jul 15, 2014
Priority date	Jul 15, 2013
Publication date	Jun 2, 2016
Grant date	—

Abstract

The invention relates to a method for producing microalgae on a support ( 14 ) that is movably mounted essentially in an aqueous medium contained in a tank ( 12 ), said method comprising a succession of phases in which the microalgae developing on the support ( 14 ) are exposed to sunlight and phases in the shade, the light intensity received in the shade being less than 50% of the average light intensity received during the sunlight exposure phases. The total length of the shade phases is more than 50% longer than the total length of the sunlight exposure phases.

First claim

1 . A method for producing microalgae on a support movably mounted essentially in an aqueous medium contained in a tank comprising:
successive phases of exposing the microalgae growing on the support to sunlight and phases of said microalgae residing in the shade, the light intensity received in the shade being less than 50% of the average light intensity received during the phases of exposure to sunlight, characterized in that the total duration of the phases of residing in the shade is 50% greater than the total duration of the phases of exposure to sunlight.

2 . The method for producing microalgae as claimed in claim 1 , characterized in that the total duration of the phases of residing in the shade is between 2 and 10 times the total duration of the phases of exposure to light.

3 . The method for producing microalgae as claimed in claim 1 , characterized in that the duration of each phase of exposure to light is between 5 seconds and 10 minutes.

4 . The method for producing microalgae as claimed in claim 1 , characterized in that the support circulates in a loop between rollers, and in that the speed of the support is between 1 cm/s and 1 m/s.

5 . The method for producing microalgae as claimed in claim 1 , characterized in that the total dose of illumination of the microalgae during each exposure phase is between 1 and 60 millimol photons/m 2 .

6 . The method for producing microalgae as claimed in claim 1 , characterized in that the microalgae are part of one or more of the species from the group consisting of Botryoccocus sp., Porhyridium sp., Cylindrotheca sp., Navicula sp., Haslea sp. and Chlorella sp.

7 . The method for producing microalgae as claimed in claim 1 , characterized in that the microalgae are kept in the aqueous medium at least 90% of the time.

8 . A unit for producing microalgae comprising:
a tank; a support movably mounted in an aqueous medium contained in the tank; and means for driving and guiding the support successively over sections for exposing the microalgae on the support to sunlight and over sections for resting in the shade, the arrangement being such that the light intensity received during travel on the sections for resting in the shade is less than 50% of the average light intensity received during travel on the sections for exposure to sunlight, characterized in that the means for driving and guiding the support are set up such that the total duration of travel on the sections for resting in the shade is 50% greater than the total duration of travel on the sections for exposure to sunlight.

9 . The unit for producing microalgae as claimed in claim 8 , characterized in that the support is folded into a loop and in that the support is guided along superposed sections, the upper section forming an exposure section arranged above the other sections forming rest sections located in the shadow of the exposure section.

10 . The unit for producing microalgae as claimed in claim 8 , characterized in that the support is folded into a loop and in that it comprises means for guiding the support along vertical rising and falling sections substantially perpendicular to the surface of the aqueous medium which is contained in the tanks which are arranged in the shade.

11 . The unit for producing microalgae as claimed in claim 1 , characterized in that the support is a Möbius strip.

Assignees

• Inst Nat Rech Inf Automat
• Centre Nat Rech Scient
• Ecole Centrale Paris
• Univ Pierre Et Marie Curie Paris 6

Inventors

• Bernard Olivier
• Lopes Filipa
• Pruvost Eric
• Sciandra Antoine

Classifications

• C12M23/48

  Holding appliances; Racks; Supports (holding devices for laboratory apparatus B01L9/00) · CPC title

• C12M21/02 Primary

  Photobioreactors (culturing algae A01G33/00, A01H4/001, C12N1/12) · CPC title

• C12M41/06

  of illumination · CPC title

• C12M33/20

  Ribbons · CPC title

• C12M41/08

  Means for changing the orientation · CPC title