Microalgae cultures using sealed vertical photobioreactors

Abstract

A microalgae culture broth producing system includes a device for culture broth sterilization using a micro bubble generator, an air compression and pressure equalization device for the injection of carbon dioxide and oxygen in the atmosphere into the culture broth. The system also includes an air chilling device to maintain suitable culture broth temperature when water temperature is too high, an automatic carbon dioxide supply device to promote photosynthesis, and a sealed vertical photobioreactor to block out pollutants and increase dissolved carbon dioxide and oxygen concentration. The system further includes a high-efficiency harvesting device using hollow fiber membranes, and a hot air drying device using the waste heat generated by air compression.

1 - 14 . (canceled) 
     
     
         15 . An apparatus for cultivation of microalgae in a culture broth, comprising:
 a device for culture broth sterilization using a micro bubble generator;   an air compression and pressure equalization device for injection of carbon dioxide and oxygen from atmosphere into a culture broth;   an air chilling device to maintain suitable culture broth temperature;   an automatic carbon dioxide supply device to promote photosynthesis;   a sealed vertical photobioreactor configured to contain a culture medium inoculated with a microalgae;   a harvesting device comprising hollow fiber membranes; and   a hot air drying device.   
     
     
         16 . The apparatus according to  claim 15 , wherein the air compression and pressure equalization device comprises a device to compress carbon dioxide and oxygen in atmosphere to 10 bar, a device (tank) to equalize air pressure, and pipes and a gas backflow preventing device to inject compressed gases into the culture broth. 
     
     
         17 . The apparatus according to  claim 15 , wherein the automatic carbon dioxide supply device supplies liquefied carbon dioxide into the culture broth using a pH sensor. 
     
     
         18 . The apparatus according to  claim 17 , wherein the automatic carbon dioxide supply device automatically supplies carbon dioxide when pH of a culture broth is 7.26 or higher, and automatically cuts off carbon dioxide when pH of a culture broth is less than 7.26 if microalgae is a freshwater microalgae, and automatically supplies carbon dioxide when pH of a culture broth is 7.30 or higher, and automatically cuts off carbon dioxide when pH of a culture broth is less than 7.30 if a microalgae is a seawater microalgae. 
     
     
         19 . The apparatus according to  claim 15 , wherein compressed gas is injected into bottom of the apparatus. 
     
     
         20 . The apparatus according to  claim 19 , further comprising a device for control of gas pressure. 
     
     
         21 . The apparatus according to  claim 20 , wherein mutual exchange and flow of culture broth among identical connected vertical photobioreactors is induced solely by buoyant force of pressure-adjusted air. 
     
     
         22 . The apparatus according to  claim 15 , wherein a concentrated microalgae harvested through pipes from the photobioreactor is passed through a hollow fiber membrane to allow for separate harvesting of culture broth and biomass. 
     
     
         23 . A system for culturing microalgae, comprising:
 a device for culture broth sterilization using a micro bubble generator;   an air compression and pressure equalization device for the injection of carbon dioxide and oxygen from the atmosphere into the culture broth;   an air chilling device to maintain suitable culture broth temperature;   an automatic carbon dioxide supply device to promote photosynthesis;   a sealed vertical photobioreactor configured to contain a culture medium inoculated with a microalgae;   a harvesting device comprising hollow fiber membranes; and   a hot air drying device.   
     
     
         24 . The system according to  claim 23 , wherein the air compression and pressure equalization device comprises a device to compress carbon dioxide and oxygen in atmosphere to 10 bar, a device (tank) to equalize air pressure, and pipes and a gas backflow preventing device to inject compressed gases into the culture broth. 
     
     
         25 . The system according to  claim 23 , wherein the automatic carbon dioxide supply device supplies liquefied carbon dioxide into the culture broth using a pH sensor. 
     
     
         26 . The system according to  claim 25 , wherein the automatic carbon dioxide supply device automatically supplies carbon dioxide when pH of a culture broth is 7.26 or higher, and automatically cuts off carbon dioxide when pH of a culture broth is less than 7.26 if microalgae is a freshwater microalgae, and automatically supplies carbon dioxide when pH of a culture broth is 7.30 or higher, and automatically cuts off carbon dioxide when pH of a culture broth is less than 7.30 if a microalgae is a seawater microalgae. 
     
     
         27 . The system according to  claim 23 , wherein compressed gas is injected into bottom of the apparatus. 
     
     
         28 . The system according to  claim 27 , further comprising a device for control of gas pressure. 
     
     
         29 . The system according to  claim 28 , wherein mutual exchange and flow of culture broth among identical connected vertical photobioreactors is induced solely by buoyant force of pressure-adjusted air. 
     
     
         30 . The system according to  claim 23 , wherein a concentrated microalgae harvested through pipes from the photobioreactor is passed through a hollow fiber membrane to allow for separate harvesting of culture broth and biomass. 
     
     
         31 . The system according to  claim 23 , further comprising a vinyl greenhouse to ensure optimized year-round microalgae culturing, and operating devices therefor.