REFERENCE
[Advantages of Continuous Culture]
(Compared to batch type)
The most inefficient harvesting system for mass cultivation of microalgae is the "batch type".
The batch type is a method in which cultivation is started, the entire amount is harvested when it reaches the maximum concentration, and after cleaning and sterilizing the equipment, a huge amount of seed bacteria that has been prepared separately is planted, and the cultivation is restarted almost from the water stage. As far as I know, this method is used in all algae cultivation facilities.
The cleaning and sterilization work at this time, and the seed bacteria (similar to rice seedlings) production work are the most labor-intensive, human- and money-consuming parts of mass cultivation of algae.
Then, it starts again from the ultra-low concentration stage, and it takes time to reach the maximum concentration, and during that period the risk of contamination increases.
This is because when cultivation is restarted, there are abundant nutrients inside the cultivation equipment, but the number of algae cells is low, making it an ideal breeding ground for contaminating organisms.
On the other hand, continuous cultivation does not involve any of the above three major elements that require labor, manpower and money.
What's more, in the case of half-harvesting, although it depends on the type of algae, in most cases the concentration will recover to its original level within a few days.
Therefore, in the graph of culture concentration, with the batch method the concentration value will be zero at the time of harvest and will remain at zero for the cleaning period, but with continuous culture, the concentration is only half of the maximum concentration at the time of harvest, and therefore it takes only a short time for the concentration to reach its maximum again.
In short, a high concentration can be maintained continuously.
(Compared to batch type)
The batch type is a method in which cultivation is started, the entire amount is harvested when it reaches the maximum concentration, and after cleaning and sterilizing the equipment, a huge amount of seed bacteria that has been prepared separately is planted, and the cultivation is restarted almost from the water stage. As far as I know, this method is used in all algae cultivation facilities.
The cleaning and sterilization work at this time, and the seed bacteria (similar to rice seedlings) production work are the most labor-intensive, human- and money-consuming parts of mass cultivation of algae.
Then, it starts again from the ultra-low concentration stage, and it takes time to reach the maximum concentration, and during that period the risk of contamination increases.
This is because when cultivation is restarted, there are abundant nutrients inside the cultivation equipment, but the number of algae cells is low, making it an ideal breeding ground for contaminating organisms.
On the other hand, continuous cultivation does not involve any of the above three major elements that require labor, manpower and money.
What's more, in the case of half-harvesting, although it depends on the type of algae, in most cases the concentration will recover to its original level within a few days.
Therefore, in the graph of culture concentration, with the batch method the concentration value will be zero at the time of harvest and will remain at zero for the cleaning period, but with continuous culture, the concentration is only half of the maximum concentration at the time of harvest, and therefore it takes only a short time for the concentration to reach its maximum again.
In short, a high concentration can be maintained continuously.