While in the simple semi continuous extraction the system is equipped with 2 extraction vessels, in the overlapping extraction the system is equipped with 3 extraction vessels.
Taking advantage on the typical flowers and leaves extraction kinetic, the intelligent automation of the system will apply a different extraction strategy.
As we see, the most of the extract comes out in the first half of the extraction. The new process program will apply a new approach: after the first half of the extraction, the system will put in series the extractors nr. 1 and nr.2
As the most of the compounds has been extracted from extractor nr. 1, after the first half of the extraction the CO2 is no more saturated by the compounds like before.
This means the CO2 has room to solubilize more compounds than what available in extractor nr. 1.
Connecting the extractor nr. 2 in series to extractor nr. 1 after the first half of the process will give to the production manager the advantage to recover the last 15% to 30% left in extractor nr. 1
while extracting the most of the compounds from extractor nr. 2, and so on with extractor nr. 2 and extractor nr. 3 and then again with extractor nr. 3 and extractor nr. 1 in an endless circle.
The serial semi continuous automation program is completely different if compared with the simple semi continuous.
The advantage is clear: in the same time we will have results almost comparable to a double sized system.