extraktlab CO2 extractors  continuously add clean CO2 to the process at the beginning of each run. Approximately half of the CO2 is recycled into the next run and half of the CO2 is fresh CO2. This means that  the entire amount of CO2 is continuously  replaced approximately every two runs.
Some CO2 extraction equipment recycles  nearly 100% of the CO2. We do not recommend  this approach for the following reasons:
Recycling cylinders are typically designed with a single small Inlet and a single small Outlet. This design is typically driven by cost considerations and renders the recycling cylinder impossible to clean.  By extension, CO2 expansion tanks that are often installed before the pump become a dead volume that is not swept.  We do not deploy these on our pumping systems for the same reasons.
When recycling Co2 via a compressor, Terpenes and other contaminants become entrained in the recycling system. These compounds degrade over time and are then introduced to the fresh hemp being extracted. For this reason, we do not recycle 100% of the CO2 using compressive technology.
Large energy-intensive compressors are required for recycling.
Even though extraktlab  CO2 extraction equipment does not recycle 100% of the CO2, we do have a CO2 recycler on the system so that CO2 can be recycled during a single run.   that recycler is designed for maximum cleanability.  both the inlet and the outlet to the recycler cylinder is a large enough diameter to reach your entire arm into the cylinder. It can be cleaned because all of the surfaces are accessible.
Extraktlab does not use energy-intensive compressors to recycle 100% of the CO2. The reason for this is cross contamination avoidance and the fact that CO2 is extremely inexpensive.