General description of the process
Solid/Liquid extraction process is a very common process in the pharmaceutical, cosmetic and food industry to obtain natural ingredients as e.g. flavors and fragrances from natural raw material.
The extraction can be carried out with cold or hot solvents.
The solid raw material is packed in a container with a retainer on the bottom called extractor B2 and extracted batch wise.
The solvent is guided through the extractor in different ways
- Continuous trickle bed extraction
- Continuous overflow extraction
- Soxhlet extraction (periodically filled and drained container)
Using solvents with a lower density than the raw material avoids floating of the raw material and eases the process.
Very often the solvent is evaporated in B1 from the extract directly after leaving the extractor, then condensed in W2 and guided back into the extractor B2.
Once the ingredients are extracted from raw material the solvent is evaporated under most gentle conditions to avoid any eventual degradation of the desired ingredient.