Processing raw material by SFE and selectively separating ingredients is named upgrading of raw material. Different to SFE for production of extracts the raffinate, i.e. the extracted raw material, is the product in this process. The extract is recovered as a by-product or a waste stream.

This process is mostly applied for upgrading of natural substances in the food industry:

• Decaffeination of coffee and tea
• Removal of pesticides, cholesterol, solvents, etc. from natural substances and extracts

In these applications of SFE CO₂ is most commonly used as fluid and the process is similar to the aforementioned SFE.

SFE can also be used for processing and removal of unwanted ingredients in mixtures to re-achieve initial properties. Some examples of these processes are:

• Removal of binder from construction parts
  (removal of binder from parts made of sintered pulvers).

• Removal of solvents from synthetic products.

• Cleaning of contaminated substances
  (cleaning of soils, regeneration of used adsorbents, etc.).

• Processing of used oil
  (processing lubricant oils, abrasive slurries, etc.).

The applicability of extractive processing is versatile and almost unlimited. Uhde is always well informed about recent developments in this field and participates and collaborates with proprietary know-how in R&D projects with partners as well as own developments.