There are hundreds of patents filed/published in past two to three decades regarding the method, process, apparatus, and techniques for SFE and PLE of a wide range of substances. These documents can be accessed through the database of United States Patent and Trademark Office (http://www.uspto.gov/), the European Patent Office (http://www.epo.org/), and the German Patent and Trade Mark Office (http://www.dpma.de/), among the others. An interesting statistical review of the patents on the application of supercritical fluids between 1980 and 2005 was presented by Schütz [9].