Application of compressed gases as solvents has found widespread interest within the scientific community, with processes having industrial applications. Gas extraction deals with the possibilities of supercritical gases as solvents for separation processes. The volume combines physico-chemical aspects with chemical engineering methods. The text generalizes as far as possible and treats examples in detail. Gas extraction covers, for the first time, the subject in textbook form. Most of the examples provide new results that will be helpful for practicing scientists, engineers, and students who want to make use of the techniques.