Abstract: The present invention is an apparatus for separating volatile from nonvolatile substances, separation of volatile substances, one from the other, and for performing various chemical reactions. In particular, an apparatus which performs these functions utilizing a combination of above ambient temperatures and above one inch of mercury vacuum within a rotating vessel. The apparatus uses a conventional rotary vacuum seal. The apparatus, however, operates well above the maximum operating temperature of the conventional rotary vacuum seal by isolating and cooling the conventional rotary vacuum seal.