Patents by Inventor David L. Parks, Jr.

David L. Parks, Jr. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for the recovery of nitric acid
    Patent number: 5006325
    Abstract: This invention relates to an improved process for the recovery and regeneration of nitric acid from spent acid obtained from the mixed acid nitration of aromatic compounds. In that process a mixed acid of sulfuric acid and nitric acid is contacted with an aromatic composition at a temperature and pressure sufficient for producing a nitroaromatic composition and a spent acid containing unreacted nitric acid, sulfuric acid and solubilized nitroaromatic compounds in said spent acid. The improvement comprises initially heating the spent acid to a temperature of from about 120.degree. to 200.degree. C. for a time sufficient to convert said nitroaromatics in said spent acid to a nitroaromatic composition having a boiling point greater than 300.degree. C. at atmospheric pressure and then flash distilling the hot spent acid containing nitroaromatics compositions at a pressure from about 5 to 15 psia and temperature of 150.degree. to 200.degree. C.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: April 9, 1991
    Assignee: Air Products and Chemical, Inc.
    Inventors: David L. Parks, Jr., Carl J. Martin