Granted Patent
Utility
US 4,457,830 · App. 06/334,857
Petroleum hydroconversion using acid precipitation of preasphaltenes in resid recycle
Inventor:
Paul H. Kydd
Patented Case
View Patent ↗
Granted: Jul 3, 1984
Filed: Dec 28, 1981
Inventor
Paul H. Kydd
Assignee (at issue)
HRI
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.