Granted Patent
Utility
US 4,180,552 · App. 05/888,103
Process for hydrogen recovery from ammonia purge gases
Inventors:
Tommy E. Graham, Donald L. MacLean
Patented Case
View Patent ↗
Granted: Dec 25, 1979
Filed: Mar 20, 1978
Inventors
Tommy E. Graham
Donald L. MacLean
Assignee (at issue)
Monsanto Company
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.