Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7909989 | Method for obtaining bitumen from tar sands | Willem P. C. Duyvesteyn, Raymond L. Morley | 2011-03-22 |
| 6007709 | Extraction of bitumen from bitumen froth generated from tar sands | William P. C. Duyvesteyn, James J. Lutch | 1999-12-28 |