|
| US4076312 | 30. Juli 1976 | 28. Febr. 1978 | Occidental Oil Shale, Inc. | Method and apparatus for retorting oil shale at subatmospheric pressure |
| US4093026 | 15. Apr. 1977 | 6. Juni 1978 | Occidental Oil Shale, Inc. | Removal of sulfur dioxide from process gas using treated oil shale and water |
| US7980312 | 19. Juni 2006 | 19. Juli 2011 | | Integrated in situ retorting and refining of oil shale |
