LLNL HRS (hot recycled solid) process is an above-ground shale oil extraction technology.
In 1984–1987, Lawrence Livermore National Laboratory operated a LLNL HRS process-based pilot pant at Parachute, Colorado, with capacity of one tonne of oil shale per day.
[2] Later the process was modified and tested in the field of waste treatment and environmental cleanup for removing organic compounds and for decomposing sodium nitrate in contaminated soils.
From the fluidized bed mixer oil shale moves downward to the packed-bed pyrolyzer.
The spent oil shale, still including residual carbon (char), by the air pneumatic lift pipe to the delayed-fall combustor where it is combusted to heat the process.