The LLNL RISE process was an experimental

shale oil extraction Shale oil extraction is an industrial process for unconventional oil production. This process converts kerogen in oil shale into shale oil by pyrolysis, hydrogenation, or thermal dissolution. The resultant shale oil is used as fuel oil or up ...

technology developed by the

Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory (LLNL) is a federal research facility in Livermore, California, United States. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response ...

. The name comes from the abbreviation of the Lawrence Livermore National Laboratory and words 'rubble in situ extraction'. LLNL RISE is a modified ''in situ'' extraction technology originally proposed by Rio Blanco Oil Shale Co. and developed by the Lawrence Livermore National Laboratory. It is classified as an internal combustion technology. The process was described in 1975 by Lewis A. E. and A. J. Rothman. In the LLNL RISE process a part of the

oil shale Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitut ...

deposit (roughly 20% of the total deposit) is removed by the conventional mining technique. The remaining deposit is then broken up with explosives to increase

porosity Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measur ...

of the deposit. As a result, a large underground retort chamber by square and high is created. The retort chamber is ignited at the top. The combustion zone moves downward as an

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

gas provided, similar to the process developed by the Occidental Petroleum. The heat causes retorting process converting

kerogen Kerogen is solid, insoluble organic matter in sedimentary rocks. Comprising an estimated 1016 tons of carbon, it is the most abundant source of organic compounds on earth, exceeding the total organic content of living matter 10,000-fold. It ...

in oil shale to

oil shale gas Oil shale gas (also: retort gas or retorting gas) is a synthetic non-condensable gas mixture (syngas) produced by oil shale thermal processing (pyrolysis). Although often referred to as shale gas, it differs from the natural gas produced from shale ...

and

shale oil Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock ( kerogen) into synthetic oil and gas. The resulting ...

vapors. Some oil is collected at the bottom of the retort, other collected at the surface as vapors. The process was never used commercially. It was tested by using experimental simulated retort with capacity of 6 tonnes of oil shale per day.

References

{{Lawrence Livermore National Laboratory, state=autocollapse Oil shale technology Thermal treatment Lawrence Livermore National Laboratory