In case of surface retorting
, oil shale needs first to be transported to the surface by open pit or underground mining.
They found that HPTS may reduce the levels of food processing contaminants in products and create sterile foods that are similar to products that have undergone retorting
When prolonging the residence time for Yaojie oil shale, the yield of retorting
gas was increased and that of water did not change much.
50 grams of dried oil shale samples was placed inside the retort before each test and electrically heated from room temperature to a final retorting
temperature of 430[degrees]C at a fixed heating rate of 12[degrees]C [min.
Therefore, it is a rewarding task to investigate the relation between the retorting
temperature and shale hold time, and their sequential effect on oil yield through an optimum retorting
The process carried out in the SJ-type retort represents an aboveground retorting
method for obtaining shale oil from oil shale.
There are two oil shale retorting
plants in Fushun, including 220 retorts with the daily capacity of 100 t of oil shale per each retort.
In 1851, James Young opened Britain's first commercial mineral oil refinery in Bathgate and patented his retorting
process in both the UK and US .
Yefimov was focused on optimisation of lump shale retorting
process in vertical retorts, but he was also competent at comparing the advantages of various technologies used in oil shale plants.
In the surface retorting
, the product was to send directly to primary upgrading plants of catalytic and hydrogen treating to remove nitrogen and metals.
There are different removal characteristics of trace elements during oil shale retorting
The detailed description of the retorting
experiments and their results is published in  and autoclavic experiments in .