—=- ot haa oe 
NECESSITY FOR RESEARCH IN OIL-SHALE INDUSTRY. 
off the oil products formed. Distillation with steam increases the yield 
of ammonia about two and one-half times as compared with dry 
distillation, and also produces more oil which is of higher quality. 
TEMPERATURE AND Hxars. 
The maximum temperature to which the shale is subjected is not 
much in excess of 1,500 degs. F., although temperature measurements 
have never been accurately made within the retort itself. The retort 
operators are skilled in judging retort temperatures by heat colours, 
and keep temperatures under careful control by looking into the furnace 
through peepholes. In general, in retorting and refining practice in 
Scotland, one is struck with the very definite way conditions are con- 
trolled. Many years of practical experience haye determined these 
conditions. 
The spent shale is discharged cont:nucusly from the retorts, and the 
mechanisms used for this purpose constitute the main points of differ-: 
ence between the types of retorts. The spent shale is refuse. No 
commercial use has ever been found for it, although it-has been tried 
in road and brick making. he fixed carbon remaining in the shale 
amounts to only 14 to 2 per cent. This is the economic limit with 
reference to fuel consumption, throughput of shale, and ammonia and 
gas yield. A greater yield of ammonia could be obtained by reducing 
the amount of carbon, but at the expense of throughput. 
Vavours Separatep rrom Gases AND Rerinep. 
 Vapours pass out of the retort through the vapour line, which is 
cast integral with the upper part of the retort. Large suction fans in 
the dry gas main, between the scrubbers and gas burners, put @ slight 
suction on the retorts. The vapours pass to large headers and thence 
to a series of U-shaped, vertical, air-cooled condensers made of cast-iron 
pipe. Below each U is a receiving box for condensate, and from this 
box the condensed oil and ammonia water are drawn off to separating 
tanks. Uncondensed gases pass through water scrubbers, which remove 
any ammonia remaining in the -permanent gases, and through oil 
scrubbers, which remove the light hydro-carbons, commonly known as 
“scrubber naphtha.” The gas-is then led back to the retort furnaces, 
where it is burned. 
Shale now being worked in Scotland yields per short ton approxi- 
mately 10,000 cubic feet of gas having a heat value of about 240 B.t.u. 
per 1,000 cubic feet, approximately 24.5 U.S. gallon of crude oil, and 
36 Ibs. of ammonia sulphate. 
The crude oil, after having the bulk of the water separated, is run 
to the refinery. ‘The refining of this oil is more involved and com- 
plicated than the refining of petroleum, as the oil must be subjected to 
more acid and alkali treatments and a greater number of distillations. 
Therefore a shale-oil refinery contains more small stills and agitators 
than does a petroleum refinery of equal capacity. More* batch stills 
are used than continuous stills, and the Scotch shale-oil refineries have 
extraordinary large wax plants compared with petroleum refineries of 
equal capacity. 
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