20 BULLETIN 1010, U. S. DEPARTMENT OF AGRICULTURE. 
The cost of the material used and the oil lost in the bleaching 
operation after treating the oil with caustic amounts to about 0.21 
cent a pound of crude oil, of which approximately one half represents 
the cost of the fuller's earth and the other half the value of the oil 
lost in the operation. 
DEODORIZING. 
Deodorizing is an entirely mechanical operation and involves no 
charge for chemicals. There is a small loss of oil in the entrain- 
ment, which varies according to the local conditions, but even this 
small quantity of oil is recovered by means of the grease trap in the 
sewer. 
FUEL. 
The cost of fuel for caustic treatment and bleaching is compara- 
tively low. For deodorization, however, the fuel charge is the main 
item of cost. Not only must the oil itself be heated to over 400° F., 
but it must be maintained at this temperature while approximately 
25,000 pounds of steam are blown through it. Unless the steam has 
been previously superheated, it is evident that its passage through 
the oil will raise its temperature to that of the oil itself, which would 
operate to lower the temperature of the oil. Therefore not only must 
25,000 pounds of steam be generated but it must be superheated to 
at least 450° F. before it can effectively serve its purpose. The oil 
itself must likewise be raised to this temperature, all of which accounts 
for the large quantity of fuel used. This consists not only of coal as 
burned under plant boilers for steam but also of fuel oil used in the 
direct-fired oil heater. 
LABOR. 
The labor necessary for handling the oil through the refinery is 
quite evenly distributed among the three principal operations. It 
is estimated that two men — one skilled workman and one unskilled 
laborer — can operate the plant under the general direction of the 
chemist and plant superintendent. A charge of $13.80 is made for 
these two workmen for each of the three operations, or a total of 
$41 .40 for each batch of 25,000 pounds of oil. The cost of the techni- 
cal supervision is charged to overhead by including the salaries of the 
chemist and plant superintendent with those of the general executive 
force and assuming that a tenth of their time will be devoted to 
matters connected with the refinery. 
OVERHEAD. 
The overhead item covers all plant charges not enumerated in the 
above, and consists of such costs as the following: Interest on a 
$40,000 equipment, building charge, water, insurance, power, office 
expenses, and selling charges. 
