ABSTRACT
In a very general sense, petroleum refining can be traced back over 5000 years to the times
when asphalt materials and oils were isolated from areas where natural seepage occurred
(Abraham, 1945; Forbes, 1958; Hoiberg, 1960). Any treatment of the asphalt (such as hard-
ening in the air prior to use) or of the oil (such as allowing for more volatile components to
escape prior to use in lamps) may be considered to be refining under the general definition of
refining. However, petroleum refining as we know it is a very recent science and many
innovations evolved during the twentieth century.