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March
2017
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HYDROCARBON
ENGINEERING
L
ubricating oil is one of the most valuable
components that can be refined from a barrel of
crude oil. Today, virtually all moving machinery
requires lubrication to protect the equipment.
However, lubricating oil cannot be used indefinitely as it
can get contaminated, and the chemical additives within
the oil can degrade under high heat or stressful
environments. The degraded chemical additives will
contaminate and, ultimately, decrease the quality and
performance of the lubricating oil. Therefore, old
lubricating oil must be changed out periodically and
replaced with fresh lubricating oil in order to protect the
equipment from damage. The degraded, spent lubrication
oil is also known as used oil.
Used oil is a mixture of lubricating oils from a variety of
applications. Thus, it is difficult to define the exact
chemical properties and compositions of used oil.
Furthermore, used oil can contain varying amounts of
chemical additives, fuels and possibly water.
The majority of typical used oil is made up of the
following components:
Motor oil (crankcase).
Transmission fluid.
Gear oil.
Hydraulic fluid.
In addition, used oil may contain some amounts of
contaminants, including the following:
Water.
Antifreeze.
Chlorides.
Fuels.
USE IT OR
LOSE IT
James Au and David Ng,
Chemical Engineering
Partners, USA,
examine
various re-refining and
recycling processes that
can be undertaken to
reduce contaminants and
preserve the value and
usability of used oil.