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مجلة النفط والتعاون العربي
161
العدد
- 2017
أربعون
المجلد الثالث و ال
2016
أوابك العلمية لعام
�
ص لبحوث العلمية الفائزة بجائزة
�
عدد خا
64
54
Chapter 4 - Burning Used Oil for Fuel
Used oil for fuel is a competitor to the re-refining industry in many countries as
we shall see.
The European Union (EU), the U.S. Federal Government and other
countries have given priority to the re-refining of used oils but most of the
generated and collected used oil still goes to fuel
1, 4, 7, 22, 23
.
Instead of re-refining, used lubricating oil for fuel and energy recovery is called
recycling which means here, using a waste material to make something new and
useful from it.
Therefore, used lubricating oils are often recycled to be combusted in high
temperature industrial combustion systems to ensure complete combustion and
avoid the release of harmful substances into the environment
4
. These systems
include cement kilns, blast furnaces, power plants, industrial plants boilers and
space heating
7
.
While used lubricating oil can and is used directly as fuel, replacing coal or fuel
oil in the above mentioned applications, there are processes that can treat the stuff
for better fuel applications
including diesel fuel or marine and railway engines
fuel.
The estimation of global used oil generated globally is not an easy task “
as users
and recyclers either do not collect, or do not share, data.”
4
The same source
estimates that about 5.25 million tons a year are “burnt as fuel and dumped an
d/or
land filled
4
.” With environmental regulations tightened in many countries, this
estimate is conservative as we shall see later.
Direct Burning of Used Oils:
In the beginning, when heat value of used lubricating oils was appreciated, it was
used without pre-treatment or processing and without any quality control or
specification
1
. As environmental awareness spread, it was realized that such
practise is harmful to health and the environment and had to be controlled.
Perhaps the first kind of treatment was no more than settling in a heated tank at
70 to 80
o
C, decanting to drain water and filtration to remove sludge and
suspended matter
4
.
Utilizing used oil for the partial replacement of fuel oil is now widely applied
around the world
1
under controlled conditions in cement kilns, stone quarries,
asphalt coating plants, smelters, coking plants, brickworks, large industrial
boilers and power plants
1
. The word “partial” is
not obligatory as some of the
above applications can utilize only used oil if the volume is available. It was also