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البحـث الأول
مجلة النفط والتعاون العربي
161
العدد
- 2017
أربعون
المجلد الثالث و ال
2016
أوابك العلمية لعام
�
ص لبحوث العلمية الفائزة بجائزة
�
عدد خا
21
11
* Base oils are produced in a complex sequence of steps in a refinery by vacuum
distillation of atmospheric residue, propane deasphalting, solvent extraction,
dewaxing and hydro-finishing.
* The re-refining processes involve filtration and settling, removing water and
light hydrocarbons, removing gasoil, rejecting heavy materials and contaminants
and treating the remaining oil with solvent or hydrogen. There are three major
categories of processes to treat used oils by sulphuric acid and clay, distillation
and clay and solvent extraction or hydro-treatment.
* The acid clay process does not give good base oils and is environmentally risky.
The Meinken process is the same but with clay only. CEP Mohawk Process is an
improvement by using hydro-treatment
and so are many others such as KTI,
Hylube, Snam Progetti and Revivoil. Avista and Dollbergen processes use
solvent extraction instead.
* The selection of environmentally sound re-refining process depends on
feedstock quality and nature of contaminants, the desired quality and yield of base
oil, the disposal of any hazardous waste, economic feasibility, availability of
feedstock and consideration of the plant location. The national and local
legislation and the Socio-economic benefits must be given consideration. The
majority of modern plants are either solvent extraction or hydro-treating based.
* Used oil for fuel is a competitor to the re-refining industry where the used oil
burned is near or much more than the oil re-refined.
They are combusted in
industrial applications such as cement kilns, blast furnaces, power plants,
industrial plants boilers and space heating sometimes directly and others after
settling, filtering and decanting.
* The prevailing view is that re-refining is uneconomic due to high investment as
compared to burning applications, the lower prices in the market for re-refined
base oils and the cost of getting rid of environmentally stressful waste in some
processes.
* The price of crude oil affects base oil prices and lubricants demand in addition
to other economic parameters. But high oil prices encourage investment in re-
refining of used oil.
* The growth in the world lubricants demand is modest but the highest rates are
in Asia - pacific and the Middle East. Forecasters remain different on how much
growth is expected while additives are capturing increasing share of the lubricants
market. Lubricants demand is forecast between 42 and 45.4 million tons in 2019