59 / 222
مجلة النفط والتعاون العربي
161
العدد
- 2017
أربعون
المجلد الثالث و ال
2016
أوابك العلمية لعام
�
ص لبحوث العلمية الفائزة بجائزة
�
عدد خا
52
42
Fig (6) - CEP Mohawk Process - Source 1
The Avista process:
1,3,92
Fig (7). Formerly Vaxon a Danish fuel preparation process. The process is
modified and now licenced by Avista. After settling and filtration of the used oil
feed water and light hydrocarbons are separated in a pre-flash distillation step. N-
Methyl-2-pyrrolidone
solvent (NMP) is then used to treat and remove
contaminants of hydroxides, chlorides, metals and spent additives.
The operation of liquid/liquid extraction is conducted in a column where the feed
rises from the bottom to meet the solvent coming from the top. In the following
step, the solvent is stripped and recycled and the oil is distilled in a vacuum tower
to recover the base oils as side streams and the asphalt from the bottom. Propane
is used in other solvent extraction processes.