Evaluation of Sudanese crude oils for the production of Lubricants base stocks

Abstract

Due to the fast growing of the petroleum industry in the Sudan and the very huge need of lubricating oils as it's considered to be the backbone of the modern industry. This study is carried out to determine the visibility of producing base oil stocks to supply the local demand of the Sudanese market. Three different types of crude oils are produced in the country namely; Nile blend, Dar blend and Fula blend were preliminary evaluated to choose the most suitable crude oil to produce base oils stocks through the comparison of their yields percentage, pour point and wax content. it was found that Fula blend is the most suitable one for the producing of the base oils stocks due to many technical and economical reasons. The studied crude oil samples were collected from the fields and distillated atmospherically using the Minitop - combi apparatus which, is a very advanced automatic equipment complying with the ASTM D2892 (15 theoretical plate column) to separate the light component from the crude oil. Then, appropriates lube cuts were collected by vacuum distillation according to ASTM D5236 using the same equipment. The predetermined temperature ranges of the collected cuts were analyzed and tested to determine their characteristics. As in the industry all cuts were subjected to several processes either to eliminate some of the undesired components or to enhance some other properties. The vacuum residue were subjected to deasphalting process to remove all the asphalts from the cut, after that all cuts were dewaxed including the Deasphalted Oil (DAO), using Methyl Ethyl Ketone (MEKl to enhance the cooled properties of the collected cuts i.e. pour point. A solvent extraction process was then carried out to all cuts to improve the viscosity index and quality of the produced base oil cuts. The produced cuts were tested to determine their characteristics and the production yields were calculated. This study came to conclude that the Fula crude is quite suitable for the manufacturing of lube base oils and it gave different grades of lube base stocks with reasonable yields.