Evaluation of sudanese crude oil of the production of lubridcants base stoks

Abstract

Abstract Due to fast growing of the petroleum industry in the Sudan and the very huge need for lubricating oils, they are considered to be the back bone of the modern industry. This study is carried out to determine the suitability of saponin as a natural detergent to be used in engine lubricating oil and also to determine the visibility of producing base oil stocks to supply the local demand of the Sudanese market. Three different blends of crude oils are produced in the Sudan namely: Nile blend, Dar blend block 5B blend. These were preliminary evaluated to choose the most suitable crude oil to produce base oil stocks by comparing of their percentage yields, pour point and wax content. It was found that block 5B blend is the most suitable one for the producing of base oil 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 very advanced automatic equipment complying with the ASTM D2892 (15theoretical plate column) to separate the light component from the crude oil. Then appropriate lube cuts were collected by vacuum distillation according to ASTM D 5236 using the same equipment. The cuts collected at predetermined temperature ranges 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. XV The vacuum residues 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 solvent system "methyl ethyl keton (MEK) and toluene" to enhance the cooling 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 yield was calculated. This study came to conclude that block 5B blend is quite suitable for the manufacturing of lube base oils and it gave different grades of lube base stocks with reasonable yields. The extraction of saponin was carried out from three different plants (Ziziphus abyssinica, Citrullus colocynthis, Balanistes aegyptiaca). The quantity of saponin in these species is 0.3823, 0.1779 and 3.5626 respectively. Then the thin layer chromatography was done for the three saponin to determine the best one. The saponin from Balanistes aegyptiac is the best one and the quantity is greater than the other two saponin. Then the blend of sea w30 was done between cut 480-520°C and cut 520+ and its clearly was done and it found 432mg in 240 hour and classify that it is very clean.