Improvement of air release value of general quality base oils by percolation process

Abstract

The purpose of this study are to investigate the possibility of using percolation process in reducing air release value of lubricating base oils, to find the suitable contact time of the process and to study the effect of the temperature of feed oil on the effectiveness of the process. The studies were carried out on six types of base oil such as 150SN, 450SN, 500SN and 600 SN. Five litre bauxite was packed in a steel column with 6 inch in diameter and 75 cm.high. Each base oil was warmed up in the stirred heating tank until oil temperature reached at 5 degree celsius above the desired temperature which were 60 degree celsius and 100 degree celsius respectively. Then the warm oil was forced through the bauxite column at specific flowrate which gave the desired contact time. The experiments were run at contact time of 0, 20, 40, 60, 80,100 and 120 minute respectively. Sample were taken for testing after constant flowrats were achieved for 15 minute. Test carried out on each sample were viscosity at 40 degree celsius, viscosity at 100 degree celsius, viscosity index, color, sulphur content, compositions and air release value at 50 degree celsius. The results showed decreasing in air release value and sulphur content for sample from both different operating temperatures while the other properties, except color, slightly changed. Colour of samples processed at 60 degree Celsius were significantly improve while those processed at 100 degree celsius were slightly improve due to the deterioration of oil at high temperature. To avoid this problem the process should be operated at 60 degree celsius or below depending on the viscosity of oil to be processed. To increase productivity, three percolation column (or more) in series may be used and operated at 60 minute of contact time.