Study on the Influence of Surfactant Addition for Bitumen Separation from Asbuton Rocks using Hot Water Process

Abstract

Abstract Indonesia has a bitumen reservoir in a form of rocks located in Buton Island, Southeast Sulawesi. These rocks contain both bitumen and mineral. Bitumen was mostly used for road preparation, hence bitumen had to be separated from its mineral. It was concluded from previous researches that bitumen extraction using the hot water process had a low bitumen recovery. One way to improve its recovery was by adding surfactant. This research aimed to study the effects of anionic and cationic surfactant addition to the percent recovery of bitumen. There were three main processes of bitumen extraction using hot water namely; preparation, mixing-preheating, and digesting. First, asbuton rocks were ground into fine material, then it was sieved using sieve number 30. Then it was continued by mixing asbuton and diesel oil with a ratio of 60:40 at 250 rpm at 60°C for 30 minutes. Then the second process was done by mixing diesel oil-asbuton and wetting agent solution that contains Sodium Dodecyl Benzene Sulfonate (SDBS) as anionic surfactant and NaOH at 1500 rpm for 30 minutes. The other mixture is Dodecyl Trimethyl Ammonium Bromide (DTAB) as a cationic surfactant and NaOH. In this research, the concentrations of surfactant used were 0.125; 0.25; 0.375; 0.5%, the used NaOH concentrations were constant at 0.5% (% mass), while the variation of temperature used were 60, 70, 80, to 90°C. The product of the digestion process was taken into beaker glass for 24 hours to separate into 3 layers by gravitational force. The top layer is a bitumen-diesel oil solution. The result showed that the performance of SDBS is better than DTAB, this could be because DTAB is positively charged, yet the minerals are negatively charged, so they tend to bind. It can be concluded from this study that the highest percent recovery of bitumen was 72.30 % at a temperature of 90°C with SDBS surfactant concentration of 0.125%, which means anionic surfactant had a better result than cationic surfactant.