Authors: H Devianto1*, M Eviani2, R A Rahardi1 and F Yusupandi1
Corrosion is one of major problems in refinery industry which leading to mechanical failure of equipments. Corrosion mechanism and rate depend on the corrosive substance, temperature, and material of equipment. Refinery feedstock commonly is a blending of different oils contains different corrosive substance. One of corrosive substance, Sulfur Content and TAN, can cause thinning of material surface at high temperature. This research aims to study the effect of sulfur content and TAN on corrosion mechanism and rate of equipment and piping in small scale refinery. Corrosion mechanism and rate for several refinery feedstocks, containing various sulfur content and TAN, were determined using API-581RP. Mass and energy balance for small scale refinery consists of distillation unit, sulfur removal unit, and platformer unit was done based on process simulator. Materials concerned in this research were carbon steel, alloy steel, and stainless steel. The result showed most of the mechanism in distillation column was thinning high temperature sulfidic/naphthenic corrosion while in sulfur removal and platformer were thinning high temperature H2S/H2 corrosion. The change of sulfur and acid content caused change corrosion rate in non-linear way. These results can be used as prediction for future corrosion assessment based on sulfur and TAN composition.