CARBON STEEL CORROSION IN NaCl SOLUTION CONTAINING H2S

• Main Author: RIZKI MUJAHID (NIM : 13014029) - ALMIRA RAHMAIDA (NIM : 13014101), FAISAL
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27101
• Institution: Institut Teknologi Bandung

<p align="justify"> Hydrogen sulphide can cause corrosion of process equipment made of carbon steel. This study is focused on the effect of temperature and H2S concentration on carbon steel corrosion in NaCl solutions containing H2S and in solution vapor containing H2S. To achieve this objective, the corrosion rate of carbon steel, and the corrosion mechanism of carbon steel in both media, as well as the corrosion product composition has been determined during this research. The experiments have been conducted at temperatures of 35oC, 45oC, and 55oC, H2S concentrations of 60 ppm, 85 ppm, and 108 ppm, in a 10% NaCl solution at atmospheric pressure. The corrosion rate of carbon steel in NaCl solution containing H2S has been measured by using potentiodynamic method, the corrosion mechanism has been determined by cyclic voltammetry and EIS method. Meanwhile, corrosion product has been analysed by X-ray diffraction method. <br /> <br /> Results show that corrosion rate of carbon steel in the NaCl solution containing H2S increases as the temperature and H2S concentration increase. The corrosion rate of carbon steel in the solution containing H2S is lower that the corrosion rate in the solution without H2S. The experiment in the system of vapor containing H2S shows that the corrosion rate of carbon steel in vapor containing H2S is increasing as the temperature and H2S concentration increase. The corrosion rate of carbon steel in the vapor containing H2S is higher than in the vapor of solution with H2S absence. <br /> <br /> The corrosion product analysis shows that corrosion of carbon steel in solution containing H2S produces iron sulphide compound called pyrrhotite. The mechanism of corrosion starts when the iron is oxidized into iron(II), while the H+ is reduced into hydrogen gas. Iron and iron(II) will be converted into iron sulphide compound called mackinawite. Later on, mackinawite will be further converted into pyrrhotite. <p align="justify">