INHIBITION TEST OF AMONIUM HEPTAMOLIBDAT AND IT’S SYNERGIST WITH SODIUM SALT 2-MERCAPTOBENZOTHIAZOLE FOR CORROSION ON CARBON STEEL

• Main Author: TIFANI PUARI (NIM : 10508099); Pembimbing : Dr. Bunbun Bundjali, ANINDA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/14927
• Institution: Institut Teknologi Bandung

The presence of Cl- ions and CO2 in crude oil creates extensive localized attack and cause corrosion to carbon steel used as crude oil diverter in petroleum industry. The addition of corrosion inhibitor is one of the methods to slow the rate of corrosion on carbon steel pipe surface. Ammonium heptamolybdate is one of the inorganic inhibitors, while sodium salt 2-mercaptobenzothiazole is organic inhibitor. In this study, ammonium heptamolybdate and it’s synergist with sodium salt 2-mercaptobenzothiazole were investigated as corrosion inhibitors for carbon steel with varying concentration and temperature in NaCl 1% with CO2 aerated. Concentration of ammonium heptamolybdate was tested in range 20-100 ppm with addition 5 ppm of sodium salt 2-mercaptobenzothiazole. Corrosion test was calculated by using the wheel test method, Tafel polarization curves and electrochemical impedance spectroscopy at temperature 303-333 K. It is indicated that ammonium heptamolybdate inhibit carbon steel and act as anodic inhibitor. Inhibition of ammonium heptamolybdate increases at higher temperature. Maximum inhibition of efficiency ammonium heptamolybdate at the concentration 100 ppm reaches of 70% at 303 K and 94% at 333 K. Organic salt inhibitor give good inhibition with small concentration but unstable at high temperature. The combination of ammonium heptamolybdate and sodium salt 2-mercaptobenzothiazole enhances the inhibition efficiency to 99%. The mixture of ammonium heptamolybdate and sodium salt 2-mercaptobenzothiazole give a synergist effect for inhibition carbon steel in NaCl 1% solution with CO2 aerated.