THE EFFECT OF ROTATION AND TEMPERATURE ON THE INHIBITION PERFORMANCE OF CASHEW (ANACARDIUM OCCIDENTALE L.) NUT SHELL LIQUID ON CO2 CORROSION OF CARBON STEEL

Abstract

A natural extract of cashew nut shells, Cashew Nut Shell Liquid (CNSL) was investigated as a corrosion
inhibitor for carbon steel in 3% NaCl solutions saturated with CO 2 gas using electrochemical techniques (i.e.
potentiodynamic polarization and ac-impedance). The investigation was performed at different temperatures
under static and dynamic conditions using a Rotating Disk Electrode (RDE). It was found that CNSL reduces
the electrochemical processes taking place on carbon steel undergoing corrosion. The percentage inhibitor
efficiency increases with increase in CNSL concentration and decreases with rise in temperature. Better
performance at low CNSL concentration was registered under dynamic conditions and room temperatures.
Thus CNSL is a potential corrosion inhibitor for carbon steel undergoing corrosion in CO2 medium.