Elephant grass biomass extract as corrosion inhibitor for mild steel in acidic medium

Wild elephant grass species (pennisetum purpureum) was extracted in acetone and investigated as alternative oilfield chemical for inhibiting the corrosion of mild steel surface in 3.5% hcl. corrosion was monitored by weight loss (wl),electrochemical impedance spectroscopy (eis),potentiodynamic polarization (pdp) and linear polarization resistance (lpr) techniques. inhibition efficiency of elephant grass extract (ege) up to 81.7% was obtained at 30°c but this efficiency decreased as temperature increased. increase in ege concentration increased charge transfer resistance and decreased double layer capacitance. adsorption isotherms and kinetic models were also used to describe the adsorption and activation processes. results reveal that the presence of ege increases the activation energy and reduces the rate corrosive attack of the acid on the steel specimens. ege acts as mixed type inhibitor and was physically adsorbed on mild steel surface. © 2017,university of mohammed premier oujda morocco.