Preparation and Evaluation of Corrosion Inhibitor SM-12B for Liquid and Gas Phases of Carbon Dioxide

Quaternary ammonium bio-imdazoline and polyunit morpholine cyclohexylamnonium moiety were synthesized firstly and then complexed with sulfur-containing organic compounds and acetylenic alcohol corrosion inhibitor for preparing the inhibitor SM-12B which could inhibit the corrosion of CO2 gas-liquid two phases. Weight loss tests indicated that the inhibition rate of gas corrosion was more than 71.57% and inhibition rate of liquid phase corrosion was more than 80.82% when SM-12B was 400 mg/L and the temperature was between 90 ℃ and 110 ℃. SM-12B was suitable to corrosion environment in which carbon dioxide partial pressure was lower than 1.0 MPa. The results of polarization curves and X-ray diffraction (XRD) indicat that SM-12B is a mixed type of inhibitor which mainly inhibit anodeio reaction; and the corrosion product was FeCO3 when the concentration of corrosion inhibitior SM-12B was between 300 and 1000 mg/L.