Corrosion Inhibition of Benzyl Quinoline Chloride Derivative-Based Formulation for Acidizing Process

Due to the severe and rapid corrosion of metallic equipment by strong acids at high temperatures, a high concentration of acidizing corrosion inhibitors (ACIs) is required during acidizing processes. There is always a need to develop more effective and environmentally friendly ACIs than current products. In this work, a highly effective ACI obtained from a novel main component and its synergistic effect with paraformaldehyde (PFA) and potassium iodide (KI) is presented. The ACI was prepared from the crude product of benzyl quinolinium chloride derivative (BQD) synthesized from benzyl chloride and quinoline in a simple way. The new ACI formulation, named “synergistic indolizine derivative mixture” (SIDM), which consists of BQD, PFA, and KI, showed superior corrosion inhibition effectiveness (IE) and temperature stability compared with commercially available ACI. More importantly, the SIDM formulation eliminates the need for commonly used highly toxic synergists (e.g., propargyl alcohol and As2O3). In a 20 wt% hydrochloric acid (HCl) solution, the addition of 0.5 wt% SIDM mitigates the corrosion rate of N80 steel down to less than 0.00564 lbm·ft−2 at 194°F, while the corrosion rate at 320 °F is 0.0546 lbm·ft−2·when 4.0 wt% SIDM is added.