Work

Sustainable corrosion inhibitor derived from Moroccan oil shale: calcium acetate for steel protection

Year: 2026

Type: article

Abstract: This study presents a sustainable route for producing calcium acetate from Moroccan Tarfaya oil shale and evaluates its performance as a corrosion inhibitor for steel in chloride-rich media. Calcium acetate was synthesized by reacting oil shale with acetic acid under optimized conditions of 2.5 M, 30 min, and a liquid-to-solid ratio of 10. The process achieved approximately 65.4% decarbonation and produced calcium acetate with a CaO content of 98.48%, close to that of commercial calcium acetate (98.98%). XRD, FTIR, TGA, and SEM analyses confirmed the formation of calcium acetate hydrate phases and their structural characteristics. Electrochemical measurements demonstrated significant corrosion inhibition in 3.5 wt% NaCl solution. Potentiodynamic polarization showed a decrease in corrosion current density from 23.2 μA for the blank to 2.3 μA at 10 −3 M inhibitor concentration, while EIS measurements indicated that 10 −5 M provided the most stable long-term protection. The polarization behavior indicates mixed-type inhibition with predominant cathodic character, associated with the formation of a protective surface film. These findings demonstrate the potential of Tarfaya oil shale as a low-cost calcium source for producing an environmentally friendly corrosion inhibitor.

Source: Results in Chemistry

DOI: 10.1016/j.rechem.2026.104002