Antipsychotic drug waste: A potential corrosion inhibitor for mild steel in the oil and gas industry. (15th May 2022)

• Record Type: Journal Article
• Authors: Bobby Kannan, M.; Rahuma, Mohamed; Khakbaz, Hadis; Melchers, Robert
• Is Part Of: Waste management. Volume 145(2022)
• Page Start: 38
• Page End: 47
• Publication Date: 2022-05-15
• Subjects: Corrosion inhibitor -- Drug waste -- Mild steel -- Pipelines -- Oil and gas industry; Ag/AgCl Silver/Silver-chloride -- DP Degree of protection -- EIS Electrochemical Impedance Spectroscopy -- HCl Hydrochloric acid -- PP Potentiodynamic Polarisation -- SEM Scanning Electron Microscopy -- SiC Silicon Carbide -- TH Thioridazine hydrochloride -- THSO TH Sulphoxide; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2022.04.029
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: Thioridazine hydrochloride (TH) is an effective corrosion inhibitor for mild steel. 100 ppm of TH is sufficient for high corrosion inhibition in 1 M HCl. Corrosion inhibition efficiency of TH is 98.8% after 7-day exposure in 1 M HCl. TH (antipsychotic drug) is a potential corrosion inhibitor in oil and gas industry. Abstract: In this study, the corrosion inhibition efficiency of thioridazine hydrochloride (TH), an antipsychotic drug, on mild steel (commonly used pipeline material in the oil and gas industry) in 1 M hydrochloric acid (HCl) was evaluated using electrochemical techniques and weight loss method. Electrochemical impedance spectroscopy (EIS) results suggest that TH significantly enhances the polarization resistance (Rp ) of mild steel. Similarly, potentiodynamic polarization results showed that the corrosion current density (icorr ) of mild steel decreased significantly with addition of TH. To understand the long-term effect of TH, mild steel was tested for 7 days in 100 ppm TH containing electrolyte. EIS results showed that the Rp did not change significantly after 24 h exposure as compared to 2 h exposure; whereas the Rp increased by 28% after 7-day exposure. Weight loss measurements revealed that the inhibition efficiency of TH is remarkably high (98.8%) after 7-day exposure. The adsorption free energy calculation suggests that at the initial stage (1-day) of mild steel exposure, TH was physically adsorbed onto the surface. However, at a later stage (7- day) the binding of TH was chemical, and hence the corrosion protection increased with increase in the exposure period. As compared to the wide range of corrosion inhibitors reported in the literature, TH has shown to be highly effective for mild steel. Thus, it can be suggested that TH drug waste is a potential corrosion inhibitor for mild steel pipelines in the oil and gas industry.