Manufacturing of Corrosion Inhibitors and Flow Improvers from Recycling of Waste at Hail City, Saudi Arabia: Physicochemical and Electrochemical Studies on Steel in Petroleum Industries

[Image: see text] The aim of the present research paper is to convert daily waste materials generated by human activity at Hail city into useful petroleum additives. In this respect, novel multifunctional corrosion inhibitors working as inhibitors and flow improvers for crude oil were prepared. Polyethylene terephthalate (PET) plastic waste is used in the production of corrosion inhibitors and flow improvers for petroleum crude oil. A multifunctional corrosion inhibitor for the SABIC carbon steel in corrosive seawater for application in the petroleum industry was manufactured using PET waste that was gathered, cleaned, and used as starting materials. The PET green recycling method takes place via the Abdel-Hameed green recycling reported method. In the first step, PET waste was reacted without a solvent with a diamine to form the diamino derivative of phthalic acid amide (PETAA), which was characterized by FT-IR, (1)HNMR, and elemental analysis. In the presence of a catalyst, the used recycling method is a solvent-free green recycling process that is environmentally friendly. Chemical and electrochemical measurements were performed, and the effects of concentration and temperature were studied. The inhibition efficiency was found to increase with concentration. A maximum inhibition of 97% was obtained using 4000 ppm from the prepared PETAA inhibitor, while the efficiency decreased with temperature. Potentiodynamic polarization (PDP) data indicates the mixed-type nature of the used inhibitor. According to potentiodynamic polarization data, the inhibitor boosts polarization resistance and inhibition performance by adsorbing on the metal/electrolyte interface. The data from electrochemical impedance spectroscopy (EIS) show that the charge-transfer mechanism is the primary governing factor in the steel dissolution process. The size of the semicircle grows in direct proportion to the concentration of the inhibitor. The prepared additive acts as a flow improver (viscosity improvers and pour point depressants) for waxy crude oil, indicating that it can be used in the manufacturing of multifunctional inhibitors in the petroleum industry. The depression in the pour point temperatures depended on the concentration and composition of the additive prepared from the plastic waste collected from Hail city.