The equipment of refineries and oil production facilities is subject to corrosion due to the supply of crude oils with a high content of mineralized water. The use of inhibitors is one of the most common corrosion protection methods. However, increasing requirements of environmental standards give impetus to developing new types of corrosion inhibitors from natural raw materials. The article deals with the synthesis conditions of new corrosion inhibitors (CIs) produced from distilled higher acids of beef fat (DHFAs) or vegetable oils (VO), as well as research on the protective effect of the synthesized corrosion inhibitors compared with industrial inhibitors (5 samples). The gravimetric method studied the protective effect in a solution of salts and jet fuel using a St20 steel plate. At 50 °C and a CIs content of 100 ppm, the protective effect of corrosion inhibitors based on VO and triethanolamine was 9.7–75.6%. Under similar conditions, CIs obtained from DHFAs and diaminoethyl exhibited a protective effect of 81.6–94.1%. When DHFAs and diethanolamine were used to synthesize CIs, the protective effect was 93.0–95.6%. CI synthesized at 130 °C and a DHFAs: diethanolamine ratio of 72:28 showed a 99.2% protective effect at 50 °C and a CI content of 200 ppm, which was higher or equal to the impact of using industrial inhibitors (91.6–99.5%). The results prove the possibility of alternative use of animal fats and waste from their production as new resources for obtaining highly effective equipment corrosion inhibitors. Using alternative inexpensive raw materials (fats, vegetable oils, waste from their output) to obtain CIs will improve the economic performance of inhibitor production. In addition, at least the fatty (oil) part of organic CIs is biodegradable and will not harm the environment.

The application of corrosion inhibitors remains one of the most efficient approaches to safeguarding oil refining equipment from degradation. In the context of modern ecological and economic demands placed on industrial technologies, inhibitors synthesized from renewable natural resources are gaining increasing importance. This study aimed to analyze the corrosion behavior of refinery equipment exposed to straight-run gasolines derived from Ukrainian oil fields and to assess the protective performance of newly synthesized organic inhibitors in such environments. The inhibitors under investigation were produced on the basis of higher distilled fatty acids (HDFA) obtained from natural animal fats and further modified using diethanolamine (DEA) and diaminoethane (DAE). The reaction between HDFA and ethylenediamine resulted in the formation of mono- and disubstituted ethylamides (MZEA and DZEA), while the interaction of HDFA with diethanolamine produced dihydroxyethylamides of higher fatty acids (DHEA). The protective efficiency of these inhibitors was assessed via the gravimetric method, which determines the mass loss of metal samples immersed in a medium both with and without the inhibitor. Experimental studies were performed in environments consisting of straight-run gasolines obtained from the Kachanivska, Novohryhorivska, and Bugruvativska fields, as well as a blend from the Yablunivske field (Ukraine). Each gasoline sample was mixed with an aqueous saline solution in a 9:1 ratio. The analysis demonstrated that the efficiency of the inhibitors is strongly influenced by both the composition of the gasoline and the chemical nature of the inhibiting agent. The highest degree of protection—up to 95.45%—was recorded for the DHEA inhibitor in gasoline derived from Kachanivska oil. Consequently, the corrosion inhibition efficiency is determined not only by the molecular characteristics of the inhibitor but also by the physicochemical properties of the fuel medium. These inhibitors exhibit optimal performance in low-acid, low-sulfur, and light gasoline environments, while in more aggressive conditions their protective capacity decreases due to complex adsorption behavior and partial destruction of the formed protective layer by active components of the fuel.