Известия Томского политехнического университета: Инжиниринг георесурсов (Dec 2023)
Determination of stabilizing additives in kerosenes by the multisensor stripping voltammetry method
Abstract
Relevance. To ensure the operational reliability of equipment, an urgent task is to control the content of antioxidant and antiwear additives in engine fuel at all stages from its production to its intended use. At the stages of fuel use (storage, transfer, transportation, etc.), antioxidant additives can be used up due to natural oxidative processes that inevitably occur in the fuel. As for the antiwear additives, being surfactants by their nature, they can be adsorbed on the surfaces of the process equipment with which the fuel comes into contact. As a result, at the stage of intended use, the level of fuel quality can significantly decrease. Controlling the content of additives in the fuel at the stage of application will allow taking timely measures to restore the fuel quality and reduce the risks of accidents. Aim. To propose an approach to the analysis of the component composition of fuels, which makes it possible to control the content of additives. Objects. Samples of kerosene fractions that are used as the basis or components of commercial fuels of the TС-1 and RT brands produced by oil refineries, stabilizing anti-wear additives "Hi-Tech" and DNA (distilled petroleum acids). Methods. In the framework of the research devoted to solving the problem of operational control of the content of certain additives in various petroleum products, much attention was paid to the possibility of using voltammetry methods for these purposes. Voltammetry is a set of electrochemical methods of research and analysis based on the patterns of electric current flow through an electrochemical cell – an analytical system of two electrodes separated by an analyzed electrolyte solution. Analytical information using voltammetric methods is obtained on the basis of studying the dependence of the current strength in an electrolytic cell on the potential of the indicator microelectrode immersed in the analyzed solution, on which the analyzed reaction proceeds. Results. The paper introduces an approach to the analysis of the component composition of fuels by the multisensor stripping voltammetry method. This approach makes it possible to control the content of additives in the fuel. A feature of the electrochemical behavior of various grades of hydrogenated jet fuel was studied in order to develop a mobile express method for determining additives in them. The authors have developed a test system consisting of an aqueous solution of dimethylformamide (40%) with potassium chloride (0,1 M), cobalt, zinc and mercury cations (2,5×10–4 M). The analyzed fuel was introduced in a ratio of 30:1. The resulting mixture, 50 μl in volume, was mixed and applied to an indicator electrode for subsequent electrochemical measurements. The determination of additives in kerosene in the developed method was carried out by their influence on the peaks of the currents of dissolution of metals in the test system. In this case not only the task of determining the presence of additives in kerosene was solved, but also the problem of their identification.
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