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Objectives. Development of a domestic technology for producing environmentally friendly non-phthalate plasticizers, lubricants and transformer fluids based on neopentyl glycol (NPG), an oxo-synthesis product.Methods. The methodology of the work was to study the kinetic laws of NPG esterification with acetic and 2-ethylhexanoic acids under self-catalysis conditions with an 8-fold molar excess of monocarboxylic acids. The production of NPG esters was carried out by azeotropic esterification in the presence of solvents—benzene and m-xylene. The resulting diesters were isolated from the reaction mass by vacuum rectification. The purity of the obtained NPG diesters was no less than 99.7 wt %. Analysis of the qualitative and quantitative composition of reaction samples was carried out using infrared spectroscopy, gas chromatography–mass spectrometry and gas–liquid chromatography.Results. The paper presents the results of kinetic studies on NPG esterification of with acetic and 2-ethylhexanoic acids. It compares the reaction rates and reactivity of the acids used. Under the given conditions, NPG diesters were produced, and some of their physicochemical properties were determined. This enabled the data obtained to be used for the development of industrial technology in the production of NPG diesters.Conclusions. It was established that with an eightfold molar excess of acid under self-catalysis conditions, a yield of NPG diacetate equal to 95% is achieved within 20–22 h at an optimal process temperature of 100–110℃; NPG di(2-ethylhexanoate)—within 26–28 h at 160–170℃. The activation energies and pre-exponential factors for the formation of NPG mono- and diesters with acetic and 2-ethylhexanoic acids were established. The paper presents the kinetic models of esterification.

In this paper, extractive distillation flowsheets for water–formic acid–acetic acid mixtures were designed. Flowsheets not involving preliminary dehydration were considered, and the relative volatilities of the components in the presence of sulfolane were analyzed. The result of extractive distillation depends on the amount of sulfolane. The structure of the flowsheet is determined by the results of the basic ternary mixture extractive distillation. In three-column flowsheets (schemes I, II), water is isolated in the distillate of the extractive distillation column. In the second column, distillation of the formic acid–acetic acid–sulfolane mixture is carried out, yielding formic acid (90 wt %) and acetic acid (80 wt %). The recycled flow is returned to the first column. Dilution of the formic acid–acetic acid–sulfolane mixture with sulfolane (second column of flowsheet II) allows for acids of higher quality (main substance content equal to or more than 98.5 wt %) to be obtained. Flowsheet III includes four columns and two recycling stages. First, the water–formic acid mixture is isolated in the distillate of the extractive distillation column. Then, water and formic acid are separated in a two-column complex by extractive distillation, also with sulfolane. We were carrying out calculations for column working pressure 101.32 and 13.33 kPa. To prevent thermal decomposition of sulfolane, working pressure for regeneration columns was always 13.33 kPa. The extractive distillation column of the basic three-component mixture is the main factor contributing to the total energy consumption for separation (in all schemes).