Research Into Epoxidation Process of the С9 Fraction Hydrocarbons and Unsaturated Co-oligomers by Peroxyethanoic Acid

We have studied regularities of the epoxidation process of the С9 fraction of liquid by-products of the pyrolysis of hydrocarbons and co-oligomers based on the С9 fraction with peracetic acid. It is established that the use of the specified system makes it possible to achieve high values of conversion for double bonds and the selectivity of epoxidation process, sufficiently high yield of epoxy-containing co-oligomers. We established the possibility to use the С9 fraction of liquid by-products of hydrocarbon pyrolysis (the accompanying product of ethylene production) as a raw material for obtaining epoxides, which is a rational method in order to dispose of the fraction. We analyzed experimental dependences of reagents consumption and the formation of epoxide in the reaction of the С9 fraction epoxidation. It was established that the resulting values for selectivities of the epoxidation process by double bonds when obtaining epoxy-containing co-oligomers are the highest in the case of epoxidation of co-oligomers, synthesized by the heterogeneous catalytic co-oligomerization of the С9 fraction S9 hydrocarbons using, as a catalyst, activated bentonite clay. The synthesized epoxy-containing co-oligomers retain residual unsaturation. It is obvious that the unsaturated bonds of styrene, vinyl toluene, α-methyl styrene, allylbenzene links at the ends of a co-oligomer macromolecules are easily epoxidized. The selectivity of epoxidation of co-oligomers, obtained by different methods of co-oligomerization of the С9 fraction hydrocarbons (homogeneous catalytic, heterogeneous catalytic, initiated, and thermal) is different (60.2‒96.1 %) and depends on the nature of the starting co-oligomer. Using the methods of 1H NMR-, Raman-, and infrared spectroscopy, we confirmed the high content of epoxy groups in the composition of epoxy-containing co-oligomers and the progress of the epoxidation reaction. Applying the method of 1H NMR spectroscopy, we established the presence of epoxy groups formed based on the resulting vinyl double bonds of co-oligomers. Due to the content of oxirane oxygen and a high reaction ability of the oxirane ring, epoxy-containing co-oligomers can act as the raw material for subsequent obtaining of various chemical substances: glycols, carbonyl compounds, plasticizers, polymers

Examining the Epoxidation Process of Soybean Oil by Peracetic Acid

The main principle of green chemistry is the use of renewable, ecological raw materials, which will contribute to subsequent biodegradation and reduction of toxicity of the product in the production of polymers. Vegetable oil (VO) is the cheapest and most common biological raw material, the use of which has such advantages as low toxicity and natural biodegradation.We analyzed experimental dependences of the consumption of reagents and the accumulation of epoxide in the interaction between a solution of soybean oil (SO) in toluene and the epoxidizing systems H2O2/acetic acid (AA)/KU-2´8 and H2O2/acetic anhydride (AAn)/KU-2´8.It was established that the use in the process of epoxidation of soybean oil of the specified systems makes it possible to achieve high values of selectivity of epoxidation by double bonds. The resulting values of selectivities in the epoxidation process by double bonds and by the consumption of peroxide when studying the epoxidizing system Н2О2/AAn/KU-2´8 are higher. The advantages of using the specified epoxidizing system include a reduction in the total volume and mass of the reaction mixture. Obtaining the epoxidized soybean oil with a low resulting value of bromine number provides subsequent good thermal and oxidative stability of materials on its base.We calculated the values of rate constants of the epoxidation reaction of SO at different temperatures. By using the methods of IR and Raman spectroscopic studies, we demonstrated structural changes in raw materials and confirmed the progress of the epoxidation reaction. The developed technique for recalculating the values of bromine, iodine numbers of products of the epoxidation reaction, unsaturation and epoxy number, selectivity of the process in the epoxidation of mixtures of unsaturated compounds allows comparing the results of research. The use of the specified technique also makes it possible to draw unambiguous comparative conclusions about the effectiveness of reagents consumption and the selectivity of reaction. In this case, there is a possibility to improve the technology of obtaining the epoxidized compounds. The calculation formulas obtained were applied to analyze the progress of the epoxidation process of soybean oil

Synthesis of Acrylates From Methyl Propionate, Propionic Acid and Formaldehyde in the Gas Phase on Solid Catalysts

Development of active and selective catalysts for the process of obtaining methacrylic acid and methyl methacrylate from methyl propionate, propionic acid and formaldehyde is one of important stages to industrial implementation of this process. In order to solve this problem, we designed catalysts based on oxides of boron and phosphorus that were promoted by oxides of zirconium, tungsten and bismuth with varied content of oxides. The effect of temperature was examined on the conversion of reagents, the selectivity of formation and the yield of methyl methacrylate and methacrylic acid on the created catalysts. With increasing temperature, the conversion increases, the selectivity of formation of acrylates decreases and the total yield of acrylates has the maximum. It was found that without adding methanol, the optimal catalyst by acrylates yield is the one, in which the molar ratio of the ZrO2:WO3 promoters is 0.15:0.15. The total yield of the target products at optimum temperature of 593 K is 52.3 % with the total selectivity of their formation at 96.4 % and the conversion of reagents of 54.2 %. We determined the effect of adding methanol to the reagent mixture. Adding methanol increases the ratio of products MMA/MAA, and the optimal catalyst by the total selectivity of formation of the target products is the one promoted by bismuth oxide with the molar ratio of Bi2O3/Р2О5 – 0.3, which at a temperature of 593 K provides for the selectivity of formation of acrylates of 100 % with the yield of 33 %. The maximum total single­pass yield of MMA and MAA on this catalyst at a temperature of 623 K is 51.5 %, at the total selectivity of their formation of 91.6 %. However, the share of MMA in products is lower in comparison to the catalyst, promoted by the mixture of tungsten and zirconium oxides