Eugeniusz Milchert

Epoxidation of allyl alcohol over mesoporous Ti-MCM-41 catalyst

Epoxidation of allyl alcohol with 30 wt% hydrogen peroxide over Ti-MCM-41 catalyst under atmospheric pressure and in the presence of methanol as a solvent has been studied. The influence of the following parameters: temperature (20-60 degrees C), the molar ratio of AA/H(2)O(2) (0.5-5), methanol concentration (5-90 wt%), catalyst concentration (0.1-5.0 wt%) and reaction time (5-180 min) has been investigated. The process has been described by the following functions: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, conversions of the substrates and selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The technological parameters, at which the functions describing the process take the optimum values, have been established.

Technological Aspects of Chemoenzymatic Epoxidation of Fatty Acids, Fatty Acid Esters and Vegetable Oils: A Review

The general subject of the review is analysis of the effect of technological parameters on the chemoenzymatic epoxidation processes of vegetable oils, fatty acids and alkyl esters of fatty acids. The technological parameters considered include temperature, concentration, amount of hydrogen peroxide relative to the number of unsaturated bonds, the amounts of enzyme catalysts, presence of solvent and amount of free fatty acids. Also chemical reactions accompanying the technological processes are discussed together with different technological options and significance of the products obtained.

Continuous dehydrochlorination of 1,3-dichloropropan-2-ol to epichlorohydrin: process parameters and by-products formation

The influence of pre-reactor and reactor temperatures on the conversion of 1,3-dichloropropan-2-ol and the selectivity of its transformation to epichlorohydrin in continuous dehydrochlorination for two modes of the reaction product collection was studied. The dehydrochlorination process and mechanism of diglycidyl ether formation are described.

Technological aspects of vegetable oils epoxidation in the presence of ion exchange resins: a review

Abstract A review paper of the technology basics of vegetable oils epoxidation by means of peracetic or performic acid in the presence of acidic ion exchange resins has been presented. The influence of the following parameters: temperature, molar ratio of acetic acid and hydrogen peroxide to ethylenic unsaturation, catalyst loading, stirring intensity and the reaction time on a conversion of ethylenic unsaturation, the relative percentage conversion to oxirane and the iodine number was discussed. Optimal technological parameters, mechanism of epoxidation by carboxylic peracids and the possibilities of catalyst recycling have been also discussed. This review paper shows the application of epoxidized oils.

N-hexylpyridinium bis(trifluoromethylsulfonyl)imide and Lewis acids — catalytic systems for Diels-Alder reaction

AbstractA comparative study of the Diels-Alder reactions between cyclopentadiene (1) and dienophiles (2 a–c) in N-hexylpyridinium bis(trifluoromethylsulfonyl)imide in a temperature range of 20–45°C is reported. The reaction rate constants and activation energies were calculated. Moreover, the catalytic systems based on N-hexylpyridinium bis(trifluoromethylsulfonyl)imide and Lewis acids were tested as a reaction media to perform the Diels-Alder reaction. Yb, Y, Mg, Zn triflates and chlorides (0.005 to 0.1 mmol) were used as catalysts. The recycling of catalytic system consisted of YCl3 and ionic liquid was performed.

Mg(OTf)2 + ionic liquid - recyclable catalytic system in diels-alder reaction

Mg(OTf)2 + ionic liquid - recyclable catalytic system in diels-alder reaction A comparative study of Diels-Alder reaction between cyclopentadiene and dimethyl maleate in catalytic system is reported. The catalytic system was formed from ionic liquid which was made of N-hexylpyridinium bis(trifluoromethylsulfonyl)imide and magnesium trifluoromethanesulfonate. The yields, TONs, TOFs and endo:exo ratios were calculated. The optimal catalyst concentration was found in order to obtain the mixture of endo, exo isomers with the highest yields. Moreover recycling of the catalytic system consisting of Mg(OTf)2 (2 mol%) and ionic liquid was performed. The distillation was noticed to be a better product removal method than extraction by organic solvent, taking into consideration both the TON and TOF values.

Kinetic study of the phase-transfer catalytic epoxidation of 1,4-bis(allyloxy)butane

The epoxidation of 1,4-bis(allyloxy)butane (DiBan) with hydrogen peroxide as an oxidant in the presence of o-phosphoric acid and sodium tungstate as an epoxidation catalyst was carried out in an organic solvent/aqueous solution two-phase medium. A few different phase-transfer catalysts were used in the process. The effect of the stirring speed, nature of solvent, the type of PT catalyst and molar ratio of H(2)O(2):DiBan, DiBan:Na(2)WO(4):H(3)PO(4) on the DiBan conversion as the function of time was studied. Based on the experimental results, a pseudo-first-order expression for the reaction rate was applied and most efficient conditions epoxidation were developed.

Utilization of waste chloroorganic compounds

Utilization of waste chloroorganic compounds Efficient methods of utilization of waste chloroorganic compounds coming from waste water and the waste streams formed e.g. in the production of vinyl chloride by dichloroethane method and in the production of propylene oxide by chlorohydrin method have been presented. First the separation of chloroorganic wastes by the adsorption methods has been described in the article. Three valuable methods of chlorocompounds utilization have been then discussed. The first one is isomerization of 1,1,2-trichloroethane to 1,1,1-trichloroethane as the valuable product with less toxicity than a substrate. The second method is ammonolysis of waste 1,2-dichloropropane and 1,2,3-trichloropropane. The third described method is chlorolysis. This method can be used for the utilization of all types of waste chloroorganics.

Topical and prospective processes of acetoxylation

Topical and prospective processes of acetoxylation The latest acetoxylation processes have been described in this work: oxidative acetoxylation of propene to allyl acetate, acetoxylation of propene to propene glycol and its acetates, acetoxylation of methyl tert-butyl ether and oxidative acetoxylation of cyclohexene by hydrogen peroxide. Acetoxylation of 1,3-butadiene, isobutene and toluene were presented together with a short description of the acetoxylation catalysts.

Dehydrochlorination of 1,3-dichloropropan-2-ol by calcium and sodium hydroxide solutions

Abstract The results of dehydrochlorination of 88 wt% aqueous solution of 1,3-dichloropropan-2-ol to epichlorohydrin are reported. The process was carried out in the reaction-stripping column system with a continuous removal of epichlorohydrin in the steam stream. Aqueous solutions of sodium and calcium hydroxides at concentrations in the range of 3-14 wt% were used for the dehydrochlorination. The infl uence of the type and concentration of dehydrochlorination agent on 1,3-dichloropropan-2-ol conversion, the selectivity of transformation to epichlorohydrin and by-products, and the composition of distillate and wastewater were studied.