摘要:
3-Hydroxypropanal is prepared by reacting acrolein with water under pressure and in the presence of an ion exchange resin while adding a carboxylic acid to the reaction mixture.
摘要:
A process for the catalytic epoxidation of olefins by means of hydrogen peroxide and a titanium zeolite catalyst, wherein the epoxidation reaction is carried out in a reaction system through which the reaction mixture flows continuously and the regeneration of deactivated catalyst is carried out by means of hydrogen peroxide in the presence of the olefin while continuing the epoxidation reaction.
摘要:
A process for the catalytic epoxidation of olefins with hydrogen peroxide in a continuous flow reaction system, wherein the reaction mixture is passed through a fixed catalyst bed within a reactor equipped with cooling means while maintaining a temperature profile within the reactor such that the cooling medium temperature of the cooling means is at least 40° C. and the maximum temperature within the catalyst bed is 60° C. at most.
摘要:
The present invention relates to a process for the working up of a product stream from the epoxidation of olefins that contains olefin, olefin oxide, water-miscible organic solvent and water, by separating this product stream into an overhead product containing olefin, olefin oxide and organic solvent, and into a bottom product containing organic solvent and water, wherein the separation takes place in a pre-evaporator with at most 5 theoretical separation stages, and 20 to 60% of the total amount of organic solvent introduced with the product stream is removed with the overhead product and the residue remains in the bottom product, as well as a process for the epoxidation of olefins that includes this working up stage.
摘要:
A process for the catalytic epoxidation of olefins with hydrogen peroxide in a continuous flow reaction system, wherein the reaction mixture includes at least one liquid phase which is passed through a fixed catalyst bed positioned between parallel heat exchange plates and the reaction heat is at least partially removed during the course of the reaction by passing a cooling medium through the heat exchange plates.
摘要:
A process for desensitization of water insoluble peroxycarboxylic acids with essentially sodium sulfate in the aqueous phase, wherein the desensitized peroxycarboxylic acids is separated from the mother liquor, and the sodium sulfate contained in the mother liquor is isolated by one- or multi-stage crystallization in purified form as the deca (hepta) hydrate and this, directly or after conversion to an aqueous sodium sulfate solution, and/or anhydrous sodium sulfate is returned to the desensitization process. The process is nonpolluting and can be operated safely on the industrial scale. The peroxycarboxylic acids desensitized according to the invention are characterized by lower heavy metal content and high storage stability.
摘要:
Aliphatic epoxides of the formula: ##STR1## can be prepared in a technically efficient manner from the corresponding olefins by means of perpropionic acid in a benzene solution. The benzene solution can also be 1.5 weight percent of hydrogen peroxide, 1.5 weight percent of water and about 800 ppm of mineral acid.
摘要:
Process for continuous production of substantially anhydrous solutions of percarboxylic acid in solvent. Aqueous hydrogen peroxide is first reacted with the corresponding carboxylic acid in the presence of acid catalyst to form percarboxylic acid and water (1). The percarboxylic acid is extracted with solvent (5), to provide a solvent phase containing the percarboxylic acid (11) and an aqueous raffinate (7). The solvent phase is subjected to distillation (12) to provide the anhydrous solution (13). In this distillation (12) the hydrogen peroxide remaining in the solvent phase produced in the extraction (5), is distilled off together with water and some solvent, and the hydrogen peroxide is recovered as an aqueous phase and recycled (14). The aqueous raffinate, which contains hydrogen peroxide, is distilled to remove water (8) and the resulting concentrate is recycled (2) for use in the reaction (1).
摘要:
A catalyst for the synthesis of methyl mercaptan from hydrogen sulfide and methanol, as well as a process for preparing the catalyst. The catalyst contains active aluminum oxide on which 15% to 40% by weight cesium tungstate is deposited as the activator. The activator, cesium tungstate, gives an unexpected increase in activity and selectivity as compared with potassium tungstate, which is used exclusively at the present state of the art.
摘要:
In order to safely prepare peracetic acid in an organic solvent, the bottom is maintained in a certain stationary state during the preparation of aqueous peracetic acid, whereupon the vapor current of peracetic acid, acetic acid and water is absorbed with an organic phosphate with 3-30 carbon atoms. The solution obtained in this manner can be transferred by means of desorption with a low-boiling compound, e.g. an alkyl ester, into this lower-boiling solvent.