Abstract: Disclosed is a method for the preparation of cumene by reacting isopropanol or a mixture of isopropanol and propene with benzene in the presence of a ?-zeolite catalyst having a SiO2/Al2O3 molar ratio greater than 10:1 that can be integrated in a process for preparing phenol, which comprises preparing cumene as described above, oxidizing cumene to cumene hydroperoxide, acid-catalyzed cleavage of cumene hydroperoxide to give phenol and acetone, and hydrogenating acetone to form isopropanol.

Abstract: The invention relates to a process for preparing phenol derivatives by catalytic oxidation of an aromatic hydrocarbon to the hydroperoxide and subsequent cleavage of the hydroperoxide to give the phenol derivative and a ketone, wherein a compound of the formula I where R1, R2=H, aliphatic or aromatic alkoxy radical, carboxyl radical, alkoxycarbonyl radical or hydrocarbon radical, in each case having from 1 to 20 carbon atoms, SO3H, NH2, OH, F, Cl, Br, I and/or NO2, where R1 and R2 are identical or different radicals or R1 and R2 may be joined to one another via a covalent bond, and X, Z=C, S, CH2 Y=O, OH k=0, 1, 2 l=0, 1, 2 m=1-3; is used as oxidation catalyst in the presence of a free-radical initiator, where the molar ratio of the catalyst to the aromatic hydrocarbon is less than 10 mol %.

Abstract: The invention relates to a process for manufacturing zeolite catalysts containing subgroup metals by hydrothermal synthesis with subsequent calcination, which is characterized in that the subgroup metals are used in hydrothermal synthesis in the form of carbonyl, isonitrile or cyanocomplexes.

Abstract: The present invention claims a process and an apparatus for the work-up by distillation of cleavage product mixtures produced in the cleavage of alkylaryl hydroperoxides. Usually, in the work-up by distillation of cleavage product mixtures which are produced in the cleavage of alkylaryl hydroperoxides, the cleavage product mixture is divided into three main fractions, for which at least two distillation columns are used. The use of two distillation columns has the disadvantage that the capital costs, and also the energy costs, in these conventional processes are relatively high. By means of the inventive process for the work-up by distillation of cleavage product mixtures, the equipment requirements and the energy consumption can be markedly reduced in comparison with customary plants, since the cleavage product mixture can be resolved into the three main fractions in only one apparatus.

Abstract: The present invention relates to a process for preparing phenols, in which the pH of the reaction product from the acid-catalyzed cleavage of alkylaryl hydroperoxides is set to a value of at least 8 at a temperature of at least 100° C. prior to the work-up of the product. This measure enables the content of undesirable by-products, e.g. hydroxyacetone, in the cleavage product to be significantly reduced. This procedure is particularly advantageously integrated into a process for preparing phenols by: a) acid-catalyzed cleavage of alkylaryl hydroperoxides and b) thermal after-treatment of the cleavage product from step a), with the temperature in step b) being higher than in step a) and is at least 100° C., wherein the adjustment to a pH of at least 8 is carried out after the thermal after-treatment and prior to cooling of the cleavage product.

Abstract: The invention relates to a process for the preparation of cumene by reacting isopropanol or a mixture of isopropanol and propene with benzene in presence of a &bgr;-zeolite catalyst having a SiO2/Al2O3 molar ratio greater than 10:1 that can be integrated in a process for preparing phenol, which comprises the steps I. preparation of cumene as described above, II. oxidation of cumene to cumene hydroperoxide, III. acid-catalyzed cleavage of cumene hydroperoxide to give phenol and acetone and IV. hydrogenation of acetone to form isopropanol. In the reaction of isopropanol with benzene, propene is formed by dehydration of isopropanol simultaneously with the alkylation of benzene to cumene by means of isopropanol and the propene formed is likewise used for the alkylation of benzene to cumene. Formation of n-propylbenzene in this process step according to the invention is barely observed or is in the range below 150 wppm.

Abstract: Phenol is separated from a mixture containing hydroxyacetone, cumene, water and phenol, by fractionating the mixture in a process with a fractional distillation step and a phase separation step to provide a single phenol fraction containing less than 300 ppm of hydroxyacetone. In the work-up by distillation of cleavage product mixtures, the hydroxyacetone can be removed from the cleavage product mixture together with a phenol fraction from which the hydroxyacetone has to be removed. A process can be used for purifying cleavage product mixtures obtained in the cleavage of alkylaryl hydroperoxides such as cumene hydroperoxide. The process allows separation of phenol and acetone from mixtures obtained in the cleavage of cumene hydroperoxide.

Abstract: The invention relates to a process for preparing phenol derivatives by catalytic oxidation of an aromatic hydrocarbon to the hydroperoxide and subsequent cleavage of the hydroperoxide to give the phenol derivative and a ketone, wherein a compound of the formula I 1

Abstract: The cleavage product from the acid-catalyzed cleavage of cumene hydroperoxide into phenol and acetone is subjected to thermal after-treatment by a process, which comprises heating the cleavage product in a reactor, wherein the heat supplied for the thermal treatment is the heat generated by at least one exothermic reaction which occurs in the reactor. The exothermic reaction which proceeds in the cleavage product is preferably the cleavage of cumene hydroperoxide.

Abstract: The present invention relates to industrial applications of nitrous oxide, e.g. the hydroxylation of benzene to phenol, requires large quantities of nitrous oxide having a very low impurity content. According to the present invention, nitrous oxide which is obtained by reaction of ammonia with nitric acid can be used for the hydroxylation of aromatics, the use of nitrous oxide from the reaction of ammonia with nitric acid in particular being economically advantageous because all starting materials are available in sufficient quantity and at a favorable price.

Abstract: The present invention relates to a process for preparing phenols, in which the pH of the reaction product from the acid-catalyzed cleavage of alkylaryl hydroperoxides is set to a value of at least 8 at a temperature of at least 100° C. prior to the work-up of the product. This measure enables the content of undesirable by-products, e.g. hydroxyacetone, in the cleavage product to be significantly reduced.

Abstract: A process for the cleavage of alkylaryl hydroperoxides includes steps for producing a mixture of a concentrate that contains at least one alkylaryl hydroperoxide to be cleaved and a cleavage product obtained from the cleavage of an alkylaryl hydroperoxide, dividing this mixture into at least two parts and cleaving the alkylaryl hydroperoxides in parallel at different temperatures. One of the two parts is treated at a temperature sufficiently high for an integrated thermal post-treatment to be achieved. The process consumes less energy since less steam has to be used. Problems which can result from fouling in heat exchangers are largely prevented. No second feed point for alkylaryl hydroperoxide has to be provided. The process can be used in the preparation of phenol and acetone by the Hock method.

Abstract: The present invention claims a process and an apparatus for the work-up by distillation of cleavage product mixtures produced in the cleavage of alkylaryl hydroperoxides. Usually, in the work-up by distillation of cleavage product mixtures which are produced in the cleavage of alkylaryl hydroperoxides, the cleavage product mixture is divided into three main fractions, for which at least two distillation columns are used. The use of two distillation columns has the disadvantage that the capital costs, and also the energy costs, in these conventional processes are relatively high.

Abstract: Phenol is separated from a mixture containing hydroxyacetone, cumene, water and phenol, by fractionating the mixture in a process with a fractional distillation step and a phase separation step to provide a single phenol fraction containing less than 300 ppm of hydroxyacetone. In the work-up by distillation of cleavage product mixtures, the hydroxyacetone can be removed from the cleavage product mixture together with a phenol fraction from which the hydroxyacetone has to be removed. A process can be used for purifying cleavage product mixtures obtained in the cleavage of alkylaryl hydroperoxides such as cumene hydroperoxide. The process allows separation of phenol and acetone from mixtures obtained in the cleavage of cumene hydroperoxide.

Abstract: A process for the cleavage of alkylaryl hydroperoxides includes steps for producing a mixture of a concentrate that contains at least one alkylaryl hydroperoxide to be cleaved and a cleavage product obtained from the cleavage of an alkylaryl hydroperoxide, dividing this mixture into at least two parts and cleaving the alkylaryl hydroperoxides in parallel at different temperatures. One of the two parts is treated at a temperature sufficiently high for an integrated thermal post-treatment to be achieved. The process consumes less energy since less steam has to be used. Problems which can result from fouling in heat exchangers are largely prevented. No second feed point for alkylaryl hydroperoxide has to be provided. The process can be used in the preparation of phenol and acetone by the Hock method.

Abstract: An electrochemical cell comprising a negative electrode, a solid electrolyte which conducts oxygen ions, and a positive electrode comprising zeolites, mordenites, silicates, phosphates or mixed-metal oxides having a pore size of less than 200 nm can be used in a process for partially oxidizing organic compounds, for example alkanes, olefins or aromatic compounds.

Abstract: A process for the continuous preparation of 3-halopropylorganosilanes of the general structure RbH3-a-bXaSiCH2CH2CH2Y  (III), where: R is CH3, C2H5, C3H7, OCH3, OC2H5 or OC3H7, X is F, Cl, Br or I, Y is F, Cl, Br or I, and a and b are each one of the numbers 0, 1, 2 or 3 and the sum a+b is 1, 2 or 3, comprising reacting, as starting materials, an allyl halide with a silane carrying at least one H atom, wherein the starting materials are present in stoichiometric amounts or one of the starting materials is present in substoichiometric amounts, wherein the reaction carried out is a partial reaction of from 10% to 80%, on a molar basis, of the starting materials, based on either material, when both are present in stoichiometric amounts, or based on the substoichiometric material.

Abstract: The invention relates to a process for bleaching aqueous alkyl polyglycoside solutions using hydrogen peroxide, in a first step the actual bleaching being carried out at alkaline pHs in the presence of an inorganic additive (hydrogen peroxide decomposition inhibitor) and in a second step a specific decomposition of the unreacted hydrogen peroxide being performed by contact with transition metals or inorganic compounds thereof.

Abstract: A process for preparing 2-ethylhexanol by the liquid-phase catalytic hydrogenation of 2-ethylhexenal and a catalyst for preforming this catalytic hydrogenation are disclosed.