Abstract: The invention relates to a method for cleaning hydrocarbon mixtures, in which a contaminated hydrocarbon mixture comprising hydrocarbons having three to eight carbon atoms is at least partly freed of impurities by contacting with a solid sorbent, wherein the hydrocarbon mixture is exclusively in the liquid state during contact with the sorbent. The object of the invention is to specify a process for cleaning liquid C3 to C8 hydrocarbon mixtures, which is based on a readily available but non-carcinogenic sorbent and which achieves better purities compared to traditional molecular sieves. This object is achieved by using, as sorbents, solid materials of the following composition: copper oxide: 10% to 60% by weight (calculated as CuO); zinc oxide: 10% to 60% by weight (calculated as ZnO); aluminum oxide: 10% to 30% by weight (calculated as Al2O3); other substances: 0% to 5% by weight. Materials of this kind are otherwise used as catalysts in methanol synthesis.

Abstract: The invention relates to a process for preparing 1,3-butadiene by heterogeneously catalysed oxidative dehydrogenation of n-butene, in which a butene mixture comprising at least 2-butene is provided. The problem that it addresses is that of specifying a process for economically viable preparation of 1,3-butadiene on the industrial scale, which is provided with a butene mixture as raw material, wherein the 1-butene content is comparatively low compared to the 2-butene content thereof, and in which the ratio of 1-butene to 2-butene is subject to variation. This problem is solved by a two-stage process in which, in a first stage, the butene mixture provided is subjected to a heterogeneously catalysed isomerization to obtain an at least partly isomerized butene mixture, and in which the at least partly isomerized butene mixture obtained in the first stage is then subjected, in a second stage, to oxidative dehydrogenation. The two-stage process leads to higher butadiene yields compared to the one-stage process.

Abstract: The invention relates to processes for preparing aldehydes by hydroformylation of alkenes, in which an alkene-containing feed mixture is subjected to a primary hydroformylation with synthesis gas in the presence of a homogeneous catalyst system, the primary hydroformylation being effected in a primary reaction zone from which a cycle gas containing at least some of the products and unconverted reactants of the primary hydroformylation are drawn off continuously and partly condensed, with recycling of uncondensed components of the cycle gas into the primary reaction zone, and with distillative separation of condensed components of the cycle gas in an aldehyde removal stage to give an aldehyde-rich mixture and a low-aldehyde mixture. The problem that it addresses is that of developing the process such that it achieves high conversions and affords aldehyde in good product quality even in the case of a deteriorating raw material position.

Abstract: The invention relates to the in situ regeneration of heterogeneous oligomerization catalysts which are used in the liquid phase oligomerization of ethene.

Abstract: A process for the combined preparation of a butene and an octene from ethene, proceeds by: a) providing a solvent having a boiling point or boiling range above the boiling points of the butenes and below the boiling points of the octenes and wherein the solvent is an inert solvent or is hexene alone or is hexene admixed with pentane or hexane or heptane or is a mixture of pentane, hexane, and heptane; b) providing a first feed mixture containing at least the solvent and ethene dissolved therein; c) providing a second feed mixture containing at least hexene, the solvent and also ethene dissolved in the solvent and/or in the hexene; d) transferring the first feed mixture into a first synthesis and the second feed mixture into a second synthesis, wherein the first and second syntheses are physically separated from one another; e) oligomerising of at least part of the ethene present in the first feed mixture in the presence of a first heterogeneous catalyst and in the presence of the solvent in the first synthesi

Abstract: The invention relates to a process for the production of 1,3-butadiene from ethene by way of oligomerization and oxidative dehydrogenation. It is based on the finding that the 1-butene content of a feed material of an oxidative dehydrogenation must not be too high and must therefore be reduced. This occurs by way of isomerization which, however, does not take place from 2-butene to 1-butene, but vice versa from 1-butene to 2-butene. If, according to the invention, isomerization is carried out between the ethene dimerization and the oxidative dehydrogenation of 1-butene to 2-butene, it is possible to achieve a high yield of butadiene and reduce the formation of by-product.

Abstract: A process for the combined preparation of at least butene and octene from ethane, proceeds by a) providing an inert solvent having a boiling point or boiling range below the boiling point of butene; b) providing a first feed mixture comprising at least the inert solvent and ethene dissolved therein; c) converting the first feed mixture in a first synthesis; d) in the first synthesis, oligomerizing at least a portion of the ethene present in the first feed mixture in the presence of a first heterogeneous catalyst and in the presence of the inert solvent to obtain a first reaction mixture comprising at least the inert solvent, butene, hexene and octene; e) working-up of the first reaction mixture and/or a substance stream based thereon into a low boiler fraction comprising the inert solvent, at least one C4-fraction comprising butenes, a C6-fraction comprising hexenes, a C8-fraction comprising octenes and into a C8+-fraction comprising hydrocarbons having more than eight carbon atoms; f) using at least a portio

Abstract: An OCTOL process is disclosed which by limitation of the conversion in its individual oligomerization steps is set up particularly for the productive utilization of C4 feedstock mixtures with a low 1-butene content and which nevertheless yields a C8 product mixture having an Iso index suitable for the preparation of plasticizer alcohols.

Abstract: The preparation of high-quality oxo process alcohols from inconstant raw material sources is the technically demanding problem which is addressed by a process for continuously preparing an alcohol mixture, in which an input mixture which contains an olefin and has a composition that changes over time is subjected to an oligomerization to obtain an oligomerizate and at least a portion of the olefin oligomers present in the oligomerizate are hydroformylated with carbon monoxide and hydrogen in a hydroformylation in the presence of a homogeneous catalyst system to give aldehydes, at least some of which are converted to the alcohol mixture by subsequent hydrogenation. The process provides a constant plasticizer quality to be produced over a long production period and, optionally, a higher throughput with the same product quality.

Abstract: In one aspect, a process for the preparation of a superabsorbent polymer is described herein. In some embodiments, the process comprises (I) preparing acrylic acid, wherein the process comprises (a1) provision of a fluid F1 having a composition comprising from about 5 to about 20 wt. % of hydroxypropionic acid, salts thereof, or mixtures thereof; from about 0.1 to about 5 wt. % of inorganic salts; from about 0.1 to about 30 wt. % of organic compounds which differ from hydroxypropionic acid; from 0 to about 50 wt. % of solids; and from about 20 to about 90 wt. % of water; (a2) dehydration of said hydroxypropionic acid to give a fluid F2 containing acrylic acid; and (a3) purification of said fluid F2 to give a purified acrylic acid phase comprising acrylic acid having a purity of at least 70 wt. %; and (II) polymerizing the acrylic acid of (I) to form a superabsorbent polymer.

Abstract: The present invention relates to a process for purifying low molecular weight hydridosilane solutions, in which a solution to be purified comprising a) at least one low molecular weight hydridosilane, b) at least one solvent and c) at least one impurity selected from the group of the compounds having at least 20 silicon atoms and/or the group of the homogeneous catalyst systems is subjected to a crossflow membrane process with at least one membrane separation step using a permeation membrane.

Abstract: The invention relates to a process for producing hydrogen-containing chlorosilanes by reducing Si-based deposits of solid material during the operation of a pressurised reactor comprising one or more reaction spaces, wherein at least one organochlorosilane is reacted with hydrogen in at least one of these reaction spaces for at least some of the time, characterized in that at least one of the optionally two or more reaction spaces in which this reaction takes place is supplied with additional HCl for at least some of the time. The additional HCl is preferably produced by hydrodehalogenation of silicon tetrachloride with hydrogen in at least one of the optionally two or more reaction spaces of the reactor.

Abstract: The invention relates to a process for producing a product gas mixture containing hydrogen-containing chlorosilanes within an integrated process by hydrogenating integrated process by-product silicon tetrachloride and organochlorosilane, more particularly methyltrichlorosilane, with hydrogen in a pressurized hydrogenation reactor comprising one or more reaction spaces each consisting of a reactor tube of gastight ceramic material, wherein the product gas mixture is worked up and at least a portion of at least one product of the product gas mixture is used as starting material for the hydrogenation or as starting material for some other process within the integrated process. The invention further relates to an integrated system useful for practising the integrated process.

Abstract: The invention relates to a process for preparing trichlorosilane, characterized in that hydrogen and at least one organic chlorosilane are reacted in a reactor which is operated under superatmospheric pressure and comprises one or more reactor tubes which consist of a gastight ceramic material.

Abstract: Process for preparing higher hydridosilanes of the general formula H—(SiH2)n—H where n?2, in which—one or more lower hydridosilanes—hydrogen, and—one or more transition metal compounds comprising elements of transition group VIII of the Periodic Table and the lanthanides are reacted at a pressure of more than 5 bar absolute, subsequently depressurized and the higher hydridosilanes are separated off from the reaction mixture obtained.

Abstract: The invention relates to a method for producing higher hydridosilane wherein at least one lower hydridosilane and at least one heterogeneous catalyst are brought to reaction, wherein the at least one catalyst comprises Cu, Ni, Cr and/or Co applied to a carrier and/or oxide of Cu, Ni, Cr and/or Co applied to a carrier, the hydridosilane that can be produced according to said method and use thereof.

Abstract: The invention provides for the use of a particular burner design to heat reactors for conversion of chlorosilanes, wherein the burner has a jet tube and the jet tube surrounds the flame and the flame tube in a gastight manner, as a result of which the combustion air, the gaseous and/or liquid fuels, and also the flue gases cannot get into the reaction furnace space. The advantage is the complete separation of the flue gas from the actual interior of the reaction furnace, which prevents critical interactions between flue gas moisture and chlorosilanes in the case of fracture of the arrangement accommodating the chlorosilanes. This in turn makes it possible to use gaseous or liquid fuels to heat such a reaction furnace. Excessive local input of heat as a result of direct flame contact is prevented; the heat input is homogenized.

Abstract: The invention relates to the use of a ceramic tube composed of silicon carbide variants in processes for converting chlorosilanes, wherein the tube has a flange or a flare at one end and is closed at the other end.

Abstract: In one aspect, a process for the preparation of a superabsorbent polymer is described herein. In some embodiments, the process comprises (I) preparing acrylic acid, wherein the process comprises (a1) provision of a fluid F1 having a composition comprising from about 5 to about 20 wt. % of hydroxypropionic acid, salts thereof, or mixtures thereof; from about 0.1 to about 5 wt. % of inorganic salts; from about 0.1 to about 30 wt. % of organic compounds which differ from hydroxypropionic acid; from 0 to about 50 wt. % of solids; and from about 20 to about 90 wt. % of water; (a2) dehydration of said hydroxypropionic acid to give a fluid F2 containing acrylic acid; and (a3) purification of said fluid F2 to give a purified acrylic acid phase comprising acrylic acid having a purity of at least 70 wt. %; and (II) polymerizing the acrylic acid of (I) to form a superabsorbent polymer.

Abstract: The invention relates to a method for producing acrolein by dehydrating an aqueous glycerin phase in an acrolein reaction region, obtaining an aqueous acrolein reaction phase; at least partially separating the aqueous acrolein reaction phase into an acrolein-rich acrolein phase and an acrolein-poor residual phase comprising glycerin, water and various other residuals; and recirculating at least part of the residual phase into the acrolein reaction region. Additionally, removing at least one of the residuals, other than glycerin or water, from either of the glycerin phase or a mixture phase obtained by mixing the glycerol phase with the low-acrolein residue phase and feeding the resulting purified glycerin or mixture phase into the acrolein reaction region. The invention furthermore relates to a method for producing acrylic acid, water-absorbing polymer formations, compounds and hygiene articles, and to devices for carrying out those methods.