摘要:
The invention relates to a process for preparing tert-butanol by reaction of a homogeneous mixture comprising water, tert-butanol and an isobutene-containing hydrocarbon mixture over an acidic ion-exchange resin at from 30 to 120° C., wherein the homogeneous mixture contains, at a proportion by mass of isobutene of above 10%, from 30 to 80% of the maximum amount of water made possible by the solubility of water in the mixture of tert-butanol and the isobutene-containing hydrocarbon mixture.
摘要:
The invention relates to a process for preparing tert-butanol (TBA) by reacting isobutene-containing hydrocarbon mixtures with water over acidic solid catalysts in a plurality of reactors, wherein the conversion is increased upstream of the last reactor by removing a portion of the TBA present in the reaction mixture.
摘要:
The invention relates to a supported catalyst based on palladium-γ-alumina, which is characterized in that the catalyst support material contains 1 to 1000 ppm by mass of sodium oxide and has a specific pore volume of 0.4 to 0.9 ml/g and a BET surface area of 150 to 350 m2/g. The invention further relates to a process for hydrogenating polyunsaturated ethers with hydrogen to the corresponding saturated ethers, in which the catalyst used is such a catalyst.
摘要:
A continuous process for preparing an isoolefin having 4 to 6 carbon atoms is performed by cleaving a compound of the formula I R1—O—R2 (I) wherein R1=a tertiary alkyl radical having 4 to 6 carbon atoms, and R2=H or an alkyl radical, in a gas phase over a solid catalyst, in the temperature range of 200 to 400° C., at a pressure of 0.1 to 1.2 MPa, in a reactor which is equipped with a heating jacket and is heated with a liquid heat carrier, wherein the cleavage is carried out in such a way that a temperature drop in the catalyst zone at any point in relation to the entrance temperature is less than 50° C., wherein (i) a reaction mixture in the reactor and (ii) the heat carrier in the jacket flow through the reactor in cocurrent, and wherein a temperature difference of the heat carrier between a feed point to the reactor and an outlet from the reactor is adjusted to less than 40° C.
摘要:
Isobutene is prepared by a process in which a) an MTBE-containing stream I is separated by distillation into an MTBE-containing overhead stream II and a bottom stream III which comprises compounds having boiling points higher than that of MTBE; and b) the MTBE present in the overhead stream II is dissociated over a catalyst to give a dissociation product IV; wherein the stream I has a proportion of 2-methoxybutane (MSBE) of greater than 1000 ppm by mass, based on MTBE, and wherein the separation by distillation in step a) and/or the dissociation in step b) is carried out so that the dissociation product IV has a concentration of less than 1000 ppm by mass of linear butenes, based on a C4-olefin fraction.
摘要:
A catalyst, useful in the preparation of isoolefins and containing 0.1 to 20% by mass of an alkali metal oxide, an alkaline earth metal oxide and mixtures thereof; 0.1 to 99% by mass of aluminum oxide; and 0.1 to 99% by mass of silicon dioxide, is prepared by a) treating an aluminosilicate with an aqueous alkali metal salt solution, an alkaline earth metal salt solution and mixtures thereof, under acidic conditions, to obtain a treated aluminosilicate; and b) calcining the treated aluminosilicate, to obtain the catalyst.
摘要:
Isobutene is prepared by dissociation of MTBE in the gas phase, by a) fractional distillation of an MTBE-containing stream comprising feed MTBE (I) and a recycle stream (VIII) to give an MTBE-containing overhead stream (II) and a bottom stream (III) having a boiling point higher than MTBE, b) catalytic dissociation of the overhead stream (II) obtained in step a) to give a dissociation product (IV), c) separation by distillation of the dissociation product (IV) obtained in step b) into an overhead stream (V) comprising more than 90% by mass of isobutene and a bottom stream (VI) comprising diisobutene, MTBE and more than 50% of the methanol present in the dissociation product (IV), d) fractional distillation of the bottom stream obtained in step c) under conditions under which the methanol is obtained as bottom product (VII) and more than 99% of the MTBE is obtained in the overhead product (VIII), and e) recirculation of the overhead product (VIII) to step a).
摘要:
The present invention relates to a process for preparing a catalyst which, in a formal sense, comprises 0.1 to 20% by mass of alkali metal and/or alkaline earth metal oxide, 0.1 to 99% by mass of oxide and 0.1 to 99% by mass of silicon dioxide, which is characterized in that it aluminum comprises the steps of treating an aluminosilicate with an aqueous alkali metal and/or alkaline earth metal salt solution under acidic conditions and calcining the aluminosilicate treated with aqueous alkali metal and/or alkaline earth metal salt solution, and to a catalyst which is obtainable by this process and, in a formal sense, comprises alkali metal and/or alkaline earth metal oxide, aluminum oxide and silicon dioxide, which is characterized in that the catalyst, in a formal sense, has a content of alkali metal and/or alkaline earth metal oxides of 0.5 to 20% by mass, a content of aluminum oxide of 4 to 30% by mass and a content of silicon dioxide of 60 to 95% by mass, and to the use of this catalyst in a process for preparing isoolefins having 4 to 6 carbon atoms by catalytic gas phase cleavage of tertiary alcohols or alkyl tert-alkyl ethers.
摘要:
The invention relates to a process for preparing ETBE from technical mixtures which comprise at least 1-butene, isobutene, n-butane and 2-butenes, by reacting the isobutene present, distillatively removing a fraction comprising 1-butene and isobutene and again reacting the isobutene present therein to give ETBE.
摘要:
A process for the dissociation of methyl tert-butyl ether (MTBE), which includes at least a) catalytic dissociation of MTBE which is present in two streams I and VII over a catalyst to give a dissociation product II, b) separation by distillation of the dissociation product II obtained in a) into an overhead stream III containing more than 90% by mass and a bottom stream IV containing diisobutene, MTBE and more than 80% of the methanol present in the dissociation product II, c) separation by distillation of the bottom stream IV obtained in b) into a methanol-containing bottom stream V, a side stream VI containing diisobutene, methanol and MTBE and an overhead stream VII containing MTBE and methanol and d) recirculation of the overhead stream VII to a).