Abstract: A process for working up by distillation the crude products obtained in the process according to DE-A 196 07 954 and containing 1,6-hexanediol (HDO), 1,5-pentanediol (PDO) or caprolactone (CLO) in order to obtain the corresponding pure products, the working-up by distillation being carried out in each case in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper common column region (1), a lower common column region (6), a feed section (2, 4) having a rectification section (2) and stripping section (4), and a take-off section (3, 5) having a stripping section (3) and rectification section (5), with feeding of the respective crude product HDO, PLO or CLO in the middle region of the feed section (2, 4) and removal of the high boiler fraction (C) from the bottom of the column, of the low boiler fraction (A) via the top of the column and of the medium boiler fraction (B) from the middle region of the take-off section (3, 5), or

Abstract: Unsubstituted or alkyl-substituted THF is obtained by catalytic hydrogenation in the gas phase of C4-dicarboxylic acids and/or their derivatives using a catalyst comprising <80% by weight, preferably <70% by weight, in particular from 10 to 65% by weight, of CuO and >20% by weight, preferably >30% by weight, in particular from 35 to 90% by weight, of an oxidic support having acid centers, at a hot spot temperature of from 240 to 310° C., preferably from 240 to 280° C., and a WHSV over the catalyst of from 0.01 to 1.0, preferably from 0.02 to 1, in particular from 0.05 to 0.5, kg of starting material/l of catalyst×hour.

Abstract: The present invention relates to a process for the gas-phase hydrogenation of C4-dicarboxylic acids and/or their derivatives over a catalyst based on copper oxide to give substituted or unsubstituted &ggr;-butyrolactone and/or tetrahydrofuran, which comprises, which a first reaction zone in which the C4-dicarboxylic acid and/or its derivatives is/are reacted to give a mixture comprising a substituted or unsubstituted &ggr;-butyrolactone as main product and a subsequent second reaction zone in which the substituted or unsubstituted &ggr;-butyrolactone present in the mixture from the first hydrogenation step is reacted at a temperature lower than the temperature in the first hydrogenation step to give substituted or unsubstituted tetrahydrofuran.

Abstract: A catalyst for the hydrogenation of C4-dicarboxylic acids and/or their derivatives, preferably maleic anhydride, in the gas phase comprises from 5 to 100% by weight, preferably from 40 to 90% by weight, of copper oxide and from 0 to 95% by weight, preferably from 10 to 60% by weight, of one or more metals or compounds thereof selected from the group consisting of Al, Si, Zn, Pd, La, Ce, the elements of groups III A to VIII A and groups I A and II A as active composition applied in the form of a thin layer to an inert support material.

Abstract: A system for making presentations to audience clients in a computer network. The presentation is made by a presenter client via a Web server connected to one or more audience client units. Each audience client unit has a browser for linking to the network. The system comprises a receiver for receiving and processing page requests from at least one presenter client; a transmitter for transmitting requested pages to the presenter client; and a server siphon for intercepting composed pages and sending copies of each composed page to at least one connected audience client.

Abstract: In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.

Abstract: A process for preparing cyclopentanone by reacting adipic esters of the formula R1OOC—(CH2)4—COOR2  I where R1 and R2 are each alkyl having from 1 to 12 carbon atoms, cycloalkyl having 5 or 6 carbon atoms, aralkyl or aryl and R2 may additionally be hydrogen, in the presence of oxidic catalysts comprises reacting adipic esters of the formula I having less than 5% by weight of by-products other than adipic esters in the gas phase in the presence of water, a carrier gas and a) from 0.01 to 10% by weight of at least one metal oxide selected from the first or second main group of the periodic table or from the group of the rare earth metals on titanium dioxide or zirconium dioxide as catalyst support, or b) from 0.01 to 50% by weight of at least one metal oxide selected from the second main group of the periodic table on zink oxide as catalyst support.

Abstract: A process for the preparation of 1,6-hexanediol and 6-hydroxycaproic acid or esters thereof by catalytic hydrogenation of adipic acid, adipic acid monoesters or adipic acid diesters or streams of starting material which contain adipic acid or esters thereof as essential constituents, in which the bottom product obtained in the distillation of the hydrogenation product, following removal of the hexanediol and hydroxycaproic acid or esters thereof, and essentially comprises oligomeric esters of 6-hydroxycaproic acid, is recycled to the hydrogenation, and the resulting mixture of starting material and recycle stream is reacted at from 100 to 300°C., at from 10 to 300 bar in the liquid phase and at a molar ratio of carboxyl groups to be hydrogenated to hydrogen in the reactor of from 1:5 to 1:100 on hydrogenation catalysts is described.

Abstract: A process for producing 1,6-hexanediol by hydrogenation of adipic esters and/or 6-hydroxycaproic esters in the gas phase at elevated temperature and elevated pressure in the presence of chromium-free catalysts comprises hydrogenating a) over a catalyst comprising copper, manganese and aluminum as essential constituents or over Raney copper, b) at a temperature of from 150 to 230° C. and a pressure of from 10 to 70 bar, c) at a molar ratio of hydrogen to ester to be hydrogenated within the range from 150:1 to 300:1, and d) at a catalyst space velocity of from 0.01 to 0.3 kg of C6 ester per liter of catalyst per hour.

Abstract: A process for polymerizing cyclic ethers over a heterogeneous catalyst comprises using a heterogeneous catalyst comprising one or more pillared interlayered clays (PILCs).

Abstract: A process for preparing cyclopentanone and cyclopentene-1-carboxylic acid or an ester thereof of the formula I where R is hydrogen or an aliphatic radical having 1-6 carbon atoms or a cycloaliphatic, araliphatic or aromatic radical having 6-12 carbon atoms comprises heating a compound of the formula II X—(CH2)4—COOR  II where X is formyl or hydroxymethyl and R is defined as above, and/or a compound which is converted into a compound of the formula II by reaction with water or alcohols ROH under the reaction conditions to from 200 to 450° C. in the gas or liquid phase in the presence of a heterogeneous oxidic catalyst.

Abstract: Hexanediol is prepared by hydrogenating dialkyl adipates or mixtures which contain a dialkyl adipate as the essential component and organic halogen compounds as impurities, by a process in which, before the hydrogenation, the dialkyl adipates or the mixtures containing dialkyl adipates are passed at from 50 to 250° C. and from 1 to 100 bar over copper catalysts which have a copper content, calculated as CuO, of from 0.5 to 80% by weight, a surface area of from 5 to 1500 m2/g, a porosity of from 0.05 to 1.5 cm3/g and a copper surface area of from 0.1 to 20 m2/g, in order to remove the organic halogen compounds.

Abstract: A process for preparing 1,6-hexanediol from a carboxylic acid mixture obtained as by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or oxygen-comprising gases and by aqueous extraction of the reaction mixture and comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols by esterification of the acids and hydrogenation, by a) reacting the mono- and dicarboxylic acids in the aqueous dicarboxylic acid mixture with a low molecular weight alcohol to form the corresponding carboxylic esters, b) conducting a first distillation to remove excess alcohol and low boilers from the esterification mixture obtained, c) conducting a second distillation to separate the bottom product into an ester fraction which is essentially free from 1,4-cyclohexanediols and a fraction which includes at least the larger proportion of the 1,4-cyclohexanediols, d) subjecting the ester fraction essentially free from 1,4-cyclohexanediols to a catalytic hydrogenation, and e)

Abstract: Polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers are prepared by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer on a heterogeneous carrier catalyst which contains on an oxidic carrier material as active mass a catalytically active amount of at least one oxygenous molybdenum and/or tungsten compound and, when the precursor compounds of the active mass have been applied to the carrier material precursor, has been calcined at temperatures of between 500° C. and 1000° C. The catalyst used contains a promotor which comprises at least one element or a compound of an element of the 2nd, 3rd including the lanthanides, 5th, 6th, 7th, 8th or 14th group of the periodic system of elements.

Abstract: Polytetrahydrofuran, copolymers of tetrahydrofuran and 2-butyne-1,4-diol, diesters of these polymers with C.sub.2 -C.sub.20 -monocarboxylic acids or monoesters of these polymers with C.sub.1 -C.sub.10 -monocarboxylic acids are prepared by polymerization of tetrahydrofuran in the presence of one of the telogens water, 1,4-butanediol, 2-butyne-1,4-diol, polytetrahydrofuran having a molecular weight of from 200 to 700 Dalton, a C.sub.1 -C.sub.10 -monocarboxylic acid or an anhydride of a C.sub.2 -C.sub.20 -monocarboxylic acid or a mixture of these telogens over a heterogeneous supported catalyst which comprises a catalytically active amount of an oxygen-containing molybdenum and/or tungsten compound on an oxidic support material and which has been calcined at from 5OO.degree. C. to 1OOO.degree. C.

Abstract: 1,6-Hexanediol is prepared from a carboxylic acid mixture comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols which is obtained as a by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol by water extraction of the reaction mixture, by esterification of the acids and hydrogenation whereina) the monocarboxylic and dicarboxylic acids present in the aqueous dicarboxylic acid mixture are reacted with a low molecular weight alcohol to give the corresponding carboxylic esters,b) the resulting esterification mixture is freed of excess alcohol and low boilers in a first distillation stage,c) the bottoms are fractionated in a second distillation stage to give an ester fraction essentially free of 1,4-cyclohexanediols and a fraction comprising at least the major part of the 1,4-cyclohexanediols,d) the ester fraction essentially free of 1,4-cyclohexanediols is catalytically hydrogenated ande) in a pure distillation stage, 1,6-hexanediol is isolated from the hydrogena

Abstract: 1,6-hexanediol and .epsilon.-caprolactone are prepared from a carboxylic acid mixture comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols which is obtained as a by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol using oxygen or oxygen-containing gases by water extraction of the reaction mixture, by esterifying and hydrogenating a substream to give hexanediol and cyclizing 6-hydroxycaproic esters to give caprolactone.