Abstract: A process for preparing N,N-dimethylacetamide (DMAC) by continuously reacting methyl acetate (MeOAc) with dimethylamine (DMA) in the presence of a basic catalyst, wherein MeOAc is used in the form of a methanolic solution and the continuous distillative workup is effected in such a way that methanol and any other low boilers are initially removed overhead in a column A and the bottom effluent of column A is fed to a column B in which DMAC is removed via a side draw a purity of ?99.7% by weight.

Abstract: The invention relates to a method of controlling a hydrogenation of a starting material in a hydrogenation reactor, in which the amount of hydrogen reacted in the hydrogenation is firstly determined, the ratio of the amount of hydrogen reacted to the amount of starting material fed in is then derived, this ratio is compared with a prescribed value and, finally, at least one process parameter is altered if the ratio of the amount of hydrogen reacted to the amount of starting material fed in deviates by a prescribed amount from the prescribed value.

Abstract: The present invention relates to a process for preparing tetrahydrofuran by absorption of C4-dicarboxylic acids and/or derivatives thereof from a crude product mixture into an organic solvent or water as absorption medium, removal of the absorption medium, catalytic hydrogenation of the resulting C4-dicarboxylic acids and/or derivatives thereof and distillation of the water-comprising crude tetrahydrofuran in at least one distillation column, wherein THF-comprising waste streams from the distillation are catalytically hydrogenated with complete or partial recirculation to the process.

Abstract: Process for preparing olefins, which comprises the following steps: a) preparation of a synthesis gas comprising carbon monoxide and hydrogen, b) introduction of carbon dioxide recirculated from step d) into the synthesis gas during or after the preparation of synthesis gas as per step a), c) conversion of the synthesis gas having a hydrogen to carbon monoxide ratio of ?1.2:1 which is obtained in step b) into olefins in the presence of a Fischer-Tropsch catalyst, d) removal of the carbon dioxide comprised in the reaction product from step c), where the ratio of hydrogen to carbon monoxide in step c) is set via step b).

Abstract: A process for preparing N,N-dimethylacetamide (DMAC) by continuously reacting methyl acetate (MeOAc) with dimethylamine (DMA) in the presence of a basic catalyst, wherein MeOAc is used in the form of a methanolic solution which is obtained as a byproduct in the preparation of polyTHF by transesterifying polyTHF diacetate with methanol.

Abstract: A process for decreasing fumaric acid deposits in the preparation of maleic anhydride by heterogeneously catalyzed oxidation of a hydrocarbon with molecular oxygen, in which the maleic anhydride is absorbed from the crude product mixture in an absorbent in an absorption column and desorbed again in a desorption column, the entirety or a portion of the absorbent depleted in maleic anhydride, for controlled precipitation of fumaric acid, being cooled and/or concentrated by evaporating a portion of the absorbent to such an extent that the difference between the concentration of fumaric acid in the recycle stream at the outlet of the desorption column under the conditions existing there and the equilibrium concentration of fumaric acid according to the solubility curve after the cooling and/or evaporation of a portion of the absorbent is greater than or equal to 250 ppm by weight, and the fumaric acid precipitated as a solid is removed completely or partly from the absorbent recycling system and the fumaric acid-

Abstract: The invention relates to a catalyst provided in the form of an extrudate, which contains 5 to 85% by weight of copper oxide and comprises, in the active material and as binders, the same oxidic carrier material. The invention also relates to the use of the catalyst for hydrogenating carbonyl compounds.

Abstract: A process for preparing N,N-dimethylacetamide (DMAC) by continuously reacting methyl acetate (MeOAc) with dimethylamine (DMA) in the presence of a basic catalyst, wherein MeOAc is used in the form of a methanolic solution and the continuous distillative workup is effected in such a way that methanol and any other low boilers are initially removed overhead in a column A and the bottom effluent of column A is fed to a column B in which DMAC is removed via a side draw a purity of ?99.7% by weight.

Abstract: The present invention provides a process for distillatively purifying tetrahydrofuran in the presence of a polar solvent.

Abstract: The present invention relates to a process for preparing polytetrahydrofuran, polytetrahydrofuran copolymer, diester or monoester by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer and of an acidic heterogeneous catalyst based on activated sheet silicates or mixed metal oxides in a fluidized bed.

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile, by contacting the vaporous product of the ammoxidation stage directly with a liquid organic solvent (quench), and hydrogenating the phthalonitrile in the resulting quench solution or suspension, wherein the organic solvent is N-methyl-2-pyrrolidone (NMP).

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile and hydrogenating the phthalonitrile, which comprises contacting the vaporus product of the ammoxidation stage directly with a liquid organic solvent or with molten phthalonitrile (quench), partly or fully removing components having a boiling point lower than phthalonitrile (low boilers) from the resulting quench solution or suspention or phthalonitrile melt and, before the hydrogenation, of the phthalonitrile, not removing any products having a boiling point higher than phthalonitrile (high boilers).

Abstract: Catalyst in the form of an extrudate which comprises from 5 to 85% by weight of copper oxide and in which the same oxidic support material is present in the active composition and as binder, and the use of the catalyst for the hydrogenation of carbonyl compounds.

Abstract: A process for variably preparing mixtures of optionally alkyl-substituted BDO, GBL and THF by two-stage hydrogenation in the gas phase of C4 dicarboxylic acids and/or derivatives thereof, which comprises a) hydrogenating in a gas phase a gas stream of C4 dicarboxylic acids and/or derivatives thereof over a particular catalyst at a particular pressure and temperature to give a stream mainly containing of optionally alkyl-substituted GBL and THF, b) removing any succinct anhydride, c) converting the products remaining predominantly in the gas phase in the partial condensation, THF, water and GBL to give a stream comprising a mixture of BDO, GBL and THF, d) removing the hydrogen from the products and recycling it into the hydrogenation, e) distillatively separating the products, THF, BDO, GBL and water, if appropriate recycling a GBL-rich stream or if appropriate discharging it, and working up BDO, THF and GBL distillatively, and setting the ratio of the products, THF, GBL and BDO, relative to one another wi

Abstract: A process for preparing N,N-dimethylacetamide (DMAC) by continuously reacting methyl acetate (MeOAc) with dimethylamine (DMA) in the presence of a basic catalyst, wherein MeOAc is used in the form of a methanolic solution which is obtained as a by-product in the preparation of polyTHF by transesterifying polyTHF diacetate with methanol.

Abstract: The invention relates to a process for separating off maleic anhydride from a gas stream comprising maleic anhydride, in which a) the gas stream comprising maleic anhydride is brought into contact with a liquid absorbent phase comprising at least one high-boiling inert absorption medium for maleic anhydride and b) maleic anhydride is separated off from the resulting liquid absorbate phase by stripping with a hydrogen-comprising gas as stripping medium in a column, wherein the stripping medium is fed in at two points on the column which are at least one theoretical plate apart.

Abstract: The invention relates to a method of controlling a hydrogenation of a starting material in a hydrogenation reactor, in which the amount of hydrogen reacted in the hydrogenation is firstly determined, the ratio of the amount of hydrogen reacted to the amount of starting material fed in is then derived, this ratio is compared with a prescribed value and, finally, at least one process parameter is altered if the ratio of the amount of hydrogen reacted to the amount of starting material fed in deviates by a prescribed amount from the prescribed value.

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile and hydrogenating the phthalonitrile, which comprises contacting the vaporous product of the ammoxidation stage directly with a liquid organic solvent or with molten phthalonitrile (quench), partly or fully removing components having a boiling point lower than phthalonitrile (low boilers) from the resulting quench solution or suspension or phthalonitrile melt and, after the low boiler removal and before the hydrogenation, removing products having a boiling point higher than phthalonitrile (high boilers).

Abstract: A process for preparing N,N-dimethylacetamide (DMAC) by continuously reacting methyl acetate (MeOAc) with dimethylamine (DMA) in the presence of a basic catalyst, wherein MeOAc is used in the form of a methanolic solution and in the range from 0.0002 to 0.09 mol of catalyst per mole of MeOAc, and performing the reaction at a temperature in the range from 90 to 140° C. and at an absolute pressure in the range from 10 to 30 bar.

Abstract: The invention relates to a method for producing xylylenediamine, comprising the following steps: ammonoxidation of xylol to form phthalodinitrile and hydrogenation of the phthalodinitrile, whereby the vaporous product of the ammonoxidation stage is directly brought into contact with a liquid organic solvent or with melted phthalodinitrile (quench); constituents having a boiling point lower than that of phthalodinitrile (low boilers) are partially or completely separated out from the obtained quench solution or suspension or phthalodinitrile melt, and; before the hydrogenation of the phthalodinitrile, no products having a boiling point higher than that of phthalodinitrile (high boilers) are separated out.