Abstract:
PROBLEM TO BE SOLVED: To produce a carried catalyst used for converting a carboxylic acid or its ester into an aldehyde by a selective hydrogenation reaction, having reasonable stability, capable of being regenerated, hardly or quite not forming a by-product, having at least comparable selectivity with the corresponding non-carried catalyst. SOLUTION: This method for producing an aldehyde of formula I (R is an aliphatic, alicyclic, aromatic or aromatic aliphatic group which may be substituted, if necessary, with one or more substituents and/or if necessary, may have more heterogeneous atom) comprises selectively hydrogenating an acid of the formula: R-COOH or an ester of the acid with a 1-10C alcohol with hydrogen in the presence of a metal oxide catalyst in a gaseous phase. Therein, the hydrogenation is carried out in the presence of the carried catalyst containing a metal oxide suitable for the selective hydrogenation of the carboxylic acid or the carboxylate ester as an essential catalyst on SiC (silicon carbide) as a carrier at a temperature of 150-450 deg.C under a pressure of 0.1-150 bars.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for industrially efficiently and continuously producing an aldehyde by hydrogenating an ester, while recycling the unused hydrogen and the unreacted ester, wherein the selectivity of the aldehyde is maintained at a satisfactory level. SOLUTION: This method for producing an aldehyde of the formula: R-CHO comprises hydrogenating an ester of the formula: R-COOR' (R is a non- substituted or substituted aliphatic group, alicyclic group, aromatic group or aralkyl group; R' is a group derived from a 1-10C alcohol] with excessive hydrogen in an amount of 2-200 moles per mole of the ester in the presence of a heterogeneous hydrogenation catalyst at 200-450 deg.C in a gas phase, while recycling the unreacted hydrogen and the unreacted ester. Therein, the alcohol is removed from the recycling flow in such an extent as the initial concentration of the produced alcohol: R'-OH in the reaction mixture is maximally 1 mole per mole of the carboxylic acid ester II.
Abstract:
PROBLEM TO BE SOLVED: To obtain the subject compound in a short time without generating a coupling product and effectively utilizing the starting substances by reacting a specific cyclopentene with formic acid in the presence of an acidic catalyst. SOLUTION: The objective cyclopentyl formate of the formula II is produced by reacting (A) 1mol of a cyclopentene compound of the formula I (R1 to R3 are each H or a 1-8C alkyl, preferably a 1-4C alkyl) with (B) 0.1-25mol of formic acid in the presence of (C) 0.0001-25mol of an acidic catalyst (e.g. a Lewis acid) at -80 to +200 deg.C, preferably 35-80 deg.C. The component A is available as a 5C stream from a cracking apparatus or an oil refinery plant. Cyclopentyl formate is useful as a production raw material for cyclopentanol.
Abstract:
Verfahren zur Herstellung von 4-Pentensäureestern durch Isomerisierung, wobei man isomere Pentensäureester bei erhöhter Temperatur in Gegenwart von Zeolithen mit einem Gehalt an Metallen der achten Gruppe des Periodischen Systems behandelt und 4-Pentensäureester aus dem Reaktionsgemisch abdestilliert und die Zeolithe einen Gehalt an Eisen, Cobalt und/oder Nickel haben.
Abstract:
Verfahren zur kontinuierlichen Abscheidung von Maleinsäureanhydrid aus gasförmigen Reaktionsgemischen, bei dem man das das Maleinsäureanhydrid enthaltende gasförmige Reaktionsgemisch mit einem Butanol in Kontakt bringt, die dabei anfallenden gasförmigen Stoffe im Gegenstrom mit einem Bernstein- oder Fumarsäuredibutylester in Berührung bringt und das flüssige Verfahrensprodukt dem Sumpf entnimmt.
Abstract:
Disclosed is a process for simultaneously preparing caprolactam and hexamethylenediamine from adiponitrile. The invented preparation process is characterized by (a) partial hydrogenation of adiponitrile, (b) subjecting the obtained mixture to distillation to obtain a portion of ammonia as a top product and a heavy fraction I, whereby distillation is carried out in the presence of an inert compound A, (c) subjecting the heavy fraction I to a second distillation to obtain a mixture of the inert compound A and ammonia as a top product and a heavy fraction II, (d) subjecting the heavy fraction II to another distillation to obtain the inert compound A as a top product and a heavy fraction III, whereby the distillation is optionally carried out in the presence of a compound B, (e) subjecting the heavy fraction to distillation to obtain a top product KP1 and a heavy fraction IV, (f) subjecting the KP1 top to distillation to obtain a top product KP2 and a heavy fraction V, whereby the se KP2 top product is supplied at least partially to a third column and the residue is discharged, and (g) subjecting the heavy fraction IV to distillation in order to obtain 6-aminocapronitrile as a top product with adiponitrile at the column bottom, and so obtained 6-aminocapronitrile is then recycled to caprolactam.
Abstract:
The invented continuous purification process of raw caprolactam by hydrogenation followed by subsequent treatment in acid environment and then by distillation in alkaline medium is characterized by (a) converting 6-aminocapronitrile by reaction thereof with water to raw caprolactam, (b) separating high- and low-boiling components from the raw caprolactam of the stage (a), (c) treating the raw caprolactam obtained in the stage (b) with hydrogen at a temperature ranging from 50 to 150 degC and pressure in the range of 0.15 to 2.5 MPa in the presence of a hydrogenation catalyst and a required solvent and so obtaining a mixture A, (d1) conducting the mixture A in the solvent and at a temperature ranging from 30 to 80 degC and pressure in the range of 0.1 to 0.5 MPa through an ion exchanger containing acid terminal groups and to thereby obtaining a mixture B1 or (d2) distilling the mixture A in the presence of sulfuric acid, whereby prior addition of sulfuric acid the solvent being present can be removed and to thereby obtaining a mixture B2 and (e) distilling the mixture B1 or the mixture B2 in the presence of a base to thereby obtaining raw caprolactam.
Abstract:
PCT No. PCT/EP96/05071 Sec. 371 Date May 22, 1998 Sec. 102(e) Date May 22, 1998 PCT Filed Nov. 18, 1996 PCT Pub. No. WO97/19939 PCT Pub. Date Jun. 5, 1997In a process for the catalytic hydrogenation of 2,5- and 2,3-dihydrofuran with hydrogen to give tetrahydrofuran, use is made of a catalyst in which a metal or a plurality of metals have been deposited by vapor deposition or sputtering on a metal wire mesh or a metal foil as support.
Abstract:
The invention relates to a method for separating 2-aminomethylcyclopentylamine from a mixture containing hexamethylene diamine and 2-aminomethylcyclopentyl-amine, characterized in that separation by distillation occurs at a pressure of 1-3,000 mbars.