Abstract:
The invention relates to a method for producing 1,6-hexanediol and, optionally, e-caprolactone. According to the inventive method, the carboxylic acid obtained by oxidizing cyclohexane is esterified, the esterified mixture is separated into an ester fraction and a bottom fraction, and the ester fraction is hydrated so as to obtain 1,6-hexanediol. The bottom fraction is hydrolyzed with water and is returned into the esterified mixture. Hydrolyzing the bottom fraction with water allows the method to be simplified while preventing metal oxides from being emitted and being deposited on parts of the installation, a phenomenon that occurs during reprocessing of the bottom fraction by means of reesterification.
Abstract:
The invention relates to a method for drying microporous particles containing fluid in which the heat required for increasing the temperature is supplied by means of convection by reducing the interfacial tension of the fluid, preferably to 0 to 1/10, especially to 0 to 1/20, pertaining to the interfacial tension of the fluid at room temperature, by correspondingly increasing the temperature when the pressure of the fluid is at a near-critical to supercritical level. The invention also relates to a method for producing microporous, spatially cross-linked particles in which said drying method is applied. In addition, the invention relates to a device for carrying out the drying method. The device comprises a pressure vessel having an inner vessel and a pressure-carrying outer vessel. Said device also comprises suited measuring and regulating devices as well as pumping and heat exchange devices, whereby the inner vessel is provided for accommodating the particles which are to be dried. A gap is provided between the inner and outer vessels.
Abstract:
Procedimiento para la elaboración por destilación de productos crudos obtenidos en el procedimiento según la DE-A 196 07 954, que contienen 1, 6- hexanodiol (HDO), 1, 5-pentanodiol (PDO), o bien caprolactona (CLO), para la obtención de los correspondientes productos puros, caracterizado porque la elaboración por destilación se lleva a cabo respectivamente en una columna de pared separadora (TK), en la que está dispuesta una pared separadora (T) en el sentido longitudinal de la columna bajo formación de una zona de columna superior común (1), una zona de columna inferior común (6), una parte de alimentación (2, 4) con parte de enriquecimiento (2), y parte de descarga (4), así como una parte de extracción (3, 5) con parte de descarga (3) y parte de enriquecimiento (5), con alimentación del respectivo producto crudo HDO, PLO, o bien CLO en la zona media de la parte de alimentación (2, 4), descarga de una fracción de punto de ebullición elevado (C) a partir de la cola de la columna, una fracción de bajo punto de ebullición (A) por encima de la cabeza de la columna y una fracción de punto de ebullición medio (B) de la zona media de la parte de extracción (3, 5), o en columnas acopladas térmicamente.
Abstract:
Procedimiento para el secado de partículas, que contienen fluido, microporosas, por reducción de la tensión interfacial del fluido, preferentemente de 0 hasta 1/10, particularmente de 0 hasta 1/20, la tensión interfacial presente a temperatura ambiente del fluido, de tal manera que se aumente correspondientemente la temperatura hasta una presión hipercrítica del fluido la temperatura, caracterizado porque se alimenta de forma convectiva el calor necesario para el aumento de la temperatura.
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, bya) 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, ande) subjecting the hydrogenation effluent to a distillation to recover 1,6-hexanediol in a conventional manner,comprises using an aqueous dicarboxylic acid mixture comprising more than 20 ppm of cobalt and more than 40 ppm of phosphorus in the form of phosphate and passing this aqueous dicarboxylic acid mixture through a cation exchanger and after the esterification of step (a) through an anion exchanger.
Abstract:
In a process for drying microporous, fluid-containing particles, the fluid-containing particles to be dried are fed as a moving bed countercurrently to a drying fluid, the interfacial tension of the fluid being reduced in comparison with the interfacial tension of the fluid at room temperature, at near-critical to supercritical pressure of the fluid, preferably to a value in the range from 0 to 1/10, in particular from 0 to 1/20, of the interfacial tension at room temperature. Furthermore, microporous, three-dimensionally networked particles are prepared by a process comprising preparation of microporous particles containing pore liquid, exchange of the pore liquid in the particles for a fluid and drying of the fluid-containing particles, the exchange and drying being carried out in the moving bed by the countercurrent method.
Abstract:
The invention relates to a method for the distillative processing of the crude products 1,6-hexandiols (HDO), 1,5-pentandiol (PDO) or caprolactone (CLO) obtained according to the method of German patent application DE-A 196 07 954 in order to obtain the corresponding pure products. The distillative processing proceeds in a separation column (TK) in which a separating wall (T) is arranged in the column longitudinal direction forming an upper common column section (1), a lower common column section (6), a feed part (2, 4) with reinforcement part (2) and drive part (4), and a removal part (3, 5) with output part (3) and reinforcement part (5). The corresponding crude product HDO, PDO or CLO is fed in the center section of the feed part (2, 4), the high-boiling fraction (C) is removed from the column sump, the low-boiling fraction (A) is removed via the column head and the medium-boiling fraction (B) is removed from the center section of the removal part (3, 5). The inventive method can also be carried out in thermally coupled columns.
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 in thermally coupled columns.