Abstract:
A process is described for the preparation of 5-hydroxymethylfurfural (HMF), which comprises the following steps: provision or preparation of a starting mixture, comprising one, two or more starting compounds selected from the group consisting of hexoses, oligosaccharides comprising hexose units, and polysaccharides comprising hexose units, one, two or more organic salts with a melting point 200°C at 1013.25 hPa, optionally additionally one or more catalysts for the conversion of the one starting compound or at least one of the two or more starting compounds to 5-hydroxymethylfurfural (HMF), optionally water, optionally further substances, adjustment of reaction conditions such that an amount of the starting compound or starting compounds converts to HMF.
Abstract:
The invention relates to a centrifugal mist eliminator for separating liquid droplets from a gas stream, comprising: - a shell (1), which has a circular cross-section and a vertical longitudinal axis (11); - a an upper hood (2), which delimits the shell (1) at the top and has a gas outlet connecting piece (7) for the gas stream purified in the centrifugal mist eliminator; - a drip plate (8), which is disposed below the gas outlet connecting piece (7); - a lower hood (10), which delimits the shell (1) at the bottom and which has a liquid outlet connecting piece (4) for discharging the separated liquid droplets; and - an inlet (3) for feeding the gas stream, the inlet leading tangentially into the shell (1); the centrifugal mist eliminator being characterized in that at least two nozzles (9) for feeding a stabilizer liquid into the interior of the centrifugal mist eliminator are provided, the nozzle outlet (15) of each nozzle being disposed between the tangential inlet (3) and the drip plate (8) in the vertical direction, and the main spray direction (12) of the nozzles (9) being directed upward at an interior angle of 0 to 60° to the vertical longitudinal axis (11). The invention also relates to a method for separating liquid droplets from a gas stream in a centrifugal mist eliminator of this type.
Abstract:
La invención se refiere a un método para producir 2-octil (met)acrilato al hacer reaccionar 2- octanol con ácido (met)acrílico en presencia de un catalizador de esterificación ácido, un inhibidor de polimerización y el agente azeotrópico ciclohexano, que comprende las etapas de: ? proporcionar una unidad de reactor (24), en donde un reactor (1) que tiene un elemento de calentamiento de reactor (30) se ubica dentro de la unidad de reactor (24), ? alimentar 2-octanol (13), ácido (met)acrílico (14), catalizador de esterificación ácido (15), ciclohexano (17) e inhibidor de polimerización (31) al reactor (1), ? llevar a cabo una esterificación en el reactor (1) para formar una mezcla de reacción líquida, en donde la esterificación en el reactor (1) se lleva a cabo a una temperatura de fondo en el rango de 90 a 130°C y a una presión absoluta en el rango de 0.5 a 2.0 bar, y se obtiene una descarga de reacción del reactor (1), en donde la descarga de reacción resultante comprende al menos 2-octil (met)acrilato, 2- octanol, ácido (met)acrílico, catalizador de esterificación ácido, ciclohexano, agua de esterificación e inhibidor de polimerización, y el agua de esterificación formada en la esterificación junto con el agente azeotrópico de ciclohexano forma un azeótropo heterogéneo, ? evaporar el azeótropo heterogéneo de la mezcla de reacción líquida del reactor (1), en donde la evaporación se logra mediante el elemento de calentamiento del reactor (30), y ? retirar el azeótropo heterogéneo gaseoso del reactor (1), en donde el azeótropo heterogéneo gaseoso se condensa en un condensador (5) y luego se introduce en un separador de fases (6), y el agua de esterificación se separa como la fase inferior y el ciclohexano como la fase superior en este separador de fases (6).
Abstract:
A process for the production of C6-C12-alkyl (meth)acrylic esters, comprises an esterification step of esterifying (meth)acrylic acid with an alcohol to obtain a crude (meth)acrylic ester, the (meth)acrylic acid containing trace amounts of acetic acid; and purification steps of purifying the crude (meth)acrylic ester. The purification steps comprise introducing crude (meth)acrylic ester into the side of a low boiler column with a rectifying section disposed above the feed point of the crude (meth)acrylic ester and a stripping section disposed below the feed point; withdrawing purified (meth)acrylic ester from the low boiler column; withdrawing a low boiler fraction from the top of the low boiler column, the low boiler fraction comprising alcohol and acetic ester and less than 10 wt.-% of (meth)acrylic ester; directing the low boiler fraction to an acetate column, the acetate column being operated at a pressure at least 50 mbar higher than the low boiler column pressure, and separating the low boiler fraction into an alcohol fraction withdrawn at the top of the acetate column and an acetic ester fraction withdrawn at the bottom of the acetate column; and recycling the alcohol fraction at least partially to the esterification step; the process comprising no recycle from the acetate column to the low boiler column. The process provides an effective and economically viable process for preparing of C6-C12-alkyl (meth)acrylic esters with a low acetate content.
Abstract:
Process for isolating pure 2-ethylhexyl acrylate or pure 2-propylheptyl acrylate from the corresponding crude alkyl acrylate by distillation, wherein the process is carried out in a dividing wall column (1) which has separation-active internals and vaporizer (7) and in which a dividing wall (8) is arranged in the longitudinal direction of the column to form an upper joint column region (9), a lower joint column region (14), an inflow section (10, 12) having a side feed point (2) and an offtake section (11, 13) having a side offtake point (3), the column has a number of theoretical plates in the range from 10 to 60, where the number of theoretical plates of the dividing wall column (1) relates to the sum of the theoretical plates in the joint upper column region (9), the joint lower column region (14) and the inflow section (10, 12), the side feed point (2) for the corresponding crude alkyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate, the side offtake point (3) for the pure 2-ethylhexyl acrylate or pure 2-propylheptyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate and the dividing wall (8) is arranged in the column in the region commencing at least one theoretical plate above the bottommost theoretical plate and ending at least one theoretical plate below the uppermost theoretical plate, where the ratio of amount of liquid at the upper end of the dividing wall (8) going to the enrichment section (10) and the stripping section (11) of the column is set in the range from 1:0.2 to 1:5. (Fig.1)
Abstract:
Process for preparing a solution of pure triethylenediamine (TEDA), in which TEDA is vaporized, the gaseous TEDA is passed into a liquid solvent 1 (quench) and the TEDA is crystallized from the resulting solution and separated off (solid-liquid separation), wherein the crystalline TEDA obtained is dissolved in a solvent 2 and a stripping gas is passed through the resulting solution (stripping).