摘要:
The invention relates firstly to a discontinuous process for conducting a heterogeneously catalyzed reaction taking place at elevated temperature, in which heat-sensitive products are formed, a heat transfer unit (4) different from the reactor (1) being used for heating and a fixed-bed catalyst (3) being used as the catalyst and the reaction mixture being continuously circulated in succession through the catalyst (3) and then through the heat transfer unit (4). The problem to be solved in this process is to avoid losses of catalyst and product and to shorten the batch time and, optionally, the reaction time in accordance with German patent applications P 38 13 612.0 and P 38 26 320.3. The invention also relates to a plant for the discontinuous heterogeneously catalyzed production of heat-sensitive products at elevated temperature comprising a reactor (1), characterized by a heat transfer unit (4) arranged outside and connected to the reactor (1), a catalyst container (3) containing a fixed-bed catalyst preceding the heat transfer unit and a pump (2) for continuously circulating the reaction mixture in succession through the catalyst (3) and then through the heat transfer unit (4).
摘要:
Process for carrying out an equilibrium reaction in which one or more products are separated off by vapor permeation comprising the steps of:A) forming a reaction mixture comprising the reactants to be reacted in at least one reaction zone at a reaction temperature and reaction pressure selected so as to provide a reaction temperature above the boiling temperature of at least the product or products to be removed, wherein at least the product or products to be removed enters the resulting vapor phase in vapor form;B) passing the vapor phase containing the product or products to be removed to a zone remote from the reaction zone, which remote zone contains a semi-permeable membrane permeable to the product or products to be removed;C) carrying out vapor permeation in said remote zone to remove at least a portion of the product or products to be removed from said vapor phase; andD) returning the resulting vapor retentate from step C) to a reaction zone in step A). The process is especially useful in carrying out esterification reaction between a carboxylic acid and an alcohol.
摘要:
The invention relates to an optimized process for conditioning a stream of superheated steam laden with steam-volatile organic components by condensation of the steam phase with recovery of the heat of condensation and at least partial separation of the steam-volatile organic components from the water-based condensate. The process operates with a first heat exchange stage in which the continuously introduced vapor stream is combined with a circulated and cooled liquid stream of condensed vapors. In a following second energy transfer stage, heat is indirectly removed from the liquid stream thus heated. A sidestream is removed from the liquid circuit of the condensed vapors and subjected to separation in a membrane process while the rest of the liquid stream is returned to the first stage. The invention also relates to the use of this working principle for industrial applications, more particularly for the separation of organic mixtures by superheated steam and/or the drying of water-based useful-material preparations with superheated steam as the drying gas.
摘要:
The waste gas accumulating in the drying of products containing volatile ingredients is cooled, the condensate obtained is subjected to crossflow membrane filtration and part of the cleaned waste gas is returned to the drying process. The concentrate obtained is put to a material, thermal or other use. The both effective and economic process is suitable for eliminating the aerosols, particularly the organic aerosols, present in the waste gas.
摘要:
Processes for refining dialkyl carbonate-containing compositions are described, wherein a composition comprising a dialkyl carbonate is provided; and the composition is subjected to a rectification wherein low-boiling impurities are removed, and a rectification wherein high-boiling impurities are removed; and subsequently to a deodorization wherein medium-boiling impurities are removed.
摘要:
Processes for preparing fatty acids are described wherein a C4-C12 fatty acid methyl ester is subjected to hydrolysis in the presence of an enzyme to form an organic phase comprising a C4-C12 fatty acid and an aqueous phase comprising methanol, wherein at least a portion of the methanol is continuously removed; and the organic phase is subsequently separated from the aqueous phase, and optionally, where the organic phase further comprises an unhydrolyzed portion of the C4-C12 fatty acid methyl ester, the unhydrolyzed portion of the C4-C12 fatty acid methyl ester is separated from the C4-C12 fatty acid.