摘要:
A process for preparing diglycerol in high concentrations and high yields by partially reacting glycerol in the presence of an alkaline catalyst to form a reaction mixture containing from 10 to 15% by weight of diglycerol and separating the unreacted glycerol from the reaction mixture in a wiped film or short path first distillation zone at a reduced pressure of 0.5 to 5 mbar and distilling a bottoms product from the first distillation zone in a second distillation zone which is a short path distillation zone at a pressure of 0.05 to 0.3 mbar to obtain a second bottom product containing at least 90% by weight diglycerol. Diglycerol of higher purity can be obtained by recovering diglycerol as a distillate from a third distillation zone.
摘要:
A process is provided for simultaneously recovering tocopherol and sterol from a mixture containing tocopherol, fats and/or fat derivatives, more particularly fatty acids, and sterol and/or sterol derivatives, more particularly from a steamer distillate of natural oils and fats. The steps of said process comprise:free fatty acids present in the mixture are esterified with a lower alcohol, preferably methanol, 0.4 to 1.6 and more particularly 1 to 1.5 parts by volume of mixture being esterified with 1 part by volume of the lower alcohol,the mixture is subsequently transesterified with the lower alcohol in the presence of a basic catalyst,the excess lower alcohol is distilled off from the reaction mixture after the transesterification,the transesterification catalyst and the glycerol optionally present are removed, more particularly by washing,the fatty acid alkyl ester is distilled off from the mixture, more particularly after removal of the transesterification catalyst, andif desired, tocopherol and sterol are separated by methods known per se. After the transesterification reaction, the alkali catalyst is preferably neutralized with an inorganic acid and the mixture is then washed with water.
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:
A process is disclosed for preparing .alpha.-branched aliphatic monocarboxylic acids with 12 to 48 carbon atoms. In a first step of the process (a), .alpha.-branched aliphatic monohydric alcohols (Guerbet alcohols) are converted in the presence of caustic alkali into the alkali salts of the corresponding .alpha.-branched aliphatic monocarboxylic acids. In a second step of the process (b), the .alpha.-branched aliphatic monocarboxylic acids are released from the alkali salts by soap splitting in the presence of an inert diluting agent.
摘要:
The invention relates to a continuous process for the production of lower alkyl esters at temperatures of up to 100.degree. C. and under pressures of up to 10 bar by reaction of fatty acid triglycerides containing less than 1% free fatty acid with a lower alcohol in two stages in the presence of a homogeneous alkaline catalyst, the glycerol formed being removed after the first stage. To enable the process to be carried out with high yields and with lower maintenance, investment and energy costs than in the prior art, the reaction mixture is passed through a reactor and a following static separator only once in each stage, tube reactors are used as the reactors and the Reynolds number of the flow of the reaction mixture is greater than 2,300.
摘要:
A process for the production of fatty ketones by pyrolysis of fatty acid magnesium salts wherein fatty acids corresponding to formula (I):R.sup.1 COOH (I)in which R.sup.1 CO is an aliphatic acyl radical containing 12 to 22 carbon atoms and 0, 1, 2 or 3 double bonds, are heated to temperatures of 320.degree. to 360.degree. C. in the presence of magnesium oxide and the fatty ketones formed are distilled off from the reaction mixture under reduced pressure.
摘要:
The epoxidation of terminally and/or internally olefinically unsaturated hydrocarbon compounds which are liquid at 50.degree. to 100.degree. C. and at atmospheric pressure (oil phase), in which the oil phase is treated with an acid phase containing acetic acid, hydrogen peroxide and peracetic acid in aqueous solution, after which the aqueous acid phase is separated from the oil phase, the peracetic acid in the aqueous acid phase is regenerated and the regenerated aqueous acid phase is returned to the epoxidation reactor. Epoxidation is carried out using an aqueous acid phase containing at most about 10% by weight of peracetic acid, and the peracetic acid content in the aqueous acid phase is reduced by at most about 50%, based on the peracetic acid content of the aqueous acid phase used, after a single passage through the epoxidation stage. After separation from the oil phase, the aqueous acid phase preferably is cooled before regeneration.
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:
A process for the production of solid or paste-form products by fast reactions is carried out stoichiometrically wherein a gaseous medium is introduced into each of the reactants to be reacted with one another, the reactant streams formed are combined and are subsequently forced through a spray unit in a weight ratio of gaseous medium to product stream of from 0.04 to 0.3 (kg/kg) and at a rate of 0.1 to 15 m/second, as calculated from the gas-free reactant streams and based on the free cross-section of the spray unit. The products obtained are free from readily volatile constituents.
摘要:
The invention is a process for the continuous liquid-phase esterification of C.sub.2 -C.sub.24 fatty acids with alkanols in countercurrent contact and reaction in a reaction column, the catalysts and fatty acids are introduced at the top plate and the alkanols below the lowest plate, at a head pressure of the reaction column of 200 to 900 hPa. The process reduces dehydration of the alkanols.