GB679538A - Improvements relating to the hydrolysis of fatty acid esters - Google Patents

Abstract

<PICT:0679538/IV (b)/1> In the hydrolysis of fatty acid esters, a mixture of water and ester without a catalyst is passed co-currently under appropriate conditions of temperature and pressure through a substantially vertical partitioned reaction vessel which is kept filled with the reaction mixture, the rate of supply being such that the vessel holds from about 1.5 to 3 hours' input. Alternatively, the reaction mixture may include a catalyst, e.g. zinc oxide, and in this case the rate of supply is such that the vessel holds from about 20 to 60 minutes' input. A suitable reaction vessel comprises a vertical container 1 having an inlet 10 for the reaction mixture, an outlet 11 for the products, a heater 13, which may be replaced by means for injecting steam, partitions 5 and a rotary shaft 6 carrying stirrers 8. The partitions 5 have apertures 9 which may be staggered, as shown, or located around the shaft 6; the apertures are substantially equal in area to the inlet 10 and the outlet 11. Not all the compartments defined by the partitions 5 need be provided with stirrers. The products leaving the outlet 11 may be used to preheat the starting materials. The process is particularly applicable to the hydrolysis of fats and fatty oils, and further details of this p application are given (see Group III).ALSO:In the hydrolysis of fats and fatty oils to yield fatty acids and glycerine water, a mixture of water and fatty material without a catalyst is passed co-currently under appropriate conditions of temperature and <PICT:0679538/III/1> <PICT:0679538/III/2> pressure, e.g. 250 DEG C. and 35-40 atm., through a substantially vertical partitioned reaction vessel which is kept filled with the reaction mixture, the rate of supply being such that the vessel holds from about 1.5 to 3 hours' input. Alternatively, the reaction mixture may include a catalyst, e.g. zinc oxide, and in this case the rate of supply is such that the vessel holds from about 20 to 60 minutes' input. A suitable reaction vessel comprises a vertical container 1, Fig. 1, having an inlet 10 for the reaction mixture, an outlet 11 for the products, a heater 13, which may be replaced by means for injecting steam, partitions 5 and a rotary shaft 6 carrying stirrers 8. The partitions 5 have apertures 9 which may be staggered, as shown, or located around the shaft 6; the apertures are substantially equal in area to the inlet 10 and the outlet 11. Not all the compartments defined by the partitions 5 need be provided with stirrers. The products leaving the outlet 11 may be passed to a separator from which fatty acid and glycerine water are withdrawn, the latter passing to an evaporator in which it may be concentrated by heat-exchange with the hot reaction products. Alternatively, the reaction products may be used to preheat the starting materials. Fig. 3 shows an apparatus in which two reaction vessels 1 and 51 are provided and the products from the first reaction vessel 1 are separated into fatty acid (with some unhydrolysed fatty material) and relatively concentrated glycerine water; the former is passed with additional water to the second reaction vessel 51, the products from which are separated into fatty acid and dilute glycerine water, which is returned to the first reaction vessel. As shown, the products from the first reaction vessel pass to a separator 29 by way of a heat-exchanger 36 in which they preheat the mixture of fatty material and additional water passing to the second reaction vessel, this mixture coming from a mixer 43 which is supplied with water from a container 42 and, by way of a container 41, with fatty material separated in the separator 29. The products from the second reaction vessel pass to a separator 49 by way of a heat-exchanger 28 in which their heat is used to concentrate glycerine water separated in the separator 29. The dilute glycerine water recovered from separator 49 is returned by pipe 53 and container 21 to a mixer 23 for the mixture passing to the first reaction vessel 1. The arrangement shown may be modified by causing the products from the vessel 51 to exchange heat with the weak glycerine water passing from the separator 49 to the vessel 1 or with the whole reaction mixture passing to the vessel 1.