RU83773U1 - DEVICE FOR TRANSESTERIFICATION OF FATS WITH ALCOHOLS - Google Patents

Abstract

A device for transesterifying fats with alcohols, including a reactor for a solution of fat, alcohol and a catalyst with mechanical stirring, characterized in that the reactor is equipped with an upper fitting for supplying fat and a lower fitting made in the form of a nozzle for supplying a catalyst and alcohol under pressure to the reactor, and also a sampler for process control and selection of the target product.

Description

The claimed technical solution relates to biotechnology, in particular, to the field of processing fats or oils of biological origin into biofuels, and can find application in the energy, agriculture, chemical and food industries.

Recently, in connection with an increase in the production of diesel fuel from natural raw materials, the urgency of the problem of obtaining alkyl esters of fatty acids through the transesterification reaction of fats using methanol or ethanol (alcoholysis reaction) has substantially increased.

It is known that for the transesterification of fats with alcohols there are a wide variety of settings. For example, conventional stirred reactors are often used for this purpose (Loktev S.M., Klimenko V.L. et al. Higher fatty alcohols. Fields of application, production methods, physicochemical properties. - M.: Chemistry, 1970, p. .601). The main disadvantage of these devices is the insufficiently effective mixture of reagents under the conditions of interfacial separation in the water-fat-alcohol system and a gradual decrease in fat conversion due to inefficient removal of viscous glycerol released as a result of the equilibrium transesterification reaction.

To carry out the alcoholysis of fatty raw materials, it is also possible to use reactors with multi-circuit mixing (Bailey J., Ollis D. Fundamentals of biochemical engineering. - M.: Mir, 1989. - p.247). In this case, the main disadvantages of the reactors are the frequency of the alcoholysis process and its substantial duration, which in some cases reaches

several days, since the transesterification reaction is equilibrium and its rate is determined by the efficiency of the introduction of the catalyst.

In addition, all these types of reactors do not allow to achieve high values of the conversion of fatty raw materials.

The closest analogue of the proposed technical solution is a device that is a reactor with mechanical stirring (P. Siegfried. Method for transesterification of fat or oil of biological origin by alcoholysis. - RF Patent 2263660, CL S07C 69/24, 1999).

The disadvantages of this device are also insufficiently effective mixing of the reagents under the conditions of interfacial separation in the water-fat-alcohol system and a low degree of fat conversion due to inefficient removal of viscous glycerol released as a result of transesterification. The described device is a batch reactor, therefore, its essential disadvantage is the frequency of the process.

The objective of the proposed technical solution is to increase the efficiency of the device by increasing its productivity and the possibility of multiple implementation of the process of transesterification of fat in it without unloading the reactor.

The solution to this problem is provided by the fact that in a device comprising a reactor for a mixture of fat, alcohol and an acid-base catalyst with mechanical stirring, the reactor is equipped with: an upper fitting for supplying fat; a lower nozzle-shaped fitting for feeding catalyst and alcohol to the reactor under pressure; a sampler for process control and selection of the target product.

The schematic diagram of the proposed device for transesterification of fatty raw materials with alcohols in the presence of acid-base catalysts is shown in figure 1.

A device for transesterifying fats with alcohols contains a reactor 1 for mixing fat, a catalyst solution and alcohol. The reactor 1 is equipped around the perimeter with a heat exchange jacket 2, in which the coolant (water) circulates. The heat exchange jacket 2 is equipped with fittings 3 and 4 for supplying and withdrawing water, respectively. The reactor 1 in the upper part is equipped with a fitting 5 for supplying fat or oil to the reactor. The reactor 1 in the lower part is equipped with a nozzle 6, which is a nozzle, through which the catalyst solution (acid or alkali) is supplied under pressure through the inner central part, and alcohol (methanol or ethanol) is supplied through the external nozzle. The nozzle is located at a height of about 1/3 of the bottom of the reactor 1, which allows you to enter the catalyst solution into the middle and upper zones of the reactor volume, where the viscous glycerin formed during the reaction does not accumulate. The fitting 6 is equipped with shut-off valves 7 and 8. To control the degree of conversion of fat into ethers in the upper part through the reactor cover. A sampler is installed 1. A transesterification process is carried out continuously with a stirrer 10. To separate the resulting fat esterification product, a nozzle 11 is installed in the upper part of the reactor 1. An outlet 12 is made in the center of the lower part of the reactor 1 to remove glycerol or completely unload the reactor 1.

The device operates as follows. In the reactor 1, heated to a temperature of 60-70 ° C under a small air pressure of 0.2-0.5 atm, molten fat or oil is fed through the upper nozzle 5, and served through the lower nozzle 6, made in the form of a nozzle catalyst solution and alcohol. The decision to use alkaline

or an acid catalyst (potassium hydroxide or sulfuric acid) is taken depending on the acid number of the fat used (with an acid number equal to more than 10 mg KOH per 1 g of fat, acid is used). Every 10-15 minutes, using a sampler 9, samples of the reaction liquid are taken and the degree of fat conversion is determined using the traditional titration method. Upon reaching the specified completeness of fat conversion, the lower nozzle 6 is closed and, while stirring with a stirrer 10, the product is taken through the nozzle 11. After this procedure is performed, the formed glycerin with the remaining reaction mixture is poured from the reactor 1 through the lower nozzle 12 and transferred to the separation by settling. The reactor is again loaded with fatty raw materials, alcohol, a catalyst solution and the process is repeated.

The proposed device allows the alcoholysis of fats to almost complete conversion and use the general system for transesterification of fatty raw materials almost continuously. High efficiency and productivity of the device is achieved in a special way of mixing the starting materials in the reactor, namely, by constant injection of the droplets of the catalyst through the nozzle into the stream of alcohol and immediately into the esterified mass of fat. In this case, a high concentration of reagents is created in a narrow zone of the reactor volume and the maximum esterification reaction rate is ensured under conditions of removal of by-products from the reaction zone and their subsequent accumulation in the lower part of the reactor.

Claims (1)

A device for transesterifying fats with alcohols, including a reactor for a solution of fat, alcohol and a catalyst with mechanical stirring, characterized in that the reactor is equipped with an upper fitting for supplying fat and a lower fitting made in the form of a nozzle for supplying a catalyst and alcohol under pressure to the reactor, and also a sampler for process control and selection of the target product.