RU2227068C2 - Method of production of a catalyst for acid hydrolysis - Google Patents

Abstract

FIELD: medicine and chemical industries. SUBSTANCE: the invention presents a method of production of a catalyst for acid hydrolysis. (57) The invention is dealt with production of a liquid catalysts based on the aromatic sulfoacids used for hydrolysis of fats. The offered method may be used both for acid hydrolysis of fats and vegetable oils, in which 90 98 % sulfuric acid or an equivalent to it mixture of sulfuric acid of lower concentration is entered in an intensive contact with an aromatic hydrocarbon taken with a 10 20% stoichiometrical surplus in a beaded grinding mill of vertical type at the temperature of 100-135 C at the presence of a boosting additive based on a mixture of ferrous acetate (II) and potassium acetate in a molar ratio of 3:2 - 1:1 in the form of a solution in acetic acid with concentration of ferrous salt equal to 0.1-0.15 gram-molecule / kg in amount of the dry catalyst of 0.028-0.055 mass % for 45-120 minutes with following settling, separation and return the hydrocarbon layer in repeated process. Technical result: a liquid catalyst for a hydrolysis is produced without specially organized water separation, the process of sulfurization and its instrumental support are simplified. EFFECT: the invention allows to produce a liquid catalyst for a hydrolysis without specially organized water separation and to simplify the process of sulfurization and its instrumental support. 3 cl, 32 ex, 4 tbl

Description

The invention relates to the production of liquid, water-containing catalysts based on aromatic sulfonic acids for the hydrolysis of fats and vegetable oils, and can be used in paint and varnish, leather, rubber and other industries.

It is known to use p-toluenesulfonic acid or its sodium salt with an equivalent amount of hydrochloric acid as a catalyst for hydrolysis of vegetable oils and fats (RF patent No. 2166534). p-Toluenesulfonic acid was obtained by the sulfonation reaction by boiling with water separation of a mixture of sulfuric acid (concentration 96%) and toluene in excess of the latter. From the reaction mixture, the target product was isolated as crystalline hydrate, washed with HCl conc. Prior to the negative reaction to sulfate ions, they were dried and dosed in this form into a hydrolysis reactor. Further studies showed that there was no justified need for the isolation of an individual sulfonic acid in solid form and its thorough purification from sulfate ions and, moreover, revealed a number of significant inconveniences in using a solid hydrolysis catalyst.

A known method of producing aromatic sulfonic acids (USSR AS No. 835104), in which an additional chemical reaction eliminates water accumulation in the course of the interaction of aromatic hydrocarbons with sulfuric acid. To realize this, a complex is formed which is formed by 100% sulfuric acid and acetic anhydride, which is subsequently treated with aromatic hydrocarbons at 20-60 ° C. In it, the desired sulfonic acids in the final reaction mixture are mixed with acetic acid.

Closest to the claimed is a method of producing a liquid anhydrous catalyst based on aromatic sulfonic acids (AS USSR No. 952319), including sulfonation of an aromatic hydrocarbon with sulfuric acid at a temperature of 110-120 ° C, azeotropic distillation of water and aging of sulfomass at 180-200 ° C for 2 -3 hours, further transmission of aromatic hydrocarbon vapors with simultaneous azeotropic distillation of water.

The disadvantages of this method are:

- two to three-fold excess of sulfuric acid, and not any, but 98%;

- the need for a fairly long (2-3 hours) and high temperature (180-200 ° C) exposure to complete the process of sulfonation and removal of reaction water;

- the need to pass aromatic hydrocarbon vapors, which requires not only additional amounts of hydrocarbon, additional energy costs, but also additional equipment for producing vapors, and then for condensing them in the form of an azeotropic mixture with water, for separating water, drying and refining hydrocarbons .d .;

- In general, high energy intensity, multi-stage and a wide range of equipment used.

It is known that sulfonation is often carried out in the presence of a catalyst, in particular sodium sulfate and vanadium pentoxide, sulfates of mercury, cadmium, aluminum, lead, arsenic, bismuth, iron (Preparative Organic Chemistry / Ed. By N.S. Wulfson. - M .: Goskhimizdat, 1959.P.242-244).

The disadvantage of such solid catalysts is poor solubility and a long dissolution process, which creates inconvenience in their use and leads to an unsteady mode of catalysis. A direct experiment showed that the effectiveness of such additives in the fast flowing sulfonation in a bead mill is very small.

The objective of the proposed solution is to obtain a liquid catalyst for the hydrolysis of vegetable oils and fats in the form of reaction masses of sulfonation of aromatic hydrocarbons or their mixtures with concentrated sulfuric acid in the absence of specially organized water separation introduced with the raw material and formed during the process of water, stimulation of sulfonation with a liquid additive, reduction of stage and simplification of sulfonation process and its hardware design.

The problem is achieved in that 90-98% sulfuric acid or a mixture of sulfuric acid of a lower concentration with oleum is brought into intensive contact with a 10-20% excess taken over the stoichiomeric amount of aromatic hydrocarbon in a vertical type bead mill with free exit of the reactor gas space to the atmosphere at 100-135 ° С in the presence of a stimulating additive based on a mixture of iron (II) acetates and cadmium in a molar ratio of 3: 2-1: 1 in the form of a solution in acetic acid with a concentration oli iron 0.1-0.15 mol / kg in an amount on a dry catalyst 0,028-0,055 wt.% for 45-120 minutes followed by settling and separation of hydrocarbons.

In this case, toluene, o-xylene, m-xylene, p-xylene, mixtures of xylene isomers and ethylbenzene are taken as aromatic hydrocarbon. A stimulating additive for sulfonation of aromatic hydrocarbons with sulfuric acid is obtained by concentration during distillation with reflux of reaction mixtures formed during the quantitative oxidation of potassium iodide with stoichiometric iron oxide Fe ₃ O ₄ or Fe ₂ O ₃ in glacial acetic acid at a temperature of 75-85 ° C in a bead mill.

Characteristics of the raw materials used

Toluene GOST 5789-78

o-Xylene TU 6-09-3825-78

m-Xylene TU 6-09-2438-82

p-Xylene TU 6-09-3780-78

Egilbenzene TU 6-09-2786-73

A mixture of xylene isomers TU 6-09-3829-74

Sulfuric acid GOST 4204-77 (90% and above)

Oleum TU 6-09-3881-75

Iron (II) acetate, 4-water TU 6-09-08-1287-78

Potassium acetate GOST 5820-78

Acetic acid GOST 61-75

GOST 4159-79 iodine

The process of preparing a hydrolysis catalyst of the claimed method is as follows. Sulfuric acid or a mixture of sulfuric acid with oleum, an aromatic hydrocarbon, and a stimulant are charged into a vertical bead mill. With a closed outlet to the atmosphere, mechanical stirring and heating are turned on, the outlet of the gas space into the atmosphere is opened, the temperature is brought to the set value and stabilized. In this mode, stirring is continued for the required time. After that, the heating is turned off, mechanical stirring is stopped and the reaction mass is allowed to settle and exfoliate. Then, first the lower layer of the concentrated sulfonic acid solution and then the upper hydrocarbon layer are unloaded by gravity through the drain pipe. The sulfonic acid solution is suitable for direct use as a catalyst for the hydrolysis of vegetable oils and fats. The hydrocarbon layer (a very dilute solution of sulfonic acid in a hydrocarbon) is recycled.

Obtaining a stimulating additive for sulfonation is as follows. In a vertical type bead mill heated with glass beads, the appropriate amounts of glacial acetic acid, potassium iodide are introduced as a grinding agent. With stirring, this load is heated to operating temperature, after which an appropriate amount of iron oxide Fe ₂ O ₃ or Fe ₃ O ₄ is introduced. Mechanical stirring is turned on again and the redox process is carried out until the oxidizer and reducing agent are almost completely consumed. After that, the resulting reaction mixture was subjected to simple distillation with reflux, controlling the content of iron salt in the cube. As soon as the latter is in the range of 0.1-0.15 mol / kg, the distillation process is stopped, the bottoms liquid is drained and used for these purposes.

Example 1

In a vertical-type bead mill with a casing and a 6.5-liter stainless steel paddle mixer with a loading nozzle and a nozzle with a shut-off valve as a free exit to the atmosphere, located in the upper cover, an electric heating element on the side walls and a lower drain pipe with a metal 2.18 kg of 90% sulfuric acid (20 mol), 2.44 kg of o-xylene (0.14 kg) are introduced into a slightly spherical bottom, containing 2.75 kg of glass beads 2-3 mm in diameter, continuously 23 moles; stoichiometric excess 15%) and 5 0 g of a stimulating additive in the form of a solution of iron (II) acetates and potassium in a molar ratio of 1: 1 in acetic acid with an iron salt concentration of 0.1442 mol / kg (1.962 g of anhydrous salts, i.e. 0.042% by weight of the initial reaction mixture , of which 1.2546 g account for anhydrous iron (II) acetate and 0.7077 g for potassium acetate). Mechanical stirring and heating are turned on and in 17 minutes the temperature is removed by 115 ° C. The temperature is stabilized at this level with an accuracy of ± 1 ° and the sulfonation process is carried out for 75 minutes. They stop mechanical stirring, turn off the heating and for 30 minutes allow the mixture to drain from the walls and settle. During this time, the temperature dropped to 107 ° C. Open the lower drain pipe and collect the xylene sulfonic acid-containing layer in an amount of 4280 g, and then 360 g of the hydrocarbon layer; loss of 30 g. The full material balance showed that the degree of conversion of sulfuric acid was 97%. The hydrocarbon layer is returned to re-sulfonation without any processing.

The stimulant for this example is prepared as follows. 393.8 g of glacial acetic acid and 4.16 g of KJ are loaded into a vertical type bead mill. Mixing and heating are turned on and the mixture is heated to 80 ° C. Upon reaching this temperature, 2 g of Fe ₂ O ₃ (hematite) are introduced and the process is conducted until the oxidizer and reducing agent are almost completely consumed. The control is carried out according to the kinetics of the selection of molecular iodine. In this case, it took 37 minutes to achieve a 97% degree of oxide conversion.

By filtering through a mesh with dimensions of 0.5 × 0.5 mm, the reaction mass is separated from glass beads and transferred to a cube for distillation of volatiles with reflux, which is carried out until the iron salt concentration reaches 0.1442 mol / kg (the content of iron salts in the initial mass before concentration it was ~ 0.062 mol / kg).

Examples 2-10

Sulfonated hydrocarbon, installations for carrying out the sulfonation process and producing a sulfonating additive, sulfuric acid concentration, order and size of sulfuric acid and hydrocarbon loads, as well as reagents for the stimulating additive, temperature and other characteristics of the sulfonation technique are similar to those described in Example 1. They differ in the dosage of the stimulating additives, the amount introduced in terms of anhydrous salts, the concentration of iron salts in the stimulating additive, the nature of iron oxide and temperature swarm while receiving a stimulant supplement. Here are examples of sulfonation in the absence of a stimulating additive, using only acetic acid as the last, and also with a model stimulating additive in the form of a specially prepared solution of iron (II) acetate and potassium acetate in acetic acid. The characteristics of the sulfonation process and the preparation of a stimulating additive for these examples are summarized in Table 1.

Examples 11-14

Sulfonated hydrocarbon, plants for carrying out the sulfonation process and obtaining a stimulating additive for sulfonation, the concentration of sulfuric acid, the order and size of the loads of sulfuric acid and hydrocarbon, as well as reagents for the stimulating additive, temperature and other characteristics of the sulfonation technique are similar to those described in Example 1. They differ in the nature of the oxidizing agent in the process of obtaining a stimulating additive, a lower molar ratio of iron and potassium acetates in the stimulating additive, the concentration of iron salt in dilution and mass content of dry catalyst in the initial charge for sulfonation.

In particular, to obtain a stimulant, 395.3 g of glacial acetic acid and 2.80 g of KJ are charged. The specified mass is heated to 80 ° C. And 1.95 g of Fe ₃ O ₄ are introduced. After 54 minutes of carrying out the process in a bead mill, the degree of conversion of iron oxide Fe ₃ O ₄ reached 98%. And after concentration by distillation of the volatiles, the concentration of the iron salt in the cube was 0.147 mol / kg. The ratio of the concentrations of iron acetate and potassium acetate 3: 2.

The characteristics of the sulfonation process are given in table.2

Examples 15-24

Download sulfonated hydrocarbon, sulfuric acid and a stimulating additive, as well as the initial concentration of sulfuric acid and salts in a stimulating additive, the molar ratio of iron and potassium acetates in the additive, as well as obtaining a stimulating additive are similar to those described in example 1. The procedure for sulfonation is similar to example 1 . They differ in temperature and nature of sulfonated hydrocarbon. The characteristics of the process are summarized in table 3

Examples 25-32

The installation, order and temperature of sulfonation are similar to those described in example 16. They differ in the concentration of sulfuric acid, the method of obtaining such a concentration in excess and the nature of the sulfonated hydrocarbon, the characteristics and dosage of the stimulant used. The characteristics of such processes are given in table 4.

As can be seen from the above data, all the processes of sulfonation of aromatic hydrocarbons in a bead mill went practically quantitatively without specially organized wastewater, which was facilitated by intensive mechanical mixing and the use of an effective stimulating additive. The sulfonation process has become almost one-stage, taking place at easily achieved moderate temperatures, and quite quickly. Simplified and hardware design. Quite simple and getting a stimulating supplement. Moreover, the latter can be performed in the same bead mill as the sulfonation process itself. The sulfomass obtained after separation of the hydrocarbon layer is used as a hydrolysis catalyst without any purification.

Claims (3)

1. A method of producing an acid hydrolysis catalyst, characterized in that 90-98% sulfuric acid or a mixture of a lower concentration of sulfuric acid with oleum is contacted with a 10-20% excess taken over a stoichiometric amount of aromatic hydrocarbon in vertical type bead mill with a free exit of the reactor gas space to the atmosphere at 100-135 ° С in the presence of a stimulating additive based on a mixture of iron (II) acetates and potassium in a molar ratio of 3: 2h1: 1 in the form of a solution in acetic acid those with a concentration of iron salt 0.1-0.15 mol / kg in an amount on a dry catalyst 0,028-0,055 wt.% for 45-120 minutes followed by settling, separation and recovery of a repeated process of hydrocarbons. 2. The method according to claim 1, characterized in that toluene, o-xylene, m-xylene, p-xylene, a mixture of xylene isomers, ethylbenzene are taken as aromatic hydrocarbon. 3. The method according to claim 1, characterized in that the stimulating additive for sulfonation of aromatic hydrocarbons with sulfuric acid is obtained by concentration during distillation and reflux of reaction mixtures formed during the quantitative oxidation of potassium iodide taken in stoichiometric ratio with iron oxide Fe ₃ O ₄ or Fe ₂ O ₃ in glacial acetic acid at a temperature of 75-85 ° C in a bead mill.