SU721435A1 - Method of preparing furfural - Google Patents

Description

one

The invention relates to an improved method for the production of furfural which is used as a monomer in the chemistry of polymers and a semi-organic synthesis product.

A known method of producing furfural by thermal hydrolysis of plant phosphorus in the presence of alkali metal monophosphates as a salt catalyst contains 1.7–2% free tlj.

The consumption of catalyst per simple superphosphate is 18% and for double superphosphate g 7, O% by weight of absolutely dry raw material.

The disadvantage of this method is the high consumption of the catalyst and the relatively low yield of the target product (65%).

The aim of the invention is to increase the yield of the target product and reduce catalyst consumption.

This goal is achieved by the fact that vegetable raw materials are subjected to thermal

(vty hydrolysis in the presence of alkaline-earth metal, ammonium chloride or alkali metal, mono-sulphate, mono-sulphate or their mixtures in an amount of 1-5% by weight of absolutely dry coal and the process is carried out in the solid phase as a salt catalyst of myophosphate.

Distinguishing this method from the known one is that the alkaline earth metal monophosphate, ammonium or alkali chloride, ammonium sulfate or their mixture in an amount of 1-5% by weight of absolutely dry phase is used as a salt catalyst and the process is carried out in the solid phase.

The salt catalyst is pre-ground and mixed with the suspension in suspension. Grinding and application of the catalyst in a suspended state allows one to evenly distribute small amounts of it between the particles and ensure the conditions for the uniform extraction of furfural and the filter.

Example. Odubin, in viyoy proakstrastruirovannogo shepey, lasts to the production waste / bil extracts, containing 13.05% of potassium furfural, is mixed with a mechanically crushed catalyst in the form of a dry salt in a suspended state. The raw material with a finely dispersed catalyst deposited on its surface is loaded into a flow type reactor and treated

Average indicators of the process of obtaining furfural from tannins using various catalysts

steam at a pressure of 8-12 MPa and temperature 16O-19O C. The process indicators obtained using different catalysts are given in table 1.

In order to carry out the npouedca, the catalyst is taken in the amount of 1, O-5, O% by weight, in table I, the consumption of the catalyst per I t of absolutely dry raw material is given.

Table I

M onocalcium phosphate Ammonium Chloride Blend, wt.%: Monocarbonate 55 Ammonium Sulphate 34 Potassium Chloride 11 Blend, wt.%: Monocalcium Phosphate 83 Potassium Chloride 17 EXAMPLE 2 Birch sawdust containing 14.25% of potential furfural is mixed with powdered catalyst in the form of dry salt according to the method described in Example 1, and treated with steam under the same conditions. Average of n birch sawdust with

10.0

Monocalcium (Yusfat 32.2 Ammonium Sulphate

10.7

75.1

8.1 56.8 98.0 292.0 581.4 292.5 The obtained parameters of the processes are listed in Table 2. For carrying out the process, the catalyst is taken in the amount of 1, O-5, O% by weight, in table. 2 shows the consumption of catalyst per 1 ton of absolutely dry raw materials. Table 2 for furfural production of various catalysts

Mixture, wt.%: Monocalcium phosphate 42 Ammonium sulfate 50 Potassium chloride, 8 Comparative known and

Odubin

Mixture, wt.% Monocalcium phosphate 83

Potassium Chloride 17 Monocalcium phosphate Ammonium Chloride

From the data given in Table 3, it can be seen that in the proposed method, the yield of furfural is 75-8 O% of its potential content, while in the prototype it is 65% of the potential content of furfural in the raw material.

When used as a corn stalk, the yield of furfural using the proposed method will be, respectively, 16.5-17.6% of the absolutely dry raw material, i.e. higher than by the known method.

63.6

9.6

520,8

13.05

Data

72.0

9.4 predictable method

4.25

10.7

75.1 11.4 80.4

At the same time, the consumption of double superphosphate catalyst as compared with its

the consumption of the prototype on I t cf reduced by a factor of 7, and by 1 t of furfural by 7.0-7.4 times. Thus, only by reducing the consumption of the catalyst when using double

superphosphate is reduced by 40-60 rubles.

Claims (1)

Invention Formula The method of obtaining furfural by thermal hydrolysis of vegetable raw materials in the table of the proposed methods -. .V .; : v- 7l 72 14358 the presence of a salt catalyst, about 1–5% by weight, is absolutely dry because in this way the raw material and the process are carried out in solid I increase the yield of the target product-fae. and reducing catalyst consumption, in as the latter use mono-5 sources of information alkaline earth metal phosphate taken into account in the examination ammonium or alkali metal chloride, 1. French patent number 1161О87, ammonium sulfate or mixtures thereof in co-cl. C O7 (Founded 1958 (prototype).