RU2454392C1 - Method of processing butanol-butyl formate fraction - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of processing a butanol-butyl formate fraction, relating to by-products of the propylene hydroformylation process. The method involves splitting butyl formates at temperature 220-260°C, pressure 1.5-10 atm, volume rate of feeding raw material and hydrogen of 0.2-0.5 h^-1 and 360-2150 h^-1, respectively, to obtain butanols and carbon monoxide as end products. The process is carried out on a catalyst having the following composition, wt %: zinc oxide - not less than 98.0, sulphur - not more than 0.3, carbon - the balance.

EFFECT: method enables to obtain end products (butanols) with high output and selectivity with high conversion of butyl formates.

11 tbl, 6 ex

Description

The invention relates to the field of petrochemical synthesis, and more specifically to methods for producing butyl alcohols by splitting butyl formates on heterogeneous catalysts. Butyl alcohols are hydrogenation products of oil aldehydes obtained in the process of hydroformylation of propylene. The most significant by-products of this process are butyl formates, the amount of which is 2-8 wt.% Of the sum of oxygen-containing compounds obtained by hydroformylation. The presence of butyl formates makes it difficult to isolate alcohols in pure form during distillation due to the formation of azeotropic mixtures. The solution to this problem is to isolate the majority of butyl formates at the stage of rectification of decobaltized mixtures of hydroformylation products in the form of butanol-butyl formate fraction (BBFF). The composition of this fraction is as follows (wt.%): Butanol 30-50, butyl formate 35-65, ethers 1-2, high-boiling products (VKP) 0.5-2. Skilled processing of this product may produce an additional significant amount of marketable alcohols. Such processing involves the decomposition of butyl formates to produce butanol and carbon monoxide as the final products with a minimum methanol yield, since the presence of the latter among the decomposition products makes it difficult to isolate commodity butanol from them. The aim of the present invention is to provide an effective method for processing BBFF.

Known methods for the chemical cleavage of butyl formates by heating in the presence of alkalis, acids, ion exchange resins or alkaline salts of lower carboxylic acids (R. Schmuck, R. Daute et al. Sat. Obtaining oil aldehydes and butyl alcohols by oxosynthesis. 4.1, L .: VNIINeftekhim, 1977, p. 86-99). Using these methods, butyl formates are decomposed to butanols, CO, CO ₂ , H ₂ O. However, this method of processing butyl formates is characterized by the presence of a large amount of wastewater contaminated with salts of organic and mineral acids and, as industrial practice has shown, has proved to be economically disadvantageous. One of the economically feasible methods for processing butyl formates is their cleavage in the presence of heterogeneous catalysts. Thus, a copper-nickel catalyst, nickel based on aluminum or silicon with alkaline modifiers, etc., ensures almost complete conversion of alkyl formates at atmospheric pressure, a space feed rate of 0.2-0.5 h ^-1 and temperatures up to 160 ° C with a yield by-products up to 2 wt.%. However, the butyric acids present in the fraction reduce the activity of these catalysts, the increase of which requires an increase in temperature, which in turn causes a sharp increase in the number of VKP.

More stable catalysts during the decomposition of butyl formates are iron-chromium (GDR patent No. 109372, 12C 5/02). But these catalysts are characterized by low selectivity, and at temperatures above 250 ° C and atmospheric pressure, the loss of C ₄ alcohols reaches 16%. It was proposed to add 1-5 mol per 1 mol of formate (SU 566449, С07С 29/24) to the feedstock at 250-320 ° С and a pressure of 1-250 atm to increase the selectivity of the process, but this will significantly complicate the rectification stage and increase losses target products, since water forms an azeotropic mixture with butanol. The closest solution to the problem in its technical essence is a method for processing butanol-butyl formate fractions (RU 2284313, С07С 31/12; С07С 29/141, prototype), which uses a K-140 brand catalyst of the following chemical composition (wt.%): copper oxide 48.0-63.0; zinc oxide 9.0-18.1; chromium oxide 19.0-34.8; graphite 3.0-5.1. The catalyst activity index should be less than 40. The catalyst is preliminarily restored at elevated temperature in nitrogen circulating at a speed of 500-4000 h ^-1 and at a pressure of 0.05-3 atm, followed by the replacement of nitrogen with hydrogen (SU 2178781, С07С 29/141 31/125).

According to the method of RU 2284313, the process of decomposition of butyl formates is carried out at temperatures of 200-280 ° C, a pressure of 1-30 at, and space velocities of feed of raw materials and hydrogen, respectively, 0.1-0.5 and 50-500 h ^-1 . As a raw material, a real undiluted butanol-butyl formate fraction is used. The catalyst provides a conversion of butyl formates of 94.5-99.5%, while the methanol content in the hydrogenate is 0.8-1.5 wt.%, VKP 2.9-3.5 wt.%. The disadvantages of this method are the relatively high yield of the CPSU and the need to use a previously deactivated catalyst (K-140 catalyst is produced by the industry with an activity index greater than or equal to 40).

We propose a method for splitting butyl formates contained in BBFF at a temperature of 220-260 ° C, a pressure of 1.5-10 ata, bulk feed rates of hydrogen and 0.2-0.5 and 360-2150 h ^-1 on a catalyst containing no less than 98.0 wt.% zinc oxide. In addition to the cleavage reaction of butyl formates, a hydrogenation reaction to a small extent with the formation of butanol and methanol is possible. The advantages of the proposed method are the possibility of working with a fresh catalyst that does not require preliminary deactivation, and a significant decrease in the yield of the CPSU with the following indicators: the conversion of butyl formates 98.8-99.8%, the methanol content in the hydrogenate 0.4-2.0 wt. %, VKP 1.4-2.5 wt.%. The total yield of C ₄ alcohols is 94.4-106.7% (a yield of more than 100% is achieved due to the conversion of other by-products contained in BBFF). Industrial applicability of the proposed method is illustrated by the following examples.

Example 1

A sample of an industrial catalyst brand KRBF-05 (TU 2174-041-33160428-2008), having the following chemical composition, wt.%: Zinc oxide 98.6, sulfur 0.15, the rest is carbon, loaded into a laboratory flow unit, heated in a stream of hydrogen to the temperature of the experiment and experience in the process of splitting the butyl formates contained in the industrial sample of BBFF, under the following conditions: pressure of 1.5; four; 10 ata, the space velocity for raw materials and hydrogen, respectively 0.25 and 360 h ^-1 , temperature 240 ° C.

The compositions of raw materials, hydrogenates and the conversion of butyl formates are shown in table 1.

Table 2 presents the material balance of experience. The balance is given without taking into account hydrogen, the share of which among the substances involved in the conversion is only 0.03-0.05%. Table 2 shows the yield of butanols on converted formates. Exceeding the yield of alcohols of 100% indicates the formation of alcohols in other reactions (hydrogenation).

Table 1 Component composition, wt.% Raw materials, wt.% Product, wt.% 1,5 ata 4 ata 10 ata Water 0.1 0.2 0.17 0.18 Methanol 0 0.36 1.05 1.97 Isobutyric Aldehyde 0.24 0.83 0.71 0.33 n-butyric aldehyde 0.74 1,08 0.65 0.28 Amount of ethers C ₈ 0.24 0.21 0.24 0.21 Isobutyl formate 31.96 0.12 0.11 0.41 n-butyl formate 23.96 0,07 0.06 0.28 Isobutanol 28.34 59,4 59.13 58.93 n-butapol 11.32 34.25 33.92 33.75 Sum of ketones C ₇ 0.85 0.81 0.86 0.78 The sum of unidentified impurities 1.35 1.26 1,52 1.34 Amount of the CPSU 0.9 1.41 1,58 1,54 The conversion of formates,%
total 99.66 99.7 98.77 isobutyl formate 99.62 99.66 98.72 n-butyl formate 99.71 99.75 98.83

table 2 Component composition, wt.% Raw materials, g Products, g 1,5 ata 4 ata 10 ata With 0 15.03 14.52 13.67 Water 0.1 0.17 0.15 0.16 Methanol 0 0.31 0.90 1.70 Isobutyric Aldehyde 0.24 0.71 0.61 0.28 n-butyric aldehyde 0.74 0.92 0.56 0.24 Amount of ethers C ₈ 0.24 0.18 0.21 0.18 Isobutyl formate 31.96 0.10 0.09 0.35 n-butyl formate 23.96 0.06 0.05 0.24 Isobutanol 28.34 50.46 50.53 50.87 n-butanol 11.32 29.10 28,99 29.15 Sum of ketones C ₇ 0.85 0.69 0.74 0.67 The sum of unidentified impurities 1.35 1,07 1.30 1.16 Amount of the CPSU 0.9 1.20 1.35 1.33 The yield of butanols,% 98.35 98.25 99.48 total isobutanol 95.39 95.69 97.15 i-butanol 102.30 101.67 102.59

Example 2

The test catalyst KRBF-05 (sample, similar to example 1) in the process of splitting of butyl formates is carried out under the following conditions: temperature 220, 230, 240, 260 ° C; the space velocity for raw materials and hydrogen is 0.2 and 850 h ^-1 , respectively; pressure 4 ata.

The compositions of raw materials, hydrogenates and the conversion of butyl formates are shown in table 3. Table 4 presents the material balance of the experiment, the yield of butanols on converted formates is given.

Table 3 Component composition, wt.% Raw materials, wt.% Product, wt.% 220 ° C 230 ° C 240 ° C 260 ° C Water 0.2 0.73 0.46 0.51 0.8 Methanol out 0.69 0.69 0.88 0.91 Isobutyric Aldehyde 0.18 0.15 0.23 0.29 0.49 n-butyric aldehyde 0.54 0.26 0.38 0.49 0.78 Amount of ethers C ₈ 0.17 0.17 0.19 0.18 0.17 Isobutyl formate 27,99 0.25 0.16 0.06 0.06 n-butyl formate 29.36 0.25 0.15 0.06 0.05 Isobutanol 24.06 50.78 51.26 51.21 50.93 n - Butaiol 14.59 43.01 42.32 42.33 41.49 Sum of ketones C ₇ 0.70 0.76 0.83 0.78 0.77 The sum of unidentified impurities 1.16 1.38 1.39 1.48 1.40 Amount of the CPSU 1.05 1,57 1.94 1.73 2.15 The conversion of formates,%
total 99.13 99.46 99.79 99.81 isobutyl formate 99.11 99.43 99.79 99.79 n-butyl formate 99.15 99.49 99.8 99.83

Table 4 Component composition, g Raw materials, g Products, g 220 ° C 230 ° C 240 ° C 260 ° C With 0 15.61 15.66 15.71 15.71 Water 0.2 0.62 0.39 0.43 0.67 Methanol 0 0.58 0.58 0.74 0.77 Isobutyric Aldehyde 0.18 0.13 0.19 0.24 0.41 n-butyric aldehyde 0.54 0.22 0.32 0.41 0.66 Amount of ethers C ₈ 0.17 0.14 0.16 0.15 0.14 Isobutyl formate 27,99 0.21 0.13 0.05 0.05 n-butyl formate 29.36 0.21 0.13 0.05 0.04 Isobutanol 24.06 42.85 43,23 43.17 42.94 n-butanol 14.59 36.3 35.7 35.68 34.97 Sum of ketones C ₇ 0.70 0.64 0.70 0.67 0.65 The sum of unidentified impurities 1.16 1.16 1.17 1.24 1.18 Amount of the CPSU 1.05 1.33 1,64 1.46 1.81 The yield of butanols,%
total 97.33 95.51 96.61 94.35 isobutanol 92.52 94.39 94.04 92.96 n-butanol 100.79 98.00 97.91 94.61

Example 3

The test of the catalyst KRBF-05 (zinc oxide 98.4 wt.%, Sulfur 0.2 wt.%) In the process of the decomposition of butyl formates is carried out under the following conditions: the volumetric rate of 500 and 2150 h ^-1 ; feed volumetric speed 0.5 h ^-1 ; temperature 230 ° C; pressure 4 ata.

The compositions of raw materials, hydrogenates and the conversion of butyl formates are given in table 5. Table 6 presents the material balance of the experiment; the yield of butanols for converted formates is given.

Table 5 Component composition, wt.% Raw materials wt.% Product, wt.% 500 h ^-1 2150 h ^-1 Water 0.20 0.52 0.71 Methanol 0 0.98 0.82 Isobutyric Aldehyde 0.18 0.39 0.2 n-butyric aldehyde 0.54 0.53 0.33 Amount of ethers C ₈ 0.17 0.19 0.17 Isobutyl formate 27,99 0.17 0.09 n-butyl formate 29.36 0.19 0.09 Isobutanol 24.06 50.81 51.19 n-butanol 14.59 42.08 42.77 Sum of ketones C ₇ 0.70 0.81 0.76 The sum of unidentified impurities 1.16 1.68 1.36 Amount of the CPSU 1.05 1.65 1.51 The conversion of formates,%
total 99.37 99.69 isobutyl formate 99.39 99.68 i-butyl formate 99.35 99.69

Table 6 Component composition, g Raw materials, g Product g 500 h ^-1 2150 h ^-1 With 0 15,64 15.69 Water 0.20 0.44 0.6 Methanol 0 0.83 0.69 Isobutyric Aldehyde 0.18 0.33 0.17 n-butyric aldehyde 0.54 0.45 0.28 Amount of ethers C ₈ 0.17 0.16 0.14 Isobutyl formate 27,99 0.14 0.08 N-butyl formate 29.36 0.16 0.08 Isobutanol 24.06 42.86 43.15 N-butanol 14.59 35.5 36.06 Sum of ketones C ₇ 0.70 0.68 0.64 The sum of unidentified impurities 1.16 1.42 1.15 Amount of the CPSU 1.05 1.39 1.27 The yield of butanols,%
total 95.37 97.40 isobutanol 92.57 93,99 n-butanol 98.17 100.8

Example 4

Testing an industrial catalyst brand GIAP-10 (TU 2165-005-52047005-2002), having the following chemical composition, wt.%: Zinc oxide 98.0, sulfur 0.3, the rest is carbon, in the process of the decomposition of butyl formates in a laboratory flow unit carried out under the following conditions: a space velocity of hydrogen of 360 and 750 h ^-1 ; feed space velocity 0.2 h ^-1 ; temperature 240 ° C; pressure 4 ata. The compositions of raw materials, hydrogenates and the conversion of butyl formates are shown in table 7. Table 8 presents the material balance of the experiment, the yield of butanols on converted formates is given.

Table 7 Component composition, wt.% Raw materials, wt.% Product, wt.% 360 h ^-1 750 h ^-1 Water 1.00 0.48 0.47 Methanol out 0.78 0.74 Isobutyric Aldehyde 1.40 0.56 0.34 n-butyric aldehyde 0.68 0.76 0.57 Amount of ethers C ₈ 0.24 0.21 0.21 Isobutyl formate 22.72 0,07 0.08 n-butyl formate 27.40 0.05 0.08 Isobutanol 24.47 48.95 49.12 n-butanol 16.15 42.49 42.83 Sum of ketones C ₇ 0.92 0.87 0.84 The sum of unidentified impurities 3.39 2.28 2,31 Amount of the CPSU 1,63 2,50 2.41 The conversion of formates,%
total 99.76 99.68 isobutyl formate 99.69 99.65 n-butyl formate 99.82 99.71

Table 8 Component composition, g Raw materials, g Product g 360 h ^-1 750 h ^-1 With 0 13.73 13.71 Water 1.00 0.41 0.41 Methanol 0.00 0.67 0.64 Isobutyric Aldehyde 1.40 0.48 0.29 n-butyric aldehyde 0.68 0.66 0.49 Amount of ethers C ₈ 0.24 0.18 0.18 Isobutyl formate 22.72 0.06 0,07 n-butyl formate 27.40 0.04 0,07 Isobutanol 24.47 42.23 42.39 n-butanol 16.15 36.66 36.96 Sum of ketones C ₇ 0.92 0.75 0.72 The sum of unidentified impurities 3.39 1.97 2.00 Amount of the CPSU 1,63 2.16 2.07 The yield of butanols,%
total 105.47 106.71 isobutanol 107.77 108.74 n-butanol 103.17 104.68

Example 5

Test industrial catalyst KRBF-05 (sample similar to example 2) in the process of splitting butyl formates in a laboratory flow-through installation is carried out under the following conditions: temperature 240 and 280 ° C; pressure 4 ata; a hydrogen volumetric velocity of 200 h ^-1 ; feed volumetric velocity 0.2 h ^-1 .

The compositions of raw materials, hydrogenates and the conversion of butyl formates are shown in table 9. Table 10 shows the material balance of the experiment, the yield of butanols on converted formates is given.

Table 9 Component composition, wt.% Raw materials, wt.% Product, wt.% 240 ° C 280 ° C Water 0.12 0.38 0.43 Methanol out 0.94 1.14 Isobutyric Aldehyde 0.18 0.70 0.74 n-butyric aldehyde 0.58 0.75 0.83 Amount of ethers C ₈ 0.10 0.15 0.15 Isobutyl formate 37.14 3.08 2.10 n-butyl formate 29.27 3.00 1.95 Isobutanol 21.21 53.06 53.41 n-butanol 10.01 34.19 33.86 Sum of ketones C ₇ 0.17 0.40 0.42 The sum of unidentified impurities 0.70 1.35 1.32 Amount of the CPSU 0.52 2.00 3.65 The conversion of formates,%
total 90.84 93.90 isobutyl formate 91.71 94.35 n-butyl formate 89.75 93.34

Table 10 Component composition, g Raw materials, g Product g 240 ° C 280 ° C With 0 15.87 16.28 Water 0.12 0.32 0.36 Methanol 0 0.79 0.95 Isobutyric Aldehyde 0.18 0.59 0.62 n-butyric aldehyde 0.58 0.63 0.69 Amount of ethers C ₈ 0.10 0.13 0.13 Isobutyl formate 37.14 2.59 1.76 n-butyl formate 29.27 2,52 1,63 Isobutanol 21.21 44.64 43.88 n-butanol 10.01 28.76 29.18 Sum of ketones C ₇ 0.17 0.34 0.35 The sum of unidentified impurities 0.70 1.14 1,11 Amount of the CPSU 0.52 1.68 3.06 The yield of butanols,%
total 87.55 86.84 isobutanol 86.97 87.23 n-butanol 88.28 86.35

This example shows the negative effect of a decrease in the space velocity of hydrogen to 200 h ^-1 and an increase in temperature to 280 ° C.

Example 6

Testing the industrial catalyst APS-T (TU 2178-007-46693103-2004), having a chemical composition, wt.%: Zinc oxide 97.6, sulfur 0.6, the rest is carbon and moisture, in the process of butyl formate decomposition in a laboratory flow unit carried out under the following conditions: temperatures of 240 and 280 ° C; pressure 4 ata; a hydrogen volumetric velocity of 850 h ^-1 ; feed volumetric velocity 0.2 h ^-1 .

The compositions of the raw materials, hydrogenates and the conversion of formates are shown in table 11.

Table 11 Component composition, wt.% Raw materials, wt.% Product, wt.% 240 ° C 280 ° C Water 0.20 0,07 0.39 Methanol out 6.97 1.49 Isobutyric Aldehyde 0.89 0.05 0.59 n-butyric aldehyde 0.56 0.05 0.49 Amount of ethers C ₈ 0.25 0.46 0.45 Isobutyl formate 28,20 0.69 0,0 n-butyl formate 22.47 0.52 0,0 Isobutanol 30.92 55.72 57.64 n-butanol 12.51 29.94 28.17 Sum of ketones C ₇ 0.49 0.20 0.58 The sum of unidentified impurities 2.91 1.72 2.21 Amount of the CPSU 0.60 3.61 8.00 The conversion of formates,%
total 97.61 one hundred isobutyl formate 97.55 one hundred n-butyl formate 97.68 one hundred

This example illustrates the reduced activity and especially selectivity in the decomposition of butyl formate catalyst with concentrations (wt.%) Of zinc oxide - less than 98.0 and sulfur - more than 0.3.

Claims (1)

A method of processing a butanol-butyl formate fraction related to by-products of the propylene hydroformylation process by splitting butyl formates in a hydrogen atmosphere at a temperature of 220-260 ° C, a pressure of 1.5-10 ata, bulk feed rates of hydrogen and 0.2-0 , 5 and 360-2150 h ^-1, respectively, with the production of butanol and carbon monoxide as final products, characterized in that the process is carried out on a catalyst having, in its composition, wt.%:
zinc oxide not less than 98.0 sulfur no more than 0.3 rest carbon