SU1525139A1 - Method of obtaining o-sec-butylphenol - Google Patents

Abstract

The invention relates to the production of phenols, in particular the preparation of o-sec-butylphenol, used in the production of additives for motor fuels. The goal is to increase the yield and quality of the target product. Alkylation of phenol is carried out with a butylene fraction (containing @ 8% isobutylene) in the presence of KU-23 at 100-130 ° C and a molar ratio of phenol and butylene of 1: 0.5-1 using dealkylation of by-products on an AShNTs-3 catalyst at 450- 500 ° C. These conditions increase the yield (from 81-91.5 to 95-97%) and the purity of the target product (up to 99.9%) with the disposal of by-products. 1 ill., 1 tab.

Description

This invention relates to petrochemical synthesis, in particular to the synthesis of alkyl phenols, which can be used in the production of additives to motor fuels and oils.

The purpose of the invention is to increase the yield and quality of the target product, as well as the possibility of using a butylene fraction containing up to 8% isobutylene.

C r i me R 1. Phenol is alkylated with a fraction of butylenes obtained at the Novokuibyshea NKhK. The composition of the fraction,%: propane-propene 0.20 {isobutane 0.18; n-butane 16.2U; isobutylene 7.95, butene-1 23.03; trans-butene-2 29.2; cis-butene-2 22.28; butadiene 0.15. The alkylation temperature is 130 ° C, the olefin-phenol ratio is 1: 1. The resulting alkylate is subjected to rectification

In order to isolate o-IBF, side butylphenols are dealkylated at 450 ° C at a feed rate of 1 hour. The resulting catalyzate is distilled to release phenol.

The material balance of the process is presented in the table.

Conversion of phenol without recycling

is 82%, the yield of o-Vb is 65.8%, based on the phenol reacted. In view of the dealkylation, the yield of the main product is 95%.

Example 2. Alkylation was carried out at a 1: 1 ratio of olefin-phenol. The isolation of o-IBF from alkylate is carried out analogously to Example 1. The total yield of o-IBF is 97%.

Example 3. Alkylation was carried out at 130 ° C, ratio

olefin-phenol 0.75: 1. Isolation of o-IBF from alkylate is carried out as in Example 1. Dealkylation of side butylphenols is carried out at 500 ° C. The total yield of o-VBF 96.5%.

Example A. Alkylation was carried out at 1Zi C, olefin-phenol (.) Ratio, 5: 1. The isolation of o-VB from alkylate was carried out as in Example 1. Dealkylation of side butylphenols was carried out at A 75 ° C. The total yield of o-VBP was em 96%.

The temperature range of alkylation of 100-13U C is selected from the conditions of maximum selectivity of the process. In this range, the content of butylphenyl ethers (BPE) does not exceed 0, 3, 5%, while lowering the alkylation temperature to 9 U ° C leads to an alkylate content of up to 5-6% BPE. The upper temperature value due to the limit of the stable operation of the catalyst.

At the alkylation stage, the ratio between mono-HBP is at the level of o-HBP: p-HBP of 2.112.3 and does not vary with temperature, nor with the process time, nor with the ratio of initial components. The maximum yield of o-IBP is achieved at an equimolar ratio of the reactants and decreases as the ratio olefin-phenol increases in favor of the olefin. Since the resulting by-product p-IBP is further dealkylated and phenol is returned to the process, the 1: 1 ratio of reactants is optimal.

The temperature range of the dealkylation of A5U-5UO С is selected in such a way as to avoid the processes of deep cracking and tarring, as well as to ensure the maximum conversion of alkylphenols. It was established experimentally that in the selected temperature range, the conversion of butylphenols is at the level of 97-99%. Reducing the temperature only reduces the conversion to 8U-85%.

The drawing is a flow chart of the method.

Phenol and butylenes enter the alkylator 1 (column type apparatus with a weighing layer of KU-23 sulfonic cation exchanger). The alkylation process is carried out at 1UO-13U ° C (preferably at 13 ° C) and an equimolar ratio of the reactants. The resulting alkylate contains

five

0

five

0

five

0

five

0

five

Phenol and butylphenols are fed to the rectification in column 2, the top of which is taken of the unreacted phenol and sent to recycling. The cube of the column 3, where the release of marketable o-IBF (entering the column 3 from the cube of column 2) for rectification occurs, is sent to Dealkylation in the column-type apparatus 4 with a fixed catalyst bed of ASCR-3. The de-alkylation process is carried out at 45U-5UU C and a volumetric feed rate of butylphenols of 1-1.5 hours. The catalyst, 98-99% consisting of phenol, goes to the alkylation stage. The bottom product of the column contains unreacted butylphenols and their thermal degradation products. The balance amount of this product does not exceed 0.002-0.003% based on the original alkylate. In order not to accumulate resinous substances in the system of the dealkylator-rectification column, the bottom product of the column 5 is sent for recycling.

The reaction gases produced in the dealkilator are lower olefins and, in order to avoid contamination of the target product, are also sent for recycling.

In the proposed method, the conversion by phenol is 97-99%, the yield of the target product is 95-97%, in contrast to the prototype, where the total yield is 81-91.5%. The purity of the target product is 99.9%. Under the conditions of the prototype, a mixture containing 0.1-0.2% of p-butylphenol, 6.0-12.8% of dibutylphenols and 0.2-0 is formed during alkylation. , B% of tributylphenol, i.e. the by-products are 6.3–13.6% and require processing. In the proposed method, the impurities are dealkylated to phenol.

Thus, the proposed method allows to increase the yield of the target product and improve its quality, as well as to utilize by-products.

Claims (1)

Invention Formula The method of obtaining o-sec-butylphenol by alkylation of phenol with a fraction of butylene containing isobutylene in the presence of an acid catalyst at elevated temperature, followed by separation of the target product and utilization of by-products, in order to control the yield and quality of the target product cation exchanger used as catalyst KU-23 and the process is carried out at 100-130 ° С with a molar ratio of phenol-butylene 1: 0.3-1, and the by-products are subjected to dealkylation on a MSC-W catalyst at 450-500 C.