JPS6034529B2 - How to recover resorcinol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method for recovering mustard zorcin, an acid decomposition product of metadiisopropylbenzene dihydroberoxide (abbreviated as m-DHP).

Meta-disopropylbenzene (abbreviated as m-DIPB)
It is known that when m-DHF obtained by the oxidation of m-DHF is subjected to acid decomposition, high-boiling point products are produced in addition to the main products resorcinol and acetone.

High-boiling point products include compounds that are assumed to be condensates of resorcin and acetone, or condensates of resorcin and olefins such as m-isoprobenylphenol; It is also known that resorcinol can be recovered by thermally decomposing a by-product (for example, Japanese Patent Publication No. 30-1988-Ryoshi 0, Japanese Patent Publication No. 471-1982, US Pat. No. 982,514). In addition to carrying out thermal decomposition without a catalyst, each of the above-mentioned publications also teaches a method in which thermal decomposition is carried out in the presence of an acidic catalyst such as sulfuric acid or activated sulfur. However, although the use of these acidic catalysts has the effect of lowering the thermal decomposition temperature, it does not substantially increase the yield of resorcinol, and strong acidic catalysts such as sulfuric acid have the disadvantage that they tend to corrode equipment. Was. Also,
In the production of phenol by the cumene method and the production of cresol by the cymene method, methods of thermally decomposing high-boiling byproducts in the presence of various catalysts have been proposed. Even when applied to the thermal decomposition of resorcinol, in many cases it was not possible to increase the recovery rate of resorcinol.

The present inventors have conducted extensive studies on the thermal decomposition of high-boiling byproducts during the production of resorcin, and as a result, have found a catalyst that can increase the recovery rate of resorcin.

That is, the present invention provides a method for recovering resorcin by thermally decomposing a high-boiling by-product produced during the production of resorcin by an acid decomposition method of m-DHP. This is a method for recovering resorcinol, which is characterized by making a substance exist. m-
DHP is m-DIPB and/or m-diisof as is well known.

Obtained by air oxidation of lopylbenzene monohydroperoxide in the liquid phase. m-D subjected to acid decomposition
HP may be used isolated from the oxidation reaction product of m-DIPB, and is usually used in a suitable acid decomposition solvent, such as acetone, ketones such as methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, xylene, ethylbenzene. It is sent to an acid cracking reactor along with other hydrocarbons. However, m-DHP does not necessarily need to be used after being isolated from the oxidation reaction product, and the oxidation reaction product may be used as it is. In addition, when using the oxidation reaction product, in order to increase the yield of resorcinol, hydrogen peroxide, ten
Even if a method is adopted in which 2-hydroxy-2-propyl-Q,Q-dimethylbenzyl hydroperoxide in the oxidation reaction product is converted into m-DHP by the action of an oxidizing agent such as -butyl hydroperoxide or peracetic acid. good.

The acid decomposition reaction is carried out at a temperature of about 20 to 1200 C in the presence of an acid catalyst such as sulfuric acid, perchloric acid, phosphoric acid, ion exchange resin, clay, or synthetic silica alumina.

The products of the acid decomposition reaction vary depending on the raw materials used for the acid decomposition reaction, but in addition to acetone and resorcinol, the acid decomposition reaction products include m-isoph.

Phenols such as lopylphenol, m-isoprobenylphenol, ketones such as m-isoprobenylacetophenone, carbinols such as m-isopropylcumyl alcohol, and resorcinol and acetone, or It contains high-boiling point products that are thought to be condensates of resorcizo and olefins such as m-isoprobenylphenol. In the present invention, the high boiling point products contained in these acid decomposition reaction products are mainly thermally decomposed, but when the acid decomposition reaction products are distilled as described below, such high boiling point products are also thermally decomposed in the distillation process. Creation products may be generated, and such high-boiling creation products can be pyrolyzed according to the present invention.

The acid catalyst is preferably removed in advance from the acid decomposition reaction product by neutralization, heating, etc., and low-boiling substances such as acetone and the solvent used in the acid decomposition reaction are preferably further removed by distillation. The distillation residue containing high-boiling products thus obtained may be directly subjected to a thermal decomposition process, and resorcinol and other by-product phenols, ketones, carbinols, etc. that can be distilled can be further processed by distillation or extraction. Only the high-boiling by-products obtained by previously removing them may be subjected to the thermal decomposition step. In pyrolysis, metals selected from tin and zinc or their oxides are used as catalysts.

It is also possible to use these metals in the form of compounds which can be converted into these metals or oxides under reaction conditions. Particularly preferred catalysts are tin metal, followed by zinc metal or tin oxide. The catalyst can be in any form, including powder, granules,
Can be used in plate form. Depending on the reaction temperature, metal tin may be used in liquid form. The above-mentioned catalysts used in the method of the present invention do not corrode any equipment, unlike known strong acid catalysts such as sulfuric acid, and this is also a major feature of the present invention.

The use of a catalyst is optional, and the appropriate range of use also differs depending on whether the thermal decomposition is carried out batchwise or continuously, but it is usually 0.01 to 5 parts by weight, per 100 parts by weight of the pyrolysis sample. Preferably, about 0.3 to 1 part by weight is present.

On the other hand, the reaction temperature for thermal decomposition is usually 170 to 400°C.
, preferably in the range from 200 to 330q0.

The reaction time also varies depending on the thermal decomposition temperature, but the reaction time is 0.00.
Approximately 1 to 1 hour is appropriate. If the pyrolysis temperature is too low, the pyrolysis rate will be too slow and the efficiency will be poor, and if the pyrolysis temperature is too high, coking will easily occur and cause blockage of equipment and auxiliary equipment, so this is not desirable. I can not say. The type of thermal decomposition can be selected as appropriate. For example, thermal decomposition can be carried out using a closed type thermal decomposition reactor, and resorcin etc. can be isolated from the thermal decomposition reaction product by extraction, distillation, etc.

However, it is preferable to quickly distill resorcin and other distillable fractions produced by thermal decomposition from the viewpoint of separation and prevention of consumption by secondary reactions.
For example, pyrolysis is performed while feeding high-boiling raw materials into a pyrolysis device continuously or batchwise, and resorcinol and other distillable fractions are distilled under a reduced pressure of approximately 70 Hg. Alternatively, a method can be found in which superheated steam or inert gas is blown into the bottom of the distillation column and resorcinol and the like are entrained therein while being recovered from the top of the column. Next, an example will be explained. Example 1
-5, Comparative Examples 1-7 The oxidation product of m-DIPB was acid-decomposed in a toluene-acetone solvent, and toluene and acetone were removed from the reaction mixture to obtain the following composition (A) 4815. Ta.

Low boiling point created organisms 23. Mother weight % resorcinol 33.1 weight % high boiling point synthetic material 43. % by weight Composition (A) was further heated to 1400 ml and concentrated under reduced pressure of Hg on 4 sides to obtain the following composition (B), 42 gruel.

Low boiling point by-product 7. Mother weight % resorcinol 27.2 weight % high boiling by-products 65. Note that during this concentration, 27.3% by weight of the resorcinol in composition (A) was converted into high-boiling point products.

200 g of the above composition (B) (containing 54.4 g of resorcinol) and 1 g of the additive shown in Table 1 were placed in a 300 g. three-necked flask, and the flask was equipped with a 5-stage distillation apparatus equipped with sieve trays.

Heat the bottom of the tower to 250q0 with a mantle heater, and
Thermal decomposition was carried out for 3 hours while distilling the solcin fraction under a reduced pressure of 4 Yanagi Hg. The results are shown in Table 1. 1st
Table xl Bottom temperature 300C *2 This is a value based on compositional fluctuations and was determined from the following formula.

Increased amount of resorcinol recovered: 200 x 4815 x o.
3314268 Example 6 Instead of distilling under reduced pressure in Example 1, 250 o
While blowing nitrogen gas heated to 2.0 °C into the bottom of the column at a superficial velocity of 2.1 arc/sec, the sorcinol fraction was recovered from the top.

As a result, the number of resorcinol recovered was 902, and the increase was 15.
．． It was the 5th evening. Comparative Example 8 Instead of distilling under reduced pressure in Comparative Example 1, 250oo
nitrogen gas heated to at a superficial velocity of 2.1/sec*
While blowing into the bottom, the sorcin fraction was collected from the top of the column.

Claims (1)

[Scope of Claims] 1. A method for recovering resorcin by thermally decomposing high-boiling by-products produced during the production of resorcin by acid decomposition of metadiisopropylbenzene dihydroperoxide, comprising:
A method for recovering resorcinol, which comprises causing a metal selected from tin and zinc or an oxide thereof to be present during the thermal decomposition. 2. The method according to claim 1, wherein the thermal decomposition is carried out at a temperature range of 200°C to 330°C. 3. The method according to claim 1 or 2, wherein the thermal decomposition is carried out while distilling resorcin out of the system.