Preparation process of tert-butylphenols
AssigneeRhodia S/A
InventorsAntonio U. B. Queiroz, Lumi T. Aikawa, deceased
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Abstract
The present invention has as purpose a process for the manufacture of tert-butylphenols, mainly of tertbutyl-4-phenols from a phenol and an alkyltert-butylether. The improvement consists in separating in at least two steps, the reaction of phenol alkylation and transalkylation/isomerization of undesirable alkyltert-butylphenols, enabling the flexibilization of the type and quality of end product, and easily adapt to the demands of the market, plus the fact that the total yield improved as well as this improvement has good industrial hygiene properties. Tert-butylphenols are useful intermediate products is the manufacture of phenolic resins or antioxydizing agents for rubber and for several plastic substances.
Claims24
A process for obtaining tert-butylphenols, the process comprising the following steps:
- (a) alkylation in a bed reactor by reacting an alkyltert-butylether having an alkyl group containing from 1 to 6 carbon atoms with a phenol at a temperature ranging between about 60.degree. C. and 130.degree. C. and pressure ranging between atmospheric pressure and 5 kg/cm.sup.2, in the presence of an acid catalyst, the molar ratio of alkyltert-butylether to phenol ranging between 0.1:1 and 2:1;
- (b) passing the product obtained in the alkylation step (a) through a distillation column, with temperature ranging between about -15.degree. C. and 120.degree. C. and pressure ranging between about 10 mmHg and 5 kg/cm.sup.2 ;
- (c) isomerization/transalkylation of the product recovered at a bottom of the column in step (b) by routing said product to a fixed bed reactor, in the presence of a catalyst and with temperatures ranging from about 90.degree. C. to 250.degree. C. and pressure ranging between about 10 mmHg and 5 kg/cm.sup.2 ;
- (d) neutralizing the product obtained from step (c) with alkalis at a temperature ranging between about 40.degree. C. and 250.degree. C. and pressure ranging between about atmospheric pressure and 5 kg/cm.sup.2 ;
- (e) separation of lights/tert-butylphenol by distillation in a column at a temperature ranging between about 80.degree. C. and 200.degree. C. and pressure ranging between about 10 mmHg and 200 mmHg, the product from a top of the column being routed to the alkylation step (a) above;
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- (f) rectification of the product obtained at a bottom of the column from step (e), the product being sent for separation of the desired end product through distillation, tert-butylphenol being the product at the top of the column, said product being obtained at a temperature ranging from about 115.degree. C. to 200.degree. C. and a pressure of between about 10 mmHg and 200 mmHg.
A process for obtaining tert-butylphenols, comprising:
- (a) an alkylation and isomerization/transalkylation step in a reactor with simultaneous stirring and distillation in a column, wherein alkyltert-butylether having an alkyl group containing from 1 to 6 carbon atoms is reacted with a phenol, at a first phase temperature between about 60.degree. C. and 130.degree. C. and pressure between about atmospheric pressure and 5 kg/cm.sup.2, the reaction being in the presence of an acid catalyst, the molar ratio of alkyltert-butylether to phenol being between 0.1:1 and 2:1, the temperature in a second phase being between about 90.degree. C. and 250.degree. C. and the pressure between about atmospheric pressure and 5 kg/cm.sup.2 ;
- (b) neutralization of the product obtained from a bottom of the column in step (a) with alkalis and resins, at a temperature ranging between about 40.degree. C. and 250.degree. C. and pressure ranging between about atmospheric pressure and 5 kg/cm.sup.2 ;
- (c) separation of lights/tert-butylphenol by distillation in a column at a temperature of between about 80.degree. C. and 200.degree. C., and a pressure ranging between 10 mmHg and about 200 mmHg, the product from the top of the distillation column being recycled to alkylation step (a);
- (d) rectification by routing the product obtained at a bottom of the distillation column of step (c) to a separation phase for obtaining the desired end product through distillation, the tert-butylphenol being recovered from a top of the column, rectification taking place at a temperature ranging from about 115.degree. C. to 200.degree. C. and pressure of about 10 mmHg to 200 mmHg.
Dependencies are inferred from the claim text.