Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2002-09-19
2004-03-02
Parsa, J. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S558000, C568S568000, C568S569000
Reexamination Certificate
active
06700024
ABSTRACT:
FIELD OF INVENTION
The present invention relates to a process for preparing organic hydroperoxides. Such organic hydro-peroxides are suitable for use in various processes, such as in the preparation of oxirane compounds and in the preparation of alkenyl aryl.
BACKGROUND OF THE INVENTION
Processes for preparing propylene oxide employing organic hydroperoxides, are well known in the art. As described in U.S. Pat. No. 5,883,268, such process conventionally comprises peroxidation of ethylbenzene, followed by contacting the peroxidation reaction product with aqueous base in amount sufficient to neutralize acidic components thereof and separating the resulting mixture into an aqueous stream and a deacidified organic stream. The base contaminated, deacidified hydroperoxide stream is washed with water and the resulting mixture separated into an organics contaminated water phase and an organic phase having a reduced alkali metal content. The organics contaminated water phase is contacted with an extractive hydrocarbon and separated into a purified water phase having a reduced level of organic contaminants. It is described that the purified aqueous stream can be discharged with a minimum of further treatment because of its reduced organic impurity level.
From an environmental point of view, it is preferred that the volume of waste streams produced in a process is as small as possible. Further, it is generally more efficient to process wastewater streams containing concentrated organic waste compounds. Therefore, it is preferred that the concentration of organic waste compounds in an aqueous waste stream is high.
It has now surprisingly been found that wastewater, preferably wastewater obtained in one or more process steps of the present process, can be used in the aqueous solution for treating the base contaminated hydroperoxide stream. It has surprisingly been found that the contaminants present in the one or more wastewater streams, do not hamper the cleaning of the hydroperoxide hydrocarbonaceous phase. Furthermore, no negative effect on the performance of the catalyst was observed when the alkyl aryl hydroperoxide containing stream treated with wastewater, was reacted with olefin in the presence of a catalyst as described in EP-A-345856 to obtain alkylaryl hydroxide and oxirane compounds.
SUMMARY OF THE INVENTION
The present invention relates to a process for preparing organic hydroperoxides, which process comprises:
(a) oxidation of an organic compound to obtain reaction product containing organic hydroperoxide,
(b) contacting at least part of the organic hydro-peroxide containing reaction product with a basic aqueous solution,
(c) separating hydrocarbonaceous phase containing organic hydroperoxide from aqueous phase,
(d) contacting at least part of the separated hydro-carbonaceous phase containing organic hydroperoxide with an aqueous solution comprising wastewater, and
(e) separating the hydrocarbonaceous phase containing organic hydroperoxide from the aqueous phase.
Organic hydroperoxides are useful in a range of processes. One of these processes is the reaction of organic hydroperoxide with olefin in order to obtain oxirane compounds. In such process, the organic compound usually is an alkyl aryl, and the process further comprises:
(f) contacting at least part of the hydrocarbonaceous phase containing organic hydroperoxide obtained in step (e) with olefin and catalyst to obtain alkylaryl hydroxide and oxirane compounds, and
(g) separating at least part of the oxirane compound from the alkylaryl hydroxide.
The alkylaryl hydroxide obtained in step (g) can be used in a wide range of processes. Such process is preparing an alkenyl aryl by dehydrating the alkylaryl hydroxide. Another process is hydrogenating the alkylaryl hydroxide to obtain an alkyl aryl. If the process according to the present invention is to be used for dehydrating the alkylaryl hydroxide, the process suitably comprises further:
(h) converting at least part of the alkylaryl hydroxide obtained in step (g). Generally, the conversion produces reaction product and water.
Preferably, step (h) comprises either dehydration or hydrogenolysis of the reaction product. Hydrogenolysis is the reaction of the alkylaryl hydroxide with hydrogen, preferably in the presence of catalyst. Dehydration will generally produce an alkenyl aryl and water, while hydrogenolysis will generally produce alkylaryl. Preferably, the hydrogenolysis will produce the alkylaryl used as starting compound.
DETAILED DESCRIPTION OF THE INVENTION
Although the organic compound used in the process of the present invention can in principle be any compound, organic compounds which are most frequently used are alkylaryl compounds. Alkylaryl compounds which are most frequently used are benzene compounds containing at least about 1 alkyl substituent which alkyl substituent contains of from about 1 to about 10 carbon atoms, preferably of from about 2 to about 8 carbon atoms. Preferably, the benzene compound contains on average of from about 1 to about 2 constituents. The alkylaryl compounds most frequently encountered are ethylbenzene, cumene and di(iso-propyl)benzene.
The oxidation of the organic compound can be carried out by any suitable process known in the art. The oxidation can be carried out in the liquid phase in the presence of a diluent. This diluent is preferably a compound which is liquid under the reaction conditions and does not react with the starting materials and product obtained. However, the diluent can also be a compound necessarily present during the reaction. For example, if the alkylaryl is ethylbenzene the diluent can be ethylbenzene as well.
Besides the desired organic hydroperoxide, a wide range of contaminants are created during the oxidation of organic compounds. Although most of these are present in small amounts, the presence of the organic acids especially has been found to sometimes cause problems in the further use of the organic hydroperoxides. As described in U.S. Pat. No. 5,883,268, the description thereof is herein incorporated by reference, a method of reducing the amount of contaminants is contacting the reaction product containing organic hydroperoxide with an aqueous alkali solution. However, contact with the aqueous alkali solution introduces a certain amount of alkali metal into the organic hydroperoxide containing reaction product. Although the amount of organic acids can be decreased by the alkali wash, the amount of alkali metal contaminants is increased.
In the process of the present invention, the organic hydroperoxide containing reaction product is contacted with a basic aqueous solution, more specifically a basic aqueous solution containing one or more alkali metal compounds. Suitable alkali sources for use in the aqueous alkali solution include alkali metal hydroxides, alkali metal carbonates and alkali metal hydrogen carbonates. Examples of these compounds are NaOH, KOH, Na
2
CO
3
, K
2
CO
3
, NaHCO
3
and KHCO
3
. In view of their easy availability, it is preferred to use NaOH and/or Na
2
CO
3
.
The speed by which the equilibrium is reached in which the majority of the salts of the neutralized alkali metal acids are present in the aqueous phase, can be increased in the ways known to someone skilled in the art. Process step (b) is preferably carried out by intense contacting of the organic hydroperoxide containing reaction product and the basic aqueous solution. Such intense contacting can be done in any way known in the art, for example intense mixing. The exact conditions under which step (b) is carried out, strongly depend on the further circumstances. Preferably, step (b) is carried out at a temperature of between about 0° C. and about 150° C., more preferably of between about 20° C. and about 100° C.
In step (c), the hydrocarbonaceous phase is separated from the aqueous phase. A preferred method comprises allowing the hydrocarbonaceous phase and aqueous phase to settle in a settling vessel and subsequently separating a hydrocarbonaceous phase from an aqueous phase. Preferably, the hydrocarbonaceous phase c
Du Cauze de Nazelle Gerard
Foong Wan Shi
Garritsen Tjeerd Willem
June Raymond Lawrence
Othman Mohammad Azmi Bin
Parsa J.
Shell Oil Company
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