Process for purifying the waste water produced in the process of producing ester plasticizers
AssigneeRuhrchemie Aktiengesellschaft
InventorsHeinz-Dieter Hahn, Jurgen Weber
Life of this patent
Estimating the term…
Abstract
A process for removing organic components from the waste water effluent obtained in the production of an ester plasticizer through esterification of a polybasic aliphatic or aromatic carboxylic acid with an aliphatic alcohol in the presence of a sulfuric acid catalyst, which waste water contains an alkyl hydrogen sulfate or a dialkyl sulfate, esterification reactants and esterification products, which comprises: A. heating said waste water to a temperature above 200.degree. C under the particular prevailing pressure; and B. thereafter thermally or mechanically removing an organic phase from an aqueous phase.
Claims11
A process for the preparation of an ester plasticizer and the reduction of the chemical oxidation demand of the waste water obtained thereby which comprises
- a. reacting a polybasic aliphatic or aromatic carboxylic acid with an alcohol in the presence of sulfuric acid;
- b. thereafter neutralizing the raw esters with an alkaline solution thereby forming a first organic phase and a first aqueous phase;
- c. separating said first aqueous phase from said first organic phase;
- d. heating said first aqueous phase at a temperature of at least 200.degree. C at the prevailing pressure thereby forming a second aqueous phase and a second organic phase which is immiscible with said second aqueous phase and which does not redissolve in said second aqueous phase upon cooling;
- and
- e. physically separating said second organic phase from said second aqueous phase by centrifuging or decanting.
A process for removing an organic component from a single phase aqueous effluent obtained by the esterification of a polybasic aliphatic or aromatic carboxylic acid with an aliphatic alcohol in the presence of sulfuric acid, which water contains an alkyl hydrogen sulfate or a dialkyl sulfate, ester and unreacted reactants, which process consists essentially of:
- A. heating said effluent to a temperature above 200.degree. C under the particular prevailing pressure thereby forming an organic phase and an aqueous phase from said effluent, which do not redissolve into each other upon cooling thereof;
- and
- B. thereafter mechanically removing by centrifuging or decanting said organic phase from said aqueous phase.
Dependencies are inferred from the claim text.