The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 14, 1993
Filed:
Feb. 04, 1992
Robert L DeRoeck, Washington, NH (US);
Allan R Huntley, Northwood, GB;
Stone & Webster Engineering Limited, Buckinghamshire, GB;
Abstract
A process is provided for treating a sulfide-containing alkaline aqueous effluent to improve its environmental acceptability, which comprises: (a) intimately mixing a water-immiscible solvent, such as a pyrolysis gasoline, therewith for a sufficient time to extract polymerizable hydrocarbon compounds and/or other compounds which may cause fouling of downstream plant, (b) allowing the solvent phase and the aqueous phase to separate, (c) removing the solvent phase, and (d) subjecting the separated aqueous phase to an oxidation treatment which oxidizes sulfide ions to environmentally acceptable sulfur acid ions, particularly sulfate ions, e.g. a wet air oxidation process. The invention has been particularly developed for treating spent caustic which has been used to scrub gases produced by cracking for ethylene production. Such effluents have been found to cause fouling of the oxidation plant and the Applicants have found that this is due to polymerizable hydrocarbons. Furthermore they have found that prolonged contact times between a readily available solvent and the effluent can ensure that the fouling problem is cured.