GB1046099A - Continuous process for alkylating an aromatic hydrocarbon - Google Patents

Abstract

Detergent alkylate is obtained by contacting an excess of aromatic hydrocarbon with a C9-C18 alkyl chloride in a first zone in the presence of a red oil complex catalyst to effect condensation of a major proportion of the alkyl chloride, separating red oil from the effluent and contacting the remainder in a second zone with aluminium to complete condensation, separating red oil from the effluent for use as catalyst in the first zone and recovering alkylate from the remainder. In a preferred embodiment partially chlorinated n-paraffin containing 10-50% mol. of alkyl chloride together wit fresh feed n-paraffin boiling in the range 300-605 DEG F. and 2-25 mols. of aromatic hydrocarbon per mol. of chloride are contacted with red oil complex forming 5-25% by volume of the reaction mixture are contacted in the first zone at 100-185 DEG F. for 3-15 minutes to condense 90-95% of the alkyl chloride. Part of the red oil complex is recycled and an amount equivalent to that from the second zone is discarded. Hydrogen chloride may also be separated and washed with the n-paraffin feed to recover organic compounds. Consumption of aluminium in the second zone is regulated either by using a zone packed with metal and limiting the amount of hydrogen chloride introduced, e.g. 1-30 parts per 1000 parts of feed or a saturated solution, or by feeding aluminium at a controlled rate of 0.03-0.1 gram atom per gram atom of chlorine in the chlorinated paraffin feed to the first zone. Red oil may be maintained in an amount of 5-25% vol. of the reaction mixture. Reaction is effected at 100-185 DEG F. for 0.3-15 minutes. Red oil is separated and passed to the first reactor and/or recycled to the second. The product is separated into aromatic hydrocarbon for recycle, n-paraffin which is partially chlorinated and passed to the first zone and alkylate boiling in the range 520-730 DEG F.