NL6815809A - Normal paraffin separation by urea adduct - Google Patents

Abstract

Normal paraffins are isolated by adduct formation with urea by (a) fractionating a feed contg. n-paraffins in combination with other materials, into at least one fraction contg. n-paraffins with a relatively low mol.wt. and at least one fraction contg. n-paraffins with a relatively high mol.wt. the latter fraction contg. an overlapping part of the n-paraffins with a low mol.wt., and the former fraction contg. an overlapping part of the n-paraffins with a high mol.wt., (b) supplying the fraction with a low mol.wt. together with urea to a first reactor for the formation of an adduct of n-paraffins with urea, (c) supplying the fraction with a high mol.wt. together with urea to a second reactor for the formation of an adduct of n-paraffins with urea, the amount of urea supplied to each reactor being insufficient to convert all of the supplied n-paraffins into an adduct, (d) discharging the adduct of n-paraffins with urea from each of the reactors, and (e) splitting off both the n-paraffins with low mol.wt., and the n-paraffins with a high mol.wt. from their urea adducts. The process is especially suitable for the isolation of n-paraffins with 9-23C atoms from refinery streams. Efficient separation of the n-paraffins from other hydrocarbons is obtained. The process gives products with an n-paraffins content of 94-99% wt. or in some cases, practically 100%wt. The process is useful for the isolation of C11-16 n-paraffins for use in the prepn. of biologically degradable detergents.