Patent ID: 6468399
Filing Date: 2002-10-22
Classification: C07C,Y10S

Abstract:
Process for isolating cyclopentane and/or cyclopentene by distillative separation of a partially hydrogenated pre-benzene fraction or a partially hydrogenated C5 fraction including cyclopentene and cyclopentane, consisting essentially of the steps ofa) taking off as first top product low boilers having boiling points below that of cyclopentene in a first fractional distillation of the partially hydrogenated pre-benzene fraction or the partially hydrogenated C5 fraction, and taking off as first bottom product high boilers comprising cyclopentene and hydrocarbons having boiling points higher than that of cyclopentene, and cyclopentane and hydrocarbons having boiling points higher than that of cyclopentane and, either b1) feeding the first bottom product to a second fractional distillation and taking off cyclopentene as second top product and taking off as a second bottom portion cyclopentane together with hydrocarbons having boiling points higher than that of cyclopentane, and subjecting this second bottom product to a third fractional distillation where cyclopentane is isolated as third top product and separating off as third bottom product hydrocarbons having boiling points higher than that of cyclopentane, or b2) subjecting the first bottom product to a catalytic hydrogenation and subsequently separated the catalytic hydrogenation product in a fractional distillation into cyclopentane as top product and hydrocarbons having boiling points higher than that of cyclopentane as bottom product, or b3) subjecting the first bottom product to a second fractional distillation, separating off as second bottom product the hydrocarbons having boiling points higher than that of cyclopentane and subjecting then the top product to a catalytic hydrogenation to give cyclopentane, and optionally c) subjecting the fraction, the top product, or the bottom product in any one of steps a), b1), b2), and b3) to a water scrub.