Abstract: The present invention is a process to make isoprene comprising: a) providing a reaction zone comprising an acidic aqueous solution, b) introducing, continuously or intermittently, in said reaction zone a mixture comprising (i) isobutanol and optionally (ii) t-butanol or an iso-butene precursor which is not isobutanol and not t-butanol or iso-butene or any combination of two or three of these (ii) components, an aqueous solution of formaldehyde, c) operating said reaction zone at conditions effective to dehydrate isobutanol and optionally (ii) t-butanol and optionally the iso-butene precursor to iso-butene and produce isoprene by reaction of formaldehyde and iso-butene while distilling away a mixture comprising produced isoprene, water, unreacted starting materials and other low boiling point components from this reaction zone to the outside of the reaction zone. In another embodiment isobutanol provides 10% or more of the iso-butene for the isoprene synthesis.

Abstract: The present invention is a process to make isoprene comprising: a) providing a reaction zone comprising an acidic aqueous solution, b) introducing, continuously or intermittently, in said reaction zone a mixture comprising (i) isobutanol and optionally (ii) t-butanol or an iso-butene precursor which is not isobutanol and not t-butanol or iso-butene or any combination of two or three of these (ii) components, an aqueous solution of formaldehyde, c) operating said reaction zone at conditions effective to dehydrate isobutanol and optionally (ii) t-butanol and optionally the iso-butene precursor to iso-butene and produce isoprene by reaction of formaldehyde and iso-butene while distilling away a mixture comprising produced isoprene, water, unreacted starting materials and other low boiling point components from this reaction zone to the outside of the reaction zone. In another embodiment isobutanol provides 10% or more of the iso-butene for the isoprene synthesis.

Abstract: The present invention is a process to upgrade light naphthas comprising branched paraffins and their use as a feedstock in a steam cracking unit, said light naphthas consisting essentially of 90 to 100% by weight of hydrocarbons having at least 5 and up to 8 carbon atoms, said process comprising, a) optionally providing an isomerization zone recovered from the gasoline unit of an oil refinery, b) optionally providing a separation zone capable to treat an hydrocarbon stream comprising branched paraffins and normal paraffins to produce a first hydrocarbon stream having a reduced branched paraffins content and an enhanced normal paraffins content and a second hydrocarbon stream having an enhanced branched paraffins content and a reduced normal paraffins content, c) optionally providing a depentanizer, such that at least two of a), b) and c) are present, wherein, the light naphtha is sent to one of a), b) and c), streams are circulating between the various zones a), b) or c), a stream rich in normal paraffi

Abstract: A process for preparing ethers includes the steps of: providing a feedstock containing iso-olefins selected from the group consisting of C5 iso-olefins, C6 iso-olefins and mixtures thereof; mixing the feedstock with alkyl alcohol so as to provide a reaction feedstock, feeding the reaction feedstock to a reactor zone in the presence of a first etherification catalyst whereby the alkyl alcohol reacts with the iso-olefins to form alkyl-tert-alkyl ethers so as to provide an intermediate feedstock containing the ethers and unreacted iso-olefins and alkyl alcohol; feeding the intermediate feedstock to a catalytic distillation column having a second etherification catalyst defining a catalytic zone; mixing additional alkyl alcohol to the intermediate feedstock so as to form azeotropes of the alkyl alcohol with the unreacted iso-olefins without forming azeotropes of the alkyl alcohol with the ethers whereby the catalytic zone is substantially free of the ethers and the unreacted iso-olefins react with said alkyl alc