The present invention relates to a method for the purification of natural vanillin, comprising a step involving the stripping of a liquid flow F2 containing natural vanillin. The invention also relates to the natural vanillin that can be obtained using the method of the invention, as well as a device for purifying natural vanillin.

The present invention relates to a method for the purification of natural vanillin, comprising a step involving the stripping of a liquid flow F2 containing natural vanillin. The invention also relates to the natural vanillin that can be obtained using the method of the invention, as well as a device for purifying natural vanillin.

The present invention relates to a method for the purification of natural vanillin, comprising a step involving the stripping of a liquid flow F2 containing natural vanillin. The invention also relates to the natural vanillin that can be obtained using the method of the invention, as well as a device for purifying natural vanillin.

A propylene production method includes: a reaction step of supplying a fresh raw material and a recycled raw material to a reactor to obtain a crude product; a gas-liquid separation step of separating the crude product into a gas phase and a liquid phase; a propylene recovery step of recovering propylene from the gas phase; and a recycling step of recovering the recycled raw material from the liquid phase.

A propylene production method includes: a reaction step of supplying a fresh raw material and a recycled raw material to a reactor to obtain a crude product; a gas-liquid separation step of separating the crude product into a gas phase and a liquid phase; a propylene recovery step of recovering propylene from the gas phase; and a recycling step of recovering the recycled raw material from the liquid phase.

A process for separating heavy by-products and catalyst ligand from a vapour stream comprising aldehyde, the heavy by-products and the catalyst ligand the process comprises passing the vapour stream to a fractionator in which the vapour stream is contacted with liquid aldehyde which removes at least a portion of the catalyst ligand and at least a portion of the heavy by-products from the vapour stream, recovering a liquid bottom stream, comprising removed catalyst ligand from the fractionator; recovering a scrubbed vapour stream from the fractionator, condensing a first portion of the scrubbed vapour stream to create the liquid aldehyde, and recovering a second portion of the scrubbed vapour stream as a product aldehyde stream. The liquid bottom stream is passed to a separation system to separate some aldehyde from the liquid bottom stream to create a recovered aldehyde stream, comprising the separated aldehyde.

A process for separating heavy by-products and catalyst ligand from a vapour stream comprising aldehyde, the heavy by-products and the catalyst ligand the process comprises passing the vapour stream to a fractionator in which the vapour stream is contacted with liquid aldehyde which removes at least a portion of the catalyst ligand and at least a portion of the heavy by-products from the vapour stream, recovering a liquid bottom stream, comprising removed catalyst ligand from the fractionator; recovering a scrubbed vapour stream from the fractionator, condensing a first portion of the scrubbed vapour stream to create the liquid aldehyde, and recovering a second portion of the scrubbed vapour stream as a product aldehyde stream. The liquid bottom stream is passed to a separation system to separate some aldehyde from the liquid bottom stream to create a recovered aldehyde stream, comprising the separated aldehyde.

A process for producing an aldehyde is disclosed. The process comprises: hydroformylating an olefin to form the aldehyde using a hydroformylation catalyst; recovering an effluent stream comprising the aldehyde, hydrogen and the hydroformylation catalyst; passing the effluent stream to a stripper; contacting the effluent stream with a strip gas in the stripper to produce a stripped effluent stream having a lower hydrogen concentration than the effluent stream; and recovering the stripped effluent stream.

Embodiments of the present invention relate to processes for the hydroformylation of olefins to produce aldehydes. In some embodiments, processes of the present invention are capable of maintaining high C.sub.2-C.sub.4 olefin conversion and/or provide more compact hydroformlyation processes.

Embodiments of the present invention relate to processes for the hydroformylation of olefins to produce aldehydes. In some embodiments, processes of the present invention are capable of maintaining high C.sub.2-C.sub.4 olefin conversion and/or provide more compact hydroformlyation processes.