A method for separating a mixture of materials A and B by extractive distillation, using an extraction medium having a higher affinity to B than to A, wherein a feed stream comprising A and B is conducted towards the extraction medium in a column, wherein an overhead fraction comprising A and also a liquid fraction comprising B and extraction medium are obtained, the liquid fraction is collected on a collecting tray and heated and partially evaporated in a first indirect heat exchanger, the resultant vapor is released into the column and a non-evaporated proportion of the liquid fraction is collected as sump fraction in the sump of the column, the sump fraction is successively heated in a second indirect heat exchanger and a third indirect heat exchanger and in part evaporated, wherein the resultant vapor is at least in part released into the column, the sump fraction is separated in a stripper into a fraction comprising B and an extraction medium fraction, the extraction medium fraction is used as heating medium for the second heat exchanger, wherein a partially cooled extraction medium fraction is obtained, and an external heating medium is used for the third heat exchanger, and the partially cooled extraction medium fraction is used as heating medium for the first heat exchanger.

There is provided a method for producing hydroxypivalaldehyde (HPA), including steps (i) to (iii) below in this order,

Step (i): a reaction step of reacting IBAL with FA to produce a reaction solution containing HPA,

step (ii): an extraction step of extracting the reaction solution with an aldehyde solvent represented by formula (1) under basicity to obtain an extract containing HPA, and

step (iii): a distillation and collection step of distilling the extract and then collecting HPA from the residue,

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wherein R represents a saturated alkyl group having 3 or more and 7 or less carbon atoms,

further wherein the distillation step of the step (iii) is a step of distilling an extract in the presence of water, and an amount of the water which is subjected to the distillation is 100 parts by mass or more and 2,000 parts by mass or less, with respect to a total amount, 100 parts by mass, of isobutyraldehyde (IBAL) derived from a raw material and an aldehyde solvent represented by formula (1) in an extract which is subjected to the distillation.

The method enables HPA to be mass-produced and the collecting ratio of HPA to be improved while selectively removing impurities other than water contained in HPA, specifically IBAL and the like. According to the method for producing HPA as mentioned above, it is possible to reduce the content of neopentyl glycol-isobutyrate, isobutylaldehyde-hydroxypivalaldehyde-acetal, and isobutylaldehyde-hydroxypivalaldehyde-aldol as specific impurities byproduced from HPA.

There is provided a method for producing hydroxypivalaldehyde (HPA), including steps (i) to (iii) below in this order,

Step (i): a reaction step of reacting IBAL with FA to produce a reaction solution containing HPA,

step (ii): an extraction step of extracting the reaction solution with an aldehyde solvent represented by formula (1) under basicity to obtain an extract containing HPA, and

step (iii): a distillation and collection step of distilling the extract and then collecting HPA from the residue,

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wherein R represents a saturated alkyl group having 3 or more and 7 or less carbon atoms,

further wherein the distillation step of the step (iii) is a step of distilling an extract in the presence of water, and an amount of the water which is subjected to the distillation is 100 parts by mass or more and 2,000 parts by mass or less, with respect to a total amount, 100 parts by mass, of isobutyraldehyde (IBAL) derived from a raw material and an aldehyde solvent represented by formula (1) in an extract which is subjected to the distillation.

The method enables HPA to be mass-produced and the collecting ratio of HPA to be improved while selectively removing impurities other than water contained in HPA, specifically IBAL and the like. According to the method for producing HPA as mentioned above, it is possible to reduce the content of neopentyl glycol-isobutyrate, isobutylaldehyde-hydroxypivalaldehyde-acetal, and isobutylaldehyde-hydroxypivalaldehyde-aldol as specific impurities byproduced from HPA.

In a process for separating a mixture comprising cyclohexanone and phenol, a solid-phase basic material, such as basic ion-exchange resin, is used to remove acid and/or sulfur from the mixture prior to separation. The process results in reduced amount of contamination such as cyclic ethers in the cyclohexanone and/or phenol products.

In a process for separating a mixture comprising cyclohexanone and phenol, a solid-phase basic material, such as basic ion-exchange resin, is used to remove acid and/or sulfur from the mixture prior to separation. The process results in reduced amount of contamination such as cyclic ethers in the cyclohexanone and/or phenol products.

In a process for separating a mixture comprising cyclohexanone and phenol, a solid-phase basic material, such as basic ion-exchange resin, is used to remove acid and/or sulfur from the mixture prior to separation. The process results in reduced amount of contamination such as cyclic ethers in the cyclohexanone and/or phenol products.

A process is developed for the hydroformylation of diisobutene, in which the diisobutene stream used is subjected to a distillation prior to the hydroformylation in order to enrich 2,4,4-trimethylpent-1-ene in the stream to be hydroformylated. The hydroformylation is carried out with synthesis gas in the presence of a homogeneous catalyst system that comprises at least Co or Rh and optionally a phosphorus-containing ligand.

A process is developed for the hydroformylation of diisobutene, in which the diisobutene stream used is subjected to a distillation prior to the hydroformylation in order to enrich 2,4,4-trimethylpent-1-ene in the stream to be hydroformylated. The hydroformylation is carried out with synthesis gas in the presence of a homogeneous catalyst system that comprises at least Co or Rh and optionally a phosphorus-containing ligand.

Disclosed is the use of a dividing-wall column in a process for co-producing propylene oxide and styrene monomer. Feed streams to a dividing-wall column comprise a bottoms product produced in recovering crude propylene oxide from an epoxidation reaction product, a hydrogenated byproduct styrene monomer production, and a light fraction of a bottoms product withdrawn from the dividing-wall column. Products from the dividing-wall column comprise an overhead product comprising ethylbenzene for recycle to an oxidation zone, an intermediate product comprising methylbenzyl alcohol and acetophenone as feed to a dehydration zone to produce styrene monomer, and a bottoms product comprising methylbenzyl alcohol and heavy materials.

Disclosed is the use of a dividing-wall column in a process for co-producing propylene oxide and styrene monomer. Feed streams to a dividing-wall column comprise a bottoms product produced in recovering crude propylene oxide from an epoxidation reaction product, a hydrogenated byproduct styrene monomer production, and a light fraction of a bottoms product withdrawn from the dividing-wall column. Products from the dividing-wall column comprise an overhead product comprising ethylbenzene for recycle to an oxidation zone, an intermediate product comprising methylbenzyl alcohol and acetophenone as feed to a dehydration zone to produce styrene monomer, and a bottoms product comprising methylbenzyl alcohol and heavy materials.